Understanding quality differences between kiwifruit varieties during softening

Research into variations between kiwifruit varieties particularly their softening quality during storage is important in improving kiwifruit quality. The potential reasons for ripening quality differences between 'Cuixiang' (CX) and 'Hayward' (HWD) kiwifruit were analyzed by physiology and metabolomic data combined with the random forests learning algorithm. The results showed that the storability difference between the two varieties mainly resulted from differences in polygalacturonase (PG) and β-galactosidase activities. The 1 °C slowed the fruit softening process of both varieties by decreasing their PG activities. A total of 368 metabolites were identified and amino acid, carbohydrate, cofactors and vitamins, as well as nucleotide metabolism are key metabolic modules that affect the ripening differences of CX and HWD kiwifruit. A total of 30 metabolites showed remarkable ability in distinguish the ripening quality of CX and HWD kiwifruit, in which d-glucose, d-maltose, 2-hydroxybutyric acid, phenyllactate, and vitamin B2 were noteworthy for their potential application on the evaluation of kiwifruit taste and nutritional value. These findings provide positive insights into the underlying mechanism of ripening quality differences between CX and HWD kiwifruit and new ideas for identifying key metabolic markers in kiwifruit.

Proteome Dynamics Analysis Reveals the Potential Mechanisms of Salinity and Drought Response during Seed Germination and Seedling Growth in Tamarix hispida

Understanding the molecular mechanisms of seed germination and seedling growth is vital for mining functional genes for the improvement of plant drought in a desert. Tamarix hispida is extremely resistant to drought and soil salinity perennial shrubs or trees. This study was the first to investigate the protein abundance profile of the transition process during the processes of T. hispida seed germination and seedling growth using label-free proteomics approaches. Our data suggested that asynchronous regulation of transcriptomics and proteomics occurs upon short-term seed germination and seedling growth of T. hispida. Enrichment analysis revealed that the main differentially abundant proteins had significant enrichment in stimulus response, biosynthesis, and metabolism. Two delta-1-pyrroline-5-carboxylate synthetases (P5CS), one Ycf3-interacting protein (Y3IP), one low-temperature-induced 65 kDa protein-like molecule, and four peroxidases (PRX) were involved in both water deprivation and hyperosmotic salinity responses. Through a comparative analysis of transcriptomics and proteomics, we found that proteomics may be better at studying short-term developmental processes. Our results support the existence of several mechanisms that enhance tolerance to salinity and drought stress during seedling growth in T. hispida.

Modification in structural, physicochemical, functional, and in vitro digestive properties of kiwi starch by high-power ultrasound treatment

Kiwi starch (KS) is a fruit-derived starch; in order to improve its processing performance and increase its added value, it is necessary to modify KS to enhance the positive attributes and to enlarge its application. In this study, KS was modified by high-power ultrasound treatment (HUT) to reveal the relationship between the structure and function of KS with different treatment powers (0, 200, 400, and 600 W) and different treatment times (0, 10, 20, and 30 min). The results showed that HUT destroyed the granular morphology of KS, formed holes and cracks on the surface, and reduced the particle size and the short-range molecular order of KS. After different HUTs, the apparent amylose content (AAC), swelling power (SP), water solubility index (WSI), viscosity and setback value (SB) of KS were significantly increased, while the gelatinization temperature was significantly decreased. In addition, HUT significantly reduced the content of rapidly digestible starch (RDS) and slowly digestible starch (SDS), while it significantly enhanced the content of resistant starch (RS) (64.08-72.73%). In a word, HUT as a novel physical modification method for KS, enlarged its application, and fulfilled different demands of a starch-based product, which introduces another possibility for kiwi fruit further processing.

Combined transcriptomic and metabolomic analysis reveals the potential mechanism of seed germination and young seedling growth in Tamarix hispida

Background

Seed germination is a series of ordered physiological and morphogenetic processes and a critical stage in plant life cycle. Tamarix hispida is one of the most salt-tolerant plant species; however, its seed germination has not been analysed using combined transcriptomics and metabolomics.

Results

Transcriptomic sequencing and widely targeted metabolomics were used to detect the transcriptional metabolic profiles of T. hispida at different stages of seed germination and young seedling growth. Transcriptomics showed that 46,538 genes were significantly altered throughout the studied development period. Enrichment study revealed that plant hormones, such as auxin, ABA, JA and SA played differential roles at varying stages of seed germination and post-germination. Metabolomics detected 1022 metabolites, with flavonoids accounting for the highest proportion of differential metabolites. Combined analysis indicated that flavonoid biosynthesis in young seedling growth, such as rhoifolin and quercetin, may improve the plant’s adaptative ability to extreme desert environments.

Conclusions

The differential regulation of plant hormones and the accumulation of flavonoids may be important for the seed germination survival of T. hispida in response to salt or arid deserts. This study enhanced the understanding of the overall mechanism in seed germination and post-germination. The results provide guidance for the ecological value and young seedling growth of T. hispida.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08341-x.

Optimization of ultrasonic-assisted enzymatic extraction of kiwi starch and evaluation of its structural, physicochemical, and functional characteristics

A new ultrasound-assisted enzymatic extraction (UAEE) method of starch from kiwifruit was established and optimized using response surface methodology (RSM). Under optimal conditions (the pectinase-to-cellulase-to-papain ratio = 1:2:1 g/kg, solid/liquid ratio = 1:6.68, extraction pH = 5.23, ultrasound power = 300 W, and extraction temperature = 52 °C), the kiwi starch (KS) yield was about 4.25%, and the starch content of KS was 873.23 mg/g. Compared to other extraction methods, UAEE can obtain KS with high yield and purity with a shorter extraction time and less solvent and enzyme. The extracted KS has a low gelatinization enthalpy (8.02 J/g) and a high peak viscosity (7933 cP), with obvious particle properties and low adhesion. In addition, KS is rich in polyphenols, has strong antioxidant activity, and has higher contents of amylose starch (30.74%) and resistant starch (60.18%). This study established a novel and highly efficient method for KS extraction and suggest several possible applications for KS in the food industry.

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.

Functional characterization of persimmon β-galactosidase gene DkGAL1 in tomato reveals cell wall modification related to fruit ripening and radicle elongation

Cell wall metabolism during fruit ripening is a highly organized process that involves complex interplay among various cell wall hydrolases. Among these cell wall hydrolases, β-galactosidase has been identified to participate in cell wall metabolism via its ability to catalyze galactosyl metabolism from the large and complex side chains of cell walls. In this study, the galactose content in the pericarp increased during persimmon fruit ripening, but cell wall galactosyl residues decreased, indicating a relationship between galactose metabolism and persimmon fruit ripening. Expression of a previously isolated β-galactosidase gene, DkGAL1, increased 25.01-fold during fruit ripening. Heterologous expression of DkGAL1 under the CaMV 35S promoter in tomato accelerated on-plant and postharvest fruits ripening. The fruit firmness of one of transgenic line, OE-18, was 23.83% lower than that of WT at the breaker stage. The transgenic fruits produced more ethylene by promoting the expression of ethylene synthesis-related genes and cell wall degradation-related genes. Overexpression of DkGAL1 in tomato also reduced cell-to-cell adhesion and promoted both wider intercellular spaces and less cell compaction in transgenic fruit structures. Moreover, DkGAL1 was involved in seed germination and radicle elongation in transgenic tomato seeds. These results confirm the role of DkGAL1 in fruit ripening and suggest that this gene alters galactose metabolism in the fruit, which can promote ripening and reduce cellular adhesion. In addition, the role of DkGAL1 is not limited to fruit softening; DkGAL1 was also involved in seed germination and radicle elongation in transgenic tomato seeds.

Isolation and Characterization of Two Persimmon Xyloglucan Endotransglycosylase/Hydrolase (XTH) Genes That Have Divergent Functions in Cell Wall Modification and Fruit Postharvest Softening

Fruit cell wall modification is the primary factor affecting fruit softening. Xyloglucan endotransglycosylase/hydrolase (XTH), a cell wall-modifying enzyme, is involved in fruit softening. In this study, two novel XTH genes (DkXTH6 and DkXTH7) were identified from persimmon fruit. Transcriptional profiles of both of the two genes were analyzed in different tissues of persimmon, and in response to multiple hormonal and environmental treatments [gibberellic acid (GA3), abscisic acid (ABA), propylene, and low temperature]. Expression of DkXTH6 was positively up-regulated during ethylene production and by propylene and ABA treatments, and suppressed by GA3 and cold treatment. In contrast, DkXTH7 exhibited its highest transcript levels in GA3-treated fruit and cold-treated fruit, which had higher fruit firmness. We found that DkXTH6 protein was localized in cell wall by its signal peptide, while cytoplasmic DkXTH7 protein contained no signal peptide. When expressed in vitro, the recombinant proteins of both DkXTH6 and DkXTH7 exhibited strict xyloglucan endotransglycosylase (XET) activity but no xyloglucan endohydrolase (XEH) activity. The recombinant protein of DkXTH6 showed a higher affinity with small acceptor molecules than the recombinant DkXTH7. Taken together with their opposing expression patterns and subcellular localizations, these results suggested that DkXTH6 might take part in cell wall restructuring and DkXTH7 was likely to be involved in cell wall assembly, indicating their special roles in persimmon fruit softening.

The Persimmon 9-lipoxygenase Gene DkLOX3 Plays Positive Roles in Both Promoting Senescence and Enhancing Tolerance to Abiotic Stress

The lipoxygenase (LOX) pathway is a key regulator for lipid peroxidation, which is crucial for plant senescence and defense pathways. In this study, the transcriptional expression patterns of three persimmon (Diospyros kaki L. 'Fupingjianshi') 9-lipoxygenase genes (DkLOX1, DkLOX3, and DkLOX4) were investigated. DkLOX1 was specifically expressed in fruit, particularly in young fruit, and showed little response to the postharvest environments. DkLOX4 was expressed in all tissues and slightly stimulated by mechanical damage and low temperature. DkLOX3 was expressed mainly in mature fruit, and the expression was extremely high throughout the storage period, apparently up-regulated by mechanical damage and high carbon dioxide treatments. Further functional analysis showed that overexpression of DkLOX3 in tomato (Solanum lycopersicum cv. Micro-Tom) accelerated fruit ripening and softening. This was accompanied by higher malondialdehyde (MDA) content and lycopene accumulation, advanced ethylene release peak and elevated expression of ethylene synthesis genes, including ACS2, ACO1, and ACO3. In addition, DkLOX3 overexpression promoted dark induced transgenic Arabidopsis leaf senescence with more chlorophyll loss, increased electrolyte leakage and MDA content. Furthermore, the functions of DkLOX3 in response to abiotic stresses, including osmotic stress, high salinity and drought were investigated. Arabidopsis DkLOX3 overexpression (DkLOX3-OX) transgenic lines were found to be more tolerant to osmotic stress with higher germination rate and root growth than wild-type. Moreover, DkLOX3-OX Arabidopsis plants also exhibited enhanced resistance to high salinity and drought, with similar decreased O2 (-) and H2O2 accumulation and upregulation of stress-responsive genes expression, including RD22, RD29A, RD29B, and NCED3, except for FRY1, which plays a negative role in stress response. Overall, these results suggested that DkLOX3 plays positive roles both in promoting ripening and senescence through lipid peroxidation and accelerated ethylene production and in stress response via regulating reactive oxygen species accumulation and stress responsive genes expression.

Analysis of xyloglucan endotransglycosylase/hydrolase (XTH) genes and diverse roles of isoenzymes during persimmon fruit development and postharvest softening

Xyloglucan endotransglycosylase/hydrolase (XTH) enzymes have played a role in the remodeling of cell wall hemicelluloses. To investigate the function of XTHs in persimmon (Diospyros kaki L.) fruit development and postharvest softening, five cDNAs (DkXTH1 to DkXTH5), whose putative proteins contained the conserved DEIDFEFLG motif of XTH, were cloned. Real time quantitative PCR analysis revealed that DkXTH1, DkXTH4, and DkXTH5 peaked in immature expanding fruit, and their higher expression was observed along with higher fruit firmness in cold-treated fruit or firmer cultivar fruit during storage. The opposite gene expression patterns were observed in DkXTH2 and DkXTH3, which reached maxima concomitance with pronounced fruit softening. Meanwhile, the xyloglucan endotransglycosylase (XET) enzymes play important roles in both the rapid growth and ripening of persimmon fruit. Furthermore, the recombined DkXTH1 and DkXTH2 proteins showed significant XET activity without any detected XEH activity. However, the XET activity of recombined DkXTH2 protein had a higher affinity for small acceptor molecules than that of recombined DkXTH1 protein. The former might prefer to participate in cell wall restructuring, and the latter is more inclined to participate in cell wall assembly. Besides, DKXTH proteins could function by targeting to the cell wall under regulation of a signal peptide. The data suggested that individual DKXTHs could exhibit different patterns of expression, and the encoded products possessed specific enzymatic properties conferring on their respective functions in growth and postharvest softening of persimmon fruit.

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.

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.

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.

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.

In vitro activity of ofloxacin against Mycobacterium tuberculosis

For the past 3 years, ofloxacin has been widely used in treating patients with drug-resistant tuberculosis in Taiwan. To study its usefulness in treating these patients, 139 isolates of Mycobacterium tuberculosis from patients treated at the Taiwan Provincial Chronic Disease Control Bureau from September 1994 to September 1995 were tested to determine the in vitro antituberculosis activity of ofloxacin. Of these, 131 had not been previously exposed to ofloxacin, and 130 (99.2%) were susceptible to ofloxacin. Sixty-four isolates were found to be susceptible to all conventional antituberculosis drugs, and all of these were also susceptible to ofloxacin. Of the remaining 67 isolates that were resistant to one or more conventional antituberculosis drugs, 66 (98.5%) were susceptible to ofloxacin. There was no association between susceptibility to ofloxacin and susceptibility to conventional antituberculosis drugs among the isolates tested. Of the eight isolates of M. tuberculosis previously exposed to ofloxacin, seven (87.5%) were resistant. Our results indicate that patients with multidrug-resistant strains of M. tuberculosis who have not received prior ofloxacin treatment may be safely treated with ofloxacin even without knowing the result of pretreatment ofloxacin susceptibility tests. We also found that ofloxacin resistance emerges frequently. Therefore, an adequate combination of antituberculosis drugs, along with ofloxacin, should be prescribed to prevent the development of resistance to ofloxacin.

[Study of relationship between the bacteria in air and the clinic infection]

The Source of infectious bacteria is the first problem in provension of infection considered by the medical workers. In this paper, with the method of bacteria plasmid analysis, chromosome DNA restriction fragment length polymorphism analysis, drug resistance experiment (antibacterial drug, sterilizing drug) and so on. We confirmed that staphylococci of nosocomi is mainly from air; but the gram-negative bacteria is mainly from the patient's pharyngeal portion; and cause hospital infection indirectly. The drug resistance of gram-negative from air was lower than the same gram-negative bacilli's isolated from the patient. Moreover, kill bacteria the infectious strain is same strain in air. Above-mentioed results provided the important basis for control of the hoslpital infection.

Treatment of multidrug-resistant tuberculosis in Taiwan

Eighty-seven patients with multidrug-resistant tuberculosis (MDR-TB) diagnosed between 1988 and 1990 were treated with isoniazid and at least three other effective second-line drugs based on in vitro susceptibility tests. Of these patients, 10% failed to adhere to the regimen and 43% remained sputum positive after 6 months of treatment. Only 47% showed sputum conversion within 6 months of treatment and 12% of them relapsed during the first year of follow-up. From September 1987 to July 1989, 36 patients with MDR-TB were treated with a regimen containing rifabutin, isoniazid and at least three other susceptible drugs. Only 47% achieved a sustained sputum conversion. Four died during treatment due to disease progression. From March 1992 to July 1993, 17 cases of MDR-TB were treated with an ofloxacin-containing anti-TB regimen for 12-24 months. Two failed to adhere to the regimen for more than 1 month during the first 6 months of therapy. Among the remaining 15, 26% failed to achieve sputum conversion, 73% achieved bacterial conversion, 9 within 1 month and the other 2 within 2 months. No significant adverse effect was associated with ofloxacin use. We concluded that ofloxacin is a better choice among the more toxic and less potent second-line drugs, and should be used along with other anti-TB drugs in treating patients with MDR-TB.

Percutaneous endovascular embolization of intracerebral arteriovenous malformations. Experience in 72 cases

Endovascular therapeutic embolization of arteriovenous malformations (AVMs) of the brain was performed in 72 patients between October 1986 and March 1993. From October 1986 to May 1991, 38 patients in this series were treated with isobuty1-2-cyanoacrylate (IBCA) glue. After June 1991, in the remaining 34 patients the embolic materials used included surgical silk (5-0), polyvinyl alcohol (PVA), ethanol, and estrogen. After treatment, 29 patients (40.3%) had complete angiographic obliteration of AVM, 15 (21%) transient neurologic postembolization deficit, and 3 (4%) permanent deficit without death. Embolic agents and procedures are discussed as to their curative effects, safety, normal perfusion pressure breakthrough (NPPB) problem, with silk mixture fluid being considered preferable.

[High yield techniques for bupleurum falcatum L]

The growth of plants may be controlled by clipping the aerial part. This may increase the yield of Bupleurum falcatum. Different methods of cultivation may result in different outputs of crude drugs. Compared with land plotting, deep ploughing and high ridging may increase the root weight of one-year-old plant by 28% and 50% respectively.

Suppression of hepatic natural killer activity by liver metastasis of cancer and restoration of killer activity by oral administration of a Basidomycetes-derived polysaccharide, PSK

PSK (Krestin) is a protein-bound polysaccharide with antitumor and immunomodulatory activity. In this study, the effects of the oral administration of PSK were investigated on the natural killer (NK) activity of liver-associated lymphocytes and their subfractions separated by density gradient centrifugation, in WKAH rats with liver metastasis of KDA hepatoma. PSK was administered orally, at a dose of 500 mg/kg once a day for 3 weeks. The NK activity of nonparenchymal liver cells (NPLC) and their subfractions, including large granular lymphocytes (LGL), was markedly augmented by this treatment. The effects of oral PSK were also examined in CDF1 mice with liver metastases of Colon 26 adenocarcinoma; the survival of tumor-bearing mice was prolonged and both metastatic foci and liver weight were decreased. These results suggest that PSK may be effective for the suppression of liver metastasis through activation of liver-associated NK cells.

Quantitative measurement of drug susceptibility of Mycobacterium tuberculosis for monitoring chemotherapy response

Changes in the degree of drug susceptibility of the bacterial population in tuberculosis patients during chemotherapy can be monitored by testing Mycobacterium tuberculosis isolates against various concentrations of drugs in 7H12 broth to determine radiometrically the minimal inhibitory concentration (MIC). The MICs were determined for multiple cultures isolated from 13 patients, of whom nine responded to chemotherapy within a few months, and four failed to respond at all. No changes in MICs were observed with the isolates obtained from the patients with a favorable response to chemotherapy. Determination of the MICs indicated that the failure in two cases out of four was associated with a steady increase in the degree of resistance of the patients' bacterial population. In two other failure cases, lack of change in the MIC values for multiple cultures suggests that the failure was associated with factors other than drug resistance. During the period of chemotherapy, quantitation of the degree of drug susceptibility in terms of broth-determined MICs may help to identify promptly those patients whose bacterial population is becoming resistant to the administered antimicrobial agents. For those patients who do not respond to chemotherapy, lack of change in the degree of resistance of their bacterial population may alert the physician to attempt to identify causes other than drug resistance for the chemotherapy failure.

Family factors affecting the outcome of tuberculosis treatment in Taiwan

Despite the progress of tuberculosis (TB) control, the failure of treatment mainly due to non-adherence to medical recommendations remains a major obstacle to the eradication of this disease in both industrialized and developing countries. We interviewed 397 active pulmonary TB cases (274 males and 123 females) in Taiwan and followed up their treatment outcomes. No significant differences were found between any of the groups of either sex on TB cognition scores. Positive correlations between cognition scores and compliance scores, between cognition scores and family apgar scores, and between compliance scores and family apgar scores were noted in this study. In males, the complete treatment group had a higher compliance score (mean +/- standard deviation = 13.45 +/- 2.80) and family apgar score (22.44 +/- 2.29) than the incomplete treatment group (11.61 +/- 3.21 and 14.77 +/- 3.92, respectively). In females, the complete treatment group had a higher cognition score (65.99 +/- 6.75), compliance score (13.65 +/- 2.55) and family Apgar score (22.78 +/- 2.30) than the incomplete treatment group (62.05 +/- 6.91, 11.70 +/- 3.04 and 14.84 +/- 3.80, respectively). In the logistic regression analysis, both the family Apgar score and compliance score were significantly related to the TB treatment outcomes. The subjects with a family Apgar score higher than 20 had a chance to complete treatment as high as 72-fold (95% confidence interval = 31.7-164.0) that of those with a score less than 20.(ABSTRACT TRUNCATED AT 250 WORDS)

Occupational exposure and respiratory morbidity among asbestos workers in Taiwan

To determine the prevalence of asbestos-related lung disease and the impairment of lung function among asbestos workers, we conducted a cross-sectional health survey of 459 workers in 33 asbestos-related factories in Taiwan. Each worker was asked about his medical and occupational history and was given a medical examination, chest roentgenogram and pulmonary function test. Manufacturing processes included production of asbestos cements, textiles, friction materials and insulation products. Exposure assessments were based on asbestos sampling and counting using a phase contrast microscope. The average age of the participants in the study was 41.6 years. They had an average of 8.1 years of dust exposure, with a range of one to 42 years. The majority had a cumulative asbestos exposure of less than 20 fiber years/mL. No case of asbestos-related lung disease was found during our investigation. No roentgenogram showed unequivocal changes of asbestosis. However, a multiple linear regression analysis of the pulmonary function test showed that both FVC and FEV1 decreased significantly with an increasing cumulative dose of exposure after controlling for age, height and smoking effects during analysis. FEV1/FVC and FEF25-75% were not affected by exposure dose. The absence of asbestosis and other asbestos-related lung diseases may be due to an inadequate induction time of asbestos exposure and a possible healthy selection of workers. We conclude that among workers in Taiwan, there is a significant effect on the respiratory system, especially pulmonary function, due to asbestos exposure.

Morbidity and mortality trends of pulmonary tuberculosis in Taiwan

An epidemiologic study of pulmonary tuberculosis was carried out to examine the secular trend and geographic variations of the incidence, prevalence and mortality of pulmonary tuberculosis in Taiwan. The prevalence and incidence rates declined-steadily from 1910 to 1980, but have remained unchanged during the last decade. Mortality also showed an 8.0% annual decrease from 1974 to 1986, but has remained constant without any apparent changes in recent years. Mortality for pulmonary tuberculosis is much higher in the aboriginal areas, where patients have a poor adherence to treatment and where a high prevalence of alcohol abuse exists. The mortality for pulmonary tuberculosis in Taiwan is higher than that in most developed countries, such as the U.K. and the U.S.A., but is lower than that in mainland China and the Republic of Korea.

The effect of hyperinflation on respiratory muscle strength and efficiency in healthy subjects and patients with asthma

We evaluated respiratory muscle strength and efficiency in 15 patients with asthma. There was a significant reduction in mean Plmax (89.3 +/- 4.7 versus 110.5 +/- 9.4 cm H2O, p less than 0.001) and efficiency (2.41 +/- 0.2 versus 4.2 +/- 0.6%, p less than 0.01). This reduction in strength and efficiency was seen only in the male patients. Following bronchodilator, there was a significant increase in Plmax (from 89.3 +/- 4.7 to 96.2 +/- 5.4 cm H2O, p less than 0.005) and efficiency (from 2.41 +/- 0.2 to 3.22 +/- 0.2%, p less than 0.001). There was no correlation between the change in strength and efficiency and the degree of improvement in FEV1 following bronchodilator. However, there was a significant correlation with the fall in lung volume. To determine whether hyperinflation would result in a reduction in respiratory muscle strength and efficiency, we induced a mean increase in end-expiratory lung volume of 0.66 L by applying continuous negative pressure around the chest in 10 healthy individuals. This was associated with a significant fall in Plmax (from 110.5 +/- 9.4 to 100.5 +/- 8.93 cm H2O, p less than 0.001) and efficiency (from 4.2 +/- 0.6 to 2.6 +/- 0.5%, p less than 0.005). The data suggest that the strength and efficiency of the respiratory muscles are reduced in asthmatic males but not in the females. The strength and efficiency of the respiratory muscles improve significantly following bronchodilator, and this improvement is related to reduction in lung volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficiency of the respiratory muscles in healthy individuals

We evaluated respiratory muscle performance by determining the energy cost of breathing against incremental threshold loads and calculating the efficiency of the respiratory apparatus for handling the added work. In five subjects, the energy cost of breathing against the loads, and thus the calculated efficiency of the respiratory muscles, was reproducible on repeated measurements. In all subjects, the calculated efficiency varied while breathing with low loads but was relatively constant at loads that resulted in a mouth pressure of 20 to 60% of the subjects' maximal static inspiratory pressure (PImax). The mean efficiency calculated between 20 to 60% of PImax in 30 normal subjects (15 males and 15 females) ranged between 1.54 and 7.98%. It was significantly greater in males (5.41 +/- 0.43%) (mean +/- SEM) than in females (2.41 +/- 0.17%). There was no relationship between efficiency and body size, but the efficiency correlated with inspiratory muscle strength (PImax). We suggest that measurement of the efficiency of the respiratory muscles over a spectrum of incremental threshold loads is a simple, noninvasive, and reproducible method of assessing respiratory muscle performance and may have clinical application.

Minimal inhibitory concentrations of isoniazid, rifampin, ethambutol, and streptomycin against Mycobacterium tuberculosis strains isolated before treatment of patients in Taiwan

Minimal inhibitory concentrations (MICs) of isoniazid (INH), rifampin (RMP), ethambutol (EMB), and streptomycin (SM) for susceptible "wild" M. tuberculosis strains isolated from Taiwanese patients were within the limits previously reported for strains isolated in the United States. The highest agar-determined MICs (in 7H10 and 7H11 agar) corresponded well with the critical concentrations established for these media. The highest MICs found radiometrically in 7H12 broth were significantly lower than the critical concentrations proposed for this medium. On the basis of an evaluation of the highest broth-determined MICs found in this and in the previous study (1), we suggest that the following MICs, when determined radiometrically, should be used as breakpoints to classify the strain as "susceptible": for INH, 0.1 microgram/ml or less; for RMP, 0.5 microgram/ml or less; for EMB, 4.0 micrograms/ml or less; for SM, 2.0 micrograms/ml or less.

Short-course chemotherapy of pulmonary tuberculosis in pneumoconiotic patients

This is the first prospective clinical trial recorded to date of short-course chemotherapy in pulmonary tuberculosis complicated by pneumoconiosis. Forty-eight anthrasillicotic and 11 silicotic patients with previously untreated pulmonary tuberculosis completed 9-month, short-course chemotherapy regimens: 2 months of daily streptomycin, isoniazid, rifampicin, and pyrazinamide followed by daily isoniazid and rifampicin for 7 months (2SHRZ/7HR). There were 3 treatment failures (5%). The remaining 56 patients (95%) all had their sputum converted within 4 months (mean, 1.5 months). Bacteriologic relapses were noted in 3 patients (5%) after 18 to 40 months of follow-up (mean, 28.4 months). The relapses occurred within 7 months after chemotherapy was stopped. There were 2 deaths from nontuberculosis causes during the follow-up period. Fifty-one patients (90%) remained bacteriologically sterile for 28.4 +/- 6.1 months. These results suggest that the 2SHRZ/7HR regimen is satisfactory in treating anthrasilicotic or silicotic patients with pulmonary tuberculosis, though antituberculosis chemotherapy seemed less effective in patients with pneumoconiosis than in those without pneumoconiosis.