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PubMedDate not supplied

Effects of substrate and oxygen loading rates on gas-phase toluene removal in a three-phase biofilm reactor.

A three-phase, circulating-bed biofilm reactor using macroporous carriers removed toluene from a gas stream continuously for more than six months. Three steady states were established with toluene loading rates varying from 0.030 to 0.059 mol/m2 x d. For each steady state, short-term experiments evaluated the effects of toluene and oxygen loading rates. At least 99% of the biomass in the system was accumulated inside the carrier macropores, and the total biomass was proportional to the toluene loading rate. Toluene removal ranged from approximately 100 to 55%. The lower toluene removals were associated with oxygen limitation, which also resulted in the accumulation of an intermediate (3-methylcatechol) and nontoluene chemical oxygen demand. The results suggest that excessive biomass accumulation hurt process performance by depleting oxygen within the biofilm because increased endogenous respiration consumed more oxygen, while increased biomass density may have slowed oxygen diffusion.

Biofilms↗
PubMed1999

Aqueous phase hexylchloroformate derivatization and solid phase microextraction: determination of benzoylecgonine in urine by gas chromatography-quadrupole ion trap mass spectrometry.

A derivatization/solid phase microextraction (SPME) method for the determination of benzoylecgonine in urine was developed. The derivatization is conducted directly in 1 mL of urine while sonicating for 3 min with 12 microL of hexyl chloroformate and 70 microL of a mixture containing acetonitrile:water:hexanol:2-dimethylaminopyridine (5:2:2:1 v/v), yielding benzoylecgonine hexyl ester (BHE) as the product. After the 3 min period, an aliquot of 250 microL is transferred to a vial for SPME. After the desired extraction time the 100 microns polydimethylsiloxane SPME fiber was transferred to the GC-MS for separation and analysis with a quadrupole ion trap mass spectrometer. The hexyl chloroformate derivatization and SPME procedures were optimized for compatibility and sensitivity. The method was found linear for 0.10 to 20.0 micrograms/mL (r2 = 0.999) of benzoylecgonine in urine using benzoylecgonine-d3 as an internal standard (1.5 micrograms/mL). Intra-day precisions were 8.8 and 6.8% RSD for 0.30 microgram/mL and 17 micrograms/mL benzoylecgonine standards in urine (n = 6), respectively. Inter-day precision (n = 3) were < or = 3.3% RSD, indicating good reproducibility. A detection limit of 0.03 microgram/mL (S/N = 3) was achieved, thus making the SPME method a simplified alternative to SPE for GC-MS confirmation after EMIT tests for benzoylecgonine which have a cutoff of 0.30 microgram/mL. Quantitative results by SPME and SPE of two clinical urine specimens known positive for cocaine by EMIT were in excellent agreement. Benzoylecgonine was detected by the derivatization/SPME method in 22 out of 22 other urine specimens known positive for cocaine.

Calibration↗
PubMed1999

Distinct in vivo and in vitro cytokine profiles of draining lymph node cells in acute and chronic phases of contact hypersensitivity: importance of a type 2 cytokine-rich cutaneous milieu for the development of an early-type response in the chronic phase.

Although regional lymph nodes (LN) have been extensively studied as rich sources of effector T cells in contact hypersensitivity (CH), it remains unknown whether T cell responses in the LN reflect those in effector skin sites. We previously showed that repeated elicitation of CH results in a shift in the time course of Ag-specific CH from a delayed-type hypersensitivity response to an early-type response, a reflection of a shift in cutaneous cytokine expression from a type 1 to a type 2 profile. To investigate whether repeated elicitation of CH could also drive T cell development to the type 2 phenotype in the regional draining LN, sequential cytokine gene expression after hapten application was assessed during both the acute and the chronic phase of CH. In the draining LN the shift to type 2 cytokine production was also observed, but more mixed patterns of responses were induced than in the corresponding skin sites. The chronic LN cells (LNC), when stimulated in vitro, produced markedly lower levels of type 1 cytokines and higher levels of type 2 cytokines than the acute LNC. A successful passive transfer of an early-type response by the LNC was only induced in the recipient mice when the skin sites chronically treated with hapten were elicited. These results indicate that an early-type response by regional LNC would take place only in a milieu with sufficient levels of type 2 cytokines.

Acute Disease↗
PubMed2000

Metabolism of dipropyl disulfide by rat liver phase I and phase II enzymes and by isolated perfused rat liver.

The metabolism of dipropyl disulfide (DPDS), an Allium sulfur compound, was investigated in rat liver cell subfractions and in an isolated perfused rat liver. DPDS is oxidized to dipropyl thiosulfinate (DPDSO) by rat microsomes. The contribution of cytochrome P450 enzymes (CYPs) or flavin-containing monooxygenases (FMO) to the formation of DPDSO from its precursor was investigated. In rat microsomes, the reaction followed Michaelis-Menten kinetics with a K(m) = 0.52 +/- 0.1 mM and a V(max) = 5.91 +/- 0.5 nmol/min/mg of protein, respectively (mean +/- S.E., n = 4). Both FMOs and CYPs were involved in DPDS oxidation, although the contribution of CYPs was predominant. Liver microsomes from phenobarbital-treated rats showed a 3.2-fold increase in the rate of formation of DPDSO. Among many CYP isoform-specific inhibitors, only CYP2B1/2 inhibitors decreased the formation of DPDSO and the best correlation between the rate of DPDS oxidation with specific monooxygenase activities was found with a marker of CYP2B1/2 activity. The action of phase II enzymes on DPDS metabolism was studied by incubating DPDS or DPDSO with liver cytosols or microsomes. Two metabolites were formed from DPDS: propylglutathione sulfide conjugate and propylmercaptan, whereas with DPDSO, only the glutathione conjugate was observed. No conjugate compound was detected in the presence of UDP-glucuronyl transferases. When isolated rat liver was perfused with DPDS, different metabolites were obtained in the output and in the liver tissues: propylmercaptan appeared in the output, whereas methylpropyl sulfide, methylpropyl sulfone, and propylglutathione sulfide were detected in the liver tissue.

Animals↗
PubMedDate not supplied

Mitotic activity in chondrocyte transplantation from the in vitro phase to the in vivo phase.

The transplantation of devitalized allogenic matrices vehiculating autologous chondrocytes, previously isoled and seeded on them could be a solution to the problem of repairing lesions of the joint cartilage. For the matrix/cell "composite" to be "graftable" the cells must continue to duplicate and produce cartilaginous matrix even after transport in vivo. The present study analyzes the mitotic activity of chondrocytes planted on devitalized allogenic cartilage and grafted in living animals. Chondrocytes of joint cartilage of lambs were isolated enzymatically and then seeded in vitro on devitalized allogenic cartilaginous matrices for 3 weeks. At the end of the co-culture period, these matrix/chondrocyte composites were transplanted in subcutaneous pockets of athymic mice. The experimental and control samples were evaluated subsequent to explantation by histological study and incorporation of tritiated thymidine. The results obtained revealed an important decrease in the values for the incorporation of thymidine beginning from experimental time 0 (pre-implant evaluation) up to day 28 after implantation, followed by a mild increase at the experimental time of 42 days. This study demonstrated the tendency of articular chondrocytes cultivated in vitro and subsequently transplanted in vivo on a support of devitalized allogenic cartilaginous matrix to modify mitotic activity from very high values for the first experimental times, typical of the in vitro phases of cellular expansion, to very low values, more similar to the behavior of articular chondrocytes in vivo.

Animals↗
PubMed2001

The MOSORIOT medical record system (MMRS) phase I to phase II implementation: an outpatient computer-based medical record system in rural Kenya.

The authors of this paper describe the second phase of the implementation of the Mosoriot Medical Record System (MMRS) in a remote health care facility on the outskirts of Eldoret, Kenya, located in sub-Saharan Africa. We describe of the collaboration between Indiana University (IU) and the Moi University (MU), and the process that led to the development of the computer-based Mosoriot Medical Record System (MMRS) is provided. We then provide the conceptualization and initial implementation of this basic electronic medical record system. We also describe the different processes for assessing the MMRS' effects on health care, including time-motion studies and a strict implementation plan that is necessary for the successful implementation of the system. The MMRS project has many features that make it significant in the domain of CBPR systems. It may serve as a model for establishing similar, basic electronic record systems in the developed and developing world. In developing countries there are few (if any) projects that have attempted to implement such a system. This paper describes the planning, end-user education to new technologies, and time-motion studies necessary for the successful implementation of the MMRS. The system will be used to improve the quality of health data collection and subsequently patient care. It will also be used to link data from ongoing public health surveys and this can be used in public health research programs of the Moi University.

Attitude to Computers↗
PubMed2002

[Chromatographic behavior of fat-soluble vitamin in reversed phase liquid chromatography with water-isopropanol mobile phase].

The separation of a mixture fat-soluble vitamin A, D, E by reversed-phase HPLC on elution with an isopropanol-water was studied. A procedure was developed for determining vitamin mixtures and was applied to the analysis of 9 multivitamin tablet. The vitamin was fully separated in 15 min using a short C18 column and UV detection at 280 nm. Different solvent were used for sample extraction. The recoveries were measured, and were higher than 95%. Experimental results proved that the three fat-soluble vitamin A, D, E all can be fully eluted by a solution of isopropanol-water in the ratio of 75%:25%.

2-Propanol↗
PubMed2004

Effect of mobile phase composition, pH and buffer type on the retention of ionizable compounds in reversed-phase liquid chromatography: application to method development.

Optimizing separation of ionizable compounds in order to find robust conditions has become an important part of method development in liquid chromatography. This work is an attempt to explain the observed variations of retention of acid and basic compounds with the organic modifier content in the mobile phase, according to various factors: the type of modifier, the type of buffer, the temperature and of course the type of solute. This is done by considering the variation of the so-called chromatographic pKa which refers to the pH measured in the aqueous medium and is determined from retention data. A procedure is described that accurately relates, from nine experiments, retention to solvent composition and pH. The limits of such a procedure are evaluated and two examples of optimized separations of basic compounds are given.

Acetonitriles↗
PubMed2004

Effect of solvent strength and temperature on retention for a polar-endcapped, octadecylsiloxane-bonded silica stationary phase with methanol-water mobile phases.

Synergi Hydro-RP is a new type of polar-endcapped, octadecylsiloxane-bonded silica packing for reversed-phase liquid chromatography. Its retention properties as a function of solvent strength and temperature are evaluated from the change in retention factors over the composition range (0-70% v/v methanol) and temperature range (25-65 degrees C) using the solvation parameter model and response surface methodologies. The main factors that affect retention are solute size and hydrogen-bond basicity, with minor contributions from solute hydrogen-bond acidity, dipole-type and electron lone pair interactions. Within the easily accessible range for both temperature and solvent strength, the ability to change selectivity is much greater for solvent strength than temperature. Also, a significant portion of the effect of increasing temperature is to reduce retention without changing selectivity. Response surfaces for the system constants are smooth and non-linear, except for cavity formation and dispersion interactions (v system constant), which is linear. Modeling of the response surfaces suggests that solvent strength and temperature are not independent factors for the b, s and e system constants and for the model intercept (c term).

Hydrogen Bonding↗
PubMed1987

Effect of excessive intake of ascorbic acid on hepatic and extra-hepatic phase I and phase II drug metabolism in rat.

Guinea pig is the animal model of choice for studies on effects of ascorbic acid (AA). However, rat is one of the largely used animals for investigations related to chemical carcinogenesis. Therefore, the present study was designed to evaluate the changes induced by high intake of the vitamin in xenobiotic and carcinogen metabolizing status of the organs. Male Wistar rats, dosed daily with 50 mg AA/100 g body weight for 10 weeks, demonstrated a small non-significant increase in hepatic, pulmonary and colon cytochrome P-450 (Cyt. P-450) contents, which was accompanied with a significant increase in hepatic and pulmonary arylhydrocarbon hydroxylase (AHH) activities. Phase II enzymes of drug metabolism responded in different ways to increased intake of AA. UDP-glucuronyltransferase (UDPGT) activity was unaffected in liver and colon, but it was increased (p less than 0.005) in lung. Activities of glutathione S-transferase (GST) were decreased in the three organs. Inducibility of AHH by 3-methylcholanthrene (MCA) or phenobarbital (PB) was largely reduced due to AA feeding. Besides this, MCA and PB had differential effects on enzymatic levels in AA fed rats. When compared with our earlier observations in guinea pig, it was found that rat responded similarly to guinea pig to increased intake of AA with regard to hepatic AHH, Cyt. P-450, UDPGT and GST, pulmonary AHH, Cyt. P-450 and Cyt. b5, and all studied colon enzymes, except GST.

Animals↗
PubMed1986

[Cyclophosphamide, adriamycin and platinum (CAP) in the preoperative neoadjuvant phase and the therapy phase].

Forty-two patients with metastasized, and 7 patients with locally advanced forms of carcinoma of the breast were treated with a combination of three drugs: CTX 200-400 mg/sq.m. on days 1, 3 and 5, ADM 40 mg/sq.m. on day 1, and DDP 30 mg/sq.m. on days 1, 3 and 5 (CAP), every 21 days. The 42 patients with metastasized carcinoma had already received substantial pre-treatment by surgery and with adjuvant polychemotherapy +/- chemotherapy on recurrence +/- hormonotherapy +/- radiotherapy. The disease sites were: bone (30%), skin (19%), lymph nodes (13.5%), pleura (12.5%), lung (12%) and liver (11%). The 7 patients with locally advanced carcinoma had not been pre-treated; they received the same chemotherapy in the pre-operative neo-adjuvant phase. Positive responses to CAP in the cases with metastasized carcinoma according to individual disease sites (37 pre-treated patients assessable after at least two courses of therapy) were as follows in percentage terms: 24% bone lesions, 56% skin lesions, 77% lymph node lesions, 30% liver lesions, 56% lung lesions, 22% pleural lesions. 3/37 patients (8%) showed complete remission in all disease sites, while 6/37 showed partial remission. This percentage (8 + 16 = 24%) is encouraging, as CAP, in these patients, represents on average the 3rd to 4th line of therapy. Responses to neo-adjuvant CAP therapy (7 patients assessable after at least two courses of therapy) were as follows: 5 patients showed partial remission after 3-6 courses, 1 complete remission, and 1 objective improvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

[Cytophotometric evaluation of the transition of cells from the G0 phase to the G1 phase of the cell cycle].

Feulgen stained nuclei of PHA-stimulated human blood lymphocytes were used for cytophotometric chromatin pattern analysis. Similar distributions of low optical density values indicating the predominance of diffuse chromatin were obtained for G1, S and G2 cells. Condensed chromatin was predominant in G0 and M nuclei. Integral versus average optical densities scatter plots analyses permitted one to distinguish cells undergoing different phases of cell cycle including G0 and G1.

Cell Nucleus↗
PubMed1978

[Preliminary results of polychemiotherapy and immunostimulant treatment with Corynebacterium parvum in tumors of the breast in the postoperative phase and advanced phase].

Difficulties still encountered in the coordinated interdisciplinary management of solid tumours in hospitals are discussed. Preliminary results obtained with a polychemical and immunostimulating protocol based on Corynebacterium parvum (introduced in 1973) in breast tumours immediately after surgery and in the advanced stage are presented. Two out of eight subjects with advanced forms died. Partial regression or a steady state were noted in the remainder. No locoregional recurrences or metastases were observed from 1 to 2 yr after the commencement of treatment in 22 patients treated in the immediate post-operative phase. These results are considered satisfactory, though a final evaluation would be premature. Stress is laid on the importance of immunostimulating management in the avoiding the immunodepression caused by the administration of drugs.

Adult↗
PubMed1980

[Statistical data analysis of physiologic parameters in patients with endomorphic-depressive phases. An attempt to explore the changeable effects between physiologic parameters, examination times during the phase and various experimental conditions].

Range-corrected (according to Lykken) physiological data from the parameters of heart rate (HF), respiratory rate (AF), skin potential (skin potential level; SPL; skin potential response, SPR) and skin resistance level, SRL; skin resistance response, SRR) were obtained under an acoustic activation paradigm in the course of a longitudinal investigation on 7 women with endomorph depression treated with thymoleptic medication. These data form the matrix for two- and threefold analyses of variance as well as for concordance analyses according to Kendall. During six measurements (three each taken in the morning and evening) one finds differing levels of activation: relatively low ones at the beginning and at the end, high ones during the 'labilization phase' of the treatment. The varying 'reactivity' to the diverse examination sequences of an acoustic activation program is little affected by the degree of these changes; patient-specific 'characteristics' of the course of the activation are just as recognizable throughout the course of the investigation as are 'stimulus-specific' reactions. Each of the parameters is appropriate for the estimation of different physiological variables; SPR seems rather to be a situation-specific variable, HF and AF are probably suitable for establishing the level of activation, while changes in SPL seem to represent patient-specific characteristics.

Adult↗
PubMed1995

[The automated "SynChrom" system for solid-phase synthesis of peptides and liquid column chromatography. II. Use in the solid-phase synthesis of peptides and liquid column chromatography].

Automatic solid phase peptide synthesis using the SynChrom system is described. Problems of swellographic monitoring are discussed. Combined monitoring (swellographic, spectrophotometric, and manometric) of all steps of the synthetic cycle are suggested. Potential applications of the system to liquid column chromatography were demonstrated.

Amino Acid Sequence↗
PubMed1996

Nuclear transplantation in pigs: M-phase karyoplast to M-phase cytoplast fusion.

Porcine embryonic fibroblasts in M-phase were isolated from confluent cultures by selective detachment and fused to homologous metaphase II enucleated oocytes. The fusion products were analysed by light and electron microscopy (EM). The fusion treatment, per se, did not induce the disappearance of the maturation promoting factor (MPF) in the cloned embryos and the transferred chromatin remained condensed for up to 10 h. Spontaneous decondensation started after this time and, at about 20 h post-induction of fusion, a single large nucleus was present in the cytoplasm. The prolonged exposure of introduced chromatin to MPF resulted in a total morphological remodelling as assessed by the nucleolar morphology observed by EM in all the specimens.

Animals↗
PubMed1997

Dietary modulation of phase 1 and phase 2 activities with benzo(a)pyrene and related compounds in the intestine but not the liver of the channel catfish, Ictalurus punctatus.

These studies demonstrated that intestinal mucosa of the channel catfish contained activities comparable with liver for several phase 2 xenobiotic-metabolizing enzymes, and showed that CYP1A-dependent monooxygenase activities were inducible in intestine but not liver by dietary exposure to low concentrations of the Ah agonist, beta-naphthoflavone (BNF). The diets administered were laboratory-prepared, semisynthetic pellets of known composition, commercial chow, or chow supplemented with BNF at 10 or 100 mg BNF/kg chow. Very low intestinal benzo(a)pyrene hydroxylase [aryl hydrocarbon hydroxylase (AHH)] and ethoxyresorufin O-deethylase (EROD) activities were found in catfish fed the semisynthetic diet. Intestinal EROD and AHH activities were elevated by the commercial chow diet and further induced by supplementation with 10, but not 100, mg BNF/kg diet. In vitro studies showed that catfish EROD and AHH activities were sensitive to inhibition by BNF, with mean IC50 values of 0.078 and 2.2 microM, respectively. Thus, residues of BNF retained in intestinal mucosa may have masked monooxygenase induction in catfish fed the 100 mg BNF/kg diet. Microsomal UDP-glucuronosyltransferase and cytosolic PAPS-sulfotransferase activities with 3-hydroxybenzo(a)pyrene as substrate were largely unaffected by the diets studied, and intestinal activities were similar to hepatic activities. Glutathione S-transferase activity was slightly induced in intestinal, but not hepatic cytosol of catfish treated with BNF at the 10 mg/kg diet level relative to chow controls. Epoxide hydrolase activity with styrene oxide as substrate was not affected by diet in intestinal microsomes.

Animals↗