Combined X-ray radiotherapy and laser photothermal therapy of melanoma cancer cells using dual-sensitization of platinum nanoparticles

Metal nanostructures are promising agents sensitizing by laser light and X-ray in photothermal therapy (PTT) and radiotherapy (RT) of cancer that improve treatment strategies of cancer. Nanoscale platinum materials are favorable in nanomedicine applications. In this study, platinum nanoparticles (PtNPs) were synthesized and applied for cancer therapy upon 808-nm laser light and X-ray radiation, or their combination. Two power densities of laser (1.0 and 1.5 W cm^-2) and three X-ray doses (2, 4 and 6 Gy) were selected for irradiation of B16/F10 cell line at 24 and 72 h-post treatment. The synthesized PtNPs had a spherical shape with a diameter of 12.2 ± 0.7 nm, and were cytocompatible up to 250 μg mL^-1. A photothermal conversion activity in a concentration-dependent manner at 72 h-post treatment was observed. Also, PtNPs represented cytotoxicity upon X-ray radiation doses of 2, 4, and 6 Gy after 24 h, while, 72-h time passing led to deeper outcomes. Dual radiation of laser light and X-ray into PtNPs considerably improved the treatment via reactive oxygen species (ROS) production. PtNPs can act as a novel dual absorber of laser light and X-ray, a common sensitizer, for treatment of cancer. The results of this study can be considered after further clinical investigations for treatment of tumor models.

Enhanced melanoma cell-killing by combined phototherapy/radiotherapy using a mesoporous platinum nanostructure

BACKGROUND

Metal nanomaterials have a significant potential as photosensitizer and radiosensitizer. The purpose of this study was to evaluate the cytotoxicity of a platinum mesoporous nanostructure (Pt MN) toward a melanoma cancer cell line upon combined laser radiation (808 nm, 1 and 1.5 W cm^-2) and X-ray irradiation (6 MV, 2, 4, and 6 Gy).

METHODS

Pt MN was synthesized by a simple procedure and characterized by field emission scanning and transmission electron microscopy. A mouse malignant melanoma cell line C540 (B16/F10) was treated with Pt MN, laser light and/or X-ray.

RESULTS

Pt MN had a mesoporous structure with a sponge-resemble shape comprised of ensembles of very small adhered particles of <11 nm and about 5-nm pores. While Pt MN represented a low toxicity toward and considerable uptake into the cell line in a concentration range of 10-100 μg mL^-1, laser light radiation alone was also not toxic, and X-ray irradiation alone induced a limited toxicity, Pt MN was toxic against the cells in a dose dependent manner upon laser light radiation, X-ray irradiation, or their combined exposure. The killing efficacy of Pt MN upon X-ray irradiation was more obvious at 72 h post-treatment. The combined exposure (laser radiation followed by X-ray irradiation) led to a deep cell killing and a very low melanoma cell viability (∼1%). Significant melanoma cancer cell killing of Pt MN was due to reactive oxygen species (ROS) production upon combined exposure of laser and X-ray, while cell killing upon laser light radiation was due to heat generation.

CONCLUSION

Pt MN was introduced as a supreme laser/X-ray sensitizer for treatment of cancer with a high ability to produce ROS and a potent impact on decreasing cell viability.

Continuously sustained elimination of iodine deficiency: a quarter of a century success in the Islamic Republic of Iran

BACKGROUND

Iodine deficiency and related disorders were very common in Iran prior to 1996, when universal salt iodization (USI) was implemented and in 2000 Iran was declared iodine deficiency disorders (IDD) free. The aim of this study was to evaluate the adequacy of iodine intake by Iranian households in all 30 provinces of Iran, a quarter of a century after the intervention.

METHODS

A total of 18,000 school-aged children (8-10 years with mean 8.7 ± 1 year) were included in this study. Urine samples were collected from all children for measurement of urinary iodine excretion and 1800, 210 and 3000 salt samples were randomly collected from the family kitchen, production site of 73 salt factories and distribution circles of 30 provinces, respectively.

RESULTS

The median urinary iodine concentration (UIC) of participants was 161 μg/L. The proportion of children with UIC of, 20-49, 50-99 and ≥ 100 μg/L were 10.3, 15.9 and 73.7%, respectively. The mean (± SD) and median salt iodine values were 28.2 (± 12.6) and 31.7 ppm, at the production site, and 31.5 (± 13.6) and 29.6 ppm at the distribution circles, respectively. About 80% of factory salts had more than 20 ppm iodine. 98% of households consumed iodized salt, 80% had appropriate salt storage, and 83% of the household salts contained ≥ 20 ppm.

CONCLUSIONS

Based on the results of this study, Iranian populations are consuming adequate iodine. The well-maintained and monitored USI program has improved the dietary iodine intakes of the population, and the country has achieved all criteria of a well-controlled IDD program.

Morphology-Specific Discrimination between MS White Matter Lesions and Benign White Matter Hyperintensities Using Ultra-High-Field MRI

BACKGROUND AND PURPOSE

Recently published North American Imaging in Multiple Sclerosis guidelines call for derivation of a specific radiologic definition of MS WM lesions and mimics. The purpose of this study was to use SWI and magnetization-prepared FLAIR images for sensitive differentiation of MS from benign WM lesions using the morphologic characteristics of WM lesions.

MATERIALS AND METHODS

Seventeen patients with relapsing-remitting MS and 18 healthy control subjects were enrolled retrospectively. For each subject, FLAIR and multiecho gradient-echo images were acquired using 7T MR imaging. Optimized postprocessing was used to generate single-slice SWI of cerebral veins. SWI/FLAIR images were registered, and 3 trained readers performed lesion assessment. Morphology, location of lesions, and the time required for assessment were recorded. Analyses were performed on 3 different pools: 1) lesions of >3 mm, 2) nonconfluent lesions of >3 mm, and 3) nonconfluent lesions of >3 mm with no or a single central vein.

RESULTS

The SWI/FLAIR acquisition and processing protocol enabled effective assessment of central veins and hypointense rims in WM lesions. Assessment of nonconfluent lesions with ≥1 central vein enabled the most specific and sensitive differentiation of patients with MS from controls. A threshold of 67% perivenous WM lesions separated patients with MS from controls with a sensitivity of 94% and specificity of 100%. Lesion assessment took an average of 12 minutes 10 seconds and 4 minutes 33 seconds for patients with MS and control subjects, respectively.

CONCLUSIONS

Nonconfluent lesions of >3 mm with ≥1 central vein were the most sensitive and specific differentiators between patients with MS and control subjects.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses: erratum

In this erratum the funding section of Opt. Lett.42, 215 (2017)OPLEDP0146-959210.1364/OL.42.000215 has been updated.

Laser wakefield acceleration with mid-IR laser pulses

We report on, to the best of our knowledge, the first results of laser plasma wakefield acceleration driven by ultrashort mid-infrared (IR) laser pulses (λ=3.9  μm, 100 fs, 0.25 TW), which enable near- and above-critical density interactions with moderate-density gas jets. Relativistic electron acceleration up to ∼12  MeV occurs when the jet width exceeds the threshold scale length for relativistic self-focusing. We present scaling trends in the accelerated beam profiles, charge, and spectra, which are supported by particle-in-cell simulations and time-resolved images of the interaction. For similarly scaled conditions, we observe significant increases in the accelerated charge, compared to previous experiments with near-infrared (λ=800  nm) pulses.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses

We demonstrate laser-driven acceleration of electrons to MeV-scale energies at 1 kHz repetition rate using <10  mJ pulses focused on near-critical density He and H₂ gas jets. Using the H₂ gas jet, electron acceleration to ∼0.5  MeV in ∼10  fC bunches was observed with laser pulse energy as low as 1.3 mJ. Increasing the pulse energy to 10 mJ, we measure ∼1  pC charge bunches with >1  MeV energy for both He and H₂ gas jets.

Inadequate iodine nutrition of pregnant women in an area of iodine sufficiency

PURPOSE

I. R. Iran has been considered iodine replete since 2000, but iodine nutrition of vulnerable subjects is not clear. The main goal of this study was assessment of iodine nutrition and thyroid function in pregnant Iranian women.

METHODS

A total of 1072 pregnant women from ten provinces in the different parts of the country were recruited from November to March 2014. Median urinary iodine concentration (UIC) as the measure of iodine status and serum free T4 (FT4), thyrotropin (TSH), thyroglobulin (Tg), anti-thyroglobulin and anti-thyroid peroxidase antibodies (TgAb and TPOAb) were measured.

RESULTS

Mean ± SD age of the cohort was 27.0 ± 7.2 years and gestational age was 20.7 ± 10.0 weeks. The median UIC for pregnant women was 87.3 μg/L, being 92.1, 86.0 and 76.8 μg/L, in three trimesters of pregnancy, respectively. Median UIC of <100, 100-149, 150-249, 250-499 and ≥500 μg/L was found in 58.4, 19.8, 16.2, 5.13 and 0.46 % of subjects, respectively. Median (IQR) values in the first, second, and third trimesters were 1.7 (0.9-2.8), 2.1 (1.5-2.9), and 2.1 (1.4-2.8) mIU/L for TSH, and 16.4 (12.21-21.13), 14.34 (12.16-19.69), and 14/07 (12.02-18.64) pmol/L for FT4, respectively. The frequency of elevated serum TSH was 9.0 % (6.6 % subclinical, 2.4 % overt hypothyroidism). The frequency of low serum TSH was 0.6 %. The frequency of positive TPOAb was 7.6 %.

CONCLUSIONS

Results of this study have clarified that despite iodine sufficiency of school children in Iran, pregnant women have moderate iodine deficiency and need iodine supplementation.

Quantitative 3D and 2D Head Ultrasound to Determine Thresholds for Intervention In Preterm Neonates with Posthemorrhagic Ventricular Dilation

BACKGROUND: Preterm neonates with intraventricular hemorrhage (IVH) often acquire post hemorrhagic ventricle dilation (PHVD), which, when severe, can lead to neurological impairment. Cranial 2D ultrasound (US) images are used for the diagnosis and monitoring of PHVD; however, there is no consensus on the use of 2D US images to guide treatment. This can lead to delays in interventions, and the potential for brain injury. We have developed a 3D US system that has been shown to accurately detect changes ventricle volumes (VV).

OBJECTIVES: We investigate the utility of using 3D and 2D US measurements to determine thresholds for treatment of neonates with PHVD and to predict the need for further treatments.

DESIGN/METHODS: Neonates were imaged twice weekly in accordance to a protocol approved by the research ethics board. 3D US images were manually segmented to obtain VV. 2D measurements included ventricle index, anterior horn widths, third ventricle width, and largest thalamo-occipital distance. The rate of change for each measurement was calculated. Decisions to perform ventricular taps (VTs) to relieve intracranial pressure were made independently by neurosurgeons who were blinded to study images. Receiver operator curves (ROC) were generated using the sensitivity and specificity of the rates of change of sonographic parameters in predicting the need for V T. For each parameter optimal threshold for intervention was estimated by the area under ROC; and positive and negative predictive values (PPV, NPV) were calculated. Additionally, we investigated whether US measurements predicted the need for multiple interventions.

RESULTS: 23 neonates with PHVD were enrolled, 8 required interventions. The best predictor to determine initial intervention was the rate of change in VV when a threshold of &gt;2.04 cm3/day was used within the first three weeks of life (NPV and PPV of 1) and, this measurement was able to determine if then a patient would require further interventions when a threshold of -0.04 cm3/day was used looking at imaging time points after the first intervention (NPV and PPV of 1). 2D measurements were less sensitive and/or less specific (sensitivity of 88-57%, specificity of 100-79%, PPV of 0.88-0.57 and NPV of 0.93-0.79).

CONCLUSION: 3D US VV can predict the requirement for interven-tional ventricular tap in neonates with IVH, and can identify patients that have resolving PHVD following initial intervention, with higher sensitivity and specificity than 2D US measurements. These findings show promise for early classification of neonates using 3D US for prediction of interven-tional therapy, potentiallyaiding in timely management of these patients.

Multi-MeV Electron Acceleration by Subterawatt Laser Pulses

We demonstrate laser-plasma acceleration of high charge electron beams to the ∼10  MeV scale using ultrashort laser pulses with as little energy as 10 mJ. This result is made possible by an extremely dense and thin hydrogen gas jet. Total charge up to ∼0.5  nC is measured for energies >1  MeV. Acceleration is correlated to the presence of a relativistically self-focused laser filament accompanied by an intense coherent broadband light flash, associated with wave breaking, which can radiate more than ∼3% of the laser energy in a ∼1  fs bandwidth consistent with half-cycle optical emission. Our results enable truly portable applications of laser-driven acceleration, such as low dose radiography, ultrafast probing of matter, and isotope production.

Analyzing the therapeutic effects of short wrist splint in patients with carpal tunnel syndrome (CTS) under ibuprofen treatment from an EMG-NCV perspective

Objective: Carpal tunnel symptoms are typical outside nerve involvement and a significant reason of inability. This syndrome often causes weakness and pain in the affected hand. Therefore, the researchers decided to perform a study that aimed to investigate the therapeutic effects of Wrist Splint (short wrist splint) in patients admitted to the neurology clinic of Vali Asr Hospital of Birjand with carpal tunnel syndrome (CTS) under ibuprofen treatment from an EMG-NCV perspective. Methods: This clinical trial was performed on patients admitted to the neurology clinic of Vali Asr Hospital during the spring and summer of 2013. The participants of the study were classified into two teams. The initial team of cases went under medical treatment with ibuprofen (800 mg BID for 4-6 weeks) and the second group of patients went under medical care with ibuprofen (800 mg BID for 4-6 weeks) with a short wrist splint. Results: 40 cases participated in the research. The mean age of participants was 32/ 75 ± 4/ 33 years (range 20 to 48 years), respectively. Most of the participants were females (n = 30, 75% respectively). The mean score, latency and velocity between the two groups were mainly distinct (respectively p = 0.05, 0.001, and 0.003). There were significant differences between amplitude before the start of the study (p = 0.000) among the participants. Discussion: The results showed that patients treated with ibuprofen and wrist splint along the para-clinics presented a better response to treatment.

Hepatoprotective effects of zataria multiflora ethanolic extract on liver toxicity induced by cyclophosphamide in mice

Although cyclophosphamide (CP), an alkylating agent, has been extensively used in chemotherapy, it possesses a wide spectrum of adverse effects including hepatotoxicity. This study was aimed to evaluate the protective effects of Zataria multiflora against hepatic damage induced by CP in mice.Mice were orally (gavages) pretreated with the ethanolic extract aerial parts of Zataria at doses of 50, 100, 200, or 400 mg/kg for 7 consecutive days before a single intraperitoneal injection of 200 mg/kg CP. After 24 h, animals were anesthetized, blood samples and hepatic tissues were collected and used for biochemical and histological examination.Serum levels of hepatic markers were significantly increased after only CP treated animals but restored in Zataria pretreated groups. A single dose of CP administration also markedly induced abnormality in the levels of several biomarkers associated with oxidative stress in liver tissues homogenates. However, pretreatment with Zataria significantly inhibited the abnormality of antioxidant enzymes defense system in the liver tissues. In addition, histopathological studies proved that CP causes damage to the liver, and this was evidenced by the induced dilated and congested sinusoidal space, lymphocytic infiltration between hepatocytes, portal space with moderate to severe inflammation and necrotic hepatocyte with absence of nuclei. Zataria effectively protected animals against CP-induced hepatic tissue damages.Our results reveal that Zataria produces a potent hepatoprotective role and could be a potent candidate to use concomitantly as a supplement agent against hepatotoxicity of CP for the patients undergoing chemotherapy.

Melatonin ameliorates oxidative stress and reproductive toxicity induced by cyclophosphamide in male mice

The present study evaluated the efficacy of melatonin in cyclophosphamide (CP)-induced testicular injury, lipid peroxidative damage, and antioxidant enzymes status of the mice testis on the basis of biochemical and histological studies. Mice were pretreated with four different doses of melatonin (2.5, 5, 10, and, 20 mg/kg by body weight (b.w.)) via intraperitoneal injection for five consecutive days followed by injection with CP (200 mg/kg b.w.) 1 h after the last injection of melatonin on the 5th day. After 24 h, mice were euthanized, testes were immediately removed, and biochemical and histological studies were conducted. Treatment with melatonin significantly mitigates lipid peroxidation, superoxide dismutase, and catalase activity and the level of reduced glutathione content abnormality induced by CP in mice testis. Histological examination clearly demonstrates that pretreatment of melatonin prevented CP-induced spermatogenesis toxicity and spermatogenic cells reduction in mice testis. The protective effect of melatonin is likely due to the antioxidative properties of the indolamine existed in the chemical structure. Because melatonin is a safe, natural compound, it could be used concomitantly as a supplement to protect people undergoing chemotherapy against reproductive toxicity.

Single-cell resolution diagnosis of cancer cells by carbon nanotube electrical spectroscopy

We report the use of vertically aligned carbon nanotubes (VACNTs) as electrical endoscopes (biosensors) for cancer metastatic diagnosis at single-cell resolution. The device is based on direct signal extraction by means of vertically aligned conductive carbon nanotubes from a live cell membrane, which has been disrupted during carcinogenesis at its primary and progressive stages. The value of this electrical disruption depends on the cancer metastatic grade. In addition, the electrical resonance behavior of the cell, halted during cancer progression, could be monitored as a new cancer diagnostic profile. By taking a second derivative of the cell impedance with respect to applied frequency, we have arrived at a new spectroscopy tool for distinguishing cancerous stages of colon and breast carcinoma cells.

Assessment of antibody titers and immunity to Hepatitis B in children receiving chemotherapy

BACKGROUND

There is a decrease in vaccine-specific antibody to certain vaccine-preventable diseases in children after chemotherapy, but the frequency of non-immune patients is not clear. In the present case-control study, was taken under investigation protection level to Hepatitis B infection in children 6 months after completing chemotherapy.

MATERIALS AND METHODS

In this study 68 patients with cancer and 68 healthy children were enrolled. Patients were 1.5 -12 years old with completed standard chemotherapy at least for 6 months. All the patients and healthy children were negative for HBsAg and HBeAg and had received Hepatitis B vaccination. IgG antibody concentrations against Hepatitis B Virus (HBV) were determined in the patients receiving chemotrapy and healthy subjects serum by ELISA method. IgG antibody titer > 10 mIU/ml was considered as baseline protective titer for preventing HBV infection.

RESULTS

Anti-HBs antibody titer in 19.12% of patients was less than 10 mIU/ml and 11.76% of the patients had borderline antibody titer (10-20 mIU/ml). In healthy subjects, 2.94% and 5.88% had antibody titer < 10 mIU/ml and 10-20 mIU/ml, respectively. According to statistical analysis, frequency of non immune subjects in children with cancer was significantly higher than those in healthy children (P-value=0.024).

CONCLUSION

HBV vaccination post-intensive chemotherapy in the children with cancer is strongly recommended.

Comparison between topical honey and mafenide acetate in treatment of burn wounds

Histological and clinical studies of wound healing were performed in comparable cases of fresh partial-thickness burns treated with honey dressing or mafenide acetate in two groups of 50 randomly allocated patients. Of the patients with honey-treated wounds, 84% showed satisfactory epithelialization by day 7 and 100% by day 21. In wounds treated with mafenide acetate, epithelialization occurred by day 7 in 72% of cases and in 84% by day 21. Histological evidence of reparative activity was observed in 80% of wounds treated with honey dressing by day 7 with minimal inflammation. Fifty-two per cent of the mafenide acetate treated wounds showed reparative activity with inflammatory changes by day 7. Reparative activity reached 100% by day 21 with the honey dressing and 84% with mafenide acetate. Thus, in honey-dressed wounds, early subsidence of acute inflammatory changes, better control of infection, and quicker wound healing were observed, while in mafenide acetate treated wounds a sustained inflammatory reaction was noted even on epithelialization.

Estrogen receptors alpha and beta immunohistochemical expression: clinicopathological correlations in pituitary adenomas

AIM

We investigated the immunohistochemical expression of estrogen receptors alpha (ERalpha) and beta (ERbeta) in pituitary adenoma subtypes combined with clinicopathological factors.

MATERIALS AND METHODS

Pituitary adenomas (n=75) were immunostained for ERalpha and ERbeta using the streptavidin-biotin-peroxidase complex method with a monoclonal ERalpha antibody and polyclonal ERbeta antibody.

RESULTS

Nuclear immunoreactivity for both receptors was highest among PRL, FSH/LH, null cell, and GH adenomas. ACTH, silent subtypes I and II corticotrophs, and subtype III adenomas were the least immunoreactive for both receptors. ACTH adenomas expressed significantly less ERalpha than FSH-LH, GH, and null cell adenomas. A significantly elevated ERalpha expression was observed in macroadenomas compared to microadenomas and non-invasive compared to invasive tumors.

CONCLUSION

ERalpha and ERbeta are differentially expressed in the various pituitary adenoma subtypes suggesting a cell-specific function for these receptors. To elucidate the role of ERalpha in tumor size and invasiveness, additional studies are required.

Mutations in CCBE1 cause generalized lymph vessel dysplasia in humans

Lymphedema, lymphangiectasias, mental retardation and unusual facial characteristics define the autosomal recessive Hennekam syndrome. Homozygosity mapping identified a critical chromosomal region containing CCBE1, the human ortholog of a gene essential for lymphangiogenesis in zebrafish. Homozygous and compound heterozygous mutations in seven subjects paired with functional analysis in a zebrafish model identify CCBE1 as one of few genes causing primary generalized lymph-vessel dysplasia in humans.

Anaemia control: lessons from the flour fortification programme

OBJECTIVES

Anaemia is an important public health problem in Iran; therefore, a programme of flour fortification with iron was launched in two pilot provinces. The present study was conducted in January 2009 to evaluate the effectiveness and process of this programme.

STUDY DESIGN

A 'before-and-after study' was conducted to evaluate the effectiveness of the flour fortification programme, and the process of the programme was evaluated using a cross-sectional study.

METHODS

To evaluate the effectiveness of the programme, blood haemoglobin and ferritin levels were measured in sample populations from Bushehr and Golestan provinces. The target population was women aged 15-49 years. Iron content was measured in samples of flour and bread to evaluate the flour fortification process in these two national pilot provinces.

RESULTS

The total study population was 600 women from Bushehr province and 652 women from Golestan province. Similar trends were found in the indicators of anaemia/iron deficiency among the women studied in both provinces. The flour fortification programme only appears to have had a beneficial effect on ferritin levels (iron deficiency) in the two provinces. The prevalence of iron-deficiency anaemia before and after the intervention did not differ significantly in either province. Interestingly, the prevalence of anaemia (low haemoglobin) was significantly higher after the intervention in women from both provinces. The coverage of fortified flour and bread was 90% and 98.7% in Bushehr province, and 94.1% and 95% in Golestan province, respectively.

CONCLUSIONS

In areas where anaemia is not mainly due to iron deficiency, an iron fortification programme might decrease the prevalence of iron deficiency without affecting the prevalence of anaemia.

Emerging contaminants and treatment options in water recycling for indirect potable use

Solutions to global water stress problems are urgently needed yet must be sustainable, economical and safe. The utilisation of alternative water sources like reclaimed municipal wastewater is one of the most obvious and promising options in integrated water resources management. Among the various beneficial uses of reclaimed wastewater Aquifer Recharge (AR) receives growing attention because it features advantages such as additional natural treatment, storage capacity to buffer seasonal variations of supply and demand as well as mixing with natural water bodies which promotes the acceptance of further uses, particularly indirect potable use. Major concerns about the safety of this exploitation route of an alternative water source are connected to microbial and chemical contaminants occurring in wastewater, among which are emerging trace organics like endocrine disrupters and pharmaceuticals. This paper reviews the current international debate about the relevance of emerging contaminants and technical mitigation options in water recycling for indirect potable use.

Adrenomedullin expression in pituitary adenomas and nontumoral adenohypophyses

Adrenomedullin (ADM) is a novel peptide originally identified in extracts of human pheochromocytoma. It is produced by several tissues, including the pituitary gland. The presence of ADM has been immunohistochemically demonstrated in pathologic pituitary glands, but no systematic study of ADM expression in human pituitary adenomas has been reported. Thus, we investigated ADM immunoexpression in 88 various hormone-secreting and clinically nonfunctioning pituitary adenoma types as well as 30 nontumoral adenohypophyses. Furthermore, ADM immunoreactivity was assessed on a 0 to +3 scale in all samples. We found strong immunoreativity for ADM in normal gonadotrophs also expressing FSH and LH whereas in the other adenohypophysial cell types expression of ADM was mild. Results showed that normal adenohypophyses were strongly immunopositive for ADM (2.18+/-0.11). Our findings demonstrate that ADM expression in the anterior pituitary is diminished in tumors as compared to the normal gland. The physiologic function of ADM is unknown, but it could act as a paracrine or autocrine factor in the adenohypophysis.

Assessment of bioaccumulation and neurotoxicity in rats with portacaval anastomosis and exposed to manganese phosphate: a pilot study

The use of the additive methylcyclopentadienyl manganese tricarbonyl in unleaded gasoline has resulted in increased attention to the potential toxic effects of manganese (Mn). Hypothetically, people with chronic liver disease may be more sensitive to the adverse neurotoxic effects of Mn. In this work, bioaccumulation of Mn, as well as histopathology and neurobehavioral damage, in end-to-side portacaval anastomosis (PCA) rats exposed to Mn phosphate via inhalation was investigated. During the week before the PCA operation, 4 wk after the PCA operation, and at the end of exposure, the rats were subjected to a locomotor evaluation (day-night activities) using a computerized autotrack system. Then a group of 6 PCA rats (EXP) was exposed to 3050 microg m(-3) (Mn phosphate) for 8 h/day, 5 days/wk for 4 consecutive weeks and compared to a control group (CON), 7 PCA rats exposed to 0.03 microg m(-3). After exposure, the rats were euthanized and Mn content in tissues and organs was determined by neutron activation analysis. The manganese concentrations in blood (0.05 microg/g vs. 0.02 microg/g), lung (1.32 microg/g vs. 0.24 microg/g), cerebellum (0.85 microg/g vs. 0.64 microg/g), frontal cortex (0.87 microg/g vs. 0.61 microg/g), and globus pallidus (3.56 microg/g vs. 1.33 microg/g) were significantly higher in the exposed group compared to the control group (p <.05). No difference was observed in liver, kidney, testes, and caudate putamen between the two groups. Neuronal cell loss was assessed by neuronal cell counts. The loss of cells in globus pallidus and caudate putamen as well as in frontal cortex was significantly higher (p <.05) for the EXP group. Assessment of the locomotor activities did not reveal any significant difference. This study constitutes a first step toward our understanding of the potential adverse effects of Mn in sensitive populations.