Effect of Transition Metal Layer on Bending and Interfacial Properties of W/TiN/Ta-Laminated Composite

The widespread applications of W in the fusion reactor are limited by its low-temperature brittleness, recrystallization brittleness, and irradiation-induced brittleness. Many toughening methods were used to improve the brittleness of W, such as adding second-phase particles, adding W fibers, preparing laminated composite, and so on. Among these, preparing laminated W-based composites has been proven to effectively improve both the low-temperature and high-temperature toughness of W. In this study, W/M/TiN/Ta-laminated composites with transition metal layer (M) were synthesized through the spark plasma sintering (SPS) at three different temperatures. The effects of nano-scale (Ni, Ti, and Cr) and micron-scale (Ni, Ti, and V) transition layers on the bending and interfacial properties of the W/M/TiN/Ta composite were studied via an electron probe micro-analyzer (EPMA) and transmission electron microscope (TEM). Compared with W/TiN/Ta, the flexural strength and strain of W/Ni_nm/TiN/Ta were increased by 25.6% and 17.6%, respectively. Ni, Ti, and V micron transition layers can improve the combination of the W-TiN interface and decrease the joining temperature. The micron V layer has the best strengthening effect. The flexural strength of W/V/TiN/Ta reached 1294 MPa, much higher than W/Ta's 1041 MPa.

In vitro biomineralization on poly(vinyl alcohol)/biphasic calcium phosphate hydrogels

Biomineralized tissue is considered the final product of successful cell culture in bone tissue engineering. Dulbecco’s modified Eagle’s medium (DMEM) with fetal bovine serum (FBS) not only is used as a common culture medium but also provides a natural biomineralization environment, due to having similar ionic concentrations as blood plasma. Here, poly(vinyl alcohol) hydrogel with incorporated biphasic calcium phosphate nanoparticles was immersed in a DMEM–FBS cell culture medium, and then biomineralization occurred on the nanocomposite surface, which was characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. Such formed bone-like apatite on the surface facilitated the proliferation of osteoblasts, identified by Cell Counting Kit-8 analysis and fluorescent microscopy. This study verified the spontaneous biomineralization on the surface of a calcium phosphate-based nanocomposite by using a simple DMEM–FBS immersion strategy, which was promising for biomodification of bone substitutes.

Development of chitosan/gelatin hydrogels incorporation of biphasic calcium phosphate nanoparticles for bone tissue engineering

The chitosan/gelatin hydrogel incorporated with biphasic calcium phosphate nanoparticles (BCP-NPs) as scaffold (CGB) for bone tissue engineering was reported in this article. Such nanocomposite hydrogels were fabricated by using cycled freeze-thawing method, of which physicochemical and biological properties were regulated by adjusting the weight ratio of chitosan/gelatin/BCP-NPs. The needle-like BCP-NPs were dispersed into composites uniformly, and physically cross-linked with chitosan and gelatin, which were identified via Scanning Electron Microscope (SEM) images and Fourier Transform Infrared Spectroscopy (FT-IR) analysis. The porosity, equilibrium swelling ratio, and compressive strength of CGB scaffolds were mainly influenced by the BCP-NPs concentration. In vitro degradation analysis in simulated body fluids (SBF) displayed that CGB scaffolds were degraded up to at least 30 wt% in one month. Also, CCK-8 analysis confirmed that the prepared scaffolds had a good cytocompatibility through in culturing with bone marrow mesenchymal stem cells (BMSCs). Finally, In vivo animal experiments revealed that new bone tissue was observed inside the scaffolds, and gradually increased with increasing months, when implanted CGB scaffolds into large necrotic lesions of rabbit femoral head. The above results suggested that prepared CGB nanocomposites had the potential to be applied in bone tissue engineering.

The clinicopathological and prognostic value of programmed death-ligand 1 in colorectal cancer: a meta-analysis

INTRODUCTION

Programmed death-ligand 1 (PD-L1) is reportedly expressed in colorectal tumors. However, the prognostic role of PD-L1 in colorectal cancer (CRC) remains controversial. Therefore, we performed a meta-analysis to investigate the clinicopathological and prognostic impact of PD-L1 in CRC.

METHODS

A comprehensive search in PubMed, Embase, the Cochrane Library, Web of Science and the ClinicalTrials.gov for publications about PD-L1 expression in colorectal cancer was done. The correlation between PD-L1 expression and clinicopathological features or survival outcomes was analyzed by odds ratios (OR) or hazard ratios (HR), at 95% confidence intervals (CI).

RESULTS

The results show that the pooled HR of (1.34, 95% CI 1.02-1.65, p = 0.01) indicated the association of PD-L1 expression with overall survival (OS) in CRC patients. Meanwhile, the expression of PD-L1 was positively correlated with the lymph node metastasis (OR: 0.70, 95% CI 0.51-0.95, p = 0.00), gender (OR: 0.86, 95% CI 0.76-0.98, p = 0.05) and tumor location (OR: 1.39, 95% CI 1.14-1.71, p = 0.12).

CONCLUSIONS

These results suggest that high expression of PD-L1 is associated with low OS in CRC. High PD-L1 expression may act as a negative factor for patients with CRC and help to identify patients suitable for anticancer therapy.

Nano-LC-MS/MS for the quantitation of prostanoids in immune cells

Prostanoids, derivatives of arachidonic acid, are involved in inflammation and immune reactions. To understand the role of prostanoids produced by diverse immune cells, a highly sensitive quantitation method for prostaglandin E2 (PGE2), prostaglandin D2 (PGD2), 6-keto prostaglandin F1α (6-keto PGF1α), prostaglandin F2α (PGF2α), and thromboxane B2 (TXB2) by means of nano-liquid chromatography-tandem mass spectrometry has been developed. It was validated according to the guidelines of the Food and Drug Administration (FDA) in terms of linearity, precision, accuracy, recovery, stability, and lower limit of quantitation (LLOQ). The LLOQ were 25 pg/mL in the injected solution (75 fg on column (o.c.)) for PGE2 and PGD2 and 37.5 pg/mL (112.5 fg on column) for 6-keto PGF1α, PGF2α, and TXB2, respectively. It was successfully applied to murine mast cells isolated from paws after zymosan injection and to CD4(+) and CD8(+) T lymphocytes from blood of sensitized versus non-sensitized mice in context of a delayed type hypersensitivity model. About 5,000 (T cells) to 40,000 (mast cells) cells were sufficient for quantitation. In the mast cells, the production of PGE2 increased at a significantly higher extent than the synthesis of the other prostanoids. The T lymphocytes did not show any difference in prostanoid production, no matter whether they were obtained from sensitized mice or non-sensitized mice.

Preparation, characterization and in vitro release study of gallic acid loaded silica nanoparticles for controlled release

Gallic acid (GA) is an interesting pharmaceutical component of plants. However, the short lifetime and the autoxidation of GA in aqueous solution significantly reduces its bioavailability and the residence time in the body system. In this study, GA was chemically bound to silica nanoparticles to control the release of GA based on the hydrolysis of the chemical bonds, and a silica nanoparticle drug delivery system was established. Gallic acid loaded silica nanoparticles (GA-SiO2) were synthesized by a modified Stober method. The Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) analysis proved that GA did conjugate to silica nanoparticles. The particle size of the GA-SiO2 nanoparticles observed by Scanning Electron Microscope (SEM) was about 30 nm and the drug loading efficiency determined by Thermo Gravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC) was 89.39%. The in vitro release study demonstrated that GA could be gradually released from the GA-SiO2. In addition, the antioxidant capability increased continuously during the immersion time, so the GA could serve as an excellent antioxidant to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a long release period. Therefore, this study provided a novel drug delivery system for GA with controlled release capability and prolonged antioxidant activity.

Detection of KRAS mutations and their associations with clinicopathological features and survival in Chinese colorectal cancer patients

OBJECTIVE

Mutation of the KRAS (v-Kiras2 Kirsten rat sarcoma viral oncogene homologue) gene plays an important role in colorectal tumorigenesis. This study examined associations between KRAS gene mutations and clinicopathological and survival data in Chinese patients with colorectal cancer (CRC).

METHODS

CRC patients were recruited for the detection of KRAS gene mutations using polymerase chain reaction and DNA sequencing. Data on clinicopathological features and survival times were collected.

RESULTS

The study included 78 CRC patients. The overall mutation frequency of the KRAS gene at codons 12 and 13 was 33.3% (26/78). KRAS gene mutations were significantly associated with poor tumour differentiation and liver metastasis. Patients with the wild-type KRAS gene had significantly higher median survival times than patients with KRAS gene mutations (35.05 months versus 25.72 months). Those with KRAS gene mutations at codons 12 or 13 did not have significantly different median survival times (25.69 months versus 20.67 months, respectively).

CONCLUSIONS

These findings suggest that a high frequency of KRAS gene mutations exists in Chinese patients with CRC, and that such mutations are associated with poor survival, tumour differentiation and liver metastasis in CRC patients.

Effectiveness of fast-track rehabilitation vs conventional care in laparoscopic colorectal resection for elderly patients: a randomized trial

AIM

The aim of the study was to evaluate the efficacy and safety of fast-track rehabilitation in elderly patients over 65 years of age, following laparoscopic surgery to remove colorectal cancer.

METHOD

A total of 78 elderly patients with colorectal cancer who underwent laparoscopic colorectal resection were randomly assigned to receive either the fast-track care programme (n = 40) or the conventional perioperative care protocol (control group, n = 38). Medical personnel conducting the study were blinded to patients' clinical outcomes prior to statistical analysis. The fast-track protocol included no preoperative mechanical bowel irrigation, immediate oral alimentation and earlier postoperative ambulation exercise. The length of postoperative hospital stay, the length of time to regain bowel function and the rate of postoperative complications were compared between the two groups.

RESULTS

The length of time to regain bowel function, including the passage of flatus[31 (26-40) h vs 38 (32-51) h, P = 0.001], to the first bowel movement [55 (48-63) h vs 64 (48-71) h, P = 0.009] and to start a liquid diet (12 [11-16] h vs 47 [35-50] h, P = 0.000) were significantly shorter in patients receiving the fast-track care protocol compared with those receiving the conventional care protocol. A shorter duration of postoperative hospital stay was recorded in patients receiving the fast-track program than in those receiving conventional care (P = 0.0001). A reduced percentage of patients who developed general complications was also observed in the fast-track group (5.0%vs 21.1%, P = 0.045).

CONCLUSION

This randomized controlled trial has shown that in the elderly undergoing laparoscopic colorectal surgery, the fast-track recovery programme resulted in a more rapid postoperative recovery, earlier discharge from hospital and fewer general complications compared with a conventional postoperative protocol.

P2-02-08: Int6 Regulates Both Proteasomal Degradation and Translation Initiation and Is Critical for Proper Formation of Acini by Human Mammary Epithelium

The mammalian INT6/EIF3E gene has been implicated in breast tumor formation, but its functional activities remain poorly defined. Consistent with the fact that Int6 is frequently down-regulated in human breast tumors, we found that repressing INT6 expression induced transformed properties in normal human mammary epithelial cells (MCF10A) in both 2D and 3D cultures. Int6 contains a PCI domain, found in several components of both the proteasome and the translation initiation factor eIF3, suggesting that it can functionally interact with both. Indeed, our data show that Int6 associates with proteasomes in human cells, and that INT6 knockdown prevents proper assembly of active proteasomes. In addition, we show that down-regulation of INT6 reduces translation initiation (both polysome formation and global protein synthesis). However, Int6 regulates translation selectively, reducing translation from cap-dependent and Bcl2- IRES reporters, but stimulating translation from the CVB3 IRES. These data collectively suggest that Int6 controls both protein synthesis and protein degradation, and is thus capable of fine-tuning protein levels. Abnormal levels of regulatory proteins caused by Int6 abnormalities may thus be responsible for disrupting normal morphogenesis of mammary epithelial cells and causing transformed phenotypes.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-02-08.

Structure, corrosion behavior and mechanical property of a novel poly(vinyl alcohol) composite in simulated body fluid

The data for long-term drug-delivery systems are scarce compared to the short-term systems because the required research efforts are more time-consuming. In this study, we report a novel cross-linked composite based on poly(vinyl alcohol) (PVA) containing cupric ions for long-term delivery, which is helpful for contraception and trace element balance in the human body. The composition, corrosion products, crystal structure, chemical structure and mechanical stability of the composite, after being immersed in simulated body fluid (SBF) for one year, were studied by X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR) and mechanical testing. The results show that no other new elements, such as P, Cl and Ca, appear on the surface of the composite and no Cu(2)O was formed after immersion in SBF for one year. The effectiveness of copper can be greatly improved and the side-effects caused by these compounds might also be eliminated. Furthermore, this novel composite exhibits long-term mechanical stability in SBF. The present in vitro long-term data suggest that this novel copper-containing composite may serve as a substitute for conventional materials of copper-containing intrauterine devices (Cu-IUDs) and as a carrier for controlled-release material in a variety of other applications.

Inconsistent dosing of anti-tuberculosis drugs in Taipei, Taiwan

SETTING

Taipei City, Taiwan.

OBJECTIVES

To evaluate prescribing practices for anti-tuberculosis drugs in the treatment of tuberculosis (TB).

METHOD

Medical audit of the medical charts of all patients notified and treated for TB in Taiwan in 2003 to determine the treatment regimens prescribed and to compare these with recommended dosages.

RESULTS

A total of 24 different anti-tuberculosis regimens were prescribed. Of 1700 patients notified, 1096 (64.5%) had their body weight recorded. Of 506 patients prescribed a three-drug fixed-dose combination (FDC), the dosage was adequate in 374 (73.9%), too low in 100 (19.8%) and too high in 32 (6.3%). Of 75 patients prescribed a two-drug FDC, the dosage was adequate in 57 (76.0%), too low in 15 (20.0%) and too high in 3 (4.0%). Of 481 patients prescribed rifampicin, the dosage was adequate in 302 (62.8%), too low in 152 (31.6%) and too high in 27 (5.6%). Of 451 patients prescribed isoniazid, the dosage was adequate in 396 (87.8%), too low in 29 (6.4%) and too high in 26 (5.8%).

CONCLUSION

The prescribing practices for anti-tuberculosis drugs were substandard and need improvement. These findings imply that the National TB Programme needs strengthening.

Factors associated with a clinician's decision to stop anti-tuberculosis treatment before completion

OBJECTIVES

To investigate the diagnosis of pulmonary tuberculosis (PTB) and factors associated with a clinician's decision to stop anti-tuberculosis treatment before completion.

DESIGN

The medical charts of all citizens of Taipei City, Taiwan, reported to have received treatment for PTB in 2003 were investigated.

RESULTS

Of 1126 PTB patients, 512 (45.5%) started treatment immediately based solely on chest X-ray (CXR) findings; treatment for 214 (19.0%) was based on a positive sputum smear for acid-fast bacilli, for 261 (23.2%) it was based on other findings and for 139 (12.3%) it was based on a positive mycobacterial culture. Of the 1126 PTB patients, 156 (13.9%) had their diagnosis of TB changed by a clinician. Multivariate analysis shows that patients whose diagnosis was based on CXR or other findings, female patients, patients who interrupted treatment for 2 months, patients who continued care at other health facilities (transfer) and patients with lung cancer were significantly more likely to have their diagnosis changed than other groups.

CONCLUSION

A substantial proportion of patients were prescribed anti-tuberculosis treatment based on CXR findings alone, and a considerable proportion were advised to stop treatment before completing a full course, findings that require the immediate attention of Taiwan's National Tuberculosis Programme.

Comparison of the release behaviors of cupric ions from metallic copper and a novel composite in simulated body fluid

The copper-containing intrauterine devices (Cu-IUDs) are being increasingly used worldwide as an effective contraceptive for family planning. To avoid abnormal bleeding, pain, and partial and complete expulsion which are associated with the burst release of copper during the first few days, a novel crosslinked composite based on poly(vinyl alcohol) that contained cupric ions, but not metallic copper, was synthesized. It is hypothesized that the burst release of cupric ions could be avoided and the utility of the cupric ions could be improved by this novel composite. To evaluate these effects of the composite, the corrosion products and the release rate of cupric ions after soaking in simulated body fluid (SBF) for different time spans were studied by environmental scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction, and atomic absorption spectrophotometer. In the first week, the release amount of cupric ions in the composite was 0.486 microg/mm(2). In the fifth week, it decreased to 0.0278 microg/mm(2). But for metallic copper, these were 5.93 microg/mm(2) and 0.041 microg/mm(2), respectively. No significant change on time-dependence was found for the release rates of cupric ions in the composite compared with that of metallic copper. Moreover, no other new elements, such as P, Cl, and Ca, appeared on the surface of the composite, and no Cu2O was formed after immersing in SBF for 90 days. All of these results suggested that burst release of cupric ions could be avoided and the effective utility of copper could be improved in this composite. In view of the earlier results, this novel copper-containing composite might serve as a potential substitute for conventional materials of IUDs in the future.

Release behavior of copper ion in a novel contraceptive composite

PURPOSE

The universally used contraceptive method, the Cu-IUD, an effective contraceptive, is being increasingly used worldwide for family planning. To avoid abnormal bleeding, pain, partial and complete expulsion associated with the burst release of copper during the first few days, a novel cross-linked composite based on poly vinyl alcohol (PVA) that contains copper ions, but not metallic copper, was synthesized.

MATERIAL AND METHODS

PVA, well known for its good processability, high strength, long-term temperature and pH stability and biocompatibility, was used as the matrix material. The corrosion products and the release rate of copper ions after soaking in simulated body fluid (SBF) for different time spans were studied by environmental scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction and atomic absorption spectrophotometer.

RESULTS

No significant change on time dependence for the release rate of copper ions in the composite compared with that of metallic copper was found. Moreover, no other new elements, such as P, Cl and Ca, appeared on the surface of the composite and no Cu(2)O formed after immersing in SBF for 90 days.

CONCLUSION

Burst release of copper ions can be avoided by loading copper ions in this polymer material. Release channels would not be obstructed by the deposition of corrosion products and nearly all of the copper loaded in the composites could be an effective contraceptive.

Outcome of pulmonary multidrug-resistant tuberculosis: a 6-yr follow-up study

A retrospective study was performed to determine factors associated with the outcome of pulmonary multidrug-resistant tuberculosis (MDR-TB) in Taipei, Taiwan. All patients newly diagnosed with pulmonary MDR-TB in a referral centre from 1992-1996 were enrolled and their outcome over the subsequent 6 yrs was determined. A total of 299 patients were identified, comprising 215 (71.9%) males and 84 (28.1%) females with a mean age of 47.3 yrs. The patients received a mean of 3.7 effective drugs. Out of the 299 patients, 153 (51.2%) were cured, 31 (10.4%) failed, 28 (9.4%) died and 87 (29.1%) defaulted. Of the 125 patients receiving second-line drugs with ofloxacin, 74 (59.2%) were cured. Those who received ofloxacin had a lower risk of relapse than those receiving only first-line drugs (hazard ratio (HR) 0.16, 95% confidence interval (CI) 0.03-0.81) and a lower risk of TB-related death than those receiving second-line drugs but not ofloxacin (adjusted HR 0.50, 95% CI 0.31-0.82). In conclusion, multidrug-resistant tuberculosis patients who received ofloxacin were more likely to be cured, and were less likely to die, fail or relapse. The utility of new-generation fluoroquinolones, such as moxifloxacin, in the treatment of multidrug-resistant tuberculosis needs to be evaluated. Default from treatment is a major challenge in the treatment of multidrug-resistant tuberculosis.

Tuberculin reactivity in adults after 50 years of universal bacille Calmette–Guérin vaccination in Taiwan

We aimed to assess whether tuberculin reactivity in adults is affected by bacille Calmette-Guerin (BCG) vaccination after 50 years of universal BCG vaccination with 80-95% coverage. A community-based study on tuberculin reactivity in 619 participants was conducted in February 2000 in Keelung city, Taiwan. Information on BCG vaccination policies and annual risk of infection (ARI) in the underlying population was extracted from consecutive national prevalence surveys relating to the period 1952-1997. Compared with the expected ARI estimate, the standardized morbidity ratio of positive tuberculin response for vaccination in infancy was 2.2 (95% CI 0.3-15.5) for those aged <10 years. The corresponding figures for older age groups ranged from 3.6 (95% CI 2.2-5.9) for those aged 10-12 years to 0.7 (95% CI 0.5-0.9) for those aged 57-67 years. This suggests that the effect of BCG vaccination on positive tuberculin response in adults aged >30 years is probably negligible irrespective of age at vaccination or revaccination and that the tuberculin skin test can be used to diagnose TB in control programmes in countries with moderate or high incidence of TB.

Comparative evaluation of the BACTEC MGIT 960 system with solid medium for isolation of mycobacteria

SETTING

The utilisation of new, rapid methods of diagnosis of tuberculosis is currently of great interest for tuberculosis control. This study was carried out in a teaching hospital in the eastern region of Taiwan.

OBJECTIVE

The BACTEC MGIT 960 system was evaluated and compared with Lowenstein-Jensen (LJ) medium and Middlebrook 7H11 plate for recovery rate and time to detection of mycobacteria.

DESIGN

A total of 1396 sputum samples were tested for the presence of mycobacteria. Specimens were processed and inoculated separately in the BACTEC MGIT 960 system, on LJ medium and 7H11 for comparative study.

RESULTS

The BACTEC MGIT 960 detected 235 isolates (100%), followed by LJ with 205 isolates (87.2%) and 7H11 with 178 isolates (75.7%). The mean time to detection of Mycobacterium tuberculosis complex was 11.6 days with MGIT 960, 20.1 days with LJ, and 18.7 days with 7H11. The contamination rates were 15.1% with MGIT 960, 10.1% with LJ and 9.7% with 7H11.

CONCLUSION

The BACTEC MGIT 960 system is a sensitive, rapid mycobacterial culturing system. However, the high contamination rate is a concern that should be carefully evaluated in the clinical setting.

The impact of national health insurance on the notification of tuberculosis in Taiwan

SETTING

General notification of tuberculosis in Taiwan.

OBJECTIVES

To ensure the completeness of notification of tuberculosis (TB) in Taiwan, the Bureau of National Health Insurance (NHI) introduced two policies in 1997: 1) the no-notification-no-reimbursement (NNNR) policy, and 2) the notification-fee (NF) policy. The goals of this study were to investigate the impact of the NNNR and NF policies on notification of TB.

DESIGN

Review of all cases notified to the National TB Register from 1995 to 1999 to determine calendar trend, type of case and source of notification.

RESULTS

There were 11,453 and 13,612 reported cases in 1995 and 1996, respectively. Following the implementation of the NHI policies, there was a 47% increase in 1997, with 20 021 reported cases. Quarterly reporting of cases reached a historic peak in the third quarter of 1997. The increase in reported cases was mainly from general hospitals/clinics. Since 1998, the number of reported cases has declined steadily, at a rate of 7% and 3% in 1998 and 1999, respectively.

CONCLUSIONS

The NNNR and NF policies had a significant impact on notification of TB in Taiwan. These policies substantially improved completeness of reporting, an observation with implications for surveillance of other reported diseases.

Expressional profiling of genes related to pollination and fertilization in rice

Pollination and fertilization are key steps leading to seed and fruit formation. To obtain genes involved in pollination and fertilization in rice, an RNA fingerprinting technique, cDNA-AFLP (amplified fragment length polymorphism), was used to generate transcript profiles related to pollination. Of 15,000 cDNA fragments inspected, 2,100 showed altered expression in the pollinated pistil, of which about 1/5 were up-regulated (URP) and the rest down-regulated (DRP), suggesting that gene repression is a predominant mode of gene regulation in the pollinated pistil. Over 200 URP genes were sequenced and databank searches revealed that 70% of them represented previously unnoticed rice genes. DNA blot analysis of 20 URP genes detected no restriction fragment length polymorphisms (RFLP) between two relatively distant rice varieties, suggesting that the URP genes are highly conserved and likely play important roles in pollination and fertilization. Furthermore, two genes, URP47 and URP63, probably encoding an ADP-ribosylation factor and a membrane transporter, respectively, in relation to pollination were discussed.

Pulmonary resection in the treatment of patients with pulmonary multidrug-resistant tuberculosis in Taiwan

SETTING

Chronic Disease Control Bureau, Department of Health, Taiwan.

OBJECTIVE

To evaluate the role of pulmonary resection in the treatment of pulmonary tuberculosis resistant to isoniazid and rifampin (MDR-TB).

DESIGN

In a retrospective cohort study, 27 MDR-TB patients who underwent pulmonary resection between December 1990 and March 1999 were reviewed. Individually-tailored treatment regimens were selected at a once-weekly staff conference following review of the patient's case history and drug susceptibility results. Surgery was performed for selected patients, essentially those: 1) whose medical treatment had failed, or for whom treatment failure seemed highly likely, or for whom post-treatment relapse seemed likely, 2) with predominantly localised disease, 3) with adequate cardiopulmonary reserve, and 4) whose treatment regimen had been composed of at least two effective drugs to diminish the mycobacterial burden.

RESULTS

There was no surgical mortality apart from one peri-operative death (4%). Three patients (11%) developed complications, and 24 (92%) patients demonstrated sputum conversion and/or remained negative after surgery. Twenty-three patients have already completed treatment, and during a mean of 42 +/- 18 follow-up months (range 15-80 months), one patient relapsed. This patient was disease-free after another course of treatment.

CONCLUSION

For selected patients, pulmonary resection may improve the outcome of pulmonary MDR-TB.

Annual risk of tuberculous infection in Taiwan, 1996-1998

Tuberculosis is still an important public health issue in Taiwan, and monitoring the trend of annual risk of infection (ARI) with Mycobacterium tuberculosis is essential. In this study, we conducted tuberculin skin tests to estimate the prevalence and annual risk of M. tuberculosis infection in first-grade schoolchildren in Taiwan Province. Because mass bacille Calmette-Guérin (BCG) vaccination programs have been carried out here, only non-BCG-vaccinated students were tested. From September 1996 through June 1998, there were 520,866 registered first-grade elementary school students in Taiwan Province. Of them, 15,147 (2.9%) were non-BCG-vaccinated, as determined by the absence of a BCG scar. All of them were tested for M. tuberculosis infection with 1 tuberculin unit (0.1 mL injection) of purified protein derivative RT23, by means of the Mantoux technique. Among the tested schoolchildren, 430 (2.8%) had a positive tuberculin reaction. Thus, the calculated ARI was 0.44%. The ARI varied in different areas of Taiwan, being highest (1.04%) in Nantou County and lowest (0.14%) in Miaoli and Tainan Counties. The ARI in aboriginal areas (1.16%) was 2.7 times that in nonaboriginal areas (0.42%). Our results indicate that the M. tuberculosis ARI is still high in Taiwan. To achieve the World Health Organization target of less than 0.1% for industrialized countries, we must intensify tuberculosis control programs in Taiwan.

Short-course chemotherapy for isoniazid-resistant pulmonary tuberculosis

Standard short-course chemotherapy including isoniazid, rifampicin, pyrazinamide, and ethambutol has been the recommended treatment for tuberculosis in Taiwan since November 1990. The effectiveness of this treatment was evaluated retrospectively in 108 patients with isolates resistant to isoniazid alone and 115 patients with drug-susceptible pulmonary tuberculosis diagnosed and treated at the Taiwan Provincial Chronic Disease Control Bureau from November 1990 through December 1995. The success rate of treatment was 94.4% in patients with isoniazid-resistant Mycobacterium tuberculosis strains, which was not significantly different from the 97.4% rate in patients with susceptible strains. Of the patients treated successfully, no bacteriologic relapse was found in 97 patients with isoniazid-resistant strains or 103 patients with drug-susceptible strains 12 months after the end of chemotherapy. No significant advantage in treatment outcome was found in patients infected with isoniazid-resistant strains who received chemotherapy for more than 6 months (successful treatment rate, 95.0% vs 92.8%), but the failure rate was higher in patients with a previous history of antituberculosis therapy (17.6% vs 3.3%). We conclude that short-course chemotherapy is effective for isoniazid-resistant pulmonary tuberculosis and that there is no significant difference in treatment outcome between patients with or without isoniazid-resistant disease.

Screening of human immunodeficiency virus infection in pulmonary tuberculosis patients in Taiwan

To disclose the impact of human immunodeficiency virus (HIV) infection on the tuberculosis epidemic in Taiwan, we prospectively screened for HIV infection in patients with active pulmonary tuberculosis. A total of 378 patients who were admitted to the Taiwan Provincial Chronic Disease Control Bureau from January through December 1996 were enrolled. HIV serologic testing was performed by enzyme-linked immunosorbent assay (ELISA). A positive ELISA test was confirmed by Western blot analysis. One patient was infected with HIV. We conclude that the impact of HIV infection on the epidemic of tuberculosis in Taiwan is not significant at present.

Initial drug resistance of Mycobacterium tuberculosis in Taiwan

The prevalence and mortality rate of pulmonary tuberculosis in adults are high in Taiwan. Because the emergence of drug-resistant tuberculosis is one of the major causes of this sustained high tuberculosis mortality, surveillance of initial drug resistance is important. We tested Mycobacterium tuberculosis isolates from 1,935 newly diagnosed tuberculosis patients from January 1990 through December 1995 at the Taiwan Provincial Chronic Disease Control Bureau. The overall initial drug resistance rate was 12.3%; 8.7% of isolates were resistant to only one drug, 2.6% to two drugs, 0.7% to three drugs, and 0.3% to four drugs. The resistance rates to individual drugs were: streptomycin, 5.7%; isoniazid, 9.2%; ethambutol, 0.7%; and rifampin, 1.5%. The frequency of multidrug-resistant M. tuberculosis (resistant to at least isoniazid and rifampin) was 1.2%. In view of the high initial isoniazid resistance rate and low initial ethambutol resistance rate, ethambutol should be added to the regimen for the initial treatment of tuberculosis in Taiwan. The emergence of multidrug-resistant M. tuberculosis is ominous and should be considered when treating patients in Taiwan.

Serodiagnosis of tuberculosis. A study comparing three specific mycobacterial antigens

To compare the efficacy of different mycobacterial specific antigens and to assess the applicability of the combination of several different antigens in the diagnosis of tuberculosis, three ELISA tests derived by Antigen 60, 38kda, and Kp90 were evaluated in 594 Chinese patients (312 patients with active pulmonary tuberculosis and 282 control subjects). Quantified levels of sensitivity and specificity were compared with those in the nontuberculous control groups. Antigen 60 IgG (sensitivity and specificity, 80.77 and 88.4%) was more antigenic and more effective in its determination than was 38kda IgG (sensitivity and specificity, 64.21 and 80.74%) and Kp90 IgA (sensitivity and specificity, 62.58 and 66.3%). The clinical significance of the difference, however, was not striking: negative predictive value of Antigen 60, 38kda, and Kp90 was 93, 86 and 83%, respectively; positive predictive value of Antigen 60, 38kda, and Kp90 was 71, 54, and 39%, respectively. Combination of different antigens could improve the sensitivity and specificity by no more than 10%, with the sacrifice of the opposite parameter by no less than 20%. The same improvement in sensitivity could be easily achieved by adjusting the cutoff values in the ELISA test by a single antigen. We conclude that the sensitivity and specificity of presently available antigens for serodiagnosis of tuberculosis still remains limited at around 80%, which makes it a poor diagnostic tool for disease confirmation. In low incidence areas, its clinical value may be useful in disease exclusion. A combination of several different antigens provides no more improved diagnostic yield than what can be provided by cutoff value adjustment in a single antigen serologic test.

[Study of dermatomycosis and survey of pathogens in troops of Hainan area]

Subtropical area is the prevalent area of dermatomycosis with natural conditions suptable for the growth and proliferation of fungi causing suterficial dermatomycosis. Dermatomycosis not only brings about certain sufferings to the military personnel in peacetime, but also causes nonbattle loss in manpower in war time. In the present work, a survey of dermatomycosis in Hainan subtropical area of China and isolation of the pathogens were carried out. The results were as follows: The morbidity of superficial dermatomycosis was 34.1% and it was manifested clinically as tinea pedis, tinea versicolor, tinea corporis, tinea axillaris, tinea cruris, etc.; The main pathogen causing dermatomycosis in this area was Trichophyton rubrum which accounted for 50.4% of the pathogens isolated and the next was Trichophyton gypseum which accounted for 20.3%; Trichophyton rubrum could cause dermatomycosis of many sites of the body in this area, but the main lesious were tinea corporis and tinea cruris.

[Study of the relationship between the control of environmental microorganism and infection of patients with leukemia after trasplantation of bone marrow]

After the transplantation of bone marrow, patients with leukemia are easily infected by kinds of microorganism and die. In this paper, F-mice with the 60Co-gamma irradiation (maximum lethal dose) were transplanted bone marrow, then control the microorganism in the environment. Morever the laminar flow wards for the leukemia patient of bone marrow transplantation were designed according to the data combined with the clinic condition. There is no any infection in twelve patients with bone marrow transplantation from 1989 to 1993.