Mortality associated with polymyalgia rheumatica in the United States in the 1999-2020 period: a multiple-cause-of-death study

OBJECTIVE

Multicause-of-death methods were used to analyze mortality and leading causes of death associated with polymyalgia rheumatica (PMR) in the United States from 1999 to 2020.

MATERIALS AND METHODS

We analyzed mortality data from the Centers for Disease Control and Prevention (CDC) Data analysis system and selected death certificates that listed PMR as the cause of death based on the International Statistical Classification of Diseases and Related Health Problems (ICD-10) category code. Relevant mortality rates, number of deaths and historical trends were analyzed. The number of PMR-related deaths and age-standardized mortality rate (ASMR) trend charts were made using Excel 2010 version and trend lines were added.

RESULTS

Over the last 22 years, the total number of PMR-related deaths in the United States was 15,421 women (89.8%), a ratio of about 1:9 men to women. When PMR is listed as the underlying cause of death, the ASMR for women and men (per 100,000 people) is approximately 1.8-5.1:1, and when it is listed as the non-underlying cause of death, it is 1.8-3.3:1. PMR deaths are more frequent in individuals aged 70 years and above, with patients aged 80 years and above being most affected. Among different ethnicities, the highest number of deaths was found in Caucasians, followed by Black or African American. When it comes to causes of death, heart disease still ranks first, followed by cancer. In addition, we also found that when PMR combined with malignant tumors as a multiple cause of death, the number of female deaths was higher than that of male deaths, the overall number of deaths of both showed an upward trend, and the overall ASMR of both showed a downward trend.

CONCLUSIONS

In the past 22 years, we have observed a low mortality rate of PMR in the United States. However, for patients with PMR, especially elderly women, medical workers should be vigilant and pay attention to whether they are combined with other complications, such as malignant neoplasms, and make timely diagnosis and treatment to further reduce the mortality rate of patients with PMR.

Prospects of targeting JAK/STAT signal transduction pathways for vasculitis

Vasculitis is the inflammation of blood vessels caused by autoimmunity and/or autoinflammation, and its etiology and pathogenesis remain largely unknown. The Janus kinase (JAK) and Signal transduction Transcription Activator (STAT) signal transduction pathways are a group of molecules involved in the major pathways by which many cytokines exert and integrate their functions, and their dysregulation has been implicated in the pathogenesis of a variety of autoimmune diseases. However, current data supporting the role of the JAK/STAT pathway in the development of vasculitis is limited. In terms of treatment, glucocorticoids and immunosuppressants have been the standard therapy. However, because of the huge burden of treatment side effects, people have long waited for new treatment options. JAK inhibitors reduce the production of multiple cytokines and inhibit inflammation by targeting the JAK/STAT pathway, and have the advantage of rapidly acting in oral formulations, reducing glucocorticoid dependence and associated adverse events, especially in refractory cases. Therefore, JAK inhibitors are expected to be a promising drug for the treatment of vasculitis.

[Study on behavioral risk factors and lagging effect analysis with liver cancer mortality in rural critical areas of 4 provinces of China from 2009 to 2019]

Objective: To analyze the trend of liver cancer mortality in rural key areas of Jiangsu Province, Anhui Province, Shandong Province, and Henan Province (4 provinces) from 2009 to 2019 and to explore the influence of behavioral risk factors on liver cancer mortality and its lagging effect, and provide a reference for the prevention and treatment of liver cancer in China. Methods: Based on the 2009-2019 National Cause of Death Surveillance Database of the Chinese Center for Disease Control and Prevention, and the survey data of tumor and risk factor behavior of residents in key areas of 4 provinces, Joinpoint 4.2 software was used to calculate the average annual percentage change (AAPC) for assessing the temporal trend of standardized mortality of liver cancer; Chi-square test and trend Chi-square test were used to analyze the regional distribution difference and temporal change trend of behavioral habit factors. Stata 16 was used to establish a panel model to analyze the correlation and lagging effect of behavioral risk factors with liver cancer. Results: The standardized mortality rate of liver cancer in Jinhu County, Sheyang County, Lingbi County, Shou County, Mengcheng County, Wenshang County, Juye County, Luoshan County, Shenqiu County, and Xiping County showed a downward trend (AAPC<0, P<0.05) from 2009 to 2019. The consumption frequency of pickles/salted fish, red meat, and aquatic products showed a downward trend. The consumption frequency of healthy foods such as fresh vegetables, fresh fruits, and dairy products in all counties and districts showed an upward trend, and the consumption frequency of fried foods, kimchi, smoked foods, moldy foods, coffee, and soy products remained at a low level (P<0.05); but the consumption frequency of soy products and dairy products was still <20.00%. Fried food, pickles/salted fish, current smoking rate, alcohol consumption rate, and unvaccinated hepatitis B vaccine rate were positively correlated with liver cancer death, and there was a lag effect, and the lag period was 4, 1, 6, 5, 4 years respectively. Conclusions: From 2009 to 2019, the mortality rate of liver cancer in rural key areas of 4 provinces shows a downward trend. There is a correlation and lagging effect between behavioral risk factors such as fried food, smoking, and alcohol consumption and liver cancer death.

[Comparison of corneal power assessment methods after small incision lenticule extraction]

Objective: To compare the accuracy of different corneal curvature parameters in assessing the corneal refractive status and tracking corneal power changes after small incision lenticule extraction (SMILE). Methods: This prospective cross-sectional study tracked and recorded total corneal curvature parameters measured by different instruments before and three months after SMILE for myopia. These parameters, including total keratometry (TK) from the IOLMaster 700, total corneal refractive power (TCRP) from the Pentacam AXL, real keratometry (RK) from the CASIA 2, and corrected parameters calculated using the Haigis, Shammas, and Maloney methods, were compared with data obtained using the clinical history method (CHM). Surgically induced changes in TK, TCRP, and RK were analyzed and compared with those in spherical equivalent on the corneal plane (ΔSEco). Results: The study included 40 eyes (40 participants). After SMILE, the difference was smallest between TK [(0.08±0.38) D] and CHM values (P>0.05). However, TCRP, RK, K_Haigis, K_Shammas, and K_Maloney were significantly different from CHM data (P<0.05). The width of the 95% limits of agreement of TK (1.49 D) was narrowest, followed by that of RK (1.57 D). Pearson analysis showed that each parameter had a good correlation with CHM data. The differences between the changes in TK, TCRP and RK caused by surgery and ΔSEco were (0.03±0.39) D, (0.17±0.43) D, and (-0.19±0.46) D, respectively. The width of the 95% limits of agreement of ΔTK (1.54 D) was narrowest, and the correlation coefficient of ΔTK (0.951) was highest. Conclusion: The parameter TK of the IOLMaster 700 can provide accurate and objective corneal power evaluation after SMILE.

LncRNA HOTAIR promotes colon cancer development by down-regulating miRNA-34a

OBJECTIVE

To investigate the characteristics of long non-coding RNA (lncRNA) HOTAIR in colon cancer, and to further explore its function in the development of colon cancer and its potential regulatory mechanisms.

PATIENTS AND METHODS

Quantitative Real-time polymerase chain reaction (qRT-PCR) was performed to detect HOTAIR expression in 72 colon cancer tissues along with adjacent normal tissues. Meanwhile, the relationship between HOTAIR level and colon cancer pathological parameters and patient prognosis were analyzed, respectively. QRT-PCR further verified the HOTAIR expression in colon cancer cells. Besides, knockdown and overexpression of HOTAIR models were constructed using lentivirus in HT29 and HCT-116 colon cancer cell lines. Cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EDU) and cell colony formation assays were used to analyze the effects of HOTAIR on biological function of colon cancer cell. In addition, dual luciferase reporter gene assay was performed to explore the underlying mechanisms.

RESULTS

QRT-PCR results showed that HOTAIR expression in colon cancer was significantly higher than that in normal tissues. The incidence of distant metastasis was higher in patients with high expression of HOTAIR while their survival rate was lower than that of patients with low HOTAIR expression. Meanwhile, cell proliferation, invasion as well as migration ability of the cells in HOTAIR knockdown group was significantly decreased than those in the negative control group. QRT-PCR results showed that mRNA levels of miR-34a and HOTAIR in colon cancer tissues were negatively correlated. Besides, luciferase reporter gene assay revealed that overexpression of miR-34a significantly attenuated the luciferase activity of the wild-type HOTAIR vector group without attenuating the mutant HOTAIR vector group (p>0.05) In addition, the recovery experiment also found a mutual regulation between HOTAIR and miR-34a, together they could affect the malignant progression of colon cancer.

CONCLUSIONS

HOTAIR expression was significantly increased in colon cancer, which was in association with distant metastasis and poor prognosis of colon cancer. In addition, HOTAIR may promote malignant progression of colon cancer by regulating miR-34a.

Observation of Complex Time Structures in the Cosmic-Ray Electron and Positron Fluxes with the Alpha Magnetic Spectrometer on the International Space Station

We present high-statistics, precision measurements of the detailed time and energy dependence of the primary cosmic-ray electron flux and positron flux over 79 Bartels rotations from May 2011 to May 2017 in the energy range from 1 to 50 GeV. For the first time, the charge-sign dependent modulation during solar maximum has been investigated in detail by leptons alone. Based on 23.5×10^{6} events, we report the observation of short-term structures on the timescale of months coincident in both the electron flux and the positron flux. These structures are not visible in the e^{+}/e^{-} flux ratio. The precision measurements across the solar polarity reversal show that the ratio exhibits a smooth transition over 830±30 days from one value to another. The midpoint of the transition shows an energy dependent delay relative to the reversal and changes by 260±30 days from 1 to 6 GeV.

Precision Measurement of Cosmic-Ray Nitrogen and its Primary and Secondary Components with the Alpha Magnetic Spectrometer on the International Space Station

A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×10^{6} events is presented. The detailed rigidity dependence of the nitrogen flux spectral index is presented for the first time. The spectral index rapidly hardens at high rigidities and becomes identical to the spectral indices of primary He, C, and O cosmic rays above ∼700  GV. We observed that the nitrogen flux Φ_{N} can be presented as the sum of its primary component Φ_{N}^{P} and secondary component Φ_{N}^{S}, Φ_{N}=Φ_{N}^{P}+Φ_{N}^{S}, and we found Φ_{N} is well described by the weighted sum of the oxygen flux Φ_{O} (primary cosmic rays) and the boron flux Φ_{B} (secondary cosmic rays), with Φ_{N}^{P}=(0.090±0.002)×Φ_{O} and Φ_{N}^{S}=(0.62±0.02)×Φ_{B} over the entire rigidity range. This corresponds to a change of the contribution of the secondary cosmic ray component in the nitrogen flux from 70% at a few GV to <30% above 1 TV.

Observation of Fine Time Structures in the Cosmic Proton and Helium Fluxes with the Alpha Magnetic Spectrometer on the International Space Station

We present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of 1×10^{9} events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above ∼3  GV the p/He flux ratio is time independent. We observed that below ∼3  GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise.

Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

Observation of the Identical Rigidity Dependence of He, C, and O Cosmic Rays at High Rigidities by the Alpha Magnetic Spectrometer on the International Space Station

We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.

Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.

Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500  GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500  GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

Previous history of tuberculosis is associated with rheumatoid arthritis

BACKGROUND

Previous studies have suggested that mycobacterial infections could trigger autoimmune diseases, including rheumatoid arthritis (RA).

OBJECTIVE

To explore the association between previous tuberculosis (TB) and RA.

METHODS

We conducted a case-control study using data obtained from the National Health Insurance (NHI) system of Taiwan. We identified 26 535 adults with RA from 2002 to 2011, with the date of diagnosis as the index date. This number was randomly selected and frequency-matched four times by age, sex and the year of index date from among non-RA individuals. Odds ratios (ORs) of RA were calculated for associations with TB.

RESULTS

Compared with controls, RA patients had a crude OR of 1.77 for TB (95%CI 1.61-1.94). The strength of the association between RA and TB remained at the same level after controlling for other potential risk factors (adjusted OR 1.73, 95%CI 1.57-1.90), although RA patients tended to have a higher prevalence of hypertension, coronary artery disease and kidney disease.

CONCLUSION

TB was much more prevalent in RA patients than in control subjects. Prospective cohort studies are required to establish a causal relationship between previous TB and RA.

The risk of chronic kidney disease in tuberculosis: a population-based cohort study

BACKGROUND

The relationship between tuberculosis (TB) and subsequent chronic kidney disease (CKD) remains unclear. Therefore, we examined the risk of CKD among patients with TB in a nationwide study.

METHODS

We conducted a retrospective cohort study using data from the National Health Insurance system of Taiwan. The cohort included 8735 patients who were newly diagnosed with TB. Patients were recruited between 1998 and 2002, and the date of diagnosis was defined as the index date. Each patient was randomly matched with four people from the general population without TB, according to age, gender and the index year. The occurrence of CKD was followed up until the end of 2011. The relative risks of CKD were estimated using the Cox proportional hazard model after adjusting for age, gender, index year and comorbidities.

RESULTS

The overall incidence of CKD was 1.27-fold greater in the TB cohort than in the non-TB cohort. The adjusted hazard ratio (HR) of CKD associated with TB was higher in women (1.72; 95% confidence interval [CI]: 1.33-2.22), those aged <50 years (1.67; 95% CI: 1.15-2.41) and those without comorbidities (1.39; 95% CI: 1.06-1.83). In addition, patients with more comorbidities among hypertension, diabetes and hyperlipidemia have a greater risk of developing CKD in both cohorts, and the adjusted HRs were higher in the TB cohort than in the non-TB cohort.

CONCLUSION

TB patients had a significantly higher risk of developing CKD than the general population. The detailed mechanisms need further investigation.

Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments

Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500°C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M₂₃C₆ precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.

Increased Incidence of juvenile onset systemic lupus erythematosus in children with atopic dermatitis

Herein, we investigated the risk of juvenile-onset systemic lupus erythematosus (JSLE) in children with atopic dermatitis (AD). From 2000 to 2007, 192,357 children with newly diagnosed AD and 769,428 matched non-AD controls were identified. By the end of 2008, incidences and hazard ratios (HRs) of JSLE were measured. JSLE incidence in the AD cohort was 2.90-fold greater than that in the non-AD cohort (3.25 vs. 1.12 per 100,000 person-years), with a Cox model-measured adjusted HR of 2.92 (95% CI: 1.85-4.60); the risk of JSLE was greater for older children and girls. The AD-to-non-AD cohort HR was 6.6 (95% CI: 2.88-13.1) for children aged >12 years compared with 1.81 (95% CI: 0.98-3.32) for children aged ≤ 12 years. The HR of JSLE in AD children increased from 1.55 (95% CI: 0.88-2.76) for those with ≤ 3 clinical visits to 66.3 (95% CI: 33.1-132.8) for those with >6 visits (p < 0.0001, by trend test). The risk of developing SLE in the AD cohort was the highest within five years after AD diagnosis (HR: 4.02; 95% CI: 2.83-7.08). Children with AD are at a high risk of developing JSLE during their growth period.

The risk of asthma in rheumatoid arthritis: a population-based cohort study

BACKGROUND

Several studies discussed the relations between asthma and rheumatoid arthritis (RA) but the results were controversial. These studies were either questionnaire based or with small study populations. We aimed to examine the risk of asthma among RA patients in a nationwide population.

METHODS

We conducted a cohort study using data from the National Health Insurance system of Taiwan. The RA cohort included 27 602 patients who were newly diagnosed and recruited between 1998 and 2008. Each patient was randomly frequency-matched with three people without RA on age group, sex and the year of index date from the general population. The occurrence of asthma was followed up until the end of 2010. The relative risks of asthma were estimated using Cox proportional hazard models after adjusting for age and comorbidities.

RESULT

The overall incidence rate of asthma was 2.07-fold greater in the RA cohort than in the non-RA cohort (4.56 vs. 2.22 per 1000 person-years, 95% CI = 1.99-2.15). Stratified analyses by gender, age group and comorbidity revealed that the risk of asthma associated with RA was higher in females (adjusted hazard ratio (HR) = 2.18, 95% CI = 1.97-2.41), individuals younger than 40 years old (adjusted HR = 3.26, 95% CI = 2.09-5.11) and without comorbidity (adjusted HR = 2.17, 95% CI = 1.97-2.39).

CONCLUSION

Patients with RA had a significantly higher risk of developing asthma than healthy people in all sex and age subgroups. Stratified analyses indicated that there was a higher risk in women with RA than in men with RA when compared to their counterpart. Similarly, the HR of asthma associated with RA was higher in younger subjects, although the incidence rate increased with age.

Curcumin-mediated oxidative stress resistance in Caenorhabditis elegans is modulated by age-1, akt-1, pdk-1, osr-1, unc-43, sek-1, skn-1, sir-2.1, and mev-1

Abstract Curcumin (diferuloylmethane), a pharmacologically active substance derived from turmeric, exhibits anti-inflammatory, anticarcinogenic, and antioxidant properties. We examined the modulation of oxidative-stress resistance and associated regulatory mechanisms by curcumin in a Caenorhabditis elegans model. Our results showed that curcumin-treated wild-type C. elegans exhibited increased survival during juglone-induced oxidative stress compared with the control treatment. In addition, curcumin reduced the levels of intracellular reactive oxygen species in C. elegans. Moreover, curcumin induced the expression of the gst-4 and hsp-16.2 stress response genes. Lastly, our findings from the mechanistic study in this investigation suggest that the antioxidative effect of curcumin is mediated via regulation of age-1, akt-1, pdk-1, osr-1, unc-43, sek-1, skn-1, sir-2.1, and mev-1. Our study elucidates the diverse modes of action and signaling pathways that underlie the antioxidant activity exhibited by curcumin in vivo.

Re-irradiation of metastatic disease in the neck from xeroderma pigmentosum

BACKGROUND

Xeroderma pigmentosum, an autosomal recessive disease that occurs with a frequency of 1:250,000, is caused by a genetic defect in nucleotide excision repair enzymes. Mutation of these enzymes leads to the development of multiple basal cell and squamous cell carcinomas.

OBJECTIVES

We present a case of xeroderma pigmentosum in a patient with cervical and intraparotid metastatic disease from recurrent cutaneous squamous cell carcinomas of the face and scalp, treated with neck dissection and re-irradiation. With the illustrative case report, we include a literature review of diagnosis, prognostic factors, and treatment, with emphasis on surgical and radiation treatment of cervical metastatic disease from recurrent skin carcinomas.

CASE PRESENTATION

A xeroderma pigmentosum patient presented to our clinic with a 2-cm right submental and 1-cm right infra-auricular mass after resection of multiple squamous cell carcinomas of the scalp and face, and external-beam radiation therapy to the right face and neck. Fine-needle aspiration biopsy of the submental mass revealed poorly differentiated squamous cell carcinoma. The patient was brought to the operating room for a right modified radical neck dissection and excision of the right submental and intraparotid mass. Surgical pathology revealed 3 level ia and supraclavicular lymph nodes that were positive for metastatic squamous cell carcinoma. Re-irradiation to the entire right hemi-neck and left submandibular nodal region was performed using opposed oblique portals for the upper neck and a low anterior en face hemi-neck portal. The left parotid region was also included in the re-irradiation volume. Treatment was completed without delayed complications or recurrences to date.

CONCLUSIONS

To our knowledge, this is the first case report in the literature of a patient with xeroderma pigmentosum who subsequently developed metastatic disease from recurrent cutaneous squamous cell carcinoma. Because of the rarity of xeroderma pigmentosum, this case report is also the first to describe re-irradiation to treat cervical and intraparotid metastatic disease in a xeroderma pigmentosum patient.

Theoretical investigation of polarization-insensitive data format conversion of RZ-OOK to RZ-BPSK in a nonlinear birefringent fiber

Polarization-insensitive conversion of return-to-zero (RZ) ON-OFF keying (RZ-OOK) to RZ binary phase-shift keying (RZ-BPSK) has been achieved by cross-phase modulation (XPM) in a nonlinear birefringent fiber. This work presents a theoretical analysis of the dependence of format conversion on pump-probe detuning, and the pump state-of-polarization (SOP) that can fluctuate unpredictably in a realistic system. An investigation of the impact of pump polarization fluctuation on receiver sensitivity and receiver optimal threshold for the converted RZ-BPSK probe is also carried out. It was found that although the desired XPM-induced pi phase shift can be achieved by launching both the RZ-OOK pump and the probe along the same birefringent axis of the fiber, the phase shift degrades to pi/3 if the SOP of the RZ-OOK pump unpredictably switches to the other axis of the fiber, resulting in a large receiver sensitivity penalty fluctuation of 14 dB. By contrast, launching the probe at 45 degrees relative to the birefringent axes can reduce the polarization-dependent receiver sensitivity penalty fluctuation to about 2 dB as the SOP of the RZ-OOK pump is swept over the Poincaré sphere. These conclusions are in good agreement with recently.

A novel transcript of mouse interleukin-20 receptor acts on glomerular mesangial cells as an aggravating factor in lupus nephritis

We identified a novel soluble protein, mouse (m)IL-20R1a, generated by alternative splicing of the mIL-20R1 gene, which encodes one subunit of the receptor complex for mIL-19, mIL-20 and mIL-24. mIL-20R1a has 77.14% amino-acid identity with the extracellular domain of mIL-20R1. However, no significant interaction between mIL-20R1a and mIL-19 or mIL-20 was detected. Consequently, we aimed to clarify whether mIL-20R1a might function as a novel effector on certain cells. Competitive binding assays demonstrated that mIL-20R1a bound to cell surfaces and resulted in AKT and JNK phosphorylation in primary mesangial cells (MCs) isolated from either the wild-type mice, DBA/W mice, or the SLE-prone mice, NZB/W mice. NZB/W MCs expressed more mIL-20R1a transcript than DBA/W MCs did. Furthermore, mIL-20R1a-treated NZB/W MCs produced higher level of chemokines, renal fibrogenic factors and ROS than mIL-20R1a-treated DBA/W MCs did. These factors are involved in the pathogenesis of lupus nephritis. Endogenous mIL-20R1a was upregulated in the bladder, colon and spleen tissue of NZB/W mice. Elevated mIL-20R1a in the spleen tissue of NZB/W mice was expressed mainly in monocytes and B cells. mIL-20R1a further induced mIL-10 production by the anti-IgM antibody-stimulated B cells in NZB/W mice. Therefore, mIL-20R1a-mediated effects may exacerbate the disease outcome of lupus nephritis.

Polarization-insensitive, 40 Gb/s wavelength and RZ-OOK-to-RZ-BPSK modulation format conversion by XPM in a highly nonlinear PCF

Polarization-insensitive wavelength conversion, as well as the conversion of return-to-zero (RZ) ON-OFF keying (RZ-OOK) to RZ binary phase-shift keying (RZ-BPSK), has been simultaneously achieved at 40 Gb/s for the first time by cross-phase modulation (XPM) in a highly birefringent, nonlinear photonic crystal fiber (PCF). A 10-9-BER receiver sensitivity conversion penalty of < 3 dB was achieved for a polarization scrambled, 40 Gb/s 25%-RZ-OOK pump, when the 40 Gb/s RZ probe was launched at 45 degrees with respect to the birefringence axes of the PCF and when the pump-probe detuning was greater than about 6 nm.

Packing of transmembrane helices in bacteriorhodopsin folding: structure and thermodynamics

We propose a coarse-grained (CG) model to study the native structure and physical properties of helical membrane proteins (HMPs) using off-lattice computer simulations. Instead of considering sequence heterogeneity explicitly, we model its effect on the packing of helices by employing a mean packing parameter r(0), which is calculated from an all-atom (AA) model. Specifically, this CG model is applied to investigate the packing of helices in bacteriorhodopsin (BR), and predicts the seven helix bundle structure of BR with a root mean square deviation (RMSD) in coordinates of helix backbone atoms (N, C, C(alpha)) of 3.99 A from its crystal structure. This predicted structure is further refined in an AA model by Amber and the refined structure has a RMSD (in coordinates of helix backbone atoms) of 2.64 A. The predicted packing position, tilting angle, and orientation angle of each helix in the refined structure are consistent with experimental data and their physical origins can be well understood in our model. Our results show that a reasonably good structure of BR can be predicted by using such a dual-scale approach, provided that its secondary structure is known. Starting from a random initial configuration, the folded structure can be obtained in days using a regular desktop computer. Various thermodynamic properties of helix packing of BR are also investigated in this CG model.

Catalase overexpression attenuates angiotensinogen expression and apoptosis in diabetic mice

Increased generation of reactive oxygen species (ROS) leads to oxidative stress in diabetes. Catalase is a highly conserved heme-containing protein that reduces hydrogen peroxide to water and oxygen and is an important factor decreasing cellular injury owing to oxidative stress. Hyperglycemic conditions increase oxidative stress and angiotensinogen gene expression. Angiotensinogen conversion to angiotensin II leads to a furtherance in oxidative stress through increased generation of reactive oxygen species. In this study, we utilized mice transgenically overexpressing rat catalase in a kidney-specific manner to determine the impact on ROS, angiotensinogen and apoptotic gene expression in proximal tubule cells of diabetic animals. Proximal tubules isolated from wild-type and transgenic animals without or with streptozotocin-induced diabetes were incubated in low glucose media in the absence or presence of angiotensin II or in a high-glucose media. Our results show that the overexpression of catalase prevents the stimulation of ROS and angiotensinogen mRNA in tubules owing to elevated glucose or angiotensin II in vitro. Additionally, overexpression of catalase attenuated ROS generation, angiotensinogen and proapoptotic gene expression and apoptosis in the kidneys of diabetic mice in vivo. Our studies point to an important role of ROS in the pathophysiology of diabetic nephropathy.

Transforming growth factor-beta 1 stimulates angiotensinogen gene expression in kidney proximal tubular cells

The present study investigated whether transforming growth factor-beta 1 (TGF-beta1) exerts an autocrine positive effect on angiotensinogen (ANG) gene expression in rat kidney proximal tubular cells, and delineates its underlying mechanism(s) of action. Rat immortalized renal proximal tubular cells (IRPTCs) and freshly isolated mouse renal proximal tubules were incubated in the absence or presence of active human TGF-beta1. IRPTCs were also stably transfected with rat TGF-beta1 or p53 tumor suppressor protein (p53) cDNA in sense (S) and antisense (AS) orientations. ANG mRNA and p53 protein expression were assessed by reverse transcription-polymerase chain reaction and Western blotting, respectively. Reactive oxygen species (ROS) generation was quantified by lucigenin assay. Active TGF-beta1 evoked ROS generation and stimulated ANG mRNA and p53 protein expression, whereas a superoxide scavenger and inhibitors of nicotinamide adenine dinucleotide oxidase and p38 mitogen-activated protein kinase (p38 MAPK) abolished the TGF-beta1 effect. Stable transfer of p53 cDNA (S) enhanced and p53 cDNA (AS) abolished the stimulatory effect of TGF-beta1 on ANG mRNA expression in IRPTCs. Our results demonstrate that TGF-beta1 stimulates ANG gene expression and its action is mediated, at least in part, via ROS generation, p38 MAPK activation, and p53 expression, suggesting that angiotensin II and TGF-beta1 may form a positive feedback loop to enhance their respective gene expression, leading to renal injury.

Enalaprilat blunts reflexive increases in cardiac interstitial norepinephrine in conscious rats

OBJECTIVE

We have reported that acute administration of enalaprilat, an angiotensin converting enzyme inhibitor, induces less reflexive increase in lumbar sympathetic nerve activity in spontaneously hypertensive rats (SHRs) than nicardipine, a dihydropyridine calcium-channel blocker. The current study was conducted to determine if angiotensin converting enzyme inhibitors likewise suppress cardiac sympathetic activation.

DESIGN

Cardiac interstitial levels of norepinephrine were measured in fully conscious SHRs before and after acute blood pressure lowering with enalaprilat or nicardipine.

METHODS

Microdialysis probes were inserted into the left ventricular wall of SHRs. Twenty-four to 48 hours post-implantation, myocardial interstitial fluid was collected in fully conscious rats during a 60-min baseline period. Mean arterial pressure was lowered 20 mmHg with intravenous infusion of enalaprilat or nicardipine. During continuous enalaprilat or nicardipine infusion, myocardial interstitial fluid was again collected. Norepinephrine levels were assayed in the perfusate.

CONCLUSIONS

Enalaprilat-induced reduction in mean arterial pressure did not significantly increase cardiac interstitial norepinephrine levels. In contrast, nicardipine-induced reduction in blood pressure was associated with a significant increase in interstitial norepinephrine levels. These results indicate that enalaprilat suppresses reflexive sympathetic activation of the heart during acute blood pressure lowering. These results may be clinically relevant in that reductions in end-organ sympathetic stimulation may enhance the long-term cardiovascular benefit of angiotensin converting enzyme inhibitors.

A conserved tryptophan in nitric oxide synthase regulates heme-dioxy reduction by tetrahydrobiopterin

In nitric oxide synthase (NOS), (6R)-tetrahydrobiopterin (H(4)B) binds near the heme and can reduce a heme-dioxygen intermediate (Fe(II)O(2)) during Arg hydroxylation [Wei, C.-C., Wang, Z.-Q., Wang, Q., Meade, A. L., Hemann, C., Hille, R., and Stuehr, D. J. (2001) J. Biol. Chem. 276, 315-319]. A conserved Trp engages in aromatic stacking with H(4)B, and its mutation inhibits NO synthesis. To examine how this W457 impacts H(4)B redox function, we performed single turnover reactions with the mouse inducible NOS oxygenase domain (iNOSoxy) mutants W457F and W457A. Ferrous mutants containing Arg and H(4)B were mixed with O(2)-containing buffer, and then heme spectral transitions, H(4)B radical formation, and Arg hydroxylation were followed versus time. A heme Fe(II)O(2) intermediate was observed in W457A and W457F and had normal spectral characteristics. However, its disappearance rate (6.5 s(-1) in W457F and 3.0 s(-1) in W457A) was slower than in wild-type (12.5 s(-1)). Rates of H(4)B radical formation (7.1 s(-1) in W457F and 2.7 s(-1) in W457A) matched their rates of Fe(II)O(2) disappearance, but were slower than radical formation in wild-type (13 s(-1)). The extent of H(4)B radical formation in the mutants was similar to wild-type, but their radical decayed 2-4 times faster. These kinetic changes correlated with slower and less extensive Arg hydroxylation by the mutants (wild-type > W457F > W457A). We conclude that W457 ensures a correct tempo of electron transfer from H(4)B to heme Fe(II)O(2), possibly by stabilizing the H(4)B radical. Proper control of these parameters may help maximize Arg hydroxylation and minimize uncoupled O(2) activation at the heme.

Angiotensin II modulates catecholamine release into interstitial fluid of canine myocardium in vivo

This study tested the hypothesis that exogenous infusion of angiotensin II (ANG II) leads to the release of catecholamines [norepinephrine (NE) and epinephrine (EPI)] into the cardiac interstitial fluid (ISF) space of dogs with adrenals intact (AI) (n = 7) and with adrenals clamped (AC) (n = 5). LV ISF samples were collected at 3-min intervals during administration of ANG II (100 microM ANG II at 1 ml/min for 10 min) to right atrial neurons via their local arterial blood supply and during electrical stimulation of the stellate ganglia of open-chest anesthetized dogs. In AI dogs, ANG II caused ISF NE to increase fivefold (P < 0.05) without a significant increase in coronary sinus (CS) NE. Electrical stimulation (5 ms, 4 Hz, 8-14 V, and 10 min) of the stellate ganglia caused a similar increase in ISF NE (P < 0.05), accompanied by a sevenfold increase in CS NE (P < 0.05). ISF EPI increased greater than sixfold during ANG II infusion (P < 0.05) and during stellate stimulation. However, during ANG II infusions, aorta plasma EPI levels increased fourfold in AI dogs, whereas in AC dogs, CS NE and EPI levels were unaffected during ANG II infusions. Nevertheless, baseline ISF NE and EPI did not differ and increased to a similar extent during ANG II infusions in AI versus AC dogs. Thus exogenously administered ANG II increases the amount of NE liberated into the ISF independent of the adrenal contribution, the amount matching that induced by electrical stimulation of all cardiac sympathetic efferent neurons. In contrast, NE spillover into the CS occurred only during electrical stimulation of stellate ganglia. NE release and uptake mechanisms within the myocardium are differently affected, depending on how the final common pathway of the sympathetic efferent nervous system is modified.

Risk Factors for Prophylaxis Failure in Patients Receiving Aerosol Pentamidine for Pneumocystis carinii Pneumonia Prophylaxis

OBJECTIVE

The purposes of this study were (1) to determine the incidence of prophylaxis failure in HIV-infected patients receiving aerosol pentamidine (AP) for Pneumocystis carinii pneumonia (PCP) prophylaxis, and (2) to identify risk factors for PCP prophylaxis failure.

SETTING AND DESIGN

In Ontario, Canada, AP has been made available for outpatient PCP prophylaxis through a centralized government program, the Ontario Drug Distribution and Monitoring Program. Data from this administrative observational database were extracted for 2,227 patients who received AP between May 1989 and December 1998.

OUTCOME MEASUREMENTS

The incidence of breakthrough PCP (BPCP) was calculated from the database. A Cox regression model with time-varying covariates was created to examine factors associated with BPCP. The follow-up time was divided into three eras: 1989 to 1991, 1992 to 1994, and 1995 to 1998. These eras were meant to reflect major changes in antiretroviral medication regimens.

RESULTS

The overall risk of BPCP was 16.2% over a mean follow-up of 1.67 years. The overall BPCP rate was 9.7/100 patient-years, with rates of 8.8/100, 13.1/100, and 6.3/100 patient-years in each of the three treatment eras. In the multivariate analysis, significant risk factors for prophylaxis failure were low CD4 count, previous diagnosis of PCP, history of AIDS-defining conditions other than PCP, and antiretroviral treatment era defined above.

CONCLUSION

The overall rate of PCP prophylaxis failure has decreased significantly after 1995, coincident with the era of highly active antiretroviral therapies. Initiation of PCP prophylaxis remains necessary in patients with risk factors.

Genetic variation in angiotensin-converting enzyme does not prevent development of cardiac hypertrophy or upregulation of angiotensin II in response to aortocaval fistula

BACKGROUND

Experimental and clinical evidence suggests that angiotensin II may be an important mediator of cardiac hypertrophy in response to hemodynamic stress. We investigated the effect of genetic variation in angiotensin-converting enzyme (ACE) on the development of cardiac hypertrophy and left ventricular (LV) dysfunction in response to volume overload.

METHODS AND RESULTS

Male heterozygous ACE knockout (1/0) and wild-type (1/1) mice were studied 4 weeks after the creation of an aortocaval fistula (ACF). The LV weight/body weight ratio increased 74% in ACF versus sham-operated control mice but did not differ between genotypes. Echocardiographic circumferential stress versus rate-corrected velocity of circumferential shortening curves demonstrated depressed LV function in ACF versus sham-operated mice but no difference between genotypes. LV ACE activity was higher in 1/1 versus 1/0 mice and in ACF versus sham-operated mice, and it increased significantly more in the 1/1 versus the 1/0 mice after ACF (P<0.001 for effect of genotype, ACF/sham operation, and interaction term). LV angiotensin II was higher in ACF versus sham-operated mice but did not differ between genotypes, despite 3-fold higher LV ACE activity in ACF 1/1 versus ACF 1/0 mice.

CONCLUSIONS

ACE underexpression does not prevent cardiac hypertrophy or LV dysfunction in response to volume overload. LV angiotensin II is unaffected by ACE genotype, both at baseline and after volume overload, indicating that the heart can maintain angiotensin II levels across a broad range of genetic ACE variation under both physiological and pathophysiological conditions.

Rapid kinetic studies link tetrahydrobiopterin radical formation to heme-dioxy reduction and arginine hydroxylation in inducible nitric-oxide synthase

To understand how heme and (6R)-5,6,7,8-tetrahydro-l-biopterin (H(4)B) participate in nitric-oxide synthesis, we followed ferrous-dioxy heme (Fe(II)O(2)) formation and disappearance, H(4)B radical formation, and Arg hydroxylation during a single catalytic turnover by the inducible nitric-oxide synthase oxygenase domain (iNOSoxy). In all cases, prereduced (ferrous) enzyme was rapidly mixed with an O(2)-containing buffer to start the reaction. A ferrous-dioxy intermediate formed quickly (53 s(-1)) and then decayed with concurrent buildup of ferric iNOSoxy. The buildup of the ferrous-dioxy intermediate preceded both H(4)B radical formation and Arg hydroxylation. However, the rate of ferrous-dioxy decay (12 s(-1)) was equivalent to the rate of H(4)B radical formation (11 s(-1)) and the rate of Arg hydroxylation (9 s(-1)). Practically all bound H(4)B was oxidized to a radical during the reaction and was associated with hydroxylation of 0.6 mol of Arg/mol of heme. In dihydrobiopterin-containing iNOSoxy, ferrous-dioxy decay was much slower and was not associated with Arg hydroxylation. These results establish kinetic and quantitative links among ferrous-dioxy disappearance, H(4)B oxidation, and Arg hydroxylation and suggest a mechanism whereby H(4)B transfers an electron to the ferrous-dioxy intermediate to enable the formation of a heme-based oxidant that rapidly hydroxylates Arg.

The organum vasculosum of the lamina terminalis regulates noradrenaline release in the anterior hypothalamic nucleus

Changes in either plasma sodium concentration or arterial pressure can differentially affect hypothalamic neurons. For instance, increases in plasma NaCl concentration decrease noradrenaline release from nerve terminals in the anterior hypothalamic nucleus, while increases in arterial pressure unrelated to an elevation in plasma NaCl enhance noradrenaline release in anterior hypothalamic nucleus. The present study tests the hypothesis that in the rat the organum vasculosum of the lamina terminalis (an osmosensitive area of the brain) detects rises in plasma NaCl concentration and conveys this information to anterior hypothalamic nucleus. The axons projecting from the organum vasculosum of the lamina terminalis to the hypothalamus were unilaterally cut immediately caudal to organum vasculosum of the lamina terminalis, and five days later, 3-methoxy-4-hydroxy phenylglycol (the major metabolite of noradrenaline in brain) was continuously monitored in the ipsilateral or contralateral anterior hypothalamic nucleus in response to an intravenous infusion of hypertonic saline. In spontaneously hypertensive rats, the infusion decreased the 3-methoxy-4-hydroxy phenylglycol concentration by 24+/-2% in the anterior hypothalamic nucleus contralateral to the lesion, and in control spontaneously hypertensive rats. In contrast, in the anterior hypothalamic nucleus ipsilateral to the lesion, hypertonic saline infusion caused a 58+/-3% increase in 3-methoxy-4-hydroxy phenylglycol. These data support the hypothesis that the organum vasculosum of the lamina terminalis is part of the circuit that transmits information concerning plasma NaCl concentration to anterior hypothalamic nucleus.

Cloning and expression of ZAK, a mixed lineage kinase-like protein containing a leucine-zipper and a sterile-alpha motif

A novel mixed lineage kinase-like protein ZAK, containing a leucine-zipper (LZ) and a sterile-alpha motif (SAM), was cloned. This cDNA has 2456 bp and encodes a protein of 800 amino acids that contains a kinase catalytic domain, a leucine-zipper and a SAM. The molecular weight of this protein is 91kDa. Northern blot analysis revealed that the expression of this ZAK gene is found in various parts of human tissues. We also found that ZAK proteins might form homodimers or oligomers in mammalian cells. MLKs have been proposed to function as mitogen-activated protein kinase kinase kinase in pathways leading to MAPK cascade. The expression of ZAK in mammalian cells specifically leads to the activation of the JNK/SAPK pathway as well as the activation of transcription factor, NF-kappaB. Overexpression of the ZAK gene induces the apoptosis of a hepatoma cell line.

2-Tetradecylglycidic acid, an inhibitor of carnitine palmitoyltransferase-1, induces myocardial hypertrophy via the AT1 receptor

Activation of the antiogensin II, type 1 (AT1) receptor mediates the myocardial response to numerous hypertrophic stimuli. This study tested the hypothesis that 2-tetradecylglycidic acid (TDGA), an oxirane carboxylate inhibitor of mitochondrial carnitine plamitoyltransferase-1, induces myocardial hypertrophy via the AT1 receptor system. Male Sprague-Dawley rats treated with 10 mg TDGA/kg/day for 7 days had a heart wet weight:body weight ratio of 3. 58+/-0.16 mg/g compared with a ratio of 2.79+/-0.07 for rats treated with vehicle (P<0.05). The plasma level of antiogensin II was 117. 75+/-17.39 pg/ml in rats treated with 10 mg TDGA/kg/day compared with 54.0+/-11.38 pg/ml for rats treated with vehicle (P<0.05). The plasma level of angiotensin I in these two groups of rats was not different statistically. Rats treated with TDGA and given drinking water containing 1 mg losartan/ml had a heart wet weight:body weight ratio of 2.84+/-0.05 mg/g. This value was not statistically different from the value measured in rats given drinking water containing 1 mg losartan/ml and treated with vehicle alone. No significant difference in the heart wet weight:dry weight ratio occurred among these groups of rats. Finally, treating rats with TDGA or giving rats drinking water that contained 1 mg losartan/ml altered neither their heart rate nor their mean arterial blood pressure when compared with untreated rats. This data, therefore, suggests that oxirane carboxylates induce myocardial hypertrophy by activating the AT1 receptor independent of changes in systemic hemodynamics.

Evidence for angiotensin-converting enzyme- and chymase-mediated angiotensin II formation in the interstitial fluid space of the dog heart in vivo

BACKGROUND

We have previously demonstrated that angiotensin II (Ang II) levels in the interstitial fluid (ISF) space of the heart are higher than in the blood plasma and do not change after systemic infusion of Ang I. In this study, we assess the enzymatic mechanisms (chymase versus ACE) by which Ang II is generated in the ISF space of the dog heart in vivo.

METHODS AND RESULTS

Cardiac microdialysis probes were implanted in the left ventricular (LV) myocardium (3 to 4 probes per dog) of 12 anesthetized open-chest normal dogs. ISF Ang I and II levels were measured at baseline and during ISF infusion of Ang I (15 micromol/L, n=12), Ang I+the ACE inhibitor captopril (cap) (2.5 mmol/L, n=4), Ang I+the chymase inhibitor chymostatin (chy) (1 mmol/L, n=4), and Ang I+cap+chy (n=4). ISF infusion of Ang I increased ISF Ang II levels 100-fold (P<0.01), whereas aortic and coronary sinus plasma Ang I and II levels were unaffected and were 100-fold lower than ISF levels. Compared with ISF infusion of Ang I alone, Ang I+cap (n=4) produced a greater reduction in ISF Ang II levels than did Ang I+chy (n=4) (71% versus 43%, P<0.01), whereas Ang I+cap+chy produced a 100% decrease in ISF Ang II levels.

CONCLUSIONS

This study demonstrates for the first time a very high capacity for conversion of Ang I to Ang II mediated by both ACE and chymase in the ISF space of the dog heart in vivo.

Differential expression of angiotensin-converting enzyme and chymase in dogs with chronic mitral regurgitation

The current study tested the hypothesis that angiotensin-converting enzyme (ACE) and chymase expression are subject to different regulatory processes in the heart, as well as the lungs and kidneys and, as a result, have an important effect on the efficacy of ACE inhibitor treatment in modulating tissue angiotensin II (ANG II) levels in heart failure. A total of 18 dogs underwent the induction of mitral regurgitation and were followed for 5 months. Eleven dogs were untreated and seven received the ACE-inhibitor ramipril at a dose of 10 mg PO BID. Seventeen dogs underwent a sham-operation: six of these dogs were treated with ramipril for 3 months (10 mg PO BID) and 11 were untreated and followed for 3 months prior to sacrifice. In mitral regurgitation dogs, ANG II levels were increased >2-fold in left ventricle, lungs, and kidney, but were normalized with ACE inhibitor-treatment only in the left ventricle. In the left ventricle and lungs steady state ACE mRNA levels and ACE activities were increased 2-fold in treated and untreated mitral regurgitation dogs compared to shams (P<0.05, ANOVA). In contrast, chymase mRNA levels were decreased by >50% and chymase activity was increased in left ventricle (LV) of mitral regurgitation dogs (P<0.05). Neither chymase mRNA nor chymase activity could be detected in the kidney; however, kidney ACE mRNA and ACE activity were significantly upregulated in treated and untreated mitral regurgitation dogs (P<0. 05). These results suggest that ACE and chymase expression are regulated differentially in the dog in response to chronic mitral regurgitation and ACE inhibitor treatment. Further, these responses, as well as regulation of ANG II formation, are organ specific.

The spectrum of microsatellite loci on chromosomes 7 and 8 in Taiwan aboriginal populations: a comparative population genetic study

Sixteen microsatellite loci on chromosomes 7 and 8 of Han-Taiwanese and six Taiwan aboriginal populations were systematically analyzed by a high-resolution multiple-fluorescence-based polymerase chain reaction technique. Analysis of allele frequency distribution indicated the genetic divergence among these populations. Several alleles were unique to specific tribes. Only the D8S556 locus deviated from Hardy-Weinberg equilibrium in all tribes. Its F(IS) level, as calculated with the Nei method, was also higher and more homozygous than expected. Therefore, with the exception of D8S556, these variable number of tandem repeats (VNTR) loci are suitable genetic markers for forensic and paternal testing. The F(ST) level, as the proportion of the total variation among these tribes, ranged from 1.4% at the D7S484 locus to 6.8% at the D7S550 locus. The average F(ST) was 3.9%, suggesting that there were substantial variations among these populations. The genetic identity analysis and the genetic distance analysis reached the same conclusions, viz., that the Ami and the Paiwan tribes were genetically close to each other, that the Atayal tribe was relatively unique compared with other tribes, and that the Saisiat tribe was relatively close to the Han-Taiwanese. A dendrogram for these tribes was further constructed by the UPGMA method. These VNTR data not only facilitate forensic and paternity testing, but also provide anthropometric information for further elucidating the relationship of Taiwan populations to the Austronesian family.

Hypertrophic response to hemodynamic overload: role of load vs. renin-angiotensin system activation

Myocardial hypertrophy is one of the basic mechanisms by which the heart compensates for hemodynamic overload. The mechanisms by which hemodynamic overload is transduced by the cardiac muscle cell and translated into cardiac hypertrophy are not completely understood. Candidates include activation of the renin-angiotensin system (RAS) and angiotensin II receptor (AT1) stimulation. In this study, we tested the hypothesis that load, independent of the RAS, is sufficient to stimulate cardiac growth. Four groups of cats were studied: 14 normal controls, 20 pulmonary artery-banded (PAB) cats, 7 PAB cats in whom the AT1 was concomitantly and continuously blocked with losartan, and 8 PAB cats in whom the angiotensin-converting enzyme (ACE) was concomitantly and continuously blocked with captopril. Losartan cats had at least a one-log order increase in the ED50 of the blood pressure response to angiotensin II infusion. Right ventricular (RV) hypertrophy was assessed using the RV mass-to-body weight ratio and ventricular cardiocyte size. RV hemodynamic overload was assessed by measuring RV systolic and diastolic pressures. Neither the extent of RV pressure overload nor RV hypertrophy that resulted from PAB was affected by AT1 blockade with losartan or ACE inhibition with captopril. RV systolic pressure was increased from 21 +/- 3 mmHg in normals to 68 +/- 4 mmHg in PAB, 65 +/- 5 mmHg in PAB plus losartan and 62 +/- 3 mmHg in PAB plus captopril. RV-to-body weight ratio increased from 0.52 +/- 0.04 g/kg in normals to 1.11 +/- 0.06 g/kg in PAB, 1.06 +/- 0.06 g/kg in PAB plus losartan and 1.06 +/- 0.06 g/kg in PAB plus captopril. Thus 1) pharmacological modulation of the RAS with losartan and captopril did not change the extent of the hemodynamic overload or the hypertrophic response induced by PAB; 2) neither RAS activation nor angiotensin II receptor stimulation is an obligatory and necessary component of the signaling pathway that acts as an intermediary coupling load to the hypertrophic response; and 3) load, independent of the RAS, is capable of stimulating cardiac growth.

Effects of long-term aerosol pentamidine for Pneumocystis carinii prophylaxis on pulmonary function

OBJECTIVE

The purpose of the study was to evaluate the long-term effects of aerosolized pentamidine (AP) on the pulmonary function of HIV-positive individuals receiving AP for Pneumocystis carinii pneumonia (PCP) prophylaxis.

DESIGN

A retrospective analysis of serial pulmonary function tests (PFTs) performed on a cohort of HIV-positive patients who had received AP for >2 years.

METHODS

Of the 1,787 HIV-positive patients receiving AP prophylaxis in our database, 380 patients had been receiving AP for at least 24 months. Of these 380 patients, the PFTs at baseline and at 24 months after starting AP therapy were documented in 179. We compared the baseline PFTs of these 179 patients with results obtained 24 months later to evaluate if there was any change in pulmonary function parameters.

RESULTS

Baseline and 24-month PFT parameters (total lung capacity [TLC], FVC, residual volume [RV], FEV1, FEV1/FVC, maximum midexpiratory flow rate at 50% of vital capacity [MEF50], diffusion of carbon monoxide [DLCO]) were all within the normal ranges. However, AP therapy over 24 months was associated with a modest decline in lung volume parameters (TLC, FVC, RV), a slight reduction in flow rates (FEV1, FEV1/FVC, and MEF50), but no change in DLCO. The mean treatment duration was 23.8 months (range, 21 to 27 months).

CONCLUSIONS

Long-term AP therapy is associated with a mild combined restrictive and obstructive pulmonary defect. Since 24-month PFT parameters remained within the normal ranges, this level of decline is of unclear clinical significance. Overall, AP has good pulmonary tolerance when used up to 24 months for PCP prophylaxis in patients with normal baseline pulmonary function.

Wheat germ poly(A) binding protein enhances the binding affinity of eukaryotic initiation factor 4F and (iso)4F for cap analogues

Most eukaryotic mRNAs contain a 5' cap (m7GppX) and a 3' poly(A) tail to increase synergistically the translational efficiency. Recently, the poly(A) binding protein (PABP) and cap-binding protein, eIF-4F, were found to interact [Le et al. (1997) J. Biol. Chem. 272, 16247-16255; Tarun and Sachs (1996) EMBO J. 15, 7168-7177]. These data suggest that PABP may exert its effect on translational efficiency either by increasing the formation of initiation factor-mRNA complex or by enhancing ribosome recycling. To investigate the functional consequences of these interactions, the fluorescent cap analogue, ant-m7GTP, which is an environmentally sensitive fluorescent probe [Ren and Goss (1996) Nucleic Acids Res. 24, 3629-3634] was used to investigate the cap-binding affinity. Our data show that the binding of eIF-(iso)4F or eIF-4F to cap analogue enhanced their binding affinity toward PABP approximately 40-fold. Similarly, the eIF-4F/PABP or eIF-(iso)4F/PABP complexes show a 40-fold enhancement of cap analogue binding as compared to eIF-4F or eIF-(iso)4F alone. At least part of the enhancement of the translational initiation by PABP can be accounted for by direct changes in cap-binding affinity. The interactions of these components also suggest a mechanism whereby the poly(A) tail is brought into close proximity with m7G cap. This effect was examined by fluorescence energy transfer, and it was determined that the PABP/eIF-4F complex could bind both poly(A) and 5' cap simultaneously.

Compartmentalization of angiotensin II generation in the dog heart. Evidence for independent mechanisms in intravascular and interstitial spaces

Angiotensin-converting enzyme inhibitors have beneficial effects that are presumably mediated by decreased angiotensin II (ANG II) production. In this study, we measure for the first time ANG I and ANG II levels in the interstitial fluid (ISF) space of the heart. ISF and aortic plasma ANG I and II levels were obtained at baseline, during intravenous infusion of ANG I (5 microM, 0.1 ml/min, 60 min), and during ANG I + the angiotensin-converting enzyme inhibitor captopril (cap) (2.5 mM, 0.1 ml/min, 60 min) in six anesthetized open-chested dogs. ISF samples were obtained using microdialysis probes inserted into the left ventricular myocardium (3-4 probes/dog). ANG I increased mean arterial pressure from 102+/-3 (SEM) to 124+/-3 mmHg (P < 0.01); addition of cap decreased MAP to 95+/-3 mmHg (P < 0.01). ANG I infusion increased aortic plasma ANG I and ANG II (pg/ml) (ANG I = 101+/-129 to 370+/-158 pg/ml, P < 0.01; and ANG II = 22+/-40 to 466+/-49, P < 0.01); addition of cap further increased ANG I (1,790+/-158, P < 0.01) and decreased ANG II (33+/-49, P < 0.01). ISF ANG I and ANG II levels (pg/ml) were > 100-fold higher than plasma levels, and did not change from baseline (8,122+/-528 and 6,333+/-677), during ANG I (8,269+/-502 and 6, 139+/-695) or ANG I + cap (8,753+/-502 and 5,884+/-695). The finding of very high ANG I and ANG II levels in the ISF vs. intravascular space that are not affected by IV ANG I or cap suggests that ANG II production and/or degradation in the heart is compartmentalized and mediated by different enzymatic mechanisms in the interstitial and intravascular spaces.

Translation initiation factors eIF-iso4G and eIF-4B interact with the poly(A)-binding protein and increase its RNA binding activity

The 5'-cap and the poly(A) tail act synergistically to increase the translational efficiency of eukaryotic mRNAs, which suggests that these two mRNA elements communicate during translation. We report here that the cap-associated eukaryotic initiation factors (eIFs), i. e. the two isoforms of the cap-binding complex (eIF-4F and eIF-iso4F) and eIF-4B, bind to the poly(A)-binding protein (PABP) both in the presence and absence of poly(A) RNA. The interactions between PABP and eIF-4F, eIF-iso4F, and eIF-4B were measured in the absence of poly(A) RNA using far Western analysis and confirmed by direct fluorescence titration studies. The functional consequence of the interaction between these initiation factors and PABP was examined using RNA binding assays and RNA mobility shift analysis. eIF-4F, eIF-iso4F, and eIF-4B promoted PABP activity through a shift in its equilibrium affinity for poly(A). eIF-iso4G, the large subunit of eIF-iso4F, was the subunit responsible for the interaction between eIF-iso4F and PABP and was the subunit that promoted PABP RNA binding activity. Truncation analysis of eIF-iso4G indicated that a domain close to its N-terminal end appeared to be involved in binding PABP. These results suggest that the interaction between PABP and eIF-4B and eIF-iso4G may be involved in mediating the functional co-dependence observed between the cap and the poly(A) tail during translation.

Systemic lupus erythematosus with intussusception: a case report

A 19-year-old male with systemic lupus erythematosus, had initially presented three years previous by malar rash and nephritis. In the past 2 weeks, he experienced bloody diarrhea and lower abdominal pain. Intussusceptions of the distal to the terminal ileum, terminal ileum to cecum and cecum to ascending colon were proved via exploratory laparotomy. Mesenteric lymphadenopathy was thought to be the leading cause. This is the second case of systemic lupus erythematosus with intussusception described in the literature.

Synthesis and structure-activity relationship of (lactamylvinyl)cephalosporins exhibiting activity against staphylococci, pneumococci, and enterococci

The synthesis and structure-activity relationships of a new class of vinylcephalosporins substituted with a lactamyl residue are described. These compounds show excellent activity against enterococci and retain the broad spectrum activity of third-generation cephalosporins such as ceftriaxone.

An atomic basis of cancer (V): A new marker in animal tumors

Particle-induced X-ray emission (PIXE) analysis can be applied to mark (or to localize) a cancer lesion in a benign environment in test animals. We synthesized hematoporphyrin derivative (HPD) with rare earth metals to form lanthanide-HPD to enhance the localizing efficiency. The sensitive PIXE detection of trace elements in amounts on the order of nanograms or less could possibly be used to probe carcinogenesis at the level of the cell. To explain the present approach, we present the results of an experiment in which we used paraseodynium-HPD localizer.

Dual-action cephalosporins incorporating a 3'-tertiary-amine-linked quinolone

We have previously reported that linking quinolones to the cephalosporin 3'-position through an ester bond, a carbamate function, or a bond through a quaternary nitrogen produced cephalosporins with a dual mode of antibacterial action. We now describe a new class of dual-action cephalosporins, with greater chemical stability than those previously reported, in which the basic nitrogen of ciprofloxacin is bonded directly to the 3'-cephalosporin position, i.e., the two moieties are linked through a tertiary amine function. These compounds have demonstrated potent activity against a broad spectrum of Gram-positive and Gram-negative bacteria, including beta-lactam-resistant strains.