Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Food Chem Toxicol ; 36(7): 169-82, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9687969

ABSTRACT

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.


Subject(s)
Nicotiana/chemistry , Plants, Toxic , Tobacco Smoke Pollution/analysis , Gas Chromatography-Mass Spectrometry , Hot Temperature , Nicotine/analysis , Nitrosamines/analysis , Smoking , Tars/analysis , Tobacco Industry , Toxicity Tests
2.
Food Chem Toxicol ; 36(3): 169-82, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9609390

ABSTRACT

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.


Subject(s)
Nicotiana/chemistry , Plants, Toxic , Tobacco Smoke Pollution/analysis , Hot Temperature , Nicotine/analysis , Nitrosamines/analysis , Smoking , Tars/analysis , Tobacco Industry , Toxicity Tests
3.
J Leukoc Biol ; 47(4): 332-43, 1990 Apr.
Article in English | MEDLINE | ID: mdl-2319207

ABSTRACT

Influenza A virus (IAV) has previously been shown to alter chemotactic, oxidative, and secretory functions of polymorphonuclear leukocytes (PMNL). Because of the role of cytoskeletal proteins in these processes, studies were carried out to determine if IAV altered the PMNL cytoskeleton. PMNL were incubated with buffer of IAV, stimulated with f-met-leu-phe (FMLP), fixed and stained with NBD-phallacidin (NBD-Ph) and studied by flow cytometry. Mean F-actin fluorescence was increased 18% in virus treated cells pre-FMLP stimulation and 13% 5 and 10 min post-FMLP (P less than .03); no significant difference in F-actin fluorescence was noted in virus treated PMNL 15-30 s post-FMLP compared to control cells. PMNL exposed to the same conditions were solubilized and actin content was determined following SDS-PAGE of triton insoluble precipitates. Increased actin was recovered from virus treated compared to buffer treated cells before and after FMLP stimulation in the 8,000g precipitates (P less than .001). Immunofluorescent microscopy studies of F-actin distribution were done in PMNL stained with NBD-Ph following FMLP stimulation for 10 min. These studies showed an increased lamellipod F-actin/uropod F-actin ratio in PMNL pre-incubated with IAV compared to controls (4.6 vs. 1.0; P less than .025). Phosphorylation of specific cytoskeletal proteins was examined after immunoprecipitation. IAV alone altered phosphorylation of both vimentin and vinculin, and in stimulated PMNL virus led to decreased phosphorylation of vimentin and vinculin. These data show distributional and biochemical effects of IAV on PMNL cytoskeletal proteins, indicating additional targets for IAV interference in the PMNL signal-transduction-function process.


Subject(s)
Cytoskeleton/ultrastructure , Influenza A virus/physiology , Neutrophils/ultrastructure , Actin Cytoskeleton/metabolism , Actins/metabolism , Cytoskeleton/physiology , Flow Cytometry , Humans , Microfilament Proteins/metabolism , Microscopy, Fluorescence , N-Formylmethionine Leucyl-Phenylalanine , Neutrophils/microbiology , Neutrophils/physiology , Phosphorylation , Polyethylene Glycols/pharmacology , Precipitin Tests
4.
Am J Obstet Gynecol ; 154(4): 831-8, 1986 Apr.
Article in English | MEDLINE | ID: mdl-3963073

ABSTRACT

Uterine blood flow and uterine cytosol and nuclear estrogen receptors were measured at critical times during estradiol-induced vasodilatation in acute anesthetized and chronic conscious sheep preparations at estradiol bolus injection frequencies from 1 to 24 hours. During acute experiments, the uterine blood flow response was muted and cytosol estrogen receptor replenishment did not occur whereas full replenishment occurred in 12 hours in conscious ewes. In ewes treated with daily estradiol that had a stable daily uterine blood flow response, the uterine blood flow response 24 hours after uterine biopsy was similar to the preoperative one. Analysis of the duration of peak uterine blood flow levels and the rate of uterine blood flow descent from peak levels showed that an interval of 18 hours between estradiol injections was necessary for the uterine blood flow response to approximate that observed after 24 hours. These observations suggest: (1) that uterine vascular receptor replenishment is delayed compared with that of the total uterus; (2) that operative stress compromises cytosol estrogen receptor metabolism and possibly nuclear estrogen receptor function; (3) that the delayed maximum uterine blood flow response to estradiol in ewes previously untreated with estradiol is due to a trophic uterine effect of daily estradiol stimulation.


Subject(s)
Estradiol/pharmacology , Receptors, Estrogen/drug effects , Sheep/physiology , Animals , Biopsy , Cell Nucleus/analysis , Cell Nucleus/drug effects , Cytosol/analysis , Cytosol/drug effects , Female , Ovariectomy , Pregnancy , Receptors, Estrogen/analysis , Regional Blood Flow/drug effects , Time Factors , Uterus/analysis , Uterus/blood supply , Uterus/drug effects , Vasodilation/drug effects
SELECTION OF CITATIONS
SEARCH DETAIL
...