[Biological functions of tin and disease].

Tin generates a wide variety of biological functions due to its chemical character. In this article, the modes of the biological functions of tin(especially organotin compounds) are reviewed, with special emphasis on the connection with the immune system, brain nervous system and endocrine system, on the basis of our data. To sum up this article, the biological functions of organotin compounds appear to be due to the following several processes: (1) their incorporation into the cells in vesicle form through fusion or in a similar manner to their incorporation in cationic form; (2) transport to and accumulation in the regions of the Golgi apparatus and endoplasmic reticulum (ER), but not to or in the plasma membrane or nucleus because of their hydrophobicity; (3) inhibition of intracellular phospholipid transport between organelles due to impairment of the structures and functions of the Golgi apparatus and ER; (4) inhibition of the membrane-mediated signal transduction system leading to DNA synthesis via phospholipid turnover and Ca2+ mobilization, as in cell proliferation systems; (5) disturbance of the trace element balance and the localization of certain elements; (6) disorders of membrane-mediated Ca2+ homeostasis via various channel functions including Zn modulation on the plasma and organelle membranes, and protein phosphorylation, as in the signal transduction systems of memory and olfaction; (7) necrosis or apoptosis in vivo or toxic cell death in vitro.

[A cohort study on risk factors of lung cancer in Yunnan tin miners].

BACKGROUND: Smoking is a major cause of lung cancer. Studies of lung cancer among miners have shown that occupational exposure also played an important role. The aim of this study is to investigate radon, cigarette use and other risk factors of lung cancer in Yunnan tin miners and to provide a scientific basis for the prevention and control of occupational lung cancer. METHODS: A prospective cohort study was conducted among Yunnan tin miners, the associations between potential risk factors for lung cancer were analyzed by multivariate Cox regression model. Effects of age at first radon exposure and radon exposure rate on lung cancer risk were analyzed. The relationship between cumulative working level month and lung cancer was analyzed according to smoking status. The joint effect of tobacco use and cumulative radon exposure was analyzed based on additive and multiplicative models. RESULTS: Increased risk of lung cancer was associated with age at enrollment, tobacco use, prior bronchitis, and cumulative arsenic and radon exposure, while higher education level was associated with decreased lung cancer risk. An inverse effect of radon exposure rate was observed. There was no significant association between lung cancer risk and first radon exposure age. There was a significant additive interaction between tobacco use and radon exposure on lung cancer risk. CONCLUSIONS: Several risk factors may contribute to the high incidence of lung cancer in Yunnan tin miners. Further studies are warranted to evaluate joint effect of different risk factors.

High prevalence of diffuse parenchymal lung diseases among Turkish tinners.

The objective is to investigate the prevalence of parenchymal lung diseases among tinners. Twenty-four tinners who signed an informed consent form in the Gaziantep area were the subjects of this study. Demographics, spirometric test results, and high resolution computed tomography (HRCT) scans were obtained for all the tinners. Out of 24 tinners, eleven tinners (46%) had HRCTs consistent with DPLD. Of these 11 subjects, HRCT findings were consistent with respiratory bronchiolitis interstitial lung disease in nine, usual interstitial pneumonia pattern in one, and non-specific interstitial pneumonia in one. HRCT patterns consistent with DPLDs are significantly prevalent among Turkish tinners. This is the first field study reporting this occupational lung hazard in tinners. Future research is needed to uncover the underlying mechanisms.

Exposición accidental a polvo de oro / Accidental exposure to gold powder

Se presenta un caso clínico de exposición accidental a polvo de oro utilizado en pintura artesanal conteniendo bronce (aleación de cobre y estaño), siendo el cobre responsable de la presentación clínica en la intoxicación aguda por este producto. El diagnóstico de neumonitis química se basó en el severo distrés respiratorio y en los hallazgos radiológicos. La elevación de la cupremia hallada en este caso reveló la absorción sistémica del cobre por vía respiratoria y gastrointestinal. La presencia de fiebre y algunos hallazgos de laboratorio fueron relacionados con la enfermedad conocida como metal fume fever o "fiebre por el metal". Se hace énfasis en la necesidad de tener en cuenta esta enfermedad frente a una exposición inhalatoria a productos que contengan metales, así como a la influencia de la terapia de soporte en la evolución favorable de este paciente. La indicación de penicilamina como quelante en este caso es discutida. Se destaca la necesidad de reforzar los programas preventivos a fin de evitar los accidentes en la infancia

[Occupational poisoning with psychiatric manifestations]. / Intossicazioni professionali con manifestazioni psichiatriche.

Numerous occupational intoxications (acute, chronic and their sequelae) may affect the central nervous system and result in a wide variety of neuropsychiatric effects, ranging from subtle behavioural disturbances to overt psychosis. Chemicals causing such manifestations include many metals and organometals (Hg, Mn, Pb, Al, Sn), pesticides (organophosphates), compounds utilised in the industrial setting as solvents or intermediates (carbon disulfide, hydrocarbons and their halogenated derivatives), and combustion products (carbon monoxide). Some types of toxic insults may not be reflected in any clinical manifestation. However, this type of damage may render the brain more vulnerable to additional insult or accelerate physiological loss of neurones with ageing. Thus, occupational exposures to chemicals (Al, Pb, organic solvents) might be involved in the causation of neurodegenerative diseases--such as Alzheimer's disease--which are usually labelled as "idiopathic". A careful occupational anamnesis is crucial to diagnose work-related psychiatric manifestations and--consequently--to interrupt the toxic exposure, to start therapy, and to promote insurance compensation.

Cattle mortality in the Thane district, India: a study of cause/effect relationships.

An unexpected mortality of more than 300 cattle was investigated near a metal recovery factory located in a rural area of the Thane district of India. The factory was engaged in reclaiming lead, aluminum, tin, and zinc from discarded lead storage batteries and soft drink cans. The environmental samples (soil, leaves, grass, slag, water, and sediment), human blood and hair and animal samples (blood, urine, peritoneal fluid, liver, kidney, cow dung, ribs, and femur), collected for analysis revealed toxic levels of lead, cadmium, and chromium. Clinical examination of factory workers and school children revealed cough, fever, gastric problems, abdominal pain, skin lesions (scabies), and blue line on gums. Histopathological examination of animal tissues revealed chronic pathology with lead inclusion bodies in hepatocytes and renal tubules. Based on environmental, clinical, analytical, and histopathological observations, the mortality has been attributed to toxic levels of metals in the body and the malnourished status of the animals.

Clinical application of spontaneous red blood cell labeling with Tc-99m sodium pertechnetate.

Red blood cells (RBC) may be labeled with Tc-99m after Tc-99m sodium pertechnetate is injected in the presence of a reducing agent, such as stannous chloride. Thus, spontaneous RBC labeling with Tc-99m is expected to be seen in patients with a high plasma concentration of tin. Spontaneous RBC labeling with Tc-99m was obtained in a 73-year-old woman who was clinically diagnosed with tin intoxication and proved to have a high concentration of plasma tin. The RBC labeling rate was calculated as 96% with blood sampling. Spontaneous RBC labeling with Tc-99m is a very simple method for proving a high plasma tin concentration and is adaptable to clinical diagnosis.

Tin: an overlooked contact sensitizer?

Patch tests with metallic tin in 73 nickel-sensitive patients revealed 6 positive allergic reactions. Only 4 doubtful reactions were seen, which makes irritancy unlikely. The relevance and clinical significance of the unexpected finding deserves further evaluation.

Subclinical cervico-spino-bulbar effects of lead: a study of short-latency somatosensory evoked potentials in workers exposed to lead, zinc, and copper.

Subclinical central and peripheral nervous system dysfunction among lead-exposed workers was studied by measuring short-latency somatosensory evoked potentials (SSEP) and maximal motor and sensory nerve conduction velocities (MCV and SCV) following stimulation of the median nerve at the wrist. The examinations were conducted in 20 gun-metal foundry workers exposed to lead, zinc, copper, and tin, with blood lead (BPb) concentrations of 16 to 64 micrograms/dl (mean, 42 micrograms/dl). The interpeak latency of SSEP in the cervico-spino-bulbar region [N9(Erb)-N13 latency] was significantly prolonged, and the MCV and SCV in the forearm were significantly slowed. Multiple regression analysis revealed that the yield of urinary lead following challenge with calcium disodium ethylenediamine tetraacetate (CaEDTA) and packed red blood cell volume were the major factors associated with the prolongation of SSEP latency in the cervico-spino-bulbar region. Similarly, the interpeak latency in the upper central nervous system (N13-N20 latency) was inversely related to the zinc concentration in erythrocytes; latency up to the Erb's point [N9(Erb) latency], which reflects conduction time in a long pathway of the sensory median nerve, was inversely related to urinary zinc level; the MCV and SCV in the palm were positively related to erythrocyte zinc concentration and plasma copper concentration, respectively. These findings suggest that the subclinical neurophysiological effects of lead occur not only in peripheral nerves but also in the central nervous system. It appears that zinc antagonizes the central and peripheral neurologic dysfunction caused by lead; similarly, copper antagonizes the peripheral sensory nerve dysfunction.

[Acute poisoning by inhalation of metallic vapors]. / Les intoxications aiguës par l'inhalation de vapeurs métalliques.

Seven cases of acute intoxications by inhalation of metallic vapors are reported. The metals involved were zinc in three cases, tin in one case and mercury in three cases. The severity of the respiratory symptoms was dependent from the inhalated metal. The inhalation of zinc or tin vapors produced an acute limited pneumonitis. A lesional pulmonary oedema and acute interstitial fibrosis with lethal outcome was observed in two cases of intoxication by mercury vapors. The treatment by dimercaptopropanol used in mercury intoxications, increased urinary mercury excretion, but did not improve the pulmonary symptoms.