Biodegradation of polystyrene and polyethylene by Microbacterium esteraromaticum SW3 isolated from soil

Plastic pollution is a common concern of global environmental pollution. Polystyrene (PS) and polyethylene (PE) account for almost one-third of global plastic production. However, so far, there have been few reports on microbial strains capable of simultaneously degrading PS and PE. In this study, Microbacterium esteraromaticum SW3, a non-pathogenic microorganism that can use PS or PE as the only carbon source in the mineral salt medium (MM), was isolated from plastics-contaminated soil and identified. The optimal growth conditions for SW3 in MM were 2% (w/v) PS or 2% (w/v) PE, 35°C and pH 6.3. A large number of bacteria and obvious damaged areas were observed on the surface of PS and PE products after inoculated with SW3 for 21 d. The degradation rates of PS and PE by SW3 (21d) were 13.17% and 5.39%, respectively. Manganese peroxidase and lipase were involved in PS and PE degradation by SW3. Through Fourier infrared spectroscopy detection, different functional groups such as carbonyl, hydroxyl and amidogen groups were produced during the degradation of PS and PE by SW3. Moreover, PS and PE were degraded into alkanes, ketones, carboxylic acids, esters and so on detected by GC-MS. Collectively, we have isolated and identified SW3, which can use PS or PE as the only carbon source in MM as well as degrade PS and PE products. This study not only provides a competitive candidate strain with broad biodegradability for the biodegradation of PS and/or PE pollution, but also provides new insights for the study of plastic biodegradation pathways.

Development of terpenoid repellents against Aedes albopictus: a combined study of biological activity evaluation and computational modelling

To explore novel terpenoid repellents, 22 candidate terpenoid derivatives were synthesized and tested for their electroantennogram (EAG) responses and repellent activities against Aedes albopictus. The results from the EAG experiments revealed that 5-(2-hydroxypropan-2-yl)-2-methylcyclohex-2-en-1-yl formate (compound 1) induced distinct EAG responses in female Aedes albopictus. At concentrations of 0.1, 1, 10, 100, and 1000 mg/L, the EAG response values for compound 1 were 179.59, 183.99, 190.38, 193.80, and 196.66 mV, demonstrating comparable or superior effectiveness to DEET. Repellent activity analysis indicated significant repellent activity for compound 1, closest to the positive control DEET. The in silico assessment of the ADMET profile of compound 1 indicates that it successfully passed the ADMET evaluation. Molecular docking studies exhibited favourable binding of compound 1 to the active site of the odorant binding protein (OBP) of Aedes albopictus, involving hydrophobic forces and hydrogen bond interactions with residues in the OBP pocket. The QSAR model highlighted the influential role of hydrogen-bonding receptors, positively charged surface area of weighted atoms, polarity parameters of molecules, and maximum nuclear-nuclear repulsion force of carbon-carbon bonds on the relative EAG response values of the tested compounds. This study holds substantial significance for the advancement of new terpenoid repellents.

A D-Shaped Polymer Optical Fiber Surface Plasmon Resonance Biosensor for Breast Cancer Detection Applications

Fiber-optic biosensors have garnered significant attention and witnessed rapid development in recent years owing to their remarkable attributes such as high sensitivity, immunity to electromagnetic interference, and real-time monitoring. They have emerged as a potential tool in the realm of biomarker detection for low-concentration and small molecules. In this paper, a portable and cost-effective optical fiber biosensor based on surface plasmon resonance for the early detection of breast cancer is demonstrated. By utilizing the aptamer human epidermal growth factor receptor 2 (HER2) as a specific biomarker for breast cancer, the presence of the HER2 protein can be detected through an antigen-antibody binding technique. The detection method was accomplished by modifying a layer of HER2 aptamer on the flat surface of a gold-coated D-shaped polymer optical fiber (core/cladding diameter 120/490 μm), of which the residual thickness after side-polishing was about 245 μm, the thickness of the coated gold layer was 50 nm, and the initial wavelength in pure water was around 1200 nm. For low-concentration detection of the HER2 protein, the device exhibited a wavelength shift of ~1.37 nm with a concentration of 1 μg/mL (e.g., 5.5 nM), which corresponded to a limit of detection of ~5.28 nM. Notably, the response time of the biosensor was measured to be as fast as 5 s. The proposed biosensor exhibits the potential for early detection of HER2 protein in initial cancer serum and offers a pathway to early prevention of breast cancer.

Long-range distributed vibration sensing using phase-sensitive forward optical transmission: publisher's note

This publisher's note contains corrections to Opt. Lett.48, 4825 (2023)10.1364/OL.500587.

Super-long-range distributed vibration sensor based on the polarimetric forward-transmission of light

Undersea earthquake-triggered giant tsunamis pose significant threats to coastal areas, spanning thousands of kilometers and affecting populations, ecosystems, and infrastructure. To mitigate their impact, monitoring seismic activity in underwater environments is crucial. In this study, we propose a new, to the best of our knowledge, approach for monitoring vibrations in submarine optical cables. By detecting vibration-induced polarization rotation, our dual-wavelength fiber-optic sensing system enables precise measurement of acoustic/vibration amplitude, frequency, and position. As a proof of concept, a double-ended forward-transmission distributed fiber-optic vibration sensor was demonstrated with a single vibration source with a sensitivity of 3.4 mrad/µε at 100 Hz (20 m fiber on PZT), limit of detection of 1.7 pε/Hz1/2 at 100 Hz, sensing range of 121.5 km without an optical amplifier, spatial resolution of 5 m, and position error as small as 34 m. The vibration frequency range tested is from 0.01 to 100 Hz. The sensing system has several advantages, including elegant setup, noise mitigation, and super-long sensing distance.

Comparison of Two Triple Therapy Regimens for Enhancing the Abscopal Effect in Mice

PURPOSE/OBJECTIVE(S)

Localized radiotherapy (RT) can cause a T cell-mediated abscopal effect on non-irradiated tumor lesions, especially in combination with immune checkpoint blockade (ICB). However, this effect is still clinically rare and improvements are highly desirable. We here compared two triple therapy regimens (RT+⍺PD1+⍺CTLA4 vs. RT+⍺PD1+IL2/⍺IL2 complexes (IL2c)) for their efficacy to improve systemic (abscopal) anti-tumor effects.

MATERIALS/METHODS

In mice bearing bilateral subcutaneous C51 colon carcinoma tumors, the primary tumor was irradiated with two fractions of 8 Gy. ⍺PD1 and ⍺CTLA4 were given concomitantly and weekly thereafter; IL2c was given i.p. for 3 consecutive days. Besides tumor size and survival, tumor-specific CD8+ T cells were determined flow cytometrically using MHC-I tetramers and various antibodies. In addition, isolated TILs were cultured with PMA, ionomycin, and Brefeldin A in vitro to assess polyfunctionality (based on cytokine production) of CD8+ and CD4+ TILs.

RESULTS

The abscopal effect was significantly stronger in mice treated with the ⍺CTLA4-containing triple combination (n = 13) than in mice treated with the IL2c-containing triple combination (n = 9) (p<0,05), and compared to mice treated with RT+⍺PD1 (n = 8) (p<0,05) or RT+⍺CTLA4 (n = 10) (p<0,05), respectively. The IL2c triple combination induced the abscopal effect better than RT+⍺PD1 (p<0,05). The ⍺CTLA4 triple therapy improved survival and resulted in complete cures of 8/13 mice. In mice treated with ⍺CTLA4-containing triple therapy, control of the irradiated tumor was partially dependent and that of the non-irradiated tumor was strongly dependent on T cells, primarily CD8 T cells but also CD4 T cells. With ⍺CTLA4 triple treatment (n = 9), the frequency and absolute numbers of polyfunctional TNF-⍺+IFN-γ+ AH-1 tumor-specific CD8+ T cells, IFN-γ+IL2+ AH-1 tumor-specific CD8+ T cells, TNF-⍺+IFN-γ+ CD4+ and IFN-γ+IL2+ CD4+ effector T cells were higher than with the IL2c triple combination (n = 9) (p<0,05), particularly in the non-irradiated tumors.

CONCLUSION

RT+⍺PD1+⍺CTLA4 triple treatment induced more cytotoxic effector TILs than RT+⍺PD1+IL2c triple treatment, enhancing the abscopal effect and inducing a high abscopal cure rate. More experiments underway to reveal mechanisms.

Long-range distributed vibration sensing using phase-sensitive forward optical transmission

Long-range vibration sensing is an important tool for real-time structural health monitoring. A new, to the best of our knowledge, design of a distributed fiber-optic vibration sensor is introduced and experimentally demonstrated in this study. The proposed system utilizes the transmission of light in the forward direction for sensing, and a self-interference method for laser source simplification. To extract vibration information from phase modulation of light, two Mach-Zehnder interferometers (MZIs) are employed with a 3 × 3 coupler-based differential cross multiplication algorithm for phase calculation. A folded double-ended detection configuration allows the time-of-flight difference via cross correlation (CC) to provide vibration positioning. Experimental results demonstrate a sensing range of up to ∼80 km without optical amplification, accompanied by a position accuracy of 336 m.

Experimental evaluation and structure-activity relationship analysis of bridged-ring terpenoid derivatives as novel Blattella germanica repellent

Cockroaches are urban pests that are very difficult to control. Using repellents is a green, safe and effective strategy for their control. In order to find novel cockroach repellents, the repellent activity of 45 bridged-ring terpenoid derivatives synthesized from β-pinene against Blattella germanica was tested. The relationship between the molecular structure of these bridged-ring terpenoid derivatives and their repellent activity against Blattella germanica was also analysed. The results show that some of the bridged-ring terpenoid derivatives exhibit good repellent activity against Blattella germanica, and six compounds (RR = 60.44-87.32%) show higher repellent activity against Blattella germanica than DEET (RR = 54.77%), making them promising for development as new cockroach repellents. Quantitative structure-activity relationship (QSAR) analysis revealed that the HOMO-1 energy, Kier and Hall index (order 2), Balaban index, and relative positive charged surface area of bridged-ring terpenoid derivatives have effects on repellent activity against Blattella germanica. The present study may provide a theoretical basis for the high-value use of β-pinene and can be helpful to the development of novel repellents against Blattella germanica.

Compact Surface Plasmon Resonance IgG Sensor Based on H-Shaped Optical Fiber

A compact surface plasmon resonance sensor based on an H-shaped optical fiber is proposed and demonstrated. The H-shaped optical fiber was fabricated experimentally by using hydrofluoric acid to controllably corrode the polarization-maintaining fiber. A satisfactory distance between the outer surface of the fiber and the core can be achieved, and then the surface plasmon resonance effect can be excited by coating a metal film of appropriate thickness on the surface of the fiber. This technology can realize the preparation of multiple samples at one time, compared to the traditional side-polishing technique. The H-shaped optical fiber obtained from corrosion exhibits a high surface quality and short lengths, down to only a few hundred microns. The effects of the proposed H-shaped optical fiber on spectral properties are induced by process parameters, including fiber remaining thickness, coating thickness and fiber length, and were investigated in detail. The prepared sensor was used for the specific detection of human IgG, and the minimum human IgG concentration that the sensor can distinguish is 3.4 μg/mL. Such a compact surface plasmon resonance fiber sensor has the advantages of an easy fabrication, good consistency and low cost, and is expected to be applied in the specific detection of biomarkers.

All Fiber-Optic Immunosensors Based on Elliptical Core Helical Intermediate-Period Fiber Grating with Low-Sensitivity to Environmental Disturbances

An all fiber-optic immunosensor based on elliptical core helical intermediate-period fiber grating (E-HIPFG) is proposed for the specific detection of human immunoglobulin G (human IgG). E-HIPFGs are all-fiber transducers that do not include any additional coating materials or fiber architectures, simplifying the fabrication process and promising the stability of the E-HIPFG biosensor. For human IgG recognition, the surface of an E-HIPFG is functionalized by goat anti-human IgG. The functionalized E-HIPFG is tested by human IgG solutions with a concentration range of 10-100 μg/mL and shows a high sensitivity of 0.018 nm/(μg/mL) and a limit of detection (LOD) of 4.7 μg/mL. Notably, the functionalized E-HIPFG biosensor is found to be insensitive to environmental disturbances, with a temperature sensitivity of 2.6 pm/°C, a strain sensitivity of 1.2 pm/με, and a torsion sensitivity of -23.566 nm/(rad/mm). The results demonstrate the considerable properties of the immunosensor, with high resistance to environmental perturbations, indicating significant potential for applications in mobile biosensors and compact devices.

Review of Optical Humidity Sensors

Optical humidity sensors have evolved through decades of research and development, constantly adapting to new demands and challenges. The continuous growth is supported by the emergence of a variety of optical fibers and functional materials, in addition to the adaptation of different sensing mechanisms and optical techniques. This review attempts to cover the majority of optical humidity sensors reported to date, highlight trends in design and performance, and discuss the challenges of different applications.

[The relationship between serum HBV pgRNA and antigen status in patients with chronic hepatitis B after long-term nucleotide analogues treatment]

Objective: To study the relationship between serum HBV pgRNA and antigen status in patients with chronic hepatitis B treated with long-term nucleotide analogues, and to elucidate the reason and possible mechanism of high relapse rate in antiviral therapy of nucleotide analogues in chronic hepatitis B. Methods: 94 patients with chronic hepatitis B who had been treated with long-term antiviral therapy with nucleotide analogues (more than 2 years) were divided into 5 groups according to their HBeAg and HBsAg levels: e antigen positive group(group1), e antigen negative and HBsAg > 1 500 IU/L group(group2), e antigen negative and 100 IU/L< HBsAg < 1 500 IU/L group(group3), e antigen negative and HBsAg < 100 IU/L group(group4), e antigen negative and HBsAg negative group(group5). The level and detection rate of HBVpgRNA in different antigen states groups were analyzed and compared. In addition, in order to exclude the influence of other factors on the results of this study. The study was divided into groups according to age, gender and treatment time. Results: The detection rate of HBVpgRNA was 95.0% in patients with e antigen positive, while 43.2% in patients with e antigen seroconversion, which was significantly lower than that in patients with e antigen positive (P < 0.05). The detection rate of serum HBVpgRNA was 95.0% in e antigen positive group, 75.0% in group 2, 65.0% in e antigen negative with group 3, 15.0% in group 4 and 0% in group 5. Among them, group 1, group 2 and group 3 was significantly higher than that in group 4 and group 5. There was significant difference between the two groups (P < 0.05). However, there was no difference in the positive rate of serum HBV pgRNA among group 1, group 2 and group 3 (P > 0.05). Similarly, there was no difference in the positive rate of serum HBV pgRNA between group 4 and group 5 (P > 0.05). Moreover, the detection rate of serum HBV pgRNA was not correlated with age, gender and treatment time of nucleotide analogues (P > 0.05). Conclusion: There is a significant correlation between the serological antigen status and the presence of HBV pgRNA in chronic hepatitis B after long-term treatment of nucleotide analogues. The persistence of HBV pgRNA is closely related to the low seroconversion rate of e antigen and the high level of HBsAg. HBV pgRNA can be used as one of the biomarkers to judge the transcription activity and replication status of HBV cccDNA in liver.

Survival of itinerant excitations and quantum spin state transitions in YbMgGaO4 with chemical disorder

A recent focus of quantum spin liquid (QSL) studies is how disorder/randomness in a QSL candidate affects its true magnetic ground state. The ultimate question is whether the QSL survives disorder or the disorder leads to a “spin-liquid-like” state, such as the proposed random-singlet (RS) state. Since disorder is a standard feature of most QSL candidates, this question represents a major challenge for QSL candidates. YbMgGaO₄, a triangular lattice antiferromagnet with effective spin-1/2 Yb³⁺ions, is an ideal system to address this question, since it shows no long-range magnetic ordering with Mg/Ga site disorder. Despite the intensive study, it remains unresolved as to whether YbMgGaO₄ is a QSL or in the RS state. Here, through ultralow-temperature thermal conductivity and magnetic torque measurements, plus specific heat and DC magnetization data, we observed a residual κ₀/T term and series of quantum spin state transitions in the zero temperature limit for YbMgGaO₄. These observations strongly suggest that a QSL state with itinerant excitations and quantum spin fluctuations survives disorder in YbMgGaO₄.

It remains an open question as to whether the quantum spin liquid state survives material disorder, or is replaced by some spin-liquid like state. Here, Rao et al succeed in resolving a resolving a κ₀/T residual in the thermal conductivity of YbMgGaO₄ strongly suggesting the survival of the quantum spin liquid state.

Open-care telemedicine in ophthalmology during the COVID-19 pandemic: a pilot study

Objetivo

Reportar una experiencia piloto de atención por telemedicina en la especialidad de oftalmología, en el periodo de confinamiento por la pandemia por COVID-19.

Métodos

Estudio descriptivo. Se describen características demográficas y clínicas de pacientes atendidos en periodo de confinamiento de 10 semanas. Se evalúa la satisfacción de los pacientes y médicos participantes mediante una encuesta en línea.

Resultados

En las primeras 10 semanas, se realizaron 291 atenciones de telemedicina oftalmológica. Los principales motivos de consulta fueron afecciones inflamatorias de la superficie ocular y párpados (79,4%), seguido de requerimientos administrativos (6,5%), afecciones no inflamatorias de la superficie ocular (5,2%), sospecha de estrabismo (3,4%) y síntomas vitreorretinales (3,1%); 22 pacientes (7,5%) fueron derivados a atención presencial inmediata. El nivel de satisfacción con la prestación fue alto, tanto en médicos (100%), como en pacientes (93,4%).

Conclusiones

La atención oftalmológica por telemedicina en periodo de pandemia es un instrumento de utilidad para realizar un filtro de potenciales consultas presenciales, ya sea electivas o de urgencia, y para reducir potencialmente el riesgo de contagio por COVID-19.

KRT15 overexpression predicts poor prognosis in colorectal cancer

Keratin-15 (KRT15) is a type I keratin lacking a defined type II partner and plays a key role in maintaining cytoplasmic stability. Recently, studies have reported that KRT15 was correlated with tumor formation and progression. However, the clinical significance of KRT15 in colorectal cancer is unclear. In this study, we aimed to investigate the expression of KRT15 and its clinical significance in colorectal cancer. KRT15 expression was examined in 98 cases of colorectal cancer and matched adjacent normal tissues by quantificational real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC), respectively. Then, the clinical significance of KRT15 expression was evaluated in colorectal cancer. QRT-PCR results revealed that the mRNA levels of KRT15 in colorectal cancer tissues were significantly higher compared with those in normal tissues (p<0.0001). The rates of KRT15 high-expression in colorectal cancer and normal tissues were 57.1% and 8.9%, respectively, and the difference was statistically significant (p<0.0001). KRT15 high-expression correlated with differentiation, T stage, lymph node metastasis and clinical stage in colorectal cancer (p<0.05). Meanwhile, KRT15 overexpression predicted poor prognosis and could be used as an independent prognostic factor. These data indicate KRT15 is highly expressed in colorectal cancer and may serve as a prognostic biomarker.

Prognostic value of inferior mesenteric artery lymph node metastasis in cancer of the descending colon, sigmoid colon and rectum

AIM

This study aimed to analyse the potential significance of metastasis to the inferior mesenteric artery lymph node (IMA-LN) in patients with malignancy of the left colon and rectum.

METHOD

A retrospective analysis of a cohort of 890 patients collected prospectively who underwent radical resection of a primary tumour of the descending colon, sigmoid colon and rectum in our department from 1 January 2009 to 31 December 2015 was performed. Patients were divided into an IMA-LN metastasis (IMA-LN (+)) group (n = 51) and a non IMA-LN metastasis (IMA-LN (-)) group (n = 839). A total of 801 patients were followed by a designated member of the study staff. Clinical features, pathological characteristics, recurrence patterns and survival rates were compared between the two groups.

RESULTS

In the IMA-LN (+) group, the risk ratio of overall recurrence and tumour related death was 7.786 (95% CI 4.142-14.637) and 7.756 (95% CI 4.142-14.525) respectively. Significant differences were found in overall survival (log-rank: χ²  = 69.06, P < 0.0001) and disease-free survival (log-rank: χ²  = 69.06, P < 0.0001) between the two groups. Furthermore, there were significant differences in overall survival (log-rank: χ²  = 18.47, P < 0.0001) and disease-free survival (log-rank: χ²  = 16.99, P < 0.0001) between the IMA-LN (-) and IMA-LN (+) subgroups of patients with Stage N2 disease. Multivariate survival analysis indicated that IMA-LN (+) was an independent risk factor of poor prognosis. There was no difference in the prognosis between high tie and low tie with IMA-LN dissection.

CONCLUSION

Inferior mesenteric artery lymph node metastasis was an independent predictive factor for high systemic recurrence. Low ligation of the IMA with IMA-LN dissection was not inferior to high ligation.

Status of ECR ion sources for the Facility for Rare Isotope Beams (FRIB) (invited)

Ahead of the commissioning schedule, installation of the first Electron Cyclotron Resonance (ECR) ion source in the front end area of the Facility for Rare Isotope Beam (FRIB) is planned for the end of 2015. Operating at 14 GHz, this first ECR will be used for the commissioning and initial operation of the facility. In parallel, a superconducting magnet structure compatible with operation at 28 GHz for a new ECR ion source is in development at Lawrence Berkeley National Laboratory. The paper reviews the overall work in progress and development done with ECR ion sources for FRIB.

Development of polyclonal antibodies against nucleocapsid protein of watermelon silver mottle virus and their application to diagnostic

Watermelon silver mottle virus (WSMoV) is an emerging disease of cucurbit crops in South China. Production of high-quality antibodies is necessary for the development of serological methods for detection of this virus. The nucleocapsid protein (NP) gene of WSMoV was amplified from WSMoV-infected watermelon leaves by RT-PCR and cloned into vector pET-28a (+) for prokaryotic expression. After identification via enzyme digestion and sequencing, the recombinant clone was transformed into Escherichia coli Rosetta (DE3) for protein expression. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results showed that the molecular weight of the WSMoV NP fusion protein was 34.1 kDa. The fusion protein was purified and used as antigen for the preparation of polyclonal antisera in rabbits. Results of indirect ELISA and western blot analysis showed that the antisera reacted specifically with WSMoV NP. In addition, sensitivity and specificity of the antisera were examined on a number of infected field samples by indirect ELISA. These findings will facilitate further immunological and serological studies of WSMoV. .

Prevalence of high-risk human papillomavirus types (HPV-16, HPV-18) and their physical status in primary laryngeal squamous cell carcinoma

Recently oncogenetic human papilloma virus(HPV) infection has been suggested to promote laryngeal squamous cell carcinoma(LSCC). To determine the prevalence and genotypes of HPV infection in laryngeal cancer specimens, 84 specimens from pathologically confirmed LSCC patients were studied for the presence of viral DNA and possible virus integration into the cellular genome. HPV genotyping was assayed prior to the integration analysis by using two PCR-based assays, including HPV-16 and-18 E7 type-specific and L1 general primers (GP5+/GP6+). Additionally, a quantitative real-time PCR (qRT-PCR) was used to examine the physical status of HPV-16 or-18 in HPV positive LSCC. Using HPV L1 general primer amplification, HPV DNA was detected in 23 (27.4%) of the 84 LSCC samples. When PCR products were cloned and sequenced, HPV16 were found in all 23 L1 positive samples. However, when specific primers for HPV- 16 or -18 were used to amplify E6 and E7 in all samples, 29 cases (34.5%) were positive for HPV-16, while 6 cases (7.1%) were positive for HPV 18. Coinfection of HPV-16 and -18 were found in 4 cases (4.8%). In addition, qRT-PCR assay found that HPV-16 was characterized as episomal in 51.7% of cases, mixed (i.e., episomal and integrated) in 34.5%, and integrated in 13.8%, while HPV-18 was similarly characterized as episomal in 83.3% of cases and mixed in 16.7%. In the present study, about 36.9% of patients with LSCC were found to be infected with HPV-16 and -18 and integration of HPV-16 and -18 DNA into the host genome was found.

Results of surgical treatment of congenital cystic lung disease

OBJECTIVE

To review the experience with surgical intervention for congenital cystic lung disease (CCLD).

METHODS

From April 1988 to December 2001, 68 patients were diagnosed and treated surgically for CCLD. There were 27 males and 41 females ranging in age from 2 to 65 years. The majority of the cases were diagnosed by history, clinical manifestations and chest radiography or computerized tomography (CT). There were 25 (36.8 %) right-sided and 43 (63.2 %) left-sided cystic lung lesions. Four patients had massive bleeding and needed urgent or emergency operation. Pneumonectomy, lobectomy, and/or segmentectomy were performed.

RESULTS

29 (42.6 %) patients underwent lobectomy, 25 (36.8 %) had total pneumonectomy, 9 (13.2 %) lobectomy plus segmentectomy, and 5 (7.4 %) bilobectomy. During the operation, left-sided pulmonary sequestration was confirmed in 3 patients. No death occurred in this series. Diagnoses were confirmed by pathology in all cases. Two patients had malignant lesions arising from multicystic lung lesions.

CONCLUSIONS

A history of recurrent pneumonia, often with hemoptysis and subsequent dyspnea, should raise the suspicion of CCLD. The diagnosis can be confirmed by chest X-ray and CT preoperatively, and early surgical intervention may avoid the development of serious complications. Delayed diagnosis and surgical management usually result in significant morbidity and mortality.

Patterns of lung function in asymptomatic nonsmoking men and women in the People's Republic of China

PURPOSE

To evaluate patterns of lung function in healthy, working Chinese men and women in different geographic areas of the People's Republic of China (PRC).

METHODS

We conducted lung function tests on 2926 asymptomatic, never smoking Chinese men and women aged 35-56 years residing in or around Beijing and Guangzhou. Within each of these locations, separate urban and rural samples were recruited.

RESULTS

Age and height adjusted lung function was greater in Beijing than in Guangzhou, and within each city for residents of rural vs. urban areas. Among women, estimated rates of lung aging were greater in Beijing than in Guangzhou, and in urban vs. rural areas. Both FEV(1) and FVC exhibited a curvilinear association with body mass index.

CONCLUSIONS

Lung function data from this largely working cohort exhibited marked geographic and urban-rural differences in this never smoking, adult Chinese cohort. Such variation is not uncommon and may reflect differences in body size, diet, and environmental and occupational exposures across these different settings. Caution should be used in applying published reference equations to populations from different parts of the PRC.

Real-time monitoring of formaldehyde-induced DNA-lysozyme cross-linking with piezoelectric quartz crystal impedance analysis

A novel method for monitoring, in real time, the formaldehyde (FA)-induced DNA-protein cross-linking process with the piezoelectric quartz crystal impedance (PQCI) technique is proposed. The method was used to monitor FA-induced DNA-lysozyme cross-link formation. Lysozyme was directly immobilized on the silver electrode surface of a piezoelectric quartz crystal by adsorption. The lysozyme-coated piezoelectric sensor was in contact with FA and DNA solutions. The time courses of the resonant frequency and equivalent circuit parameters of the sensor during the cross-linking were simultaneously obtained and are discussed in detail. On the basis of the feature of the multi-dimensional information provided by the PQCI technique, it was concluded that the observed frequency decrease could be mainly ascribed to the mass increase resulting from the cross-linking. According to the frequency decrease with time, the kinetics of the cross-linking process were quantitatively studied. A piezoelectric response model for the cross-linking was theoretically derived. Fitting the experimental data to the model, the kinetic parameters, such as the binding and dissociation rate constants (k(1) and k(-1)) and the cross-linking equilibrium constant (Ka), were determined. At 37 degrees C, the k(1), k(-1) and Ka values obtained were 7.0 (+/-0.1) x 10(-5) (microg ml(-1))(-1) s(-1), 6.6 (+/-0.1) x 10(-3) s(-1) and 1.06 (+/-0.02) x 10(-2) (microg ml(-1))(-1), respectively.

GC/ITMS measurement of carbonyls and multifunctional carbonyls in PM2.5 particles emitted from motor vehicles

A method was developed and tested to identify and quantitate carbonyls and multifunctional carbonyls in fine particulate matter (PM2.5; <2.5 microm aerodynamic diameter). The method relies on ultrasonic extraction of particulate matter on filters at -8 degrees C; derivatization with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA), and PFBHA along with bis (trimethylsilyl) trifluoroacetamide (BSTFA); and detection of the derivatives by gas chromatography/ion trap mass spectrometry. Ultrasonic extraction of model compounds from enriched particles was affected by solvent polarity (water > methylene chloride > toluene-isopropanol (2 + 1, v/v). Water provided the highest recovery for dihydroxy acetone, pyruvic acid, and hydroxy acetone, compared to methylene chloride, and toluene-isopropanol. Lowering the ultrasonication bath temperature from 0 degrees to -8 degrees C improved the recoveries of the less water soluble and more volatile species-methacrolein, methyl vinyl ketone, 2,3-butanedione, and tolualdehyde. The power of the method was demonstrated by identification and quantitation of carbonyls and multifunctional carbonyls in sample extracts of fine particulate matter (PM2.5) collected in the Caldecott tunnel, CA. The identities of crotonaldehyde, 2,3-butanedione, glyoxal, 9H-fluoren-9-one, glycolaldehyde, glyoxylic acid, levulinic acid, and 3-hydroxybenzaldehyde were confirmed by comparing the relative retention time and mass spectra of the analyte in the sample extract with an authentic standard. Quantitation of crotonaldehyde, glyoxal, 2,3-butanedione, glyoxylic acid, and levulinic acid was accomplished. This is the first report of glyoxylic acid, levulinic acid, and 3-hydroxybenzaldheyde in PM2.5 particles sampled in a roadway tunnel. It is also the first report of a C10 carbonyl with the molecular formula of C10H16O2, a hydroxy carbonyl with the molecular formula of C17H21NO2, and a hydroxy or dihydroxy carbonyl with the molecular formula of C16H14O2 or C9H10O3. The high-molecular weight hydroxy carbonyls, which were found only in the heavy-duty (diesel) bore, may be tracers of diesel emissions in air.

[Dietary intake of antioxidant vitamins and personal demographic characteristics of Guangdong residents]

The study aim at revealing the associations between the intake of dietary antioxidant vitamins and personal characteristics on age, sex, education, working status and household gross income etc. The intake of antioxidant vitamins in a population of Guangdong Province was studied. A total of 418 males and 503 females, aged 25-84 year were interviewed, and questionnaires on socio-demography and on a 12-month food intake frequency (FFQ) were completed in 1995. The daily average intake of antioxidant vitamins and energy was higher in male than in female. Older subjects consumed lesser antioxidant vitamins. The vitamin E intake of higher education persons as well as high family income females (> 15001RMB) was higher. Individual business owners and farmers consumed lesser antioxidant vitamins than the other counterparts. The highest vitamin E intake was found in the currently unemployed men and retired women. BMI was positively associated with the intake of antioxidant vitamins excepted for the obesity group. The result suggests that the consumption of antioxidant vitamins varies with characteristics of socio-demographic status. Health promotion programs, such as suggestions on eating more fruits and vegetables should be targeted at the elderly, the less educated, lower income families and rural community.

Comparison of electrocardiographic findings between Northern and Southern Chinese population samples

BACKGROUND

Cardiovascular disease is rare in China, but there are few data on the prevalence of electrocardiographic (ECG) abnormalities in Chinese populations.

METHODS

The ECG surveys were carried out in four Chinese population samples, in a total of 9,666 adults aged 35-54 in Beijing and Guangzhou, China from 1981 to 1984. Twelve-lead resting ECG tracings were coded by the Minnesota Code.

RESULTS

Prevalence per 1,000 of abnormal ECG ranged from 77.4 to 209.8, and was higher for men than women and higher for Guangzhou than Beijing. Prevalence per 1,000 of major abnormalities in Guangzhou was 29.8 for men and 78.4 for women, higher than the 18.4 and 29.6 for counterparts in Beijing. The ECG changes attributed in 'Western' populations to coronary heart disease (CHD), such as large Q waves (Minnesota Code 1-1, 1-2) and ST-T abnormalities, were similar between Beijing and Guangzhou men, but Guangzhou women had much higher prevalence of ST-T abnormalities than Beijing women. Other ECG abnormalities such as A-V block, left branch bundle block, and left ventricular hypertrophy were rare in people of both sites.

CONCLUSIONS

Compared with similar data from the US, these Chinese populations had a relatively low prevalence of ECG abnormalities putatively related to CHD. This corresponds with the low incidence of CHD in the Chinese population. However, within the Chinese populations of this study, a high abnormality rate appeared in a population with low incidence of CHD and hypertension (Guangzhou women). Reasons why ECG abnormalities do not parallel prevalence levels of CHD and hypertension remain to be elucidated.

Inhibition of Stat1-mediated gene activation by PIAS1

STAT (signal transducer and activator of transcription) proteins are latent cytoplasmic transcription factors that become activated by tyrosine phosphorylation in response to cytokine stimulation. Tyrosine phosphorylated STATs dimerize and translocate into the nucleus to activate specific genes. Different members of the STAT protein family have distinct functions in cytokine signaling. Biochemical and genetic analysis has demonstrated that Stat1 is essential for gene activation in response to interferon stimulation. Although progress has been made toward understanding STAT activation, little is known about how STAT signals are down-regulated. We report here the isolation of a family of PIAS (protein inhibitor of activated STAT) proteins. PIAS1, but not other PIAS proteins, blocked the DNA binding activity of Stat1 and inhibited Stat1-mediated gene activation in response to interferon. Coimmunoprecipitation analysis showed that PIAS1 was associated with Stat1 but not Stat2 or Stat3 after ligand stimulation. The in vivo PIAS1-Stat1 interaction requires phosphorylation of Stat1 on Tyr-701. These results identify PIAS1 as a specific inhibitor of Stat1-mediated gene activation and suggest that there may exist a specific PIAS inhibitor in every STAT signaling pathway.

[Yishen huanshuai recipe retard progression of chronic renal failure]

OBJECTIVE

To investigate the effect of Yishen Huanshuai recipe (YSHSR) on the progression of chronic renal failure (CRF).

METHODS

Forty-six patients with CRF were divided into two groups: group A (self-controlled group, n = 18), whose treatment was subdivided into two stages. During the first stage, the patients treated with low protein diet and controlling blood pressure, while in the second stage, YSHSR was given. Group B(n = 28), whose treatment plan was similar with that of group A in second stage. The rate of progression of CRF was estimated by slope of the creatinine reciporcal (dl/mg) with time (month).

RESULTS

Mean slope of the creatinine reciprocal with time from the group A during the first stage was -0.0104 +/- 0.0021, while during the second stage, it was -0.0034 +/- 0.0018. There was significant difference between them (P < 0.05). Mean slope from the group B was -0.0047 +/- 0.0020. There was also significant difference between that from the group B and that from the group A during the first stage (P < 0.05).

CONCLUSIONS

Low protein and controlling blood pressure plus YSHSR therapy could markedly retard the rate of progression of CRF.

Body composition as a predictor of blood pressure in three communities in Guangdong province, China

The aim of this study was to compare mean blood pressure (BP), anthropometric and body compositional measurements in three Chinese communities and to examine relationships between BP and body composition in these communities. A total of 935 adult (aged >= 25 years) men and women were randomly sampled from three communities (Chauzhou County speaking Teochew, Meixian County speaking Hakka, and Xinhui speaking Cantonese) in Guangdong Province, China. Self-administered questionnaires about food habits, lifestyle and health status were completed. Body weight, stature, waist and hip circumferences and systolic and diastolic blood pressures were measured. Body mass index, waist to hip ratio, fat free mass, total body fat mass and the percentage body fat were calculated to assess body composition. No significant differences were found in stature, body mass index, umbilical circumference, hip circumference, fat free mass, percentage body fat and defined hypertension between the three communities. However, the waist to hip ratio was lower in Chauzhou men than Meixian women. The mean BPs were different between the communities and mean blood pressure was the highest in the Chauzhou community. Intra-community non-parametric relations between BP and body composition were found mostly in men with increased total and abdominal fatness positively related to BP. The relationships of the aggregate communities with blood pressure were found consistent with those for intra-community analyses, although the body fatness-blood pressure relationship was then evident without exception. Anthropometrically assessed body composition predicts BP in Chinese men, but to a lesser extent, in Chinese women in Guangdong Province, China.

Specific inhibition of Stat3 signal transduction by PIAS3

The signal transducer and activator of transcription-3 (Stat3) protein is activated by the interleukin 6 (IL-6) family of cytokines, epidermal growth factor, and leptin. A protein named PIAS3 (protein inhibitor of activated STAT) that binds to Stat3 was isolated and characterized. The association of PIAS3 with Stat3 in vivo was only observed in cells stimulated with ligands that cause the activation of Stat3. PIAS3 blocked the DNA-binding activity of Stat3 and inhibited Stat3-mediated gene activation. Although Stat1 is also phosphorylated in response to IL-6, PIAS3 did not interact with Stat1 or affect its DNA-binding or transcriptional activity. The results indicate that PIAS3 is a specific inhibitor of Stat3.

Prediction of protein supersecondary structures based on the artificial neural network method

The sequence patterns of 11 types of frequently occurring connecting peptides, which lead to a classification of supersecondary motifs, were studied. A database of protein supersecondary motifs was set up. An artificial neural network method, i.e. the back propagation neural network, was applied to the predictions of the supersecondary motifs from protein sequences. The prediction correctness ratios are higher than 70%, and many of them vary from 75 to 82%. These results are useful for the further study of the relationship between the structure and function of proteins. It may also provide some important information about protein design and the prediction of protein tertiary structure.

Changes in average blood pressure and incidence of high blood pressure 1983-1984 to 1987-1988 in four population cohorts in the People's Republic of China. The PRC-USA Cardiovascular and Cardiopulmonary Epidemiology Research Group

OBJECTIVE

To assess comparative changes in systolic and diastolic blood pressure and incidence of high blood pressure over 4 years, and factors related to these changes, in northern and southern, urban and rural adults in the People's Republic of China.

SETTING

This is a prospective study of populations surveyed by standardized methods in 1983-1984 and 1987-1988 in north China, Beijing area steel mill workers and farmers, and south China, Guangzhou area shipyard workers and farmers.

SUBJECTS

The subjects were 8805 men and women aged 35-54 years at baseline (1983-1984), of whom 7338 were non-hypertensive (systolic blood pressure < 140, diastolic blood pressure < 90 mmHg, not being administered antihypertensive drugs).

MAIN OUTCOME MEASURES

The main outcome measures were 4-year changes in systolic and diastolic blood pressures and the 4-year incidence of high blood pressure in persons not hypertensive at baseline.

RESULTS

At baseline, the average systolic and diastolic blood pressures were higher for Beijing than for Guangzhou cohorts. At resurvey the average systolic blood pressure had increased for seven of eight sex-city-setting cohorts (all but Guangzhou urban men). The Beijing urban cohorts had the greatest increases (men 6.2 mmHg, women 4.9 mmHg, slopes of 1.6 and 1.2 mmHg/year). The incidence of high blood pressure was higher for Beijing than for Guangzhou cohorts in all four comparisons (men and women, urban and rural). Beijing men, urban and rural, had the highest incidence rates (about 21%). In multiple logistic analyses by sex, variables significantly related to 4-year high blood pressure incidence were city, baseline systolic blood pressure and body mass index, change in weight, and, for men, baseline alcohol use and heart rate.

CONCLUSION

Modifiable lifestyle traits, previously shown to be related to blood pressure and high blood pressure in cross-sectional studies, also relate to the incidence of hypertension.

Constitutive activation of STAT5 by the BCR-ABL oncogene in chronic myelogenous leukemia

Using chronic myelogenous leukemia (CML) as a model, we tested the hypothesis that cytokine-independent growth of leukemia cells results from aberrant activation of cytokine signaling pathways. The STAT5 (signal transducer and activator of transcription) protein, which is activated transiently in normal myeloid cells by cytokines such as GM-CSF (granulocyte-macrophage colony stimulating factor), was constitutively activated in cell lines derived from CML patients, even in the absence of GM-CSF. STAT5 was also activated in primary mouse bone marrow cells acutely transformed by the CML-specific BCR-ABL oncogene, but not by the serine kinase oncogene v-MOS. Reconstitution experiments in non-hematopoietic cells show that STAT5 activation by BCR-ABL occurs independent of cytokines. Results using BCR-ABL mutants which specifically uncouple connections to known signal transduction pathways show that STAT5 activation is kinase dependent and correlates directly with ability to confer cytokine independent growth in hematopoietic cells. BCR-ABL also activates JAK kinases, which may provide a mechanism for STAT activation. These findings are consistent with a role for STAT5 in hematopoietic transformation by BCR-ABL.

[Effects of smoking on lung function in populations of Beijing and Guangzhou]

OBJECTIVE

To analyse the relationship between cigarette smoking and lung function in populations of Beijing and Guangzhou.

METHODS

Complete lung function and smoking habit data were recruited from 7983 men and women aged 35-59 in or around Beijing and Guangzhou. Comparisons were made between smokers and never smokers.

RESULTS

The mean values of FEV1/H2, FEF/H2 and FEV1/FVC are all lower in smokers than in never smokers for male smokers, the observed mean value of FEV1/H2 for each age group in smaller than the respective predicted value, and its descending trend with aging is more obvious than the predicted value when re-examination after 2-4 years; furthermore, smokers had higher prevalences of respiratory symptom and COPD.

CONCLUSION

Cigarette smoking is harmful to lung function.

Cigarette smoking and socio-economic indicators as determinants of body fatness in three Southern Chinese communities of China

Obesity is one of the major risk factors for cardiovascular disease and non-insulin dependent diabetes mellitus. This study describes cigarette smoking and the socio-demographic differences of body fatness in three sub-ethnic distinctive communities in Guangdong Province, China. In this study, 935 adult Chinese (Chauzhou - 203 men and 111 women; Meixian - 169 men and 140 women; Xinhui - 194 men and 118 women) were randomly sampled from three communities. A standard protocol was used to measure stature, body weight, waist and hip circumferences. Body mass index (BMI) and waist-to-hip circumference ratio (WHR) were calculated as measures of total body fatness and abdominal body fatness, respectively. The questionnaire was self-administered and demographic and lifestyle factors were assessed. WHR was positively related to age in men (p=0.0001) and in women (p=0.0001) while BMI was associated with age only in women (p=0.0001). In women, WHR was significantly related to education levels after adjusting for age and BMI (p=0.0300). In men, BMI differed by educational level, after adjusting for age and WHR (p=0.0329). BMI was significantly associated with occupational status in men, after adjusting for age and WHR (p=0.0004). Gross household income was significantly associated with WHR in men, after adjusting for age and BMI (p=0.0469). Male smokers had a significantly lower mean BMI than the non-smokers, after adjusting for age and WHR (p=0.0037). Marital status was not related to body fatness measurements after adjusting for age and WHR. The differences in body fatness in Chinese living in Southern China can not be totally explained by educational level, occupational status, marital status, gross household income and cigarette smoking, particularly in women. Age was the only consistent predictor of abdominal body fatness in both men and women and also of total body fatness in women.

Cardiovascular risk factor prevalence in three Chinese communities in 1989

The cardiovascular risk prevalence of 935 adult Chinese living in Chauzhou, Meizhou, and Xinhui cities of Guangdong Province, China, is reported. The three communities are geographically separated, and represent the three major dialect group in Guangdong Province (Teochew, Hakka and Cantonese respectively) which are also the major donor populations of overseas Chinese to Australia and South East Asia. Taking into account historical data, the conventional cardiovascular risk factor prevalence of these combined communities in China as a whole is on the increase and approaches or even exceeds that in Western Society. However, the three communities are not very alike in their prevalences of individual conventional cardiovascular risk factors, notably for hyperlipidaemia (most prevalent in Chauzhou), hypertension (most prevalent in Chauzhou men at 12.4% and least in Meizhou women 5.0%) and cigarette smoking (most prevalent in Xinhui men at 72.7% and least in Xinhui women, 0%). They are similar in stature, body weight, BMI, and waist-to-hip ratio, with very low prevalences of overweight/obesity, or abdominal obesity. An understanding of the contributors to sub-ethnic difference in cardiovascular risk should emerge with further study of these Chinese populations.

The relationship between dietary factors and serum lipids in Chinese urban and rural populations of Beijing and Guangzhou. PRC-USA Cardiovascular and Cardiopulmonary Research Group

BACKGROUND

Serum cholesterol (TC) levels and coronary heart disease (CHD) are lower in China than in western countries. This report examines the role of diet in determining TC.

METHODS

Data were collected as part of a cross-sectional study of 10,000 men and women, 35-54 years old, conducted in 1983-1984 in four areas in China. A 10% subsample was surveyed for eating patterns and measurement of blood lipids. Six one-day dietary recalls were collected on each participant.

RESULTS

Mean daily intake of energy from fat was less than 30%. Mean Keys scores ranged from 20.4 to 32.6. In multivariable regression analysis controlling for age, body mass index (BMI), and alcohol, Keys score was statistically associated with serum TC. A 10-unit greater Keys score was associated with 6.3 mg/dl higher TC and 4.0 mg/dl higher low density lipoprotein cholesterol.

CONCLUSIONS

We conclude that in China the relation of dietary factors to serum lipids is similar to that in populations having high serum TC levels.

A north-south comparison of blood pressure and factors related to blood pressure in the People's Republic of China: a report from the PRC-USA Collaborative Study of Cardiovascular Epidemiology

OBJECTIVES

To compare blood pressures in northern (Beijing) and southern (Guangzhou) Chinese population samples aged 35-54 years, males and females, urban and rural, and to assess the role of blood pressure-related traits in explaining north-south differences.

DESIGN

Cross-sectional surveys were conducted in 1983-1984 of northern and southern populations employed in industry (urban) or farming (rural).

METHODS

In the north samples were selected from the Capital Iron and Steel Complex (urban) and Shijingshan district (rural); in the south samples from the Guangzhou Shipyard (urban) and Panyu County (rural) were used.

RESULTS

The number of subjects surveyed in north and south were 4706 and 4179, respectively: 1500 and 1052 urban males, and 717 and 914 rural males; and 1300 and 1061 urban females, and 1189 and 1152 rural females, respectively. Average systolic (SBP) and diastolic (DBP) blood pressures, were consistently higher in the north than in the south. SBP and DBP were significantly and independently related to age, body mass index, heart rate, use of antihypertensive drugs, serum triglycerides level, alcohol use (males only) and inversely to cigarette smoking. Northerners were older, taller, heavier and had higher body mass index and triglycerides level than southerners. With adjustment of SBP and DBP for blood pressure-related traits, north-south blood pressure differences decreased, but remained significant for urban males, rural males and rural females, with sizeable differences for rural samples in particular.

CONCLUSIONS

North-south differences in blood pressure in these samples are accounted for only partly by north-south differences in the cited blood pressure-related traits. The role of other traits requires assessment.

The relationship between dietary factors and serum lipids in southern Chinese population samples

As part of the PRC-USA collaborative research project on the epidemiology of cardiovascular disease, baseline surveys were conducted in four random urban and rural samples in Guangzhou, Guangdong Province in southern China on 334 men and women aged 35-54 in the fall of 1983-84 with the aim of studying the correlation between dietary intakes and serum lipids. Methods standardized by the US Centers for Disease Control were used for measuring different parameters, and quality control was emphasized to assure comparability between workers and farmers. Three 24-hour recalls were collected from each participant in each survey. Mean values of daily intakes of nutrients per capita for the four groups were as follows: 59-69% kcal carbohydrate; 10-12% kcal protein; 22-26% kcal fat. Dietary total fat, saturated fatty acid (SFA), polyunsaturated fatty acid (PUFA) and cholesterol were higher in the urban than the rural areas. Mean levels of serum total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were 4.6 mmol/l, 1.1 mmol/l, 1.3 mmol/l and 2.8 mmol/l respectively. The TC, TG and LDL-C and HDL-C were significantly higher in the urban than the rural areas. Analyses of correlation showed that the Keys 'dietary lipid score' was positively associated with TC, LDL-C and HDL-C; specifically, dietary cholesterol was positively associated with serum TC. Saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) were positively correlated with HDL-C. It seems that the traditional dietary pattern of Guangzhou favours serum lipids being at an optimal level.

Body mass, fat distribution and cardiovascular risk factors in a lean population of south China

The associations of body mass index and abdominal adiposity, represented by an elevated waist/hip circumference ratio, with cardiovascular risk factors were examined in men and women, aged 28-69 years, from urban and rural areas of Guangzhou, China. Mean body mass index ranged from 20.1 to 21.9 kg/m2 across the four sex- and area-groups. Mean waist/hip ratio was 0.84 in men and 0.80 in women. After accounting for age and body mass index, waist/hip ratio was associated negatively (p < 0.05) with fasting serum HDL cholesterol (both sexes), and positively with serum triglycerides (both sexes), total and LDL cholesterol (men only), uric acid (both sexes), glucose (women only), and mean systolic blood pressure (women only). Body mass index was associated in a similar direction with most of these risk factors. These data confirm that abdominal adiposity is independently associated with cardiovascular disease risk factors, even in a lean Asian population.

A novel combinational pH-PCO2 microelectrode

A novel combinational pH-PCO2 microelectrode based on a neutral carrier hydrogen ion exchanger is described. It is easy to fabricate and allows pH and PCO2 to be measured simultaneously. The microelectrode has a 5-microns tip. The PCO2 microelectrode exhibits a linear response in the range 1.75 x 10(-5)-10(-2) mol/liter with a Nernstian slope of 57.0 mV/decade at 25 degrees C. The detection limit is 10(-5) mol/liter. The pH microelectrode exhibits a linear response in the range pH 4-12 with a Nernstian slope of 60.0 mV/decade at 25 degrees C. The 95% steady-state response time of the PCO2 microelectrode is about 2 min, while it is about 10 s for pH microelectrode. The electromotive force drift is 4.3 mV/h (PCO2) and 2.6 mV/h (pH), respectively. The lifetime is 3 to 4 days. The microelectrode can measure pH and PCO2 in body fluids simultaneously with satisfactory results. It is also a good basic electrode for enzyme microelectrolysis.