Acute oxalate nephropathy induced by star fruit in rats

In this study, we intend to establish a connection between star fruit and acute oxalate nephropathy and also investigate predisposing factors for its development. Male Sprague-Dawley rats of 180 to 200 g were assigned to four groups; namely, control, experimental, fasting, and water-deprivation groups. The former two groups were subjected to both fasting and water deprivation, whereas the latter two groups were subjected to either fasting or water deprivation, respectively. Except for tap water for controls, the remaining groups were administered 4 mL/100 g of body weight of sour star fruit juice with an oxalate concentration of 2.46 g/dL. After these procedures, serial measurement of serum creatinine levels and kidney pathological examination were performed. Peak serum creatinine levels in the control, experimental, fasting, and water-deprivation groups were 0.50 +/- 0.04, 1.46 +/- 0.26, 0.68 +/- 0.20, and 0.52 +/- 0.08 mg/dL, respectively. The experimental group had a greater peak serum creatinine level (P < 0.05). Mean serum creatinine levels of the experimental group days 0, 1, 2, 3, 4, and 5 were 0.43 +/- 0.03, 1.11 +/- 0.18, 1.31 +/- 0.27, 1.16 +/- 0.28, 0.8 +/- 0.26, and 0.82 +/- 0.28 mg/dL, respectively. Mean serum creatinine levels days 1 to 3 were greater than that day 0 (P < 0.05). Pearson's correlation analysis of peak serum creatinine level and kidney weight for the experimental group showed a significant correlation (R = 0.75; P < 0.05; n = 9). In addition to typical changes of oxalate nephropathy, kidney pathological examination showed many refractile oxalate crystals with all rainbow colors under polarized light microscopy in the experimental group. In conclusion, sour star fruit with abundant oxalate contents could cause acute oxalate nephropathy in rats under the conditions of fasting and water deprivation.

The coronary delivery of marrow stromal cells for myocardial regeneration: pathophysiologic and therapeutic implications

OBJECTIVES

Bone marrow stromal cells contain "adult stem cells." We tested the hypothesis that coronary-infused bone marrow stromal cells may populate the infarcted heart and undergo milieu-dependent differentiation to regenerate functional tissues with different phenotypic features.

METHODS

Isogenic adult rats were used as donors and recipients to simulate autologous transplantation clinically. Myocardial infarction was created by proximal occlusion of left coronary artery in 12 recipient rats. Isolated bone marrow stromal cells were purified, expanded, and retrovirally transduced with LacZ reporter gene for cell labeling. Stromal cells were then infused into the briefly distally clamped ascending aorta of recipient rats 2 weeks after left coronary artery ligation. The hearts were harvested immediately (n = 2) or 4 weeks (n = 10) later to trace the implanted cells and identify their phenotypes.

RESULTS

Viable cells labeled with LacZ reporter gene were identified in 8 recipient hearts. Immediately after cell infusion, the labeled cells were trapped within the coronary capillaries. After 4 weeks, they could be detected individually or in clusters within myocardial scar expressing fibroblastic phenotype or outside the infarction area with morphologic features of normal cardiomyocytes. Some were incorporated into endocardium and capillary endothelium.

CONCLUSIONS

Our findings suggest that bone marrow stromal cells can traffic through the coronary system to the injured heart and form cardiomyocytes or fibroblasts, depending on the specific microenvironment. Endothelial progenitor cells in the stromal cell population may be involved in the postinfarction neovascularization process. Whether therapeutic use of bone marrow stromal cells can improve the myocardial healing and remodeling process after infarction is worthy of further investigation.

Stopped-flow kinetic study of the H2O2 oxidation of substrates catalyzed by microperoxidase-8

We have studied the oxidation of microperoxidase-8 (MP-8) by H2O2 and the subsequent reaction of the intermediates with substrate by stopped-flow experiments. Oxidation of MP-8 by H2O2 gives two intermediates, I and II. The observed rate constant for the formation of I is linearly dependent on [H2O2] and exhibits a bell-shaped dependence on pH with pKa values of 8.90 and 10.60, which are attributed to the deprotonation of MP-bound H2O2 and H2O, respectively. The observed rate constant for the conversion of I to II is independent of [H2O2], but increases sharply at pH>9.0. The predominant forms of the intermediate at pH 7.0 and 10.7 are I and II, respectively. Addition of substrate to the intermediates at pH 9.0 gives rise to three distinct stages, corresponding to the three steps (in decreasing order of rate): I-->II*, II-->MP, and II*-->MP. The rates of these steps are all linearly dependent on the substrate concentration and each individual rate constant has been determined. Substrate reactivity at pH 10.7 covers over two orders of magnitude, ranging from 1.36 x 10(7) M(-1) s(-1) for 1-naphthol to 4.03 x 10(4) M(-1) s(-1) for ferrocyanide. The substrate reactivity is linearly correlated with its reduction potential, indicating that an electron transfer process is involved in the rate-limiting step.

Genetic modification of hematopoietic progenitor cells for combined resistance to 4-hydroperoxycyclophosphamide, vincristine, and daunorubicin

AIM

To investigate whether human peripheral blood hematopoietic progenitor cells (PBPC) modified with human aldehyde dehydrogenase class-3 gene (ALDH-3) and multidrug resistance gene 1 (MDR1) would increase chemotherapy resistance to 4-hydroperoxycyclophosphamide (4-HC) and -glycoprotein effluxed drugs.

METHODS

A bicistronic retroviral vector G1Na-ALDH3-IRES-MDR1 cDNA was constructed and used to transfect the packaging cell lines PA317 by electroporation. CD34+ PBPC were isolated with a high-gradient magnetic cell sorting system (MACS), and then were transfected with supernatant of retrovirus containing human ALDH-3 and MDR1 cDNA. PCR, RT-PCR, Southern blot, Northern blot, FACS, and MTT assay were used to evaluate the transfection and expression of the transgene in target cells.

RESULTS

The bicistronic retroviral vector construction was verified by PCR and restriction endonuclease analysis. Dual drug resistance genes were integrated into the genomic DNA of CD34+ PBPC and expressed efficiently. The efficiency of gene transfection in CD34+ PBPC was tested to be 18 % on colonies. Nested PCR and Neor rescue assay indicated that no helper virus was present in this system. Compared with the untransduced cells, transgene recipient cells conferred 4.5-fold resistance to 4-HC, 6.6-fold and 7.8-fold resistance to P-glycoprotein effluxed drug, vincristine and daunorubicin, respectively.

CONCLUSION

Efficient transduction of two different types of drug resistance genes into human peripheral blood hematopoietic progenitor cells and the co-expression may decrease cumulative myelosuppression of combination chemotherapy.

Ascending aorta to lower limbs revascularization for reoperation via ministernotomy

The extra-anatomic bypasses, femorofemoral or axillofemoral, have been performed in selected patients for lower extremity revascularization of aortoiliac occlusion. However, significant graft occlusion rate does exist and reoperation constitutes an increasing proportion of vascular surgery practice. We presented our experience in a high-risk patient who received bypass surgery for the third time using the ascending aorta as the source of inflow with good result.

Field tracer-transport tests in unsaturated fractured tuff

This paper presents the results of a field investigation in the unsaturated, fractured welded tuff within the Exploratory Studies Facility (ESF) at Yucca Mountain, NV. This investigation included a series of tests during which tracer-laced water was released into a high-permeability zone within a horizontal injection borehole. The tracer concentration was monitored in the seepage collected in an excavated slot about 1.6 m below the borehole. Results showed significant variability in the hydrologic response of fractures and the matrix. Analyses of the breakthrough curves suggest that flow and transport pathways are dynamic, rather than fixed, and related to liquid-release rates. Under high release rates, fractures acted as the predominant flow pathways, with limited fracture-matrix interaction. Under low release rates, fracture flow was comparatively less dominant, with a noticeable contribution from matrix flow. Observations of tracer concentrations rebounding in seepage water, following an interruption of flow, provided evidence of mass exchange between the fast-flowing fractures and slow- or non-flowing regions. The tests also showed the applicability of fluorinated benzoate tracers in situations where multiple tracers of similar physical properties are warranted.

Ocular manifestations of tuberculosis

OBJECTIVE

To present the clinical and histopathologic findings in five cases of tuberculosis (TB) with various ocular manifestations.

DESIGN

Observational case series.

METHODS

Retrospective review of clinical findings, course, and treatment of five patients. Diagnostic techniques, including biomicroscopic, histopathologic, and molecular biologic test results, are presented.

MAIN OUTCOME MEASURES

Visual acuity, slit-lamp biomicroscopy, indirect ophthalmoscopy, and fluorescein angiography results.

RESULTS

The ocular manifestations of TB in our patients included panophthalmitis, endophthalmitis, posterior uveitis with choroidal tubercles, keratitis, and a lid mass. Mycobacterium tuberculosis was identified in four cases in ocular specimens using acid-fast bacilli microscopy and in three cases by culture. Rapid diagnosis using polymerase chain reaction was obtained in one case. Extraocular foci of TB were identified in three cases with an intraocular infection at presentation. No patients had the human immunodeficiency virus (HIV) and none were immunocompromised. Two eyes could not be saved using antituberculous treatment because of delayed diagnosis and treatment.

CONCLUSIONS

In this age of the HIV pandemic, TB is becoming more common. Because it is curable, heightened awareness and better understanding of the disease's ocular manifestations should be of concern to all ophthalmologists.

Role of chicken serum in inhibiting Leucocytozoon caulleryi development in Culicoides arakawae infected by membrane-feeding of infective blood meals

Leucocytozoon caulleryi, the most important pathogen of leucocytozoonsis in several Asian countries, is transmitted by Culicoides arakawae. Although the vector blood meal factors that influence the infectivity of L. caulleryi remain poorly understood, the factors in infected chicken serum remain vital. C. arakawae blood-fed through a membrane were used in this experiment to examine the influence of serum factors on L. caulleryi development. Experimental results indicate that C. arakawae were successfully blood-fed through a chicken-egg-shell membrane and the serum factors in infected chicks significantly affected L. caulleryi sporogony. The inhibition effect of serum factors calculated from sporozoite averages was 53.6% +/- 2.2%. The serum factors, including transmission-blocking antibody, require further detailed study.

Tai Chi Chuan training to enhance microcirculatory function in healthy elderly men

OBJECTIVE

To evaluate cutaneous microcirculatory function in geriatric Tai Chi Chuan (TCC) practitioners.

DESIGN

Case-control study.

SETTING

Community setting.

PARTICIPANTS

Ten elderly male TCC practitioners (mean age, 69.9 +/- 1.5 yr) and 10 sedentary men with matched age and body size (mean age, 67.0 +/- 1.0 yr).

INTERVENTION

The TCC group had practiced TCC for 11.2 +/- 3.4 years (mean +/- standard error of the mean), with an exercise frequency of 5.1 +/- 1.8 times weekly. Each session included 20 minutes of warm-up, 24 minutes of TCC practice, and 10 minutes of cool down.

MAIN OUTCOME MEASURES

A graded exercise test with gas analysis was conducted on a bicycle ergometer for each subject. Skin blood flow (SkBF), cutaneous vascular conductance, and skin temperature were measured at rest and during exercise testing. Plasma nitric oxide metabolite was analyzed before and immediately after exercise.

RESULTS

The TCC group had a 34% higher VO(2)peak than the control group; it also had a higher SkBF, cutaneous vascular conductance, and skin temperature than the control group at rest and during exercise; and it also had a higher level of plasma nitric oxide metabolite than the sedentary group at rest and after exercise.

CONCLUSION

Older TCC practitioners had higher cutaneous microcirculatory function during exercise than did their sedentary counterparts. Moreover, this change may be partially mediated by enhancement of nitric oxide release.

[A bicistronic retroviral vector containing MGMT and MDR1 drug resistance genes transfer into human umbilical cord blood CD34+ cells to improve combination chemotherapy tolerance]

To explore whether human umbilical cord blood hematopoietic progenitor cells transduced with human O6-methylguanine-DNA-methyltransferase (MGMT) and multidrug resistance gene (MDR1) increase resistance to 1,3-Bis(2-Chloroethy1)-1-Nitrosourea (BCNU) and P-glycoprotein effluxed drugs, the present authors obtained a full length cDNA fragment encoding MGMT from liver tissue of a patient with cholelithiasis by RT-PCR. A bicistronic retroviral vector G1Na-MGMT-IRES-MDR1 cDNA was constructed and transfected the packaging cell lines GP + E86 and PA317 by electric performation method, using the medium containing VCR and BCNU for cloning selection and ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, cord blood CD34+ cells were enriched with a high-gradient magnetic cell sorting system (MACS), and then transfected repeatedly with supernatant of retrovirus containing human MGMT and MDR1cDNA under stimulation of hemapoietic growth factors. PCR, RT-PCR, Southern blot, Northern blot, Western blot, FACS and MTT assay were used to evaluate the transfer and expression of the double genes in cord blood CD34+ cells. The cDNA encoding MGMT was verified by DNA sequencing and the bicistronic retroviral vector was confirmed by restriction endonuclease analysis. The purity of cord blood CD34+ cells was approximately 92% and recover rate was 75%, the highest titer of recombinant amphotropic retrovirus in the supernatant was up to 5.8 x 10(5) cfu/ml. The efficiency of gene transduction was 18% and 20% tested by colony formation and PCR, respectively. No helper virus was found by both nested PCR and rescue assay. The results showed that dual drug resistance genes have been integrated into the genomic DNA of cord blood CD34+ cells and expressed efficiently. The MTT analysis showed a 4.5 to 7.8-fold increase of resistance of transducted cells to BCNU and P-glycoprotein effluxed drug as compared with the nontransduced cells. This study provided a foundation for ameliorating combination chemotherapy toxicity in tumor clinical trial.

Culicoides arakawae (Diptera: Ceratopogonidae) efficiently blood-fed and infected with Leucocytozoon caulleryi through a natural membrane

Culicoides arakawae, the most common Culicoides sp. on chicken farms in East Asia, is an important blood-sucking insect and Leucocytozoon caulleryi vector. How parasites, in an ingested blood bolus, enter the midgut of insects and deal with this complex and biochemically hostile environment is poorly understood. However, successful blood-feeding through a membrane in C. arakawae is beneficial for studying this phenomenon. Therefore, a membrane-feeding method for C. arakawae was developed in. The blood-feeding success rates of C. arakawae fed through five different membranes were: turkey egg at 43.7+/-11.7%, chicken egg at 45.2+/-12.1%, duck egg at 38.8+/-12.0%, pig gut at 0% and chick skin at 0%. In fertility measurements, the average number of eggs produced for C. arakawae fed through egg-shell membrane, at 77.7+/-15.1 per female, was significantly higher (P<0.01) than the 46.7+/-10.6 found in C. arakawae fed on the breast skin of a live chicken. Meanwhile, in parasite infectivity tests, C. arakawae could be infected by L. caulleryi when the vector was blood-fed with infective blood cells reconstituted with specific pathogen-free (SPF) sera through an egg-shell membrane. The sporozoite average and infection rates of inoculated chicks were 166.8+/-12.5 and 100%, respectively. In conclusion, feeding C. arakawae blood through fowl-egg-shell membranes should be an efficient method for in vitro infection of midges as the engorged midges are infected by parasites and display reproductive potential. Furthermore, the method is practical for feeding a large number of midges.

Development of aflatoxin B(1)-lysine adduct monoclonal antibody for human exposure studies

Mouse monoclonal antibodies were developed against a synthetic aflatoxin B(1) (AFB)-lysine-cationized bovine serum albumin conjugate. The isotype of one of these antibodies, IIA4B3, has been classified as immunoglobulin G1(lambda). The affinity and specificity of IIA4B3 were further characterized by a competitive radioimmunoassay. The affinities of IIA4B3 for AFB and its associated adducts and metabolites are ranked as follows: AFB-lysine > 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl formamido)-9-hydroxy-AFB > AFB = 8,9-dihydro-8-(N(7)-guanyl)-9-hydroxy-AFB > aflatoxin M(1) > aflatoxin Q(1). IIA4B3 had about a 10-fold higher affinity for binding to AFB-lysine adduct than to AFB when (3)H-AFB-lysine was used as the tracer. The concentration for 50% inhibition for AFB-lysine was 0.610 pmol; that for AFB was 6.85 pmol. IIA4B3 had affinities at least sevenfold and twofold higher than those of 2B11, a previously developed antibody against parent AFB, for the major aflatoxin-DNA adducts 8,9-dihydro-8-(N(7)-guanyl)-9-hydroxy-AFB and 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl formamido)-9-hydroxy-AFB, respectively. An analytical method based on a competitive radioimmunoassay with IIA4B3 and (3)H-AFB-lysine was validated with a limit of detection of 10 fmol of AFB-lysine adduct. The method has been applied to the measurement of AFB-albumin adduct levels in human serum samples collected from the residents of areas at high risk for liver cancer.

Genomic analysis of the Hsp70 superfamily in Arabidopsis thaliana

The Arabidopsis genome contains at least 18 genes encoding members of the 70-kilodalton heat shock protein (Hsp70) family, 14 in the DnaK subfamily and 4 in the Hsp110/SSE subfamily. While the Hsp70s are highly conserved, a phylogenetic analysis including all members of this family in Arabidopsis and in yeast indicates the homology of Hsp70s in the subgroups, such as those predicted to localize in the same subcellular compartment and those similar to the mammalian Hsp110 and Grp170. Gene structure and genome organization suggest duplication in the origin of some genes. The Arabidopsis hsp70s exhibit distinct expression profiles; representative genes of the subgroups are expressed at relatively high levels during specific developmental stages and under thermal stress.

[Establishment of suc2 signal sequence trap system]

The secretion of proteins depends on the signal peptide located to the N-terminal of the protein precursor. We established a genetic system in yeast to screen cDNA library for the signal peptide encoding sequences. To do it, we mutated genomic suc2 gene (encoding yeast invertase) of EGY48 by one-step gene disruption method, and got yeast cell lines without invertase expression (EGY48-delta suc). To get vector for library screening, we inserted suc2 gene encoding mature peptide of invertase downstream to yeast promoter P-ADH1, and multiple cloning sites for insertion of library is between suc2 and P-ADH1. EGY48-delta suc transformed with the vector can grow on the medium with glucose as carbon source, but not on the medium with raffinose. Signal peptide of suc2 and alpha chain of human interleukin-2 was fused in frame to suc2 gene, then the two resulting vectors were transformed into EGY48-delta suc, all the transformants can grow in the medium with either raffinose or glucose as carbon source. Hence, the system established here can discern cDNA encoding signal peptide from the one not encoding signal peptide.

Evaluation of hepatoprotective activity of legumes

Mung bean, adzuki bean, black bean and rice bean are foods and folk medicines of Taiwan. We evaluated the effects of various water extract concentrations (100, 500 and 1000 mg/kg body wt.) and silymarin (25 mg/kg body wt. on acetaminophen-induced liver injury by measuring serum glutamate-oxalate-transaminase (sGOT) and serum glutamate-pyruvate-transaminase (sGPT) activities in rats. The results showed that the sGOT and the sGPT activities, increased by APAP, were decreased significantly (P < 0.05) through treatment with inceasing amounts up to 1000 mg/kg body wt. of the exracts. In particular, the mung bean aqueous extract showed the best hepatoprotective effect on APAP-induced hepatotoxicity. The pathological changes of liver injury caused by APAP improved by the treatment with all of the legume extracts, which were compared to silymarin as a standardized drug. In addition to these results, the extract of mung bean acted as a potential hepatoprotective agent in dietary supply.

Environmental impact of radionuclide migration in groundwater from a low-intermediate level radioactive waste repository

The radionuclide migration from a certain Chinese repository with low-intermediate level radioactive solid waste is studied. The migration in groundwater is analyzed and computed in detail. Under presumption of normal releasing, or the bottom of the repository has been marinated for one month with precipitation reaching 600 mm once and a 6 m aerated zone exists, a prediction for 7 radionuclides is conducted. It shows that the aerated zone is the primary barrier for migration. The migration for radionuclides 60Co, 137Cs, 90Sr, 63Ni, etc. will be retarded in it within 500 years. The concentration of 239Pu will be decreased by amount of 6 order. Only 3H and 14C can migrate through the aerated zone. The radionuclides that go through the aerated zone and enter the aquifer will exist in spring, stream and sea. Based on this, the intake dose by residents in different age group resulting from drinking contaminated spring water, eating seafood is calculated. The results showed that the impact of the repository to the key resident group is lower than the limit in national repository regulation standard. This complies with the repository management target.

Selegiline pharmacokinetics are unaffected by the CYP3A4 inhibitor itraconazole

OBJECTIVE

To characterise the effects of itraconazole, a potent inhibitor of CYP3A4, on the pharmacokinetics of selegiline in healthy volunteers.

METHODS

In this randomised, placebo-controlled crossover study with two phases, 12 healthy volunteers took either 200 mg itraconazole or matched placebo once daily for 4 days. On day 4, a single 10-mg oral dose of selegiline hydrochloride was administered. Serum concentrations of selegiline and its primary metabolites desmethylselegiline and l-methamphetamine were determined up to 32 h. A caffeine test was performed on day 3 of both phases, by measuring the plasma paraxanthine/caffeine concentration ratio 6 h after caffeine intake, to examine the role of CYP1A2 in selegiline pharmacokinetics. In addition, the effects of itraconazole on the metabolism of selegiline in vitro were characterised by using human liver microsomes.

RESULTS

Itraconazole had no significant effects on the pharmacokinetic variables of selegiline, desmethylselegiline or l-methamphetamine, with the exception that the AUC of desmethylselegiline was increased by about 10% (P < 0.05). There was a significant correlation between the AUC(desmethylselegiline)/AUC(selegiline) ratio and the paraxanthine/caffeine ratio (r = 0.41; P < 0.05), suggesting involvement of CYP1A2 in the formation of desmethylselegiline. In experiments with human liver microsomes, itraconazole had no inhibitory effect on the formation of either desmethylselegiline or l-methamphetamine from selegiline.

CONCLUSIONS

The pharmacokinetics of selegiline in healthy volunteers were unaffected by the potent CYP3A4 inhibitor itraconazole. In addition, itraconazole showed no inhibitory effect on the biotransformation of selegiline to desmethylselegiline and l-methamphetamine by human liver microsomes. These findings suggest that selegiline is not susceptible to interaction with CYP3A4 inhibitors.

Susceptibility of mosquitoes in central Taiwan to natural infections of Dirofilaria immitis

From October 1997 to September 1998, 3085 Culex quinquefasciatus (Say) (Diptera: Culicidae), 584 Cx. tritaeniorhynchus (Giles) (Diptera: Culicidae), 392 Cx. annulus (Theobald) (Diptera: Culicidae), 374 Aedes albopictus (Skuse) (Diptera: Culicidae) and 102 Armigeres subalbatus (Coquillet) (Diptera: Culicidae) were collected and examined for Dirofilaria immitis (Leidy) (Spirurida: Filariidae) infection. However, only Cx. quinquefasciatus and Ae. albopictus were infected, with a prevalence of 4.28% and 3.74%, respectively. The intensity of D. immitis found in Ae. albopictus (3.43 larvae/mosquito) was higher than that found in Cx. quinquefasciatus (2.89 larvae/mosquito). After being fed with canine blood containing 7500 microfilariae (mf) per mL, Cx. quinquefasciatus ingested approximately two times as many mf as Ae. albopictus (mean of 31.73 in comparison to 16.47). However, almost three times as many third-stage infective larvae developed in Ae. albopictus as in Cx. quinquefasciatus (mean of 3.25 as compared with 1.10), with a vector efficiency index (VEI) of 19.73 and 3.47, respectively. The results showed that Cx. quinquefasciatus and Ae. albopictus served as natural vectors of D. immitis in central Taiwan. Although Ae. albopictus was more efficient for heartworm transmission, Cx. quinquefasciatus may play a more prominent role on the transmission of dirofilariasis in central Taiwan.

Acute oxalate nephropathy after ingestion of star fruit

Acute oxalate nephropathy associated with ingestion of star fruit (carambola) has not been reported before. We report the first two cases. These patients developed nausea, vomiting, abdominal pain, and backache within hours of ingesting large quantities of sour carambola juice; then acute renal failure followed. Both patients needed hemodialysis for oliguric acute renal failure, and pathologic examinations showed typical changes of acute oxalate nephropathy. The renal function recovered 4 weeks later without specific treatment. Sour carambola juice is a popular beverage in Taiwan. The popularity of star fruit juice is not compatible with the rare discovery of star fruit-associated acute oxalate nephropathy. Commercial carambola juice usually is prepared by pickling and dilution processes that reduce oxalate content markedly, whereas pure fresh juice or mild diluted postpickled juice for traditional remedies, as used in our cases, contain high quantities of oxalate. An empty stomach and dehydrated state may pose an additional risk for development of renal injury. To avoid acute oxalate nephropathy, pure sour carambola juice or mild diluted postpickled juice should not be consumed in large amounts, especially on an empty stomach or in a dehydrated state.

Hepatocellular carcinoma and aflatoxin exposure in Zhuqing Village, Fusui County, People's Republic of China

Hepatocellular carcinoma (HCC) is a common cause of cancer morbidity and mortality in Asia and Africa. Epidemiological studies have found that dietary exposure to aflatoxin B1 (AFB1) and chronic infection with hepatitis B virus are two major risk factors for HCC. We have collated the incidence and mortality data of malignant tumors from 1973 to 1999 in Zhuqing Village, Fusui County, an area with very high HCC rates, and found that this cancer accounted for 64% of the total cancer incidence. Dietary intake of AFB1 was monitored for 1 week in a study group consisting of 15 males and 14 females from different households in this village. Four of 29 participants (13.8%) and 3 of 15 (20%) male participants were hepatitis B virus surface antigen positive. AFB1 was detectable in 76.7% (23 of 30) of ground corn samples (range, 0.4-128.1 ppb), 66.7% (20 of 30) of cooking peanut oil samples (range, 0.1-52.5 ppb), and 23.3% (7 of 30) of rice samples (range, 0.3-2.0 ppb) collected from each household. Mean levels of serum AFB1-albumin adducts in this group were 1.24 +/- 0.31 pmol/mg of albumin at the beginning of the study and 1.21 +/- 0.19 pmol/mg of albumin at the end of the period. Urinary AFB1 metabolites were detectable in 88.9% (24 of 27) samples (range, 0.9-3569.7 ng/24-h urine). These data provide the exposure and disease risk information for establishing intervention studies to diminish the impact of aflatoxin exposure in this high-risk population.

Inhibition of inducible nitric oxide synthase (iNOS) prevents lung neutrophil deposition and damage in burned rats

This study was designed to investigate the role of NO and effect of iNOS inhibitor on the lung neutrophil deposition and damage after burn. In Experiment 1, specific pathogen-free (SPF) Sprague-Dawley rats underwent 35% total body surface area (TBSA) burn. On the 4th, 8th, 16th, and 24th h after burn, blood was collected for peroxynitrite-mediated dihydrorhodamine 123 (DHR 123) oxidation assay, and lung tissues were harvested for myeloperoxidase (MPO) test and histologic study. Pulmonary microvascular dysfunction was quantitated by measuring the extravasation of Evans blue dye (EBD). In Experiment 2, S-methylisothiourea (SMT) was given (7.5 mg/kg, intraperitoneal immediately post-burn) to suppress iNOS activity. On the 8th h after burn, the effect of SMT on blood DHR 123 oxidation, lung MPO, lung damage, and lung iNOS expression were evaluated. Lung MPO activity increased up to a maximum of 2-fold 8 h after burn. Blood DHR 123 oxidation increased up to a maximum of 2-fold 8 h after burn. Lung permeability increased up to a maximum of 2.5-fold 4 h after burn. SMT significantly decreased lung MPO activity, blood DHR 123 oxidation, and lung permeability by 31%, 41%, and 54%, respectively. SMT markedly decreased the thermal injury-induced perivascular and interstitial inflammatory cell infiltration and iNOS staining in bronchiolar epithelium, endothelial cells, and perivascular and interstitial inflammatory cells. In conclusion, thermal injury induces blood DHR 123 oxidation, lung neutrophil deposition, lung iNOS expression, and lung damage. Peroxynitrite might play an important role in thermal injury-induced lung neutrophil deposition and damage. Specific inhibition of lung iNOS expression and blood DHR 123 oxidation with SMT on thermal injury not only attenuated the lung neutrophil deposition, but also reduced lung damage.

Increased toxicity of textile effluents by a chlorination process using sodium hypochlorite

Chlorinated textile effluents were tested for their toxicity using different bioassays. These assays were the Microtox assay, daphnia (Daphnia similis) 48-hr survival test, medaka embryo 14-day and juvenile 96-hr survival tests, and tilapia (Oreochromis mossambicus) juvenile 96-hr survival test. By comparing the results of toxicity tests on water samples collected at the instream prior to the chlorination process and at the outlet of the wastewater treatment facility, we found that wastewater toxicity was obviously increased by chlorination using NaOCl as the oxidant, as evidenced by the different bioassays used. Because no significant difference was observed in water chemistry, such as pH, DO, and conductivity, the induced-toxicity may be partially attributable to residue chlorine or other chlorinated compounds generated by chlorination. Future studies are warranted to identify the cause of the increase in the textile wastewater toxicity.