Aerobic Biodegradation of OCDD by P. Mendocina NSYSU: Effectiveness and Gene Inducement Studies.

The goals of this study were to assess the effectiveness of (1) enhancing octachlorinated dibenzo-p-dioxin (OCDD) biodegradation under aerobic conditions by Pseudomonas mendocina NSYSU (P. Mendocina NSYSU) with the addition of lecithin, and (2) inducing OCDD ring-cleavage genes by pentachlorophenol (PCP) and OCDD addition. P. Mendocina NSYSU could biodegrade OCDD via aerobic cometabolism and lecithin was used as a primary substrate. Approximately 74 and 67% of OCDD biodegradation was observed after 60 days of incubation with lecithin and glucose supplement, respectively. Lecithin was also used as the solubilization additive resulting in OCDD solubilization and enhanced bioavailability of OCDD to P. Mendocina NSYSU. Two intradiol and extradiol ring-cleavage dioxygenase genes (Pmen_0474 and Pmen_2526) were identified from gene analyses. Gene concentration was significantly enhanced after the inducement by PCP and OCDD. Higher gene inducement efficiency was obtained using PCP as the inducer, and Pmen_2526 played a more important role in OCDD biodegradation.

Enhanced anaerobic biodegradation of OCDD-contaminated soils by Pseudomonas mendocina NSYSU: microcosm, pilot-scale, and gene studies.

In this study, microcosm and pilot-scale experiments were performed to investigate the capability and effectiveness of Pseudomonas mendocina NSYSU (P. mendocina NSYSU) on the bioremediation of octachlorodibenzo-p-dioxin (OCDD)-contaminated soils. The objectives were to evaluate the (1) characteristics of P. mendocina NSYSU, (2) feasibility of enhancing OCDD biodegradation with the addition of P. mendocina NSYSU and lecithin, and (3) variation in microbial diversity and genes responsible for the dechlorination of OCDD. P. mendocina NSYSU was inhibited when salinity was higher than 7%, and it could biodegrade OCDD under reductive dechlorinating conditions. Lecithin could serve as the solubilization agent causing the enhanced solubilization and dechlorination of OCDD. Up to 71 and 62% of OCDD could be degraded after 65 days of incubation under anaerobic conditions with and without the addition of lecithin, respectively. Decreased OCDD concentrations caused significant increase in microbial diversity. Results from the pilot-scale study show that up to 75% of OCDD could be degraded after a 2.5-month operational period with lecithin addition. Results from the gene analyses show that two genes encoding the extradiol/intradiol ring-cleavage dioxygenase and five genes encoding the hydrolase in P. mendocina NSYSU were identified and played important roles in OCDD degradation.

Environmental exposure to lead and progressive diabetic nephropathy in patients with type II diabetes.

Studies indicate that environmental exposure to lead is associated with reduced renal function. Whether lead affects progressive diabetic nephropathy is unclear. Eighty-seven patients with type II diabetes and diabetic nephropathy (serum creatinine of 1.5-3.9 mg/dl) with normal body lead burden and no lead exposure history were observed over a 12-month period. Thirty subjects with high normal body lead burdens (80-600 microg) were randomly assigned to a chelation and control group. For 3 months, the 15 chelation-group patients underwent lead-chelation therapy with calcium disodium ethylenediaminetetraacetic acid weekly until body lead burden fell <60 microg, and the 15 control group subjects received a weekly placebo. During the following 12 months, renal function was regularly assessed at 3-month intervals. The primary outcome was an elevation of serum creatinine to 1.5 times baseline value during the observation period. A secondary outcome was temporal changes in renal function following chelation therapy. Twenty-six patients achieved the primary outcome. Basal blood lead levels and body lead burden were the most important risk factors in predicting progressive diabetic nephropathy. Following chelation, the rates of decline in glomerular filtration rates in the chelation group and the control group, respectively, were 5.0+/-5.7 ml and 11.8+/-7.0 ml/min/year/1.73 m(2) of body surface area (P=0.0084) during follow-up, although both groups had similar rates of progression of renal function during the 12-month observation period. We concluded that low-level environmental lead exposure accelerates progressive diabetic nephropathy and lead-chelation therapy can decrease its rate of progression.

Aristolochic acid-related nephropathy associated with the popular Chinese herb Xi Xin.

Chinese herbs nephropathy is known as a subacute interstitial nephritis attributed to aristolochic acid. This work describes the case of a 49-year-old male who displayed subacute renal failure induced by ingestion of herbal powder containing Xi Xin, which includes aristolochic acid. Since Xi Xin is a common ingredient in traditional formulae, care needs to be taken in the future to identify the aristolochic acid concentration of different components of Xi Xin. Xi Xin containing aristolochic acid should be forbidden for use in remedies in order to prevent the harmful effects of aristolochic acid.

Global distribution of atrial ectopic foci triggering recurrence of atrial tachyarrhythmia after electrical cardioversion of long-standing atrial fibrillation: a bi-atrial basket mapping study.

OBJECTIVES: The objective of this study was to assess the spatial distribution of atrial ectopic foci potentially triggering recurrent atrial tachyarrhythmias after electrical cardioversion of long-standing atrial fibrillation (AF). BACKGROUND: It remains unknown whether targeted ablation of atrial ectopic foci concentrated in the pulmonary veins is feasible in patients with long-standin

Lead chelation therapy and urate excretion in patients with chronic renal diseases and gout.

BACKGROUND: It is known that chronic renal insufficiency (CRI) patients with gout may have subtle lead poisoning. In addition, gout episodes frequently aggravate progressive renal insufficiency because of the use of nephrotoxic drugs and urate deposition. Our study was arranged to evaluate the causal effect of environmental lead exposure on urate excretion in CRI patients. METHODS: A cross-section study and a randomized, controlled trial were performed. Initially, 101 patients with CRI and without a history of previous lead exposure received ethylenediaminetetraacetic acid mobilization tests to assess body lead stores (BLS). Then, a clinical trial was performed; 30 CRI patients with gout and high-normal BLS and the changes of urate excretion in these patients were compared before and after lead chelating therapy. The treated group received four-week chelating therapy, and the control group received a placebo therapy. RESULTS: The BLS of patients with CRI and gout was higher than that of patients with CRI only, and none had subtle lead poisoning. The BLS, not the blood lead level (BLL), significantly correlated to indices of urate excretion in all CRI patients after related factors were adjusted. In addition, after lead chelating therapy, urate clearance markedly improved after a reduction of the BLS of patients with CRI and gout (study group 67.9 +/- 80.0% vs. control group 1.2 +/- 34.0%, P = 0.0056). CONCLUSION: Our findings suggest that the chronic low-level environmental lead exposure may interfere with urate excretion of CRI patients. Importantly, the inhibition of urate excretion can be markedly improved by lead chelating therapies. These data shed light on additional treatment of CRI patients with gout; however, more studies are needed to confirm our findings.

Environmental lead exposure and progressive renal insufficiency.

BACKGROUND: Several recent studies show that serum creatinine level or creatinine clearance is inversely associated with blood lead levels. However, the studies did not allow direct inferences about causality. OBJECTIVE: To evaluate the relation between body lead burden (BLB) and progressive renal insufficiency in patients without previous heavy lead exposure. DESIGN: A prospective, longitudinal study with a controlled clinical trial. PATIENTS: One hundred ten patients with chronic renal insufficiency (serum creatinine level, 133-354 micromol/L [1.5-4.0 mg/dL]) and normal BLB (EDTA mobilization tests, <600 microg per 72-hour urine collection) and without a history of previous heavy lead exposure were divided into 2 groups according to BLB: the high-normal BLB group (BLB > or =80 microg and <600 microg) and the low BLB group (BLB <80 microg). Patients were prospectively followed up for 2 years. MAIN OUTCOME MEASURES: The primary outcome was a 1.5 times increase in the initial creatinine level. The secondary outcome was a change over time in the value of creatinine clearance. At the end of follow-up, a 3-month clinical trial with chelation therapy for patients with high-normal BLB was performed to clarify the role of environmental lead exposure in progressive renal insufficiency. RESULTS: Fifteen patients (14 in the high-normal BLB group and 1 in the low BLB group) reached the primary outcome within 24 months. Renal outcome was significantly better in the low BLB group (P<.001). From month 12 to month 24, renal function of high-normal BLB patients had a greater rate of progressive renal insufficiency than that of low BLB patients. In the Cox multivariate regression analysis, BLB was the most important risk factor for determining the progression of renal insufficiency. After chelation therapy, significant improvement in renal function was noted. In addition, the effect of improving renal function lasted for more than 12 months in these patients. CONCLUSIONS: Long-term low-level environmental lead exposure may subtly affect progressive renal insufficiency in the general population. Progressive renal insufficiency may be improved for at least 1 year after lead chelating therapy. Further investigations are needed to clarify this observation.

Cardiac rhythm disturbances in patients with left atrial isomerism.

This long-term study sought to determine the clinical implication of defective sinus node and AV conduction tissue in patients with left atrial isomerism (LAI). From 1984 to 1998, a total of 22 patients were identified as LAI. Patient age at the last follow-up ranged from 2 to 276 months (90+/-70 months). Associated cardiac anomalies were interruption of the inferior vena cava (n = 18, 82%), common atrium (n = 9, 41%), AV canal (n = 14, 64%), double-outlet right ventricle (n = 8, 36%), and pulmonary stenosis (n = 15, 68%). Palliative interventions were performed in 16 patients (Fontan-type operation in 4 patients, shunt followed by Fontan-type operation in 2, repair of septal defect in 4, and extracardiac intervention in 6). During the follow-up, over half of the patients (n = 14, 64%) developed bradyarrhythmia (onset age: from 1 to 264 months; median 78 months): junctional rhythm (n = 11), sinus bradycardia (n = 8) (5 patients also had junctional rhythm), and AV block (n = 2, both also had junctional rhythm). The probability free from bradyarrhythmia was 80% and 46% at the age of 2 and 6 years, respectively. None of the bradyarrhythmias were directly related to open-heart surgery. Besides, junctional ectopic tachycardia occurred after Fontan-type operation in three of six patients. In two patients, a Mahaim-like pathway was identified during the electrophysiological study. The patients with LAI had a high probability of developing bradyarrhythmias due to abnormal sinus node function. Varied AV conduction abnormalities may include compromised AV conduction, junctional ectopic tachycardia after Fontan-type operation, and an association of Mahaim-like pathway.

Severe reversible bone marrow suppression induced by Selaginella doederleinii.

CASE REPORT: We report a 52-year-old female patient with cholangiocarcinoma who developed severe bone marrow suppression after taking Selaginella doederleinii as an alternative anticancer treatment. She developed severe pancytopenia with initial presentations of skin ecchymosis, itching, and gum bleeding 2 weeks after taking Selaginella doederleinii daily. Bone marrow smear and biopsy showed severe hypocellularity with no malignant cell infiltration. Approximately 1 week after stopping Selaginella doederleinii, her hemogram returned to previous levels. Selaginella doederleinii, a popular anticancer herb, may contain an as yet unidentified substance that contributes to reversible bone marrow suppression.

Chelation therapy for patients with elevated body lead burden and progressive renal insufficiency. A randomized, controlled trial.

BACKGROUND: Nephropathy is known to occur in persons exposed to high levels of lead, but the question of whether long-term exposure to low levels of environmental lead is associated with impaired renal function remains controversial. OBJECTIVE: To examine whether chelation therapy slows the progression of renal insufficiency in patients with mildly elevated body lead burden. DESIGN: Randomized, controlled trial. SETTING: Academic medical center in Taiwan. PATIENTS: 32 patients with chronic renal insufficiency (serum creatinine level > 132.6 micromol/L [1.5 mg/dL] and < 353.8 micromol/L [4.0 mg/dL]), mildly elevated body lead burden (> 0.72 micromol [150 microg] of lead per 72-hour urine collection and < 2.90 micromol [600 microg] of lead per 72-hour urine collection [EDTA mobilization tests]), and no history of heavy lead exposure. INTERVENTION: The treatment group received 2 months of chelation therapy; the control group received no therapy. MEASUREMENTS: The reciprocal of serum creatinine (1/Cr) was used as an index of progressive renal insufficiency. RESULTS: Rates of progression of renal insufficiency were similar in the treatment group and the control group during a 12-month baseline observation period (1/Cr, 0.000054 L/micromol per month compared with 0.000046 L/micromol per month; P > 0.2). After the 2-month treatment period, improvement in renal function was greater in the treatment group than in the control group. In the 12 months after the treatment period, renal insufficiency progressed more slowly in the treatment group than in the control group (1/Cr, 0.000033 +/- 0.00038 L/micromol per month compared with 0.000045 +/- 0.000038 L/micromol per month; P = 0.0030). CONCLUSION: Chelation therapy seems to slow the progression of renal insufficiency in patients with mildly elevated body lead burden. This implies that long-term exposure to low levels of environmental lead may be associated with impaired renal function in patients with chronic renal disease.

Disappearance of immune deposits with EDTA chelation therapy in a case of IgA nephropathy.

In this report, we describe the development of renal function impairment in a 33-year-old patient with mesangial IgA nephropathy and a history of recent gout. Increased body lead burden was identified with a positive EDTA mobilization test. The patient was treated with 1 g of edetate disodium calcium weekly for 2 months until normalization of urinary lead excretion. Improvement of renal function and proteinuria were noted. It was even more interesting to find that both immunofluorescence and electron microscopy studies of the second biopsy specimen revealed the loss of previous mesangial immune deposits. Our case demonstrated that lead may be a nonspecifically damaging factor related to the deterioration of renal function in patients with preexisting renal disease. Moreover, the disappearance of mesangial immune deposits after chelation therapy has not been previously documented. The pathogenetic basis of this observation is unknown, and its causal relationship with lead requires further elucidation.

Nicotine analysis of commercial tobacco products.

The use of AOAC standard methods for the determination of nicotine in commercial tobacco products is shown to be inappropriate. The methods do not provide for suitable sample preparation of these products for the analysis and, in addition, they yield high results. Evidence is presented that the nicotine or total alkaloids measured includes artifact nicotine. The distillation method was developed at a time when the complex alkaloid chemistry of tobacco was unknown, and does not take into consideration the possible contribution of substances in tobacco capable of contributing falsely to the result. The Cundiff-Markunas method, developed more recently, also fails to account for this effect--probably because it was designed to produce results matching those of the distillation method. Replacement of the standard methods is proposed and some alternative procedures are suggested.