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PubMedDate not supplied

Transport of small organic cations in the rat liver. The role of the organic cation transporter OCT1.

The kidneys and the liver are the principal organs for the inactivation of circulating organic cations. Recently, an organic cation transporter (OCT1) has been cloned from rat kidney. In order to answer the question whether OCT1 is involved also in hepatic uptake of organic cations, the pharmacological characteristics of organic cation transport in hepatocytes were compared to the characteristics of transiently expressed OCT1. Primary cultures of rat hepatocytes avidly accumulated the small organic cation 3H-1-methyl-4-phenylpyridinium (3H-MPP+). At equilibrium, the hepatocytes accumulated 3H-MPP+ 56-fold. Initial rates of specific 3H-MPP+ transport in hepatocytes were saturable. The half-saturating concentration was 13 mumol/l. 3H-MPP+ transport was sensitive to quinine (Ki = 0.79 mumol/l) and cyanine863 (Ki = 0.097 mumol/l). Quinine and cyanine863 are known inhibitors of type I hepatic transport of cationic drugs and of renal excretion of organic cations, respectively. To compare the functional characteristics of 3H-MPP+ transport in hepatocytes with those of OCT1, OCT1 has been heterologously expressed and characterized in a mammalian cell line (293 cells). Initial rates of 3H-MPP+ transport were saturable, the Km being 13 mumol/l. The rank order of inhibitory potencies of various inhibitors was almost identical in hepatocytes and 293 cells transiently transfected with OCT1. There was a positive correlation between the Ki's for the inhibition of 3H-MPP+ transport in isolated hepatocytes and transfected 293 cells (r = 0.85; P < 0.01; n = 8). The results indicate that OCT1 is functionally expressed not only in the kidney but also in hepatocytes where it is responsible for the transport of small organic cations which, in the past, have been classified as type I substrates.

Animals↗
PubMed2005

Effect of organic fertilizers derived dissolved organic matter on pesticide sorption and leaching.

Incorporation of organic fertilizers/amendments has been, and continues to be, a popular strategy for golf course turfgrass management. Dissolved organic matter (DOM) derived from these organic materials may, however, facilitate organic chemical movement through soils. A batch equilibrium technique was used to evaluate the effects of organic fertilizer-derived DOM on sorption of three organic chemicals (2,4-D, naphthalene and chlorpyrifos) in USGA (United States Golf Association) sand, a mixed soil (70% USGA sand and 30% native soil) and a silt loam soil (Typic Fragiochrept). DOM was extracted from two commercial organic fertilizers. Column leaching experiments were also performed using USGA sand. Sorption experiments showed that sorption capacity was significantly reduced with increasing DOM concentration in solution for all three chemicals. Column experimental results were consistent with batch equilibrium data. These results suggest that organic fertilizer-derived DOM might lead to enhanced transport of applied chemicals in turf soils.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2005

The influences of solid-phase organic constituents on the partition of aliphatic and aromatic organic contaminants.

The influence of natural organic matter (NOM) constituents on contaminant distribution coefficients was evaluated by determining the Koc values of aromatic and aliphatic organic compounds (solutes) with clays modified with both aromatic- and aliphatic-rich organic constituents. The studied compounds consisted of naphthalene, phenanthrene, n-pentane, and 2,3,4-trimethylmethane; the solid samples comprised two clays with little organic content, kaolinite and Ca-montmorillonite. Two aliphatic surfactants and three aromatic dyes, sorbed to the clays, served as reference NOM constituents. For solutes of comparable water solubilities, the organic-carbon normalized distribution coefficients (Koc) of the aliphatic solutes between sorbed aliphatic organic matter and aqueous solution slightly exceed those of the aromatic solutes. By contrast, the aromatic solutes exhibited higher Koc values than did the aliphatic compounds with sorbed aromatic-rich organic matter. The difference in Koc values could be attributed to either comparable solubility parameters or the difference in the chemical structure between nonionic organic solutes and specific components of the simulated NOM. The much higher Koc values observed for the aromatic solutes indicate that the NOM composition is a major factor determining the NOC environmental distribution.

Journal Article↗
PubMed1996

Defibrillation success is associated with myocardial organization. Spatial coherence as a new method of quantifying the electrical organization of the heart.

The relationship between the degree of electrical organization of ventricular fibrillation (VF) and defibrillation success was investigated in this study using a new technique to quantify organization--spatial coherence. This technique employs the use of the magnitude-squared coherence spectrum to analyze multichannel electrograms obtained during a cardiac mapping study. Magnitude-squared coherence values for all possible pairs of electrograms recorded from an epicardial plaque consisting of 112 electrodes were computed. Average coherence was plotted versus electrode separation distance, and the data were fit with an exponentially decaying curve. Two parameters indicative of myocardial organization were extracted from the curve. The coherence length (d) was defined as the distance (mm) at which the average coherence dropped to a given level, and the coherence strength was defined as the average coherence value at a given distance. Higher values for these parameters were hypothesized to indicate higher levels of organization. The spatial coherence technique was tested previously in a canine study of ventricular fibrillation (VF) and normal sinus rhythm, and the results suggested that spatial coherence parameters may be used to compare cardiac rhythms in terms of their organization. To test the hypothesis that organization is related to defibrillation success, 164 mapping sessions recorded during repeated VF induction and defibrillation trials using a monophasic waveform were performed in a close-chested canine study (n = 9) using a fixed energy and VF duration (10 seconds). Three coherence lengths and five coherence strengths were calculated for each VF episode. Results using a two-way analysis of variance with blocking between dogs showed that all of the coherence length and three of the coherence strength parameters were higher for those VF episodes that were successfully defibrillated than for those that were not (P < .05). Energy delivered and transmyocardial impedance were not significantly different between the groups. The authors conclude (1) the organization of a VF episode, as reflected in the spatial coherence parameters, is related to defibrillation success and may be partially responsible for the probabilistic nature of defibrillation and (2) the spatial coherence technique provides a means of quantifying myocardial electrical organization and is an important experimental tool that may be used to obtain a better understanding of VF and its termination.

Animals↗
PubMed2000

Comparison of the mutational spectra of the lacZ transgene in four organs of the MutaMouse treated with benzo[a]pyrene: target organ specificity.

We recently demonstrated that not all organs with a high rate of induction of mutation in the lacZ transgene develop tumors in the lambdalacZ transgenic mice (MutaMouse) used for a long-term carcinogenicity study with benzo[a]pyrene (BP). To better understand the role of chemical-induced in vivo mutations in carcinogenesis, we compared the mutational spectra of the lacZ transgene in four organs of the MutaMouse obtained 2 weeks after five daily consecutive oral treatments with 125 mg/kg/day BP. lacZ transgenes were analyzed in two target organs (forestomach and spleen) and two non-target organs (colon and glandular stomach) for BP-induced carcinogenesis in MutaMouse, and all of these organs were highly mutated in the lacZ transgene. The sequence data showed similar mutational spectra of the lacZ transgene between the two target organs; the predominant mutations were G:C-->T:A transversions (55% and 50% for forestomach and spleen, respectively), followed by deletions (20% and 21% for forestomach and spleen, respectively) mainly at G:C site. The frequent G:C-->T:A transversions are consistent with reports of the mutational spectra produced in the p53 gene in tumors generated in rats and mice exposed to BP. In contrast, the mutational spectra of the lacZ transgene in the two non-target organs are different from those in the target organs, and are also suggested to differ from one another. These findings suggest an organ/tissue-specific mechanism of mutagenesis.

Administration, Oral↗
PubMed1997

Prevalence of organ-specific and non organ-specific autoantibodies in healthy centenarians.

In the present study we have investigated the prevalence of organ-specific and non organ-specific autoantibodies in 26 healthy centenarians (6 men, 20 women; age range 101-106 years), using as controls 54 healthy old (33 men and 21 women, age range 71-93) and 56 young subjects (29 men and 27 women, age range 26-60). We assayed sera of each group for the following organ-specific autoantibodies, anti-gastric mucosa (anti-PCA), anti-thyroglobulin (anti-Tg) and non organ-specific autoantibodies, anti-cardiolipin (anti-APA IgG and IgM), anti-nuclear antigens (anti-ANA), anti-double strand DNA (anti-ds-DNA), anti-extractable nuclear antigens (anti-ENA). Finally, natural anti-alpha-galactosyl (anti-alpha-GAL) antibodies were also analyzed. As expected, in the old subjects there was a significant increase of prevalence of anti-Tg and anti-PCA autoantibodies. By contrast, in centenarians the prevalence of organ specific anti-Tg and anti-PCA antibodies was not significantly different from that observed in controls aged less than 60 years. The prevalence of non organ-specific autoantibodies anti-APA (IgG), anti-APA (IgM), anti-ANA, was significantly increased both in the elderly and centenarians when compared with the prevalence observed in sera from the young. Anti-ENA and anti-dsDNA antibodies were not detected in all groups studied. Finally, the prevalence of natural anti-alpha-GAL antibodies significantly increases with age, including centenarians. In conclusion, we confirm and extend the results previously obtained by other authors. In fact, as already described, the prevalence of organ-specific autoantibodies in the elderly is not seen after the tenth decade of life. Interestingly, the prevalence of non organ-specific autoantibodies is instead increased in these subjects, suggesting that different mechanisms are involved in the pathogenesis of these autoantibodies. Particularly, these autoantibodies could be the expression of a damaged tissue process rather than of an autoimmune one, as suggested by data concerning natural antibodies.

Adult↗
PubMed2003

Bladder and rectum dose defined from MRI based treatment planning for cervix cancer brachytherapy: comparison of dose-volume histograms for organ contours and organ wall, comparison with ICRU rectum and bladder reference point.

PURPOSE: To analyze the correlation between dose-volume histograms based on organ contour and organ wall delineation for bladder and rectum, and to compare the doses to these organs with the absorbed doses at the ICRU bladder and rectum reference points. MATERIAL AND METHODS: Individual MRI based brachytherapy treatment planning was performed in 15 patients as part of a prospective comparative trial. The external contours and the organ walls were delineated for the bladder and rectum in order to compute the corresponding dose-volume histograms. The minimum dose in 2 cm(3), 5 cm(3) and 10 cm(3) volumes receiving the highest dose were referred to as [D2], [D5] and [D10] and compared with the absorbed dose at the ICRU rectum and bladder reference point. RESULTS: The bladder (bext) and rectal (rext) doses derived from external contours and computed for volumes of 2 cm(3) [D2], provided a good estimate for the doses computed for the organ walls (bw and rw) only (mean ratio [D2](bext)/[D2](bw)=1.1+/-0.2 and [D2](rext)/[D2](rw)=1.2+/-0.1, respectively). This correspondence was no longer true when larger volumes were considered (5 and 10 cm(3)). The dose at the ICRU rectum reference point did overestimate the dose computed for 2 cm(3) of the rectum wall (mean ratio: 1.5+/-0.4). In contrast, the dose at the ICRU bladder reference point did-in the case of inappropriate topographic location of the balloon-underestimate the dose computed for 2 cm(3) of the bladder wall (overall mean ratio: 0.9+/-0.4). CONCLUSION: For clinical applications, when volumes smaller than 5 cm(3) are considered, the dose-volume histograms computed from external organ contours for the bladder and rectum can be used instead of dose-volume histograms computed for the organ walls only. External organ contours are indeed easier to obtain. The dose at the ICRU rectum reference point provides a good estimate of the rectal dose computed for volumes smaller than 2 cm(3) [D2] only for a midline position of the rectum. The ICRU bladder reference point provides a good estimate of the dose computed for the bladder wall [D2] only in cases of appropriate balloon position.

Adenocarcinoma↗
PubMed2001

Specific organ gene transfer in vivo by regional organ perfusion with herpes viral amplicon vectors: implications for local gene therapy.

BACKGROUND: Many gene therapy strategies would benefit from efficient, regional organ delivery of therapeutic genes. METHODS: Regional perfusions of lung, liver, or bladder were performed to determine if rapid and efficient gene transfer can be accomplished in vivo, and to determine if in vivo gene transfer can be limited to the organ of interest. In addition, herpes simplex virus tumor necrosis factor (HSVtnf), carrying the human tumor necrosis factoralpha gene was used as a treatment for methylcholanthrene sarcoma in a syngeneic lung metastases model in Fisher rats. RESULTS: A 20-minute perfusion using HSV carrying beta-galactosidase (HSVlac) produced significant expression of this marker gene isolated to the target organs, without organ-specific tissue injury or inflammation. Regional perfusion of organs with HSV carrying the cytokine gene tumor necrosis factor alpha also resulted in high-level local organ production of this cytokine (2851 +/- 53 pg/g tissue in perfused lung versus 0 for the contralateral lung). For the current vector construct, expression of the gene of interest peaked between 2 and 4 days and was undetectable by 2 weeks after perfusion. In animals undergoing perfusion as treatment for pulmonary sarcoma, there was no difference between tumor counts in lungs perfused with HSVlac (17 +/- 6) or HSVtnf (22 +/- 8), but either treatment resulted in lower tumor counts than controls (111 +/- 24 nodules per lung, P <.02). CONCLUSIONS: Regional organ perfusion using herpes viral vectors is an effective and well-tolerated in vivo method of transiently delivering potentially toxic gene products to target organs in directing gene therapy. Regional lung perfusion with HSV amplicons reduces tumor burden in a rat model of pulmonary metastases, though HSVtnf cannot be demonstrated to augment the cytopathic effect of the HSV amplicon alone in the current model.

Animals↗
PubMed1998

Fine particulate organic material in the Los Angeles Basin-I: assessment of the high-volume Brigham Young University organic sampling system, BIG BOSS

A multi-system, high-volume, parallel plate diffusion denuder Brigham Young University Organic Sampling System (BIG BOSS) was tested using collocated samplers at the Pico Rivera Monitoring Station of the South Coast Air Quality Management District, South Coast Air Basin, in September 1994. Six-hr daytime and 9-hr nighttime samples were collected with a flow of about 200 L/min through each of the three systems designed to collect particles smaller than 2.5, 0.8, and 0.4 microns in a diffusion denuder sampler. Efficiency for the removal of gas phase organic compounds by the diffusion denuder was evaluated using both theoretical predictions and field measurements. Both measured and calculated data indicate high denuder efficiency for the removal of gas phase aromatic and paraffinic compounds. The precision of the BIG BOSS was evaluated using collocated samplers. The precision of determination of total carbon and elemental carbon retained by a quartz filter or of semi-volatile carbonaceous material lost from particles during sampling averaged +/- 7%. The precision of determination of individual organic compounds averaged +/- 10%. An average of 42 and 62% of the particulate organic material was semi-volatile organic compounds (SVOCs) lost from particles during sampling for daytime and nighttime samples, respectively. This "negative" sampling artifact was an order of magnitude larger than the "positive" quartz filter artifact due to adsorption of gas phase organic material. Daytime concentrations of fine particulate elemental carbon and nonvolatile organic carbon were higher than nighttime concentrations, but nighttime fine particles contained more semi-volatile organic material than daytime.

Journal Article↗
PubMed2003

Cooperating mechanisms of CXCR5 and CCR7 in development and organization of secondary lymphoid organs.

Homeostatic chemokines participate in the development of secondary lymphoid organs and later on in the functional organization of these tissues. The development of lymph nodes (LNs) and Peyer's patches depends on the recruitment of CD3- CD4+ interleukin (IL)-7R alpha hi cells to sites of future organ development. CD3- CD4+ IL-7R alpha hi cells express the chemokine receptor CXCR5 and might be attracted by its ligand CXCL13, which is secreted by mesenchymal cells. Mesenchymal cells also secrete CCL19, a ligand for CCR7, yet it is not clear whether CCR7 and CCL19 are important for secondary lymphoid organ development. Analyzing CXCR5-/- CCR7-/- double deficient mice we now show that these mice lack all examined peripheral LNs suggesting a profound role for both receptors in secondary lymphoid organ development. We demonstrate that CD3- CD4+ IL-7R alpha hi cells express CXCR5 as well as CCR7 indicating that both receptors cooperate during an early step of secondary lymphoid organ development. Furthermore, CXCR5-/- CCR7-/- mice display a severely disturbed architecture of mesenteric LN and spleen. Due to an impaired migration of B cells into the white pulp, CXCR5-/- CCR7-/- mice fail to develop B cell follicles but show small clusters of unorganized lymphocytes in the spleen. These data demonstrate a cooperative function of CXCR5 and CCR7 in lymphoid organ organogenesis and organization.

Animals↗
PubMed2004

Secondary malignant involvement of gynecologic organs in radical cystectomy specimens in women: is it mandatory to remove these organs routinely?

PURPOSE: We report the incidence of concomitant secondary malignancy of gynecologic organs (uterus, ovaries and vagina) and the incidence of benign lesions affecting these organs in female radical cystectomy specimens. MATERIALS AND METHODS: Between January 1983 and December 2001, 2,055 radical cystectomies were performed, including 609 in females. Pathological findings in gynecologic organs in female cystectomy specimens were reviewed. These data were correlated with different tumor characteristics. RESULTS: Mean age of the female patients +/- SD was 47 +/- 9 years (range 20 to 73). Mean followup was 4.3 +/- 4.2 years (range 0.5 to 19). Of these women 390 (64%) had squamous cell bladder carcinoma. Gynecologic organ involvement was documented in 16 of 609 patients (2.6%). Benign ovarian lesions (49 cases or 8%), a simple serous cyst (31), a dermoid cyst (1), a hemorrhagic cyst (3), bilharzial granuloma (6) and corpus albicans (8) were detected. Benign uterine lesions (30 cases or 5%), endometrial hyperplasia (20), endometriosis (4) and fibroids (6) were diagnosed. No primary genital cancers were detected in this study. Gynecologic organ involvement was more frequent in high grade tumors and the transitional cell cancer type than low grade tumors and the squamous cell type (p = 0.01 and 0.05, respectively). Posterior wall tumors were more frequently associated with genital involvement than other sites, although the difference was not statistically significant. CONCLUSIONS: Evidence is provided that the risk of secondary malignant involvement of genital organs in female cystectomy specimens is low. This low risk together with the low risk of primary cancers of genital organs in this group of patients does not strongly support the routine removal of uninvolved gynecologic organs during radical cystectomy in women.

Adult↗
PubMed2006

From organisms to populations: modeling aquatic toxicity data across two levels of biological organization.

A critical step in estimating the ecological effects of a toxicant is extrapolating organism-level response data across higher levels of biological organization. In the present study, the organism-to-population link is made for the mysid, Americamysis bahia, exposed to a range of concentrations of six toxicants. Organism-level responses observed were categorized as no effect, delayed reproduction, reduced overall reproduction, or both reduced overall reproduction and survival. Population multiplication rates of each toxicant concentration were obtained from matrix models developed from organism-level endpoints and placed into the four categories of organism-level responses. Rates within each category were compared with growth rates modeled for control populations. Population multiplication rates were significantly less than control growth rates only for concentrations at which overall reproduction and both reproduction and survival were significantly less than the control values on the organism level. Decomposition analysis of the significant population-level effects identified reduced reproduction as the primary contributor to a reduced population multiplication rate at all sublethal concentrations and most lethal concentrations. Mortality was the primary contributor to reduced population growth rate only when survival was less than 25% of control survival. These results suggest the importance of altered reproduction in population-level risk assessment and emphasizes the need for complete life-cycle test data to make an explicit link between the organism and population levels.

Animals↗
PubMed1989

Perihemorheology: the bridge between the vessel-blood organ and the organs it penetrates.

Perihemorheology concerns the rheology of fluids and structures in the perivascular spaces. Furthermore, the term refers to the exchanges of rheological processes between the vessel-blood organ and its surrounding tissues, as well as in reverse. In 1960, the vessel wall and the circulating blood were considered by the author as an entity which in 1981 he postulated as an organ, named the 'vessel-blood organ', penetrating all other organs. This communication is not a survey but is intended to stimulate biomedical thinking regarding the importance of perihemorheology. The significance of the endoendothelial fibrin(ogenin) lining (EEFL) and fibrin(ogenin) as constituent of the interendothelial cement and the basement membrane in relation to perihemorheology is stressed. The role of albumin in the exchanges between hemorheology and perihemorheology is discussed. The protein content, as found by Witte, in the perivascular spaces as compared to the blood is emphasized regarding the importance of interrelations between the vessel-blood organ and rheological processes in the perivascular spaces. Recent studies, particularly by Laurent and his group, pertaining to hyaluronan in perivascular spaces and the blood demonstrate also the importance of the interrelationship between hemorheology and perihemorheology. The term 'blood-brain barrier', considered no longer to be adequate, is replaced by the term 'basement membrane-brain barrier'. It is proposed that the basement membrane of the vessel-blood organ penetrating the brain may contain certain constituents, unknown thus far, and may have a different structure from the basement membrane of the vessel-blood organ penetrating organs other than the brain.

Animals↗
PubMed1986

"Bi-digital o-ring test molecular identification and localization method" and its application in imaging of internal organs and malignant tumors as well as identification and localization of neurotransmitters and micro-organisms--Part 1.

Using the "Bi-Digital O-Ring Test Molecular Identification and Localization Method," one can identify and localize minute amounts of bioactive substances (including neurotransmitters), micro-organisms, toxic substances, or drugs, and, in addition, one can non-invasively image normal organs as well as screen for and image the distribution of specific types of cancer of specific internal organs without using any expensive instrumentation. One can also use this method to perform a qualitative analysis of neurotransmitters, neuromodulators, and hormones on different parts of the imaged organs. The molecule or substance being investigated is compared with a minute amount of a pure control reference substance, and if the substance identical to the control reference substance exists, then the electro-magnetic waves emitted by the identical substance will produce an electro-magnetic resonance phenomenon with the electro-magnetic waves of identical resonance frequency emitted by the control reference substance, and this resonance phenomenon is hypothesized to be the basis of the "Bi-Digital O-Ring Test Molecular Identification and Localization Method." The following substances have been used as control reference substances to identify and localize identical substances in vitro and in vivo: pure neurotransmitters (e.g. serotonin, beta-endorphin, methionine-enkephalin, norepinephrine, dopamine, L-dopa, substance P, etc.), as well as L-tryptophan and L-tyrosine; cholesterol; steroid hormones (including aldosterone, corticosterone, cortisol, progesterone, testosterone, etc.); peptide hormones; microscopic slides of normal organs; microscopic slides of specific cancer cells of specific organs (e.g. adenocarcinoma of the head of the pancreas, adenocarcinoma of the descending colon, etc.); microscopic slides of pure micro-organisms; toxic substances (e.g. lead, mercury, KCN); drugs (including non-steroidal anti-inflammatory drugs, antibiotics, beta-blockers, calcium channel blockers, etc.); and antibodies against specific substances or micro-organisms. An intensive network of serotonin and L-tryptophan was discovered, by using the "Bi-Digital O-Ring Test Molecular Identification and Localization Method," in different parts of the body. In general, in painful areas, frequently serotonin is markedly reduced, L-tryptophan is markedly increased, and substance P is markedly increased, while in non-painful areas, serotonin is markedly increased, L-tryptophan is markedly decreased, and substance P is markedly decreased.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

[Study of the mechanism of supporting cells repairing the organ of Corti in terms of cell kinetics--nuclear DNA synthesis of supporting cell of the organ of Corti in the cochlea damaged by nitromin administration].

3H-thymidine autoradiography in vivo was carried out on normal mature mice, whose organs of Corti were securely damaged by Nitrogen Mustard-N-oxide (nitromin). The cell kinetics of supporting cells of the organ of Corti were examined and relation between these changes and mechanisms of supporting cells to maintain the organ of Corti was discussed in this paper. A few grains in various kinds of supporting cells in S stage, which were not found in control mice without nitromin injection, were discovered. Those were detected in Hensen's cell, Deiters' cell, Claudius' cells, and inner phalangeal cell. Mitosis was seen in one Claudius' cell in addition. Therefore some supporting cells seem to be able to synthesize DNA and proliferate in the acutely damaged organ of Corti even in mature cochlea and those in G0 stage begin to go around cell cycle as occasion demands. Although labelled supporting cells decreased over time, the portion of supporting cell is likely to change in proportion as the extension of damage in the organ of Corti. If this new dynamic change of cell kinetics in the acutely damaged organ of Corti means the reaction to repair the organ of Corti, the supporting cells seem to have a reasonable role to maintain the organ of Corti including repairment of reticular lamina.

Animals↗
PubMed2005

Semiempirical model for organic aerosol growth by acid-catalyzed heterogeneous reactions of organic carbonyls.

Aerosol growth by heterogeneous reactions of diverse carbonyls in the presence and absence of acidified seed aerosols was studied in a 4 m long flow reactor (2.5 cm i.d.) and a 2-m3 indoor Teflon film chamber under darkness. The acid catalytic effects on heterogeneous aerosol production were observed for diverse carbonyls in various ranges of humidities and compositions of seed inorganic aerosols. Particle population data measured by a scanning mobility particle sizer were used to calculate organic aerosol growth. To accountforthe aerosol growth contributed by heterogeneous reactions, the increase in organic aerosol mass was normalized bythe organic mass predicted by partitioning or the square of predicted organic mass. The carbonyl heterogeneous reactions were accelerated in the presence of acid catalysts (H2SO4), leading to higher aerosol yields than in their absence. The experimental data from aerosol yields in the flow reactorwere semiempirically fitted to the model parameters to predict the organic aerosol growth. The model parameters consist of environmental characteristics and molecular structure information of organic carbonyls. Basicity constants of carbonyls were used to describe the proton affinity of carbonyls for the acid catalysts. Particle environmental factors, such as humidity, temperature, and inorganic seed composition, were expressed by excess acidity and the parameters obtained from an inorganic thermodynamic model. A stepwise regression analysis of the aerosol growth model for the experimental data revealed that either the chemical structure information of carbonyls or characteristic environmental parameters are statistically significant in the prediction of organic aerosol growth. It was concluded thatthis model approach is applicable to predict secondary organic aerosol formation by heterogeneous reaction.

Aerosols↗
PubMed1989

[Professional organ procurement as a prerequisite for attaining the necessary transplantation frequency: experiences with organ distribution at the transplantation center in Vienna].

In the years 1965 to 1988 one or more organs were harvested for the purpose of transplantation from 649 brain dead organ donors reported to the Vienna transplantation centre. Based on a 1982 law regulating organ donation a large number of initiatives aiming at the improvement of the organ procurement system have taken place. In particular, the introduction of a decentralized donor guidance and organ retrieval system, a few information campaigns, as well as the introduction of full-time transplantation coordinators have significantly increased the number of organ donors. This development has made the Vienna transplantation centre one of the largest centres in Europe and has recently resulted in the achievement of a virtual balance between the increase of patients on the waiting list and the growth of the rate of transplantations performed. If this organ procurement policy is consistently continued in the years to come, there is a good chance of ensuring sufficient supply of organs for all patients on waiting lists, at least within the Viennese area.

Austria↗
PubMed1997

Gastrectomy with combined resection of other organs for carcinoma of the stomach with invasion to adjacent organs: clinical efficacy in a retrospective study.

BACKGROUND: Carcinoma of the stomach invading one or more adjacent organs raises serious concerns over en bloc dissection because en bloc resection has an associated high risk and such advanced carcinoma is frequently associated with incurable factors. Thus, it is important to understand the efficacy of gastrectomy combined with other organ resection and to refine the indications for en bloc dissection. STUDY DESIGN: Seventy-seven patients with carcinoma of the stomach directly invading adjacent organs or structures were analyzed retrospectively to investigate the efficacy of en bloc resection. Forty-one patients underwent gastrectomy combined with resection of one or more invaded organs (combined resection group), while the other 36 patients underwent gastrectomy with palliative abrasion between the primary tumor and the invasion site (noncombined resection group). RESULTS: The five-year survival rate was 23 percent in the combined resection group and 0 percent in the noncombined resection group (p < .05). The 23 curative cases and 18 noncurative cases in the combined resection group had a survival rate of 41 percent and 0 percent, respectively (p < .05). The survival rate after a single organ resection was 29 percent, and after a multiple organ resection, 0 percent (p < .05). Cases of carcinoma invading either the pancreas or mesocolon had a slightly but not significantly better prognosis. In Borrmann type IV carcinoma there was no difference in survival between the curative and noncurative operation. Cases with P1 dissemination had a better prognosis than those of P2 and P3 dissemination. CONCLUSIONS: The best indication for an en bloc combined organ resection was an invasion limited to only one other organ, not more than N2, no incurable factor, and any type except Borrmann type IV. Additionally, an en bloc combined resection would be worth trying for any type of gastric carcinoma with not more than P1 dissemination and with no other incurable factor.

Carcinoma↗