Association of the D-amino acid oxidase gene with methadone dose in heroin dependent patients under methadone maintenance treatment.

Methadone is a synthetic opioid used for the maintenance treatment (MMT) of heroin dependence. It primarily binds to the µ-opioid receptor (MOR; with its gene, namely OPRM1). Methadone is also an N-methyl-D-aspartate (NMDA) receptor antagonist. The role of NMDA receptor in the regulatory mechanisms of methadone dosage in heroin dependent patients is so far not clear. D-amino acid oxidase (DAO) is an important enzyme that indirectly activates the NMDA receptor through its effect on the D-serine level. To test the hypothesis that genetic polymorphisms in the DAO gene are associated with methadone treatment dose and responses, we selected four single nucleotide polymorphisms (SNPs) in DAO from the literature reports of the Taiwanese population. SNPs were genotyped in 344 MMT patients. In this study, we identified a functional SNP rs55944529 in the DAO gene that reveals a modest but significant association with the methadone dosage in the recessive model of analysis (P = 0.003) and plasma concentrations (P = 0.003) in MMT patients. However, it did not show association with plasma methadone concentration in multiple linear regression analysis. It is also associated with the methadone adverse reactions of dry mouth (P = 0.002), difficulty with urination (P = 0.0003) in the dominant model, and the withdrawal symptoms of yawning (P = 0.005) and gooseflesh skin (P = 0.004) in the recessive model. Our results suggest a role of the indirect regulatory mechanisms of the NMDA reporter, possibly via the DAO genetic variants, in the methadone dose and some adverse reactions in MMT patients.

Genetic variants in NECTIN4 encoding an adhesion molecule are associated with continued opioid use.

Methadone is a synthetic opioid used as maintenance treatment for patients addicted to heroin. Skin irritation is one of the adverse events caused by opioid use. 344 methadone maintenance treatment (MMT) patients were recruited with records and measurements on methadone dose, plasma methadone concentrations, and treatment emergent symptom scales (TESS). 15 patients reported with skin irritation. Five SNPs located within the NECTIN4 genetic region were genotyped. The NECTIN4 gene within the adherens junction interaction pathway was associated with methadone dose in pathway-based genome wide association analyses (P = 0.0008). Three highly-linked SNPs, rs11265549, rs3820097, and rs4656978, were significantly associated with methadone dose (P = 0.0003), plasma concentrations of R,S-methadone (P = 0.0004) and TNF-α (P = 0.010) in all 344 MMT patients, and with self-report skin irritation symptom scores (P = 0.010) in the 15 MMT patients who reported with skin irritation. To identify the possible roles of plasma level of Nectin-4 in the responses to MMT and opioid use, additional age- and gender-matched 51 controls and 83 methadone-free abstinent former heroin users were recruited. Plasma level of Nectin-4 was the highest in MMT patients among the three groups. The results suggest involvement of genetic variants on NECTIN4 in methadone dose. Plasma Nectin-4 level is likely an indicator for continued use of opioids.

Genetic polymorphisms in the opioid receptor delta 1 (OPRD1) gene are associated with methadone dose in methadone maintenance treatment for heroin dependence.

Delta opioid receptor (DOR) is well known to be involved in heroin dependence. This study tested the hypothesis that single nucleotide polymorphisms (SNPs) in the opioid receptor delta 1 (OPRD1) gene coding region are associated with treatment responses in a methadone maintenance therapy (MMT) cohort in Taiwan. Three hundred forty-four MMT patients were recruited. Diastolic/systolic blood pressure, heart rate, methadone dosage, and plasma concentrations of methadone were recorded. Twenty-five SNPs located within the OPRD1 genetic region were selected and genotyped from the genomic DNA of all 344 participants. After pairwise tagger analyses, tagger SNP rs204047 showed a significant association with methadone dosage (P = 0.0019), and tagger SNPs rs204047 and rs797397 were significantly associated with plasma R, S-methadone concentrations (P < 0.0006) in patients tested negative in the urine morphine test, which indicated patients with a better response to MMT. The major genotype carriers showed a higher methadone dosage and higher plasma concentrations of R, S-methadone than the minor genotype carriers. The results indicated that OPRD1 genetic variants were associated with methadone dosage and methadone plasma concentration in MMT patients with a negative morphine test result.

GRK5 Is Associated with the Regulation of Methadone Dosage in Heroin Dependence.

Background: There is no countable biomarker for opioid dependence treatment responses thus far. In this study, we recruited Taiwanese methadone maintenance treatment patients to search for genes involving the regulatory mechanisms of methadone dose by genome-wide association analyses. Methods: A total of 344 Taiwanese methadone maintenance treatment patients were included in a genome-wide association study. The involvement of GRK5 in opioid dependence was then further confirmed by gene expression study on lymphoblastoid cell lines derived from 3 independent age- and gender-matched groups: methadone maintenance treatment patients, medication-free former heroin abusers, and normal controls. Results: The results indicated that GRK5, the gene encoding an enzyme related to µ-opioid receptor desensitization, is associated with methadone dose by additive model of gene-based association analysis (P=6.76×10-5). We found that 6 of the 55 single nucleotide polymorphisms from the genome-wide genotype platform and 2 single nucleotide polymorphisms from the 29 additionally selected single nucleotide polymorphisms were significantly associated with methadone maintenance dose in both genotype and allele type (P ≤ .006), especially in patients who tested negative in the urine morphine test. The levels of GRK5 gene expression were similar between methadone maintenance treatment patients and medication-free former heroin abusers. However, the normal controls showed a significantly lower level of GRK5 gene expression than the other groups (P=.019). Conclusions: The results suggested an important role for GRK5 in the regulatory mechanisms of methadone dose and course of heroin dependence.

The association of genetic polymorphisms in the κ-opioid receptor 1 gene with body weight, alcohol use, and withdrawal symptoms in patients with methadone maintenance.

Methadone is a synthetic opioid that binds to the κ-opioid receptor with a low affinity. This study tested the hypotheses that the genetic polymorphisms in the κ-opioid receptor 1 (OPRK1) gene region are associated with methadone treatment responses in a Taiwan methadone maintenance treatment (MMT) cohort. Seventeen single nucleotide polymorphisms (SNPs) in OPRK1 were selected and genotyped on DNA of 366 MMT patients. Six SNPs from rs7843965 to rs1051660 (intron 2 to exon 2) were significantly associated with body weight (P < 0.007). A haplotype of 4 SNPs rs7832417-rs16918853-rs702764-rs7817710 (exon 4 to intron 3) was associated with bone or joint aches (P ≤ 0.004) and with the amount of alcohol use (standard drinks per day; global P < 0.0001). The haplotype rs10958350-rs7016778-rs12675595 was associated with gooseflesh skin (global P < 0.0001), yawning (global P = 0.0001), and restlessness (global P < 0.0001) withdrawal symptoms. The findings suggest that genetic polymorphisms in OPRK1 were associated with the body weight, alcohol use, and opioid withdrawal symptoms in MMT patients.

Functional genetic polymorphisms in CYP2C19 gene in relation to cardiac side effects and treatment dose in a methadone maintenance cohort.

Abstract Methadone maintenance therapy is an established treatment for heroin dependence. This study tested the influence of functional genetic polymorphisms in CYP2C19 gene encoding a CYP450 enzyme that contributes to methadone metabolism on treatment dose, plasma concentration, and side effects of methadone. Two single nucleotide polymorphisms (SNPs), rs4986893 (exon 4) and rs4244285 (exon 5), were selected and genotyped in 366 patients receiving methadone maintenance therapy in Taiwan. The steady-state plasma concentrations of both methadone and its EDDP metabolite enantiomers were measured. SNP rs4244285 allele was significantly associated with the corrected QT interval (QTc) change in the electrocardiogram (p=0.021), and the Treatment Emergent Symptom Scale (TESS) total score (p=0.021) in patients who continued using heroin, as demonstrated with a positive urine opiate test. Using the gene dose (GD) models where the CYP2C19 SNPs were clustered into poor (0 GD) versus intermediate (1 GD) and extensive (2 GD) metabolizers, we found that the extensive metabolizers required a higher dose of methadone (p=0.035), and showed a lower plasma R-methadone/methadone dose ratio (p=0.007) in urine opiate test negative patients, as well as a greater QTc change (p=0.008) and higher total scores of TESS (p=0.018) in urine opiate test positive patients, than poor metabolizers. These results in a large study sample from Taiwan suggest that the gene dose of CYP2C19 may potentially serve as an indicator for the plasma R-methadone/methadone dose ratio and cardiac side effect in patients receiving methadone maintenance therapy. Further studies of pharmacogenetic variation in methadone pharmacokinetics and pharmacodynamics are warranted in different world populations.

CYP1A2 genetic polymorphisms are associated with early antidepressant escitalopram metabolism and adverse reactions.

AIM: The liver CYP1A2 enzyme may metabolize antidepressant escitalopram (S-CIT) to S-desmethylcitalopram (S-DCIT) and S-didesmethylcitalopram (S-DDCIT). This study tested whether genetic polymorphisms in the CYP1A2 gene are associated with the treatment responses to S-CIT. MATERIALS & METHODS: Ten SNPs in CYP1A2 were selected and genotyped in 158 patients under S-CIT treatment. The serum levels of S-CIT and its metabolites were measured by HPLC. RESULTS: CYP1A2 SNPs rs2069521, rs2069526, rs4646425 and rs4646427 are significantly associated with the metabolic ratios of S-DDCIT/S-DCIT (p = 0.002, 0.018, 0.008 and 0.004, respectively) at week 2 of treatment. Carriers of the allele types associated with higher S-DDCIT/S-DCIT ratios had more severe side effects. CONCLUSION: These results suggest that genetic variants in CYP1A2 may be indicators for S-CIT metabolism and that the fast metabolizers may experience more severe adverse reactions in the early stages of S-CIT treatment. Original submitted 27 December 2012; Revision submitted 15 May 2013.

UGT2B7 genetic polymorphisms are associated with the withdrawal symptoms in methadone maintenance patients.

AIM: To test whether the genetic polymorphisms within the gene encoding the UGT2B7 gene may have an impact on methadone treatment. MATERIALS & METHODS: Twelve SNPs in UGT2B7 were selected. 366 methadone maintenance treatment patients in Taiwan were recruited and genotyped. RESULTS: In a genotype recessive model, rs6600879, rs6600880, rs4554144, rs11940316, rs7438135, rs7662029, rs7668258, rs7439366, rs4292394 and rs6600893 showed significant associations with severity of withdrawal symptoms (permutation p < 0.002), pupil size (permutation p < 0.048) and tremor (permutation p < 0.008). Haplotypes of GATCAGCCGC and CTCTGATTCT were significantly associated with pupil size score and tremor score (p < 0.034). CONCLUSION: These results suggest that SNPs of the UGT2B7 gene may play important roles in opiate withdrawal symptoms.

Genetic polymorphisms in the opioid receptor mu1 gene are associated with changes in libido and insomnia in methadone maintenance patients.

Methadone, a synthetic racemic opioid that primarily works as a µ-opioid receptor (OPRM1) agonist, is commonly used for the treatment of heroin addiction. Genetic association studies have reported that the OPRM1 gene is involved in the physiology of heroin and alcohol addiction. Our current study is designed to test the hypothesis that genetic polymorphisms in the OPRM1 gene region are associated with methadone dosage, plasma concentrations, treatment responses, adverse reactions and withdrawal symptoms in a methadone maintenance treatment (MMT) cohort from Taiwan. Fifteen OPRM1 single nucleotide polymorphisms (SNPs) were selected and genotyped using DNA samples from 366 MMT patients. The plasma concentrations of methadone and its metabolite were measured by high performance liquid chromatography. The results obtained using dominant model analysis indicate that the OPRM1 SNPs rs1074287, rs6912029, rs12209447, rs510769, rs3798676, rs7748401, rs495491, rs10457090, rs589046, rs3778152, rs563649, and rs2075572 are significantly associated with change-in-libido side effects (adjusted p<0.042). Using recessive model analysis, these SNPs were also found to be significantly associated with insomnia side effects in this cohort (p<0.009). The significance of the insomnia findings was mainly contributed by a subgroup of patients who had a positive urine morphine test (p<0.022), and by individuals who did not use benzodiazepine hypnotics (p<0.034). Our current data thus suggest that genetic polymorphisms in OPRM1 may influence the change-in-libido and insomnia side effects sometimes found in MMT patients.

Genetic polymorphisms in CYP3A4 are associated with withdrawal symptoms and adverse reactions in methadone maintenance patients.

AIM: Methadone maintenance therapy is one of the standard treatments for heroin addiction. The isozyme CYP3A4 of the CYP system is one of the metabolic enzymes, as well as CYP2B6, responsible for the metabolism of methadone. The aim of the present study is to evaluate the potential use of genetic polymorphisms in CYP3A4 as biomarkers for the prediction of methadone treatment responses. MATERIALS & METHODS: A total of 366 Han Chinese methadone maintenance treatment patients in Taiwan were recruited in this study. Main clinical assessments included the clinical opioid withdrawal scale (COWS), the treatment emergent symptom scale (TESS) and the plasma concentrations of methadone and its metabolites. Genetic associations of six SNPs in the CYP3A4 gene were calculated using a general linear model. RESULTS: Genotypes and allele types of rs4646440 and rs2242480 were found to be significantly associated with the severity of withdrawal symptoms rated by COWS (p = 0.012, 0.0096, 0.017 and 0.012, respectively) as well as the side effects rated by TESS (p = 0.0089, 0.028, 0.0027 and 0.0085, respectively). The allele types associated with more severe withdrawal symptoms are also associated with more severe side effects and less betel nut (Areca catechu) use (p = 0.009 for rs4646440, p = 0.0063 for rs2242480). Further analyses on specific withdrawal symptoms in COWS showed that the genetic variants in rs4646440 are significantly associated with heart rate (allele type p = 0.0019). CONCLUSION: These results suggested that genetic variants in the CYP3A4 gene may be useful indicators for the severity of side effects and withdrawal symptoms for methadone treatment.

CYP2B6 polymorphisms influence the plasma concentration and clearance of the methadone S-enantiomer.

Methadone is a racemic compound composed of the R-form and S-form enantiomers. The drug is usually used in maintenance therapy for the heroin-addicted patients. In our previous study, we found that the cytochrome P-450 (CYP) isozyme 2B6 preferentially metabolizes the S-methadone enantiomer. We thus tested whether CYP2B6 gene polymorphisms had any influence on the concentration or clearance of methadone. Ten single nucleotide polymorphisms within this gene region were evaluated in 366 patients undergoing methadone maintenance for at least 3 months. The plasma steady-state levels of racemic methadone and its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine were then measured in these individuals. The rs10403955 (T allele in intron 1), rs3745274 (G allele in exon 4), rs2279345 (T allele in intron 5), and rs707265 (A allele in exon 9) CYP2B6 allele types were found to be significantly associated with a higher clearance, a lower plasma concentration, and a lower concentration-to-dosage (C/D) ratio of (S)-methadone (P < 0.0017). Two haplotype blocks of a trinucleotide haplotype (rs8100458-rs10500282-rs10403955 in intron 1) and a hexanucleotide haplotype (rs2279342-rs3745274-rs2279343-rs2279345-rs1038376-rs707265 from intron 2 to exon 9) were constructed within CYP2B6. The major combinations of T-T-T and A-G-A-T-A-A of these particular haplotypes showed significant associations with the plasma concentrations of S-methadone and its C/D ratio (P < 0.0001, respectively). We conclude that genetic polymorphisms in the CYP2B6 gene may therefore be indicators of the clearance, plasma concentration and C/D ratio of S-methadone.

ABCB1 gene polymorphisms are associated with the severity of major depressive disorder and its response to escitalopram treatment.

OBJECTIVE: ATP-binding cassette, sub-family B (MDR/TAP), member 1 (ABCB1) is a drug transporter protein expressed on the epithelial cells of the intestine and the endothelial cells of the blood-brain barrier. Intestinal ABCB1 actively transports drugs from the cell membrane and prevents them from entering the blood stream whereas the blood-brain barrier ABCB1 prevents drugs from entering the central nervous system. In this study, we tested whether genetic polymorphisms within the ABCB1 gene are associated with the severity of depression and the effectiveness of the antidepressant, escitalopram (S-CIT), in treating major depressive disorder (MDD). METHODS: Twenty single nucleotide polymorphisms in the ABCB1 gene were selected and genotyped in 100 MDD patients who had undergone S-CIT treatment continuously for 8 weeks. The serum concentrations of S-CIT and its metabolites (S-desmethylcitalopram and S-didesmethylcitalopram) were then measured at weeks 2, 4, and 8. RESULTS: The ABCB1 genotypes of rs1922242 (P=0.0028) and rs1202184 (P=0.0021) showed significant association with the severity of depressive symptoms as assessed by the Hamilton Rating Scale for Depression adjusted with Hamilton Rating Scale for Anxiety. The haplotype block, rs1882478-rs2235048-rs2235047-rs1045642-rs6949448 (from intron 27 to intron 26), of ABCB1 was found strongly associated with the remission rate (global P=0.003, d.f.=69) in which haplotype T-T-T-C-C was associated with a slower remission rate on S-CIT treatment (P=0.001). The haplotypes may not be indicators of the severity of depression or anxiety. CONCLUSION: Our findings suggest that single nucleotide polymorphisms in the ABCB1 gene may be indicators of the severity of depression and of the likely S-CIT treatment remission response in MDD.

CYP1A2 genetic polymorphisms are associated with treatment response to the antidepressant paroxetine.

AIM: Paroxetine is a drug of choice in the treatment of major depressive disorder (MDD). Its metabolism has recently been reported to be mediated through the CYP enzymes 1A2 and 2D6. In our current study, we tested whether genetic polymorphisms in CYP1A2 are associated with the treatment efficacy and side effects of paroxetine. MATERIALS & METHODS: A total of 241 MDD patients who had taken paroxetine continually for 8 weeks were recruited, and their steady state paroxetine concentrations were measured at weeks 2, 4 and 8. The genotypes of these patients were then assessed for the presence of nine SNPs, which were selected from either the HapMap Chinese ethnic group, the literature report or through their functional role in the CYP1A2 gene. RESULTS: The allele types for SNPs rs4646425 (permutation p = 0.03), rs2472304 (permutation p = 0.01) and rs2470890 (permutation p = 0.004) demonstrated significant associations with paroxetine treatment remission at week 8. Response rates in the Hamilton Rating Scale for Depression (HAM-D) and for The Hamilton Rating Scale for Anxiety (HAM-A) were significantly associated with the SNPs rs4646425 (p = 0.0126 and 0.0088 for HAM-D and HAM-A, respectively) and rs4646427 (p = 0.0067 and 0.0196 for HAM-D and HAM-A, respectively). The inducible SNP rs762551 had a significant association with paroxetine dose at week 4 (permutation p = 0.012). We did not find an association between these SNPs and the side effects or serum concentrations of paroxetine. CONCLUSION: Genetic variants in the CYP1A2 region may be indicators of treatment response in MDD patients to paroxetine.

Genetic polymorphisms of cytochrome P450 enzymes influence metabolism of the antidepressant escitalopram and treatment response.

AIMS: The antidepressant escitalopram (S-CIT) is metabolized by the cytochrome-P450 (CYP) enzymes CYP 2D6, 2C19 and 3A4. This study evaluated the impact of CYP2D6, 2C19 and 3A4 genetic polymorphisms on plasma concentrations of S-CIT and patient treatment response. MATERIALS & METHODS: A total of 100 patients diagnosed with major depressive disorder were recruited to the study and their depression symptoms were assessed using the Hamilton Depression Rating Scale. The genetic polymorphisms *4, *5 and *10 on CYP2D6, *2, *3 and *17 on CYP2C19, and *18 on CYP3A4 were selected based on their function and respective allele frequencies in Asian populations. Polymorphisms were analyzed using the SNPstream genotyping system, PCR and direct sequencing methods. The steady-state serum concentrations of S-CIT and its metabolites S-desmethylcitalopram and S-didesmethylcitalopram were analyzed by HPLC. According to semiquantitative gene dose (SGD) and gene dose (GD) models for allele combinations of these polymorphisms, CYP2D6 was clustered into intermediate (0.5, 1 and 1.5 SGD) and extensive (2 SGD) metabolizers, while CYP2C19 was clustered into poor (0 GD) and extensive (1 and 2 GDs) metabolizers. RESULTS: The group of patients with intermediate CYP2D6 metabolism (0.5 SGD) had a significantly higher frequency of remitters from major depressive disorder during the 8-week treatment (p = 0.0001). Furthermore, CYP2C19 poor metabolizers had significantly higher S-CIT serum levels than did extensive metabolizers at weeks 2, 4 and 8 (p < 0.05). The allele frequencies in CYP3A4*18 and CYP2C19*17 were too low to permit further subgroup analyses. CONCLUSION: Our results suggest that the genetic polymorphisms in CYP2C19 may be influencing S-CIT serum concentrations, and that specific CYP2D6 polymorphisms may be predicting patient treatment outcomes based on gene dosage analyses.

Development of a method to measure methadone enantiomers and its metabolites without enantiomer standard compounds for the plasma of methadone maintenance patients.

A liquid chromatography-photodiode array (LC-PDA) method using a chiral analytical column was developed to determine the plasma levels of enantiomers of methadone and its chiral metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), without the standard compounds of R-form or S-form enantiomers. This method was established by the characteristics of recombinant cytochrome P-450 (CYP) isozymes, where CYP2C19 prefers to metabolize R-methadone and CYP2B6 prefers to metabolize S-methadone. We incubated the racemic methadone standard with either enzyme for 24 h. We identified the retention times of R- and S-methadone to be around 10.72 and 14.46 min, respectively. Furthermore, we determined the retention times of R- and S-EDDP to be approximately 6.76 and 7.72 min, respectively. No interferences were shown through the retention times of morphine, buprenorphine and diazepam. With the high recovery rate of a solid-phase extraction procedure, this method was applied in analyzing plasma concentrations of seven methadone maintenance patients where R- and S-methadone and R- and S-EDDP were 233.4 +/- 154.9 and 185.9 +/- 136.3 ng/mL and 84.4 +/- 99.4 and 37.6 +/- 22.9 ng/mL, respectively. These data suggest that the present method can be applied for routine assay for plasma methadone and EDDP concentrations for patients under treatment.

Pneumococcal pneumonia with empyema and hemolytic uremic syndrome in children: report of three cases.

Streptococcus pneumoniae is an uncommon etiological organism in children with hemolytic uremic syndrome (HUS). Patients with S. pneumoniae-associated HUS commonly have a pneumonia or meningitis. Historically, S. pneumoniae-associated HUS usually has a poor clinical outcome. We report 3 pediatric cases of pneumococcal pneumonia-induced HUS. All 3 patients were <2 years old, had an empyema complicating pneumococcal pneumonia, and developed renal failure with oliguria and required peritoneal dialysis for a period of 9 to 26 days. All children received several transfusions of unwashed packed red cells and platelets. All of the patients survived. Of the 3 cases, 2 had a normal renal function at discharge, and 1 had a mild renal impairment at 16-month follow-up. Our report suggests S. pneumoniae-associated HUS remains a rare but severe complication of invasive pneumococcal infection in children. It is important for pediatricians to note that children with pneumococcal pneumonia with severe hematologic and renal dysfunction should be investigated for evidence of S. pneumoniae-associated HUS.

Intrapleural urokinase treatment in children with complicated parapneumonic effusion.

Intrapleural instillation of fibrinolytic agent such as urokinase has been shown to be effective as an adjunctive therapy for children with complicated parapneumonic effusion and empyema. In this study, we described our experience with the use of intrapleural urokinase in the management of complicated parapneumonic effusion in children. We collected 13 patients with a mean age of 50.8 months with parapneumonic pleural effusion or empyema; all were treated with intrapleural urokinase after poor response to appropriate antibiotics and simple tube drainage. We also reviewed another 13 patients with a mean age of 45.8 months from the clinical records of children hospitalized with the same conditions prior to urokinase introduction as a control group. The mean fluid drained during the first 24 hours and the first 72 hours after urokinase instillation were significantly greater than those during 24 hours before instillation, p=0.002 and p<0.001, respectively. The total volume of fluid drained was also greater in the urokinase group than that in the control group (p<0.001). The mean duration of chest tube drainage was significantly shorter in the urokinase group (8.7 +/- 2.8 days vs. 14.7 +/- 6.1 days, p<0.02). The mean length of hospitalization was also significantly shorter in the urokinase group (15.5 +/- 5.3 days vs. 24.4 +/- 6.9 days, p=0.002). All 13 patients were managed successfully with urokinase treatment without further surgical procedures. None of the patients experienced any side effect or adverse event after urokinase instillation. Two patients of the control group finally underwent surgical debridement. In conclusion, the use of intrapleural urokinase treatment in children with complicated parapneumonic effusion is an effective and safe therapy.

Relationships between the level of matrix metalloproteinase-2 and tumor size of breast cancer.

BACKGROUND: The involvements of matrix metalloproteinase-2 (MMP-2) in the pathogenesis of breast cancers have been established. We determined the concentrations of MMP-2 in serum samples and tumor tissues of breast cancer patients. METHODS: Gelatin zymography and ELISA were used to measure MMP-2 and MMP-9 concentrations in 90 breast cancer patients, including 60 tissue samples and 30 serum samples. RESULTS: ProMMP-2, activated MMP-2, proMMP-9 and activated MMP-9 levels were significantly higher in tumor tissues than that of corresponding paired adjacent normal tissue of 60 breast cancer patients (p<0.01). Further linear regression analysis has showed that the tumor size positively correlated with MMP-2 level in tumor tissue samples (R=0.55, p<0.0001), as well as with that of in serum samples (R=0.398, p=0.032). In addition, further statistical analysis for clinic pathological parameters revealed that MMP-2 level was significantly increased in patients with metastasis (p<0.05). Furthermore, MMP-2 level was significantly different between tumor grades (p=0.006). CONCLUSIONS: MMP-2 levels in serum and tumor tissue might reflect the severity of invasion of breast cancer and various MMP inhibitors might be selectively used as potential anti-metastasis agents according to tumor size.

Phylogenetic analysis of influenza B virus in Taiwan, 1997 to 2001.

Seventeen strains of influenza B virus were isolated and identified from 1997 to 2001. Throat swabs were collected in children who presented in medical centers in both central and northern parts of Taiwan. To clarify the molecular characteristics of these isolates, both partial hemagglutinin (HA) gene and nonstructural (NS) gene nucleotide sequences were cloned and subjected to nucleotide sequence analysis. The phylogenetic analysis of the HA gene revealed that 16 out of 17 strains were similar to B/Yamagata/16/88-like virus, but grouped together to form an independent cluster. Only one strain, B/Taiwan/21706/97, was similar to the B/Victoria/2/87-like lineage. In addition, all isolates, except for B/Taiwan/21706/97, were similar to B/Beijing/184/93 and B/Yamanashi/166/98, which were chosen as the recommended vaccine strains in 1999 and 2001. In contrast, the NS gene of these isolates was evolved from B/Guangdong/8/93. Based on the accumulation of antigenic drift in our isolates, we conclude that influenza B virus is still prevalent in Taiwan and the accumulation of nucleotide mutations indicated that our isolates form a new cluster that evolved from the YA88 lineage.