Chronic overexposure to cadmium fumes associated with IgA mesangial glomerulonephritis

BACKGROUND: Cadmium is a metal used in the zinc, copper and steel industries, and in the manufacture of electric batteries and solar cells. Acute cadmium poisoning is characterized by irritation of the respiratory tract, while in chronic poisoning the main target organ is the renal tubule. AIMS: We report a patient with chronic work overexposure to cadmium, who presented a IgA mesangial glomerulonephritis with no respiratory or renal tubule involvement. Case report A 39-year-old patient was referred to our hospital for evaluation of a glomerular nephropathy. For the past 12 years he had worked as a welder, using cadmium electrodes. The patient had no respiratory symptoms and the chest X-ray was normal. Tests showed a proteinuria of 2 g in 24 h with microhaematuria [150 red blood cells/high power field (rbc/hpf)], with preservation of the renal function (creatinine clearance of 137 ml/min). The concentrations of cadmium in blood and urine were 45 micro g/l and 25 micro g/g creatinine, and an environmental study showed that levels of cadmium in the workplace were 52 micro g/m(3). A renal biopsy showed an IgA mesangial glomerulonephritis. The patient ceased to work with cadmium, and 1 year later cadmium levels had decreased and renal function was found to be stable. CONCLUSIONS: IgA mesangial glomerulonephritis is a disease of unknown aetiology which has been associated with other diseases. Chronic overexposure to cadmium may contribute to the development of this nephrophathy.     

Nuclear localization of epidermal growth factor receptor (EGFR) in ameloblastomas

Background: Ameloblastoma is a locally invasive neoplasm often associated with morbidity and facial deformities, showing increased Epidermal Growth Factor Receptor (EGFR) expression. Inhibition of EGFR was suggested as a treatment option for a subset of ameloblastomas. However, there are resistance mechanisms that impair anti-EGFR therapies. One important resistance mechanism for EGFR-inhibition is the EGFR nuclear localization, which activates genes responsible for its mitogenic effects, such as Cyclin D1.Methods: We assessed EGFR nuclear localization in encapsulated (unicystic, n = 3) and infiltrative (multicystic, n = 11) ameloblastomas and its colocalization with Cyclin D1 by using anti-EGFR and anti-lamin B1 double labeling immunofluorescence analyzed by confocal microscopy. Oral inflammatory fibrous hyperplasia and oral squamous cell carcinoma samples were used for comparison.Results: Twelve cases of ameloblastoma exhibited nuclear EGFR colocalization with lamin B1. This positive staining was mainly observed in the ameloblast-like cells. The EGFR nuclear localization was also observed in control samples. In addition, nuclear EGFR colocalized with Cyclin D1 in ameloblastomas.Conclusions: Nuclear EGFR occurs in ameloblastomas in association with Cyclin D1 expression, which is important in terms of tumor biology clarification and raises a concern about anti-EGFR treatment resistance in ameloblastomas.     

Involvement of monoaminergic system in the antidepressant‐like effect of riparin I from Aniba riparia (Nees) Mez (Lauraceae) in mice

In past studies conducted by our group, riparin I (rip I) isolated from the green fruit of Aniba riparia presented antianxiety effects in mice, while its analogs rip II and III showed anxiolytic and antidepressant‐like actions. This time around, we investigated a possible antidepressant activity of rip I using the forced swimming test (FST) and tail suspension test (TST) as predictive tests for antidepressant activity in rodents. In addition, the involvement of the monoaminergic system in this effect was also assessed. rip I was acutely administered by intraperitoneal (i.p.) and oral (p.o) routes to male mice at doses of 25 and 50 mg/kg. Results showed that rip I at both tested doses and administration routes produced a significant decrease in immobility time in FST and TST. The pretreatment of mice with prazosin (1 mg/kg, i.p., an α₁‐adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an α₂‐adrenoceptor antagonist), SCH23390 (15 μg/kg, i.p., a dopamine D1 receptor antagonist), sulpiride (50 mg/kg, i.p., a dopamine D2 receptor antagonist), p‐chlorophenylalanine (100 mg/kg, an inhibitor of serotonin synthesis) or ritanserin (4 mg/kg, a serotonin 5‐HT2_a/2_c receptor antagonist) blocked the anti‐immobility effects elicited by rip I (50 mg/kg, p.o.) in the FST. Taken together, results indicate that rip I produces significant antidepressant‐like activity in the FST and TST, and this effect seems to be dependent on its interaction with noradrenergic, dopaminergic and serotonergic systems.