Effects of Chronic Exposure to Sodium Arsenite on Expressions of VEGF and VEGFR2 Proteins in the Epididymis of Rats

OBJECTIVE

To study the expressions of VEGF and VEGFR2 at protein level in the epididymis of rats with arsenism.

METHODS

Forty male Sprague-Dawley rats were randomly divided into four groups: the high dose arsenic infected group (60.0 mg/L in water), the middle dose arsenic infected group (12.0 mg/L in water), the low dose arsenic infected group (2.4 mg/L in water), and the control group (distilled water). Rats were treated with arsenic through drinking water for 6 consecutive months. At the end of the experiment, the average densitometry values of apoptotic cells in epididymis tubules were determined by TUNEL method; the protein and mRNA levels of VEGF and VEGFR2 were observed by immunohistochemistry, Western blot, and real time fluorescent quantitative PCR, respectively.

RESULTS

Compared with the control group, in each infected group, the average densitometry values of apoptotic cells in the epididymis tubules were significantly lower. Compared with control group, protein and mRNA levels of VEGF and VEGFR2 in each infected group were obviously declined. The correlations between protein and mRNA levels of VEGF and VEGFR2 were positively exhibited (r = 0.843, 0.869, p < 0.05).

CONCLUSIONS

Arsenism affects the expressions of VEGF and VEGFR2 in the epididymis of rats and results in apoptosis of pathophysiology of male infertility.

Inadvertent sodium loading in critically ill patients

BACKGROUND

Recommended daily intake of sodium is 1- 2mmol/kg. Sodium administration is rarely separated from fluid administration in critically ill patients.

OBJECTIVE

To estimate the amount of sodium administered to patients who were invasively ventilated, and to investigate whether sodium administration affected oxygenation, length of stay in ICU and serum sodium level.

DESIGN, PARTICIPANTS AND SETTING

Retrospective audit of adult patients who received invasive mechanical ventilation for ≥ 5 days in a tertiary-level intensive care unit.

MAIN OUTCOME MEASURES

Total sodium administered from resuscitation and maintenance fluids, infusions, flushes, medicines, transfusions, enteral feeds and total parenteral nutrition; oxygenation, length of ICU stay and serum sodium level.

RESULTS

13 men and 7 women were included. Their median age was 71.9 years (range, 19.8-89.2 years). Median duration of mechanical ventilation was 9 days (range, 6-20 days) and median ICU stay 11.6 days (range, 6-21 days). Median APACHE II score was 29 (range, 18-41). Daily sodium administration was 225.5mmol (151-355mmol). The median daily net fluid balance was 351mL (range, - 759 to +1125mL) and median daily fluid intake was 2352mL (range, 1437- 3798mL). Daily sodium administered correlated with net fluid balance (P<0.001; r=0.35). Of total sodium administered, infusions contributed 22.2% (1.2%-39.9%); drugs 21.6% (0.0-35.5%); flushes 17.4% (9.3%-24.5%); enteral feeds 17% (0.0-39.5%); resuscitation 16.0% (2.5%-36.9%); maintenance fluids 5.8% (0.0-24.0%); transfusions 3.9% (0.0-9.5%) and parenteral nutrition 0.1% (0.0-2.6%).

CONCLUSION

Sodium administration to this cohort of critically ill patients requiring prolonged mechanical ventilation was high. Further studies should examine ways of limiting the amount of sodium administered to such patients and to examine if this influences patient outcomes.

Protective role of the methanolic extract of Icacina trichantha on sodium arsenite induced genotoxicity and hepatotoxicity

BACKGROUND

Arsenic is a toxic metalloid, whose toxicity has raised a lot of concern. Humans are exposed to this metalloid through contaminated water, air and even foods. As a sulfhydryl reactive metal, arsenic has been found to cause extensive damage to organs such as the liver. It has also been found to be a potent clastogen, causing DNA damage leading to both benign and malignant tumors.

OBJECTIVES

The anti-hepatotoxic and anti-genotoxic effects of methanolic leaf extract of Icacina trichantha on sodium arsenite induced toxicity in rats were determined.

METHODS

Oral gavage of sodium arsenite was used to induced genotoxicity in rats and micronucleus assay was used to measure the number of micronucleated polychromatophilic erythrocytes. The determination of activities of serum alanine amino transferase (ALT), aspartate amino transferase (AST) and gamma glutamyl transferase (GGT) activities were used for the hepatotoxicity assay..

RESULTS

The mean number of micronucleated polychromatophilic erythrocytes (MPCE) per 1000 cells +/- SEM from the bone marrow smear was 57.50 +/- 9.71 in rats treated with both arsenite and extract compared to 129.00 +/- 16.34 in rats treated with arsenite alone. The serum ALT, AST and GGT activities +/- SEM were 67.04 + 3.71, 39.12 +/- 3.45 and 11.54 +/- 0.42 lu respectively for the rats treated with arsenite alone. Combined treatment of arsenite and the extract significantly decrease (p<0.05) in the activity of the enzymes, 29.75 +/- 3.43, 15.8 +/- 4.42, 6.87 +/- 0.433 lu for serum ALT, AST and GGT respectively.

CONCLUSION

The methanolic leaf extract of I. trichantha modulated both the hepatotoxic and genotoxic effect induced by sodium arsenite in rats, which suggest that Icacina trichantha may serve as a hepatoprotective and anti-tumor agent.

Activation of Hedgehog signaling by the environmental toxicant arsenic may contribute to the etiology of arsenic-induced tumors

Exposure to the environmental toxicant arsenic, through both contaminated water and food, contributes to significant health problems worldwide. In particular, arsenic exposure is thought to function as a carcinogen for lung, skin, and bladder cancer via mechanisms that remain largely unknown. More recently, the Hedgehog signaling pathway has also been implicated in the progression and maintenance of these same cancers. Based on these similarities, we tested the hypothesis that arsenic may act in part through activating Hedgehog signaling. Here, we show that arsenic is able to activate Hedgehog signaling in several primary and established tissue culture cells as well as in vivo. Arsenic activates Hedgehog signaling by decreasing the stability of the repressor form of GLI3, one of the transcription factors that ultimately regulate Hedgehog activity. We also show, using tumor samples from a cohort of bladder cancer patients, that high levels of arsenic exposure are associated with high levels of Hedgehog activity. Given the important role Hedgehog signaling plays in the maintenance and progression of a variety of tumors, including bladder cancer, these results suggest that arsenic exposure may in part promote cancer through the activation of Hedgehog signaling. Thus, we provide an important insight into the etiology of arsenic-induced human carcinogenesis, which may be relevant to millions of people exposed to high levels of arsenic worldwide.

An elderly patient with severe acute renal failure due to sodium bromate intoxication

Accidental or deliberate ingestion of bromate solution has been reported in pediatric as well as adult cases; however there have been no reports of such intoxication in the elderly. We report a 78-year-old woman who suffered severe acute renal failure due to the accidental ingestion of sodium bromate solution. The patient was successfully treated with hemodialysis therapy and renal function recovered without hearing loss. This case suggests that emergency therapeutic measures, including hemodialysis, should be taken as soon as possible, and the rapid removal of bromate is essential to prevent severe intoxication and its sequelae. To the best of our knowledge this is the first report of an elderly patient that demonstrates the clinical benefit of hemodialysis therapy for bromate intoxication.

[Molecular genetic mechanism of sodium arsenite on growth and development]

OBJECTIVE

To study the effects of sodium arsenite on gene expression related to growth and development and explored the molecular mechanism of arsenic effects using gene chips.

METHODS

Normal human hepatic cells were dripped on chips and then hybrided with the first strand of cDNA from hepatic cell exposed to different concentration of sodium arsenite. Gene sequence of clone differently expressed was determined and then defined which gene it was and finally those genes which associated with growth and development were identified.

RESULTS

The p55 gene expression level of two experimental groups was severaly 2.21 and 2.93 times as the control group. The PL gene level of two experimental groups were 0.13 and 0.27 times as the control group, and the HOXA10 gene level was 0.22 and 0.35 times of the control group. These results indicated that sodium arsenite increase p55 gene expression, and inhibited PL and HOXA10 gene expression.

CONCLUSIONS

The sodium arsenite could affect the gene expression related to growth and development and it is shown that the molecular genetic mechanism of sodium arsenite is related to growth and development.

Acute renal failure and hearing loss due to sodium bromate poisoning: a case report and review of the literature

Acute renal failure with hearing loss due to sodium bromate intoxication is described. A 48-year-old woman who ingested permanent wave neutralizer in a suicide attempt and developed anuria was admitted to our hospital for hemodialysis. Bromate intoxication was suspected and hemodialysis was carried out; she required maintenance dialysis 3 times a week. Irreversible severe sensorineural hearing loss continued and peripheral polyneuropathy developed in the lower limbs. We measured the concentration of bromine in the serum before and after the first hemodialysis and found its removal rate to be 61.3%. This is the first report that proved the utility of hemodialysis for bromate intoxication in a clinical setting.

Unusual findings in a fatal case of poisoning with chromate compounds

An interesting case of acute poisoning by chromate compounds is reported. A 51-year-old man committed suicide by ingesting a fatal dose of sodium chromate solution. He unexpectedly lost consciousness 6 h after the ingestion and died approximately 20.5 h later. An examination of the blood showed noticeable hepatic damage and thrombocytopenia. The postmortem examination revealed extensive bleeding in the alimentary tract and a severe hepatic lesion due to hepatocellular necrosis. However, the renal disorder was unusually light in the microscopic and clinical findings. Moreover, the renal lesion was observed mainly in the distal tubules instead of the proximal tubules which is more typical in cases of acute poisonings by diverse heavy metals including chromium. The patient's death was assumed to have been caused by circulatory collapse due to internal bleeding and the direct toxicity of chromate compounds with hepatic malfunction and possibly disseminated intravascular coagulation (DIC).

[Acute renal failure, neuropathy and deafness due to sodium bromate intoxication: report of one case]

The clinical manifestations of sodium bromate intoxication include among others acute renal failure and deafness. Most of the toxic manifestations are reversible with the exception of renal failure and deafness. This patient ingested about 7.5 g of sodium bromate powder, which produced gastrointestinal irritation, hypotension, fatigue, deafness, acute renal failure, anemia and peripheral neuropathy. Hemodialysis was performed three times due to acute renal failure, although the renal function improved, it did not recover completely. The patient was discharged with BUN: 42 mg/dL and creatinine: 3.4 mg/dL; she was still deaf.