The in vitro metabolism of GMDTC in liver microsomes of human, monkey, dog, rat and mouse: Metabolic stability assessment, metabolite identification and interspecies comparison.

Sodium (S)- 2-(dithiocarboxylato((2 S,3 R,4 R,5 R)- 2,3,4,5,6-pentahydroxyhexyl)amino)- 4(methylthio)butanoate (GMDTC) is a compound that removes cadmium from kidney cells. This study aims to investigate the metabolic stability and metabolite identification of GMDTC in various liver microsomes, including those from human, monkey, dog, rat and mouse. The results show that the T1/2 values of GMDTC in human, monkey, dog, rat and mouse liver microsomes were 16.54, 18.14, 16.58, 15.16 and 16.00 min, respectively. While the hepatic extraction ratios (ERh) of GMDTC measured after 60 min incubation in these liver microsomes were 0.82, 0.70, 0.80, 0.75 and 0.79, respectively, indicating that GMDTC exhibits rapid hepatic metabolism and high hepatic clearance with no significant interspecies differences. Subsequent metabolite identification by high-resolution mass spectrometry revealed the presence of three metabolites, designated M1∼M3. The major metabolite products of GMDTC were found to be M1 and M2. The relative abundances of the hydrolysis products (M1 and M2) in human, monkey, dog, rat and mouse liver microsomes were found to be 97.18%, 97.99%, 95.94%, 96.31% and 93.43%, respectively, indicating that hydrolysis is the primary metabolic pathway of GMDTC in liver microsomes in vitro, and with no significant interspecies differences.

Establishment of LC-MS/MS Method for Determination of GMDTC in Rat Plasma and Its Application in Preclinical Pharmacokinetics.

Sodium (S)-2-(dithiocarboxylato((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)-4(methylthio)butanoate (GMDTC) is the first compound to use cadmium repellent as an indication. In this paper, we established and validated a bioanalytical method for the determination of GMDTC in rat plasma, and used it to determine the drug concentrations in the plasma of rats after intravenous dosing in different genders and dosages. After pretreating the plasma samples with an acetonitrile-water-ammonia solution (70:30:1.25, v/v/v), liquid chromatographic separations were efficiently achieved with a XBridge C18 column using a 5 min gradient system of aqueous ammonium bicarbonate and 95% acetonitrile-water solution (95:5, v/v) as the eluent. The GMDTC and metolazone (internal standard, IS) detection were carried out using high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (LC-MS/MS), monitored at m/z 390.06-324.1 (for the GMDTC, tR: 2.03 min) and m/z 366.0-259.2 (for IS, tR: 3.88 min). The GMDTC was stable under various testing conditions, and this analytical method conforms to the verification standard of biological analysis methods. The half-life (t1/2) was determined to be 0.54-0.65 h for the intravenous, mean distribution volume and clearances were 1.08-2.08 L/kg and 1-3 L/h/kg, respectively. The AUC0-t and AUC0-∞ found after increasing the dosage exhibited a linear relationship with the administered dose. There were no statistically significant differences in the values obtained for the different genders at dosages of 50, 100 and 250 mg/kg, respectively (p > 0.05). This is the first report of a bioanalytical method to quantify GMDTC in rat plasma using LC-MS/MS, which provides useful information for the study of its pharmacological effects and clinical applications.

Co-exposure to perfluoroalkyl acids and heavy metals mixtures associated with impaired kidney function in adults: A community-based population study in China.

BACKGROUND: Previous studies have separately linked either perfluoroalkyl acid (PFAA) or heavy metal exposure with kidney dysfunction. However, the relationships of co-exposure to PFAAs and heavy metals with kidney function are still unclear. OBJECTIVES: To explore the associations between exposure to PFAAs and heavy metals mixtures and kidney function in adults. METHODS: We conducted a cross-sectional community-based population study in Guangzhou, China, enrolling 1312 adults from November 2018 to August 2019. We quantified 13 PFAAs in serum and 14 heavy metals in plasma. We chose estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) as outcomes of interest. Distributed lag non-linear models (DLNMs) were used to check nonlinearity of individual pollutant with kidney function. Joint associations of pollutant mixtures on kidney function were assessed by Bayesian Kernel Machine Regression (BKMR) models. We further explored modification effects of gender. RESULTS: Most individual PFAA and heavy metal were associated with declined kidney function in single-pollutant models. We also observed significant dose-response relationships of pollutant mixtures with reduced eGFR levels and increased odds of CKD in BKMR models. Perfluoroheptanesulfonic acid (PFHpS), arsenic (As) and strontium (Sr) were the predominant contributors among pollutant mixtures. A change in log PFHpS, As and Sr concentrations from the 25th to the 75th percentile were associated with a decrease in eGFR of -5.42 (95% confidence interval (CI): -6.86, -3.98), -2.14 (95% CI: -3.70, -0.58) and -1.87 (95% CI: -3.03, -0.72) mL/min/1.73 m2, respectively, when other pollutants were at their median values. In addition, the observed associations were more obvious in females. CONCLUSIONS: We provided new evidence that co-exposure to PFAAs and heavy metals mixtures was associated with reduced kidney function in adults and PFHpS, As and Sr appeared to be the major contributors. Further studies are warranted to confirm our findings and elucidate the underlying mechanisms.

Independent risk factors for axillary lymph node metastasis in breast cancer patients with one or two positive sentinel lymph nodes.

BACKGROUND: The benefit of axillary lymph node dissection (ALND) in breast cancer patients with one or two positive sentinel lymph nodes (SLNs) remains inconclusive. The purpose of this study was to identify risk factors independently associated with axillary lymph node (ALN) metastasis. METHODS: We retrospectively analyzed data from 389 Chinese breast cancer patients with one or two positive SLNs who underwent ALND. Univariate and multivariate logistic regression analyses were performed to identify ALN metastasis-associated risk factors. RESULTS: Among the 389 patients, 174 (44.7%) had ALN metastasis, while 215 (55.3%) showed no evidence of ALN metastasis. Univariate analysis revealed significant differences in age (< 60 or ≥ 60 years), human epidermal growth factor receptor-2 (Her-2) status, and the ratio of positive to total SLNs between the ALN metastasis and non-metastasis groups (P < 0.05). The multivariate analysis indicated that age, the ratio of positive to total SLNs, and occupations were significantly different between the two groups. Lastly, younger age (< 60 years), a higher ratio of positive to total SLNs, and manual labor jobs were independently associated with ALN metastasis (P < 0.05). CONCLUSIONS: The risk of ALN metastasis in breast cancer patients with one or two positive SLNs can be further increased by younger age, manual labor jobs, and a high ratio of positive to total SLNs. Our findings may also aid in identifying which patients with one or two positive SLNs may not require ALND.

Associations between clinical-pathological parameters and biomarkers, HER-2, TYMS, RRMI, and 21-gene recurrence score in breast cancer.

BACKGROUND: Chemotherapy is the predominant treatment option for patients with breast cancer. Selection of patients according to biomarker will improve chemotherapy efficacy. In the present study, we examined the relations of the expression of candidate genes and 21-recurrence score (RS) results to patients' demographic characteristics, histopathological factors, and outcomes. METHODS: A total of 146 patients were enrolled in this study. The patients underwent 21-gene RS testing. In addition, expressions of candidate genes, TYMS, RRM1, TUBB3, TOP2A, PTEN, were detected. Information was obtained on age, tumor size, TMN stage, tumor grade, and status of Ki-67, HER2, ER and PR. The treatment information on the type of endocrine therapy was also obtained. RESULTS: Results clearly showed that the 21-gene RS significantly correlated with the TNM stage of breast cancer (P = 0.047). The RS also correlated with the number of sentinel lymph node (P = 0.038). The pathological type of tumors was strongly associated with the expression of RRM1 (P < 0.015), and slightly correlated with TYMS (P = 0.095) and tumor size (P = 0.061). Further analysis showed that TYMS and RRM1 were two independent factors affecting the disease progression of patients. Besides, for HER-2 stain, staining of grade 2 or above significantly increased the risk of disease progression. CONCLUSION: Our studies showed that TNM stage and sentinel lymph node were important clinical parameters correlated with 21-gene RS results. Also, RRM1, TYMS and HER2 expressions were independent factors associated with disease progression in breast cancer patients. Future study is warranted to investigate the usefulness of these genes in treatment efficacy.

Activation of the IL-6/JAK2/STAT3 pathway induces plasma cell mastitis in mice.

Plasma cell mastitis (PCM) is a chronic mastitis with limited treatment options and common recurrence. A histopathological hallmark of PCM is the infiltration of numerous plasma cells surrounding the mammary duct. Our previous study showed that the activity of the IL-6/STAT3 signaling pathway was elevated in patients with PCM. However, the etiology of PCM remains largely unclear. In this study, we sought to explore the effects of IL-6/JAK2/STAT3 signaling pathway in the pathogenesis of PCM. Histological analysis showed that the mammary glands of mice that received human breast tissue homogenates, followed by an injection of IL-6, exhibited features of PCM similar to human PCM. The IL-6/JAK2/STAT3 signaling activity was significantly elevated and Bcl-2 was highly expressed in CD138 + plasma cells in the mammary glands of mice with PCM. Furthermore, treatment with AG-490, an inhibitor of JAK family kinases, suppressed activation of the IL-6/JAK2/STAT3 signaling cascade, in turn resulting in a decreased number of plasma cells in the mammary gland and reversing the pathogenesis of PCM. Taken together, our study indicated that a PCM mouse model was successfully established through activation of the IL-6/JAK2/STAT3 pathway by injecting IL-6 into the mammary gland of mouse that had received homogenates of human breast tissue. Thus, the IL-6/JAK2/STAT3 signaling pathway plays a critical role in orchestrating the pathogenesis of PCM.

IL-6/STAT3 signaling pathway is activated in plasma cell mastitis.

Plasma cell mastitis (PCM), a particular type of mastitis, mainly occurs in females at nonpregnant and nonlactating stages. The infiltration of abundant plasma cells and lymphocytes is the hallmark of the disease. The incidence rate of PCM increased gradually and its pathogenesis remained unclear. In this study, we investigated the expression of IL-6/STAT3 signaling pathway, which is vital not only for the differentiation of plasma cells but also for survival of plasma cells and T lymphocytes, in 30 PCM cases, 10 acute mastitis cases and 10 normal breast tissues by immunohistochemical analysis. IL-6 level was significantly higher in PCM patients than in acute mastitis patients or normal group. The positive rate of IL-6 and p-STAT3 staining in PCM samples was 93.3% (28/30) and 70% (21/30), respectively, and there was a significant positive association between IL-6 and p-STAT3 staining (r=0.408, P=0.025). In PCM group, the rate of nipple retraction was 40% (12/30). Significantly higher IL-6 expression was found in PCM patients with nipple retraction than in other PCM patients. However, no significant difference in IL-6 or p-STAT3 staining was detected between PCM patients experiencing recurrence and other PCM patients. In addition, Bcl-2 level was higher in PCM patients than in acute mastitis patients or normal group, but there was no difference in Bcl-2 immunostaining between PCM patients experiencing recurrence and other PCM patients. These indicate that IL-6/STAT3 signaling is activated in PCM and may play an important role in the pathogenesis of PCM.

[Study on activities and protein and gene expression of renal H(+)-K(+)-ATPase in rats subchronic exposed to trimethyltin chloride].

OBJECTIVE: To study the activity, protein and gene expression of renal HK-ATPase (HKA) in rats subchronic exposed to trimethyltin chloride (TMT). METHODS: In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 microg x kg(-1) x d(-1) for 14 weeks. Then serum K+ levels were measured; the activities of HK-ATPase (HKA) in kidneys were detected by the method of determinated phosphorus content; Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively. RESULTS: The serum K+ level in super-high dosage group was (5.6 +/- 0.4) mmol/L, which was significantly lower than that [(6.9 +/- 0.3) mmol/L] in control group (P < 0.01). The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50 +/- 1.45 and 4.55 +/- 0.72 micromolPi x mg prot(-1)h(-1), respectively, which were significantly lower than that (6.55 +/- 0.77 micromol Pi x mg prot(-1) h(-1)) in control group (P < 0.05). CONCLUSION: When rats were exposed subchronic to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.

[Expression and significance of PCNA and Caspase-3 in the tissue of lung cancer].

AIM: To investigate the significance of PCNA and Caspase-3 in lung cancer. METHODS: PCNA and Caspase-3 in 80 patients diagnosed with lung cancer were semi-quantitatively analyzed by using SP immunohistochemical staining. RESULTS: The positive rate of Caspase-3 and PCNA were 32.5% and 65%, respectively. Both were much lower or higher than those normal lung tissues (P<0.05). Caspase-3 protein was correlated to lymph node metastasis, pathological type and differentiation grade (P<0.05). Meanwhile, PCNA was correlated to lymph node metastasis, differentiation grade and pathological staging of lung cancer (P<0.05), but not to pathological type. PCNA was negatively correlated to Caspase-3. PCNA (+)/Caspase-3(-) indicated the potential lower differentiation grade. CONCLUSION: Up-regulation of PCNA and down-regulation of Caspase-3 are correlated to the pathological type, lymph node metastasis, staging and differentiation grade in lung cancer, especially which is indicating its clinical treatment.

[Construction and identification of recombinant adeno-associated virus vector harboring fusion gene NT4-Ant-Shepherdin[79-87]].

AIM: To construct a recombinant adeno-associated virus vector harboring fusion gene NT4-Ant-Shepherdin[79-87] and investigate Survivin as a anticancer therapeutic target by use of Shepherdin[79-87]. METHODS: The gene of Ant-Shepherdin[79-87] was obtained by PCR and T-vector method. After inserted in PBV220-NT4 vector and digested with restricted enzyme, The fusion gene of NT4-Ant-Shepherdin[79-87] was sub-cloned into the shuttle plasmid of adeno-associated virus; the products were co-transferred into HEK-293 cell line with helper plasmid pAAV-Ad and adeno-plasmid pFG140. The recombinant adeno-associated virus was produced by homologous recombination of above 3 plasmids in HEK-293 cells and its titer was measured by Dot-blot hybridization. The effect of rAAV-NT4-Ant-Shepherdin[79-87] on A549 cell line was measured by a colorimetric 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. RESULTS: DNA sequencing results verified that the sequence of Ant-Shepherdin[79-87] was consistent with that we had designed. After transformed E.coli DH5alpha, a fragment of 321 bp was confirmed. High titer of recombinant adeno-associated virus was obtained by homologous recombination in HEK-293 cell lines (3.4x10(13)pfu/L). rAAV-NT4-Ant-Shepherdin[79-87] had strong induce apoptosis effect on A549 cells. CONCLUSION: The recombinant adeno-associated virus vector encoding fusion gene NT4-Ant-Shepherdin[79-87] is successfully constructed in this experiment by molecular cloning and in vitro recombination techniques, which provided the basis of further research of Survivin for cancer gene therapy.

[Expression and effects of nuclear distribution C (NUDC) protein in nasopharyngeal carcinoma cell lines].

BACKGROUND & OBJECTIVE: Nuclear migration is essential for growth, development, and cellular function of eukaryotes. Nuclear distribution C (NUDC) protein plays an important role in nuclear migration. This study was to detect the expression of NUDC protein in nasopharyngeal carcinoma (NPC) cell lines CNE-2 and HNE-2, and to investigate the effect of anti-NUDC antibody on the growth of both cell lines. METHODS: Soluble fusion protein GST-NUDC was expressed in the cytoplasm of Escherichia coli, and its poly-antibody was prepared. The subcellular localization of NUDC protein in CNE-2 and HNE-2 cells was detected with indirect immunofluorescent staining, the expression of NUDC protein in CNE-2 and HNE-2 cells was detected by Western blot, the effect of anti-NUDC antibody on the growth of CNE-2 and HNE-2 cells was detected by MTT assay. RESULTS: NUDC protein was expressed in both nasopharyngeal non-cancerous tissues and CNE-2 and HNE-2 cells, and its expression was higher in CNE-2 and HNE-2 cells than in nasopharyngeal non-cancerous tissues. NUDC protein in CNE-2 and HNE-2 cells was distributed mainly in the karyolemma of cytoplasm, and in nuclei asymmetrically. Anti-NUDC antibody inhibited the growth of CNE-2 and HNE-2 cells in a dose-dependent manner. CONCLUSIONS: NUDC protein is expressed highly in CNE-2 and HNE-2 cells. Anti-NUDC antibody could inhibit the growth of CNE-2 and HNE-2 cells.

[The antitussive and de-sputum essential substance from the root of Gerbera piloselloides and its analytical compositions].

OBJECTIVE: To study the chemical constituents of the essential substance from the root of Gerbera piloselloides and its antitussive and de-sputum effects. METHOD: The essential substance (G4) was extracted from the root by alcohol and ethyl acetate, then it was separated by silica gel column eluted by the mixture of ethyl acetate and petroleum ether (5:95). Its chemical components were separated and identified by GC-MS. Its antitussive and de-sputum effect was tested by mice. RESULT: 4 main peaks were separated and identified by GS-MS. They are beta-caryophyllene (15.160%), caryophyllene oxide (21.140%), aristolenepoxide (2.673%) and 6-acetyl-2,2-dimethyl-8(3-methyl-2-butenyl)-2H-chromoene (60.077%) respectively. Its antitussive and de-sputum effect was prominent when the mice was given G4 2,000 mg.kg-1 ig. CONCLUSION: Itis the first time that the antitussive and de-sputum essential substance was separated from the root of Gerbera piloselloides and its main compositions were analyzed.

Guinea pig maximization test for trichloroethylene and its metabolites.

OBJECTIVES: To study the contact allergenic activities of trichloroethylene (TCE) and its three metabolites trichloroacetic acid, trichloroethanol and chloral hydrate. METHODS: A modified guinea pig maximization test (GPMT) was adopted. The skin sensitization (edema and erythema) was observed in trichloroethylene, trichloroacetic acid, trichloroethanol, chloral hydrate and 2,4-dinitrochlorobenzene. RESULTS: The allergenic rate of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 71.4%, 58.3% and 100.0% respectively, and that of trichloroethanol and chloral hydrate was 0%. The mean response score of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 2.3, 1.1, 6.0 respectively. The histopathological analysis also showed an induction of allergenic transformation in guinea pig skin by both TCE and trichloroacetic acid. CONCLUSION: TCE appears to be a strong allergen while trichloroacetic acid a moderate one. On the other hand, both trichloroethanol and chloral hydrate are weak sensitization potentials. Immunologic reaction induced by TCE might be postulated as the pathological process of this illness. Consequently, it is suggested that in the mechanism of Occupational Dermatitis Medicamentose-Like (ODML) induced by TCE, the chemical itself might be the main cause of allergy. As one of its metabolic products, trichloroacetic acid might be a subordinate factor.

Studies on hypokalemia induced by trimethyltin chloride.

OBJECTIVES: To determine the possible relationship between plasma potassium concentration and severity of acute trimethyltin chloride (TMT) poisoning and to assess the mechanism of TMT induced hypokalemia. METHODS: SD rats were treated with various dosages of TMT (i.p.). All the indices were measured and analysed for determining their possible relations with plasma K+. RESULTS: With increase of dosage, the plasma K+ level dropped rapidly, and deaths appeared more quickly. The LD50 of TMT (i.p.) was 14.7 mg/kgbw. In the low dosage group (10 mg/kgbw), the plasma K+ level dropped slowly with the lowest dosage on day 6 (4.85 mmol/L). It rose again on day 11 (5.06 mmol/L), and recovered on day 28. The poisoning signs corresponded with decline of the span of K+ level. The plasma Na+ level dropped half an hour after TMT treatment, but recovered 24 h later. In the high dosage group (46.4 mg/kgbw), the levels of plasma K+ and Na+ fell rapidly within half an hour (P < 0.05), the intracellular potassium concentration of RBC did not decrease obviously (P > 0.05), the activities of Na(+)-K(+)-ATPase and Mg(2+)-ATPase in RBC membrane were depressed remarkably (P < 0.01, P < 0.05, respectively), the plasma aldosterone concentrations rose as high as tenfold (P < 0.01), the arterial blood pH fell from 7.434 to 7.258 (P < 0.01), pCO2 was raised from 29.62 to 45.33 mmHg (P < 0.01). In the 24 h urine test, when rats were treated with TMT (21.5 mg/kgbw, i.p.), urine volume, urinary potassium, sodium and chloride increased significantly in comparison with those in the controls (P < 0.01). CONCLUSION: TMT could induce hypokalemia in SD rats. The available evidence suggests that TMT can induce acute renal leakage of potassium. At the same time, a significant rise of plasma aldosterone may play an important role in promoting potassium leakage from kidney to result in severe hypokalemia with inhaling acid-base abnormalities produced, which aggravate the poisoning symptoms. In the end the rats would die of respiratory failure.