Organotin Compounds
Trimethyltin Compounds
Ovotesticular Disorders of Sex Development
Acari
Tin
Venturicidins
Endocrine Disruptors
Triethyltin Compounds
Induction of aberrant mitosis with PCBs: particular efficiency of 2, 3,3',4,4'-pentachlorobiphenyl and synergism with triphenyltin. (1/122)
The polychlorinated biphenyls 2,2',5,5'- and 3,3',4, 4'-tetrachlorobiphenyl, 2,3,3',4,4'- and 3,3',4,4', 5-pentachlorobiphenyl and 2,2',4,4',5,5'-hexachlorobiphenyl were tested for spindle-disturbing activity in V79 Chinese hamster cells. Clones lacking endogenous cytochrome P450 activity or expressing rat CYP1A1 or CYP2B1 were used. Induction of abnormal chromosomal arrangements in mitosis were found to be favoured by o-chlorine substitutions, but not by co-planarity giving affinity, for example, for the Ah receptor and CYP1A isoenzymes. Only 2,2',5, 5'-tetrachloro- and 2,3,3',4,4'-pentachlorobiphenyl gave dose-response curves similar to many other compounds tested in vitro, showing an increase from the background level of 10 to 100% disturbed mitoses with nominal concentrations >10(-6) M, i.e. concentrations far above the total PCB concentrations found in human blood. Cells transfected with rat CYP2B1 were more sensitive to the most active congener, 2,3,3',4,4'-pentachlorobiphenyl, than cells lacking P450 activity or expressing CYP1A1. Induction of abnormal mitosis by PCB metabolites formed by P450 enzymes cannot be excluded, but does not seem likely because of the short treatment time and the reportedly slow metabolism of PCBs. 2,3,3',4, 4'-Pentachlorobiphenyl showed synergistic activity with the potent spindle poison triphenyltin. Inactive concentrations of both agents (10 and 50 nM, respectively) caused abnormal configurations when combined. This is an important finding since exposure to mixtures of compounds is common and it motivates further studies of subthreshold activities of highly lipophilic environmental contaminants. (+info)Studies on transfer ribonucleic acids and related compounds. IX. Ribooligonucleotide synthesis using a photosensitive o-nitrobenzyl protection at the 2'-hydroxyl group. (2/122)
o-Nitrobenzyl group was introduced to the 2'-hydroxyl function of uridine via 2',3'-O-(dibutylstannylene) uridine. The benzylated uridine was protected at the 5'-hydroxyl group with monomethoxytrityl chloride and condensed with 2',3'-O-dibenzoyluridine 5'-phosphate or N,N',2',3'-O-tetrabenzoyladenosine 5'-phosphate using dicyclohexylcarbodiimide (DCC). o-Nitrobenzyl ether linkage of the dinucleotides was removed by UV irradiation with wavelength longer than 320 nm. Deprotected UpU and UpA thus obtained were characterized by RNase A digestion. (+info)Degradation of triphenyltin by a fluorescent pseudomonad. (3/122)
Triphenyltin (TPT)-degrading bacteria were screened by a simple technique using a post-column high-performance liquid chromatography using 3,3',4',7-tetrahydroxyflavone as a post-column reagent for determination of TPT and its metabolite, diphenyltin (DPT). An isolated strain, strain CNR15, was identified as Pseudomonas chlororaphis on the basis of its morphological and biochemical features. The incubation of strain CNR15 in a medium containing glycerol, succinate, and 130 microM TPT resulted in the rapid degradation of TPT and the accumulation of approximately 40 microM DPT as the only metabolite after 48 h. The culture supernatants of strain CNR15, grown with or without TPT, exhibited a TPT degradation activity, whereas the resting cells were not capable of degrading TPT. TPT was stoichiometrically degraded to DPT by the solid-phase extract of the culture supernatant, and benzene was detected as another degradation product. We found that the TPT degradation was catalyzed by low-molecular-mass substances (approximately 1,000 Da) in the extract, termed the TPT-degrading factor. The other fluorescent pseudomonads, P. chlororaphis ATCC 9446, Pseudomonas fluorescens ATCC 13525, and Pseudomonas aeruginosa ATCC 15692, also showed TPT degradation activity similar to strain CNR15 in the solid-phase extracts of their culture supernatants. These results suggest that the extracellular low-molecular-mass substance that is universally produced by the fluorescent pseudomonad could function as a potent catalyst to cometabolite TPT in the environment. (+info)A photobiological and photophysical-based study of phototoxicity of two chlorins. (4/122)
To understand the fundamental determinants of phototoxic efficacy and absorbed photodynamic dose, the triplet state and photobleaching quantum yields in living cells, cellular uptake, intracellular localization, and correlation with cell viability were studied for the two purpurins tin ethyl etiopurpurin 1 (SnET2) and tin octaethylbenzochlorin (SnOEBC) in ovarian cancer cells (OVCAR5). Although the triplet yields of these two photosensitizers were not significantly affected by cellular incorporation, the photobleaching yields were shown to be 3 orders of magnitude higher for cellular-bound sensitizer than for free or albumin-bound photosensitizer and higher for SnET2 than for SnOEBC for all of the cases. The intracellular concentration of SnOEBC was half that of SnET2 after 3 h- and 24 h-incubation times for both 0.1 microM and 1.0 microM incubation concentrations. Despite the lower concentrations of SnOEBC, the phototoxicity of the two photosensitizers was comparable at 1-microM incubation concentration and was up to 10-fold higher for SnOEBC at the lower concentration. The subcellular localization established using confocal microscopy and molecular probes showed that both photosensitizers were primarily lysosomally localized. SnOEBC, however, had an extra-lysosomal, mitochondrial localization component. The photophysical measurements allowed calculation of the intracellular singlet oxygen production, which indicated that the photosensitizer-light dose reciprocity was limited by photobleaching for SnET2 but only minimally for SnOEBC, and this was confirmed through cell-survival studies. Taken together, these data indicate that the critical determinant of differences in phototoxicity between the two molecules was their relative rates of photobleaching and their subcellular localization. The study points to the importance of combining photosensitizer uptake and localization with photophysical measurements in the relevant biological milieu to reasonably interpret and/or predict photosensitization efficacies. (+info)Interaction of diphenyltin(IV) dichloride with some selected bioligands. (5/122)
The interaction of diphenyltin(IV) with selected bioligands having a variety of model functional groups were investigated using the potentiometric technique. The hydrolysis constants of diphenyltin(IV) cation and the step-wise formation constants of the complexes formed in solution were calculated using the non linear least-squares program MINIQUAD-75. The participation of different ligand functional groups in binding to organotin is discussed. The concentration distribution of the various complex species was evaluated as a function of pH. (+info)Organotin compounds alter the physical organization of phosphatidylcholine membranes. (6/122)
Organotin compounds have a broad range of biological activities and are ubiquitous contaminants in the environment. Their toxicity mainly lies in their action on the membrane. In this contribution we study the interaction of tributyltin and triphenyltin with model membranes composed of phosphatidylcholines of different acyl chain lengths using differential scanning calorimetry, (31)P-nuclear magnetic resonance, X-ray diffraction and infrared spectroscopy. Organotin compounds broaden the main gel to liquid-crystalline phase transition, shift the transition temperature to lower values and induce the appearance of a new peak below the main transition peak. These effects are more pronounced in the case of tributyltin and are quantitatively larger as the phosphatidylcholine acyl chain length decreases. Both tributyltin and triphenyltin increase the enthalpy change of the transition in all the phosphatidylcholine systems studied except in dilauroylphosphatidylcholine. Organotin compounds do not affect the macroscopic bilayer organization of the phospholipid but do affect the degree of hydration of its carbonyl moiety. The above evidence supports the idea that organotin compounds are located in the upper part of the phospholipid palisade near the lipid/water interface. (+info)Organotin compounds promote the formation of non-lamellar phases in phosphatidylethanolamine membranes. (7/122)
Organotin compounds are important contaminants in the environment. They are membrane active molecules with broad biological toxicity. We have studied the interaction of tri-n-butyltin chloride and tri-n-phenyltin chloride with model membranes composed of different phosphatidylethanolamines using differential scanning calorimetry, X-ray diffraction, 31P-nuclear magnetic resonance and infrared spectroscopy. Organotin compounds laterally segregate in phosphatidylethanolamine membranes without affecting the shape and position of the lamellar gel to lamellar liquid-crystalline phase transition thermogram of the phospholipid. This is in contrast with their reported effect on phosphatidylcholine membranes [Chicano et al. (2001) Biochim. Biophys. Acta 1510, 330-341] and emphasises the importance of the nature of the lipid headgroup in determining how the behaviour of lipid molecules is affected by these toxicants. Interestingly, we have found that organotin compounds disrupt the pattern of hydrogen-bonding in the interfacial region of dielaidoylphosphatidylethanolamine membranes and have the ability to promote the formation of hexagonal H(II) structures in this system. These results open the possibility that some of the specific toxic effects of organotin compounds might be exerted through the alteration of membrane function produced by their interaction with the lipidic component of the membrane. (+info)Comprehensive-trace level determination of methyltin compounds in aqueous samples by cryogenic purge-and-trap gas chromatography with flame photometric detection. (8/122)
A comprehensive method was developed for the sensitive and fast determination of trace levels of methyltin compounds in aqueous samples. Tin compounds in aqueous solution at pH 5 were converted to the corresponding volatile hydrides: CH3SnH3, (CH3)2SnH2, and (CH3)3SnH, by reaction with potassium borohydride. A CP-4010 purge and trap injector (PTI) was used to purge analyte species from water directly. The volatile derivatives were base-line separated on a capillary column in an Angilent-6890 gas chromatograph by a suitable temperature program and were detected by a flame photometric detector (FPD). The detection limits were 18 ng L-1 for monomethyltin, 12 ng L-1 for dimethyltin, and 3 ng L-1 for trimethyltin, respectively. This method was successfully applied to the determination of methyltin compounds in different aqueous samples. (+info)Organotin compounds are a group of chemical compounds that contain carbon, hydrogen, and tin. They have the general formula RnSnX4-n, where R represents an organic group (such as a methyl or phenyl group), X represents a halogen or other substituent, and n can range from 1 to 3. These compounds are used in a variety of applications, including as biocides, PVC stabilizers, and catalysts. However, they have also been found to have toxic effects on the immune system, endocrine system, and nervous system, and some organotin compounds have been restricted or banned for use in certain products due to these concerns.
Trialkyltin compounds are a category of organotin (oceanic) chemicals, characterized by the presence of three alkyl groups bonded to a tin atom. The general formula for these compounds is (CnH2n+1)3Sn, where n represents the number of carbon atoms in each alkyl group.
These compounds have been used in various industrial applications such as biocides, heat stabilizers, and PVC plasticizers. However, due to their high toxicity, environmental persistence, and potential bioaccumulation, their use has been restricted or banned in many countries.
Examples of trialkyltin compounds include tributyltin (TBT) and triphenyltin (TPT). TBT was widely used as an antifouling agent in marine paints to prevent the growth of barnacles, algae, and other organisms on ship hulls. However, due to its detrimental effects on marine life, particularly on shellfish and mollusks, its use has been largely phased out.
Trialkyltin compounds can have toxic effects on both aquatic and terrestrial organisms, including humans. They can cause neurological damage, impaired immune function, reproductive issues, and developmental abnormalities in various species.
Trimethyltin compounds are organometallic chemical substances that contain the trimethyltin (TMT) group, where tin is bound to three methyl groups. These compounds have been used in various industrial applications, including as biocides and polyvinyl chloride stabilizers. However, they are also known for their high toxicity, particularly affecting the nervous system, leading to symptoms such as seizures, memory loss, and behavioral changes. Therefore, their use is regulated and limited to specific applications where lower-toxicity alternatives are not available.
Ovotesticular Disorders of Sex Development (OT-DSD), also known as true gonadal intersex, are rare conditions where the individual has both ovarian and testicular tissue in their gonads. This condition is characterized by the presence of both ovarian and testicular structures in the same person, which can be found in various combinations and locations within the body.
Individuals with OT-DSD may have varying degrees of development of internal reproductive organs (such as the uterus, fallopian tubes, or vas deferens) and external genitalia that may not clearly fit typical definitions of male or female. The chromosomal patterns in these individuals can also vary, with 46,XX, 46,XY, or mosaic karyotypes (a combination of both).
The diagnosis of OT-DSD is typically made during infancy, adolescence, or adulthood, depending on the individual's presentation. Treatment usually involves surgical management of the gonads and genitalia, hormone replacement therapy, and psychological support for the person and their family. The ultimate goal is to help the individual establish a gender identity that aligns with their personal sense of self while ensuring their physical health and well-being.
'Acari' is the scientific name for a group of small arthropods that includes ticks and mites. These tiny creatures are characterized by having eight legs, lack antennae or wings, and have a hard exoskeleton. They belong to the class Arachnida, which also includes spiders and scorpions.
Ticks are external parasites that feed on the blood of mammals, birds, and reptiles, and can transmit various diseases such as Lyme disease, Rocky Mountain spotted fever, and tick-borne encephalitis. Mites, on the other hand, have diverse habits and lifestyles, with some being parasitic, predacious, or free-living. Some mites are pests that can cause skin irritation and allergies in humans and animals.
Overall, Acari is a significant group of organisms with medical and veterinary importance due to their ability to transmit diseases and cause other health problems.
I'm sorry for any confusion, but "Tin" does not have a medical definition. Tin is a chemical element with the symbol Sn and atomic number 50. It is a malleable, ductile, silvery-white post-transition metal. It is found in nature mainly as tin oxides and is obtained from the mineral cassiterite through mining and processing.
Tin has no known biological role in humans, animals, or plants, and it is not considered an essential nutrient. Small amounts of tin can be found in some foods and drinking water, but these levels are generally low and not considered harmful. High levels of tin can be toxic to the human body, causing symptoms such as nausea, vomiting, and diarrhea.
If you have any questions about a medical condition or treatment, I would recommend consulting with a healthcare professional for accurate information and guidance.
I'm sorry for any confusion, but "Venturicidins" is not a recognized term in medical terminology or pharmacology. It appears to be a made-up term, possibly related to "ventricular" (referring to the heart's lower chambers) and "-cidin" (a suffix often used in antibiotics, meaning "killing"). However, without more context, it is impossible to provide an accurate definition or explanation. If you have more information about where this term comes from or its intended meaning, I'd be happy to try to help further!
Endocrine disruptors are defined as exogenous (external) substances or mixtures that interfere with the way hormones work in the body, leading to negative health effects. They can mimic, block, or alter the normal synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body responsible for maintaining homeostasis, reproduction, development, and/or behavior.
Endocrine disruptors can be found in various sources, including industrial chemicals, pesticides, pharmaceuticals, and personal care products. They have been linked to a range of health problems, such as cancer, reproductive issues, developmental disorders, neurological impairments, and immune system dysfunction.
Examples of endocrine disruptors include bisphenol A (BPA), phthalates, dioxins, polychlorinated biphenyls (PCBs), perfluoroalkyl substances (PFAS), and certain pesticides like dichlorodiphenyltrichloroethane (DDT) and vinclozolin.
It is important to note that endocrine disruptors can have effects at very low doses, and their impact may depend on the timing of exposure, particularly during critical windows of development such as fetal growth and early childhood.
Triethyltin compounds refer to organotin substances that contain the triethyltin (C2H5)3Sn- group. These compounds have been used in various industrial applications, such as biocides and polyvinyl chloride stabilizers. However, they are highly toxic and can cause neurological damage in humans and animals. Long-term exposure to triethyltin compounds has been linked to symptoms including headaches, memory loss, tremors, and seizures.
Spectrophotometry, Infrared is a scientific analytical technique used to measure the absorption or transmission of infrared light by a sample. It involves the use of an infrared spectrophotometer, which directs infrared radiation through a sample and measures the intensity of the radiation that is transmitted or absorbed by the sample at different wavelengths within the infrared region of the electromagnetic spectrum.
Infrared spectroscopy can be used to identify and quantify functional groups and chemical bonds present in a sample, as well as to study the molecular structure and composition of materials. The resulting infrared spectrum provides a unique "fingerprint" of the sample, which can be compared with reference spectra to aid in identification and characterization.
Infrared spectrophotometry is widely used in various fields such as chemistry, biology, pharmaceuticals, forensics, and materials science for qualitative and quantitative analysis of samples.