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PubMed2003

Influence of solution composition and ultrasonic treatment on optical spectra of TiO2 aqueous suspensions.

Investigation of TiO(2) aqueous suspensions has shown that their optical spectra can be unstable, with instability not related to precipitation or adherence of TiO(2) particles to the vessel walls. Increase of ionic strength of the suspension as well as neutralization of charged TiO(2) particles via pH adjustment accelerates the optical density drop. Vice versa, increasing the charge of TiO(2) particles via shifting pH in acidic or basic directions stabilizes the suspension's optical spectra, and ultrasonic treatment promotes optical density recovery. The observed behavior is attributed to alteration in the size of the suspension aggregates.

Journal Article↗
PubMed1999

Affinity-purification of a TMV-specific recombinant full-size antibody from a transgenic tobacco suspension culture.

A TMV-specific full-size murine IgG-2b/K antibody (mAb24) was expressed in a Nicotiana tabacum cv. Petite Havana SR1 suspension culture (P9s), which was derived from a stably transformed transgenic plant (P9). The integration of an N-terminal murine leader peptide directed the assembled immunoglobulin for secretion. However, in suspension culture, the full-size recombinant antibody, rAb24, was retained by the plant cell wall and was not present in the culture medium. rAb24 expression reached a basal level of 15 microg per gram wet cell weight, corresponding to 0.3% of the total soluble plant cell protein. The level of rAb24 could be increased three-fold by amino acid supplementation of the culture medium. For purification of the recombinant antibody from batch-cultured tobacco suspension cells, the primary plant cell wall was partially digested by enzymatic treatment. This resulted in a total release of recombinant full-size rAb24 into the extraction buffer. A three-step procedure was used to purify the immunoglobulins, starting with cross-flow filtration (step 1) followed by protein A affinity chromatography (step 2) and gel filtration as a final purification step (step 3). This procedure gave a recovery of more than 80% of the expressed rAb24 from plant cell extracts. SDS-PAGE, IEF and immunoblot analyses demonstrated a high degree of homogeneity for the affinity-purified rAb24. An ELISA procedure demonstrated that the specificity and affinity of the protein A affinity purified antibody was indistinguishable from its murine counterpart, indicating the potential of plant cell suspension cultures as bio-reactors for the production of recombinant antibodies.

Animals↗
PubMed1988

Efficacy of oral sucralfate suspension in prevention and treatment of chemotherapy-induced mucositis.

The efficacy of orally administered sucralfate suspension in preventing and treating chemotherapy-induced mucositis was evaluated in a double-blind trial. Forty-eight children and adolescents with newly diagnosed acute nonlymphocytic leukemia were randomized to receive suspensions of either sucralfate or placebo orally every 6 hours during the first 10 weeks of intensive remission-induction chemotherapy. Patients given sucralfate suspension were less likely than subjects receiving placebo to acquire colonization with potentially pathogenic microorganisms: 14 (58%) of 24 versus 22 (92%) of 24, respectively (p = 0.008). However, no effect on preexisting colonization was noted. Subjective reporting of discomfort, objective scoring of the severity of mucositis, and the maximal percent of body weight lost during therapy were similar; 58% of patients receiving sucralfate reported no oral pain compared with 25% receiving placebo (p = 0.06). Ten episodes of gastrointestinal bleeding, 25 documented infections, and 886 days with fever were also equally distributed between sucralfate and placebo groups. We conclude that sucralfate suspension is of limited, if any efficacy, in the prevention and treatment of chemotherapy-induced mucositis. Sucralfate administration can, however, reduce acquisition of alimentary colonization with potential pathogens, perhaps by interfering with adherence to mucosal membranes.

Administration, Oral↗
PubMed1990

The loop-loosening procedure for urination difficulties after Stamey suspension of the vesical neck.

A main complication of an anti-stress urinary incontinence operation in women is postoperative urinary retention or difficulty in urination caused by the urethrovesical junction being suspended too tightly. A total of 7 women who complained of the complication after a modified Stamey operation underwent our procedure in which the suspension loops were loosened to an adequate tension with the patient under local anesthesia. All patients recovered normal voiding without incontinence immediately after the procedure. The Stamey operation uses a nylon loop for suspension of the urethrovesical junction. Therefore, the tightness of the suspension loop can easily be readjusted postoperatively by the procedure, even though initially the suspension of the urethrovesical junction was too tight or too loose. We believe the procedure will enhance the value of the Stamey operation.

Female↗
PubMed2002

Algal tests with soil suspensions and elutriates: a comparative evaluation for PAH-contaminated soils.

An algal growth inhibition test procedure with soil suspensions is proposed and evaluated for PAH-contaminated soil. The growth rate reduction of the standard freshwater green alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum) was used as the toxicity endpoint, and was quantified by measuring the fluorescence of solvent-extracted algal pigments. No growth rate reduction was detected for soil contents up to 20 g/l testing five non-contaminated Danish soils. Comparative testing with PAH-contaminated soil elutriates and soil suspensions showed that the suspensions had toxicity endpoints 2.5-3000 times lower than tests with the corresponding elutriates. Algal growth inhibition tests with soil suspensions are recommended for screening purposes as a supplement to elutriate testing. Experiments with a phenanthrene-spiked soil, showed that the sorbed compound did not contribute to the toxicity. However, the soil did act as a reservoir for phenanthrene, allowing desorption to occur continuously during the algal test which maintained higher concentrations of phenanthrene in the dissolved phase. Phenanthrene-spiked soil incubated for 90 days before algal testing, resulted in a reduction of the toxicity to P. subcapitata by a factor of 76 (from EC10 = 0.3 to 23.6 g soil/l). However, during this 90-day period the total concentration of phenanthrene in the soil decreased by 38% (from 322 to 199 mg/kg) indicating that phenanthrene in the aged soil had become less bioavailable.

Absorption↗
PubMed2000

Extraperitoneal laparoscopic bladder neck suspension using hernia mesh and tacker.

OBJECTIVES: To report our initial experience with extraperitoneal bladder neck suspension for female stress incontinence due to urethral hypermobility. METHODS: Between September 1996 and September 1999, 35 patients (mean age 49.5 years) underwent extraperitoneal bladder neck suspension at our institution. An extraperitoneal space was created by a trocar-mounted balloon device, and suspension was created using a 5-mm endoscopic hernia stapler and polypropylene mesh. RESULTS: The mean operative time was 39.5 minutes. In 2 patients, the bladder was inadvertently perforated during the bladder neck dissection. The perforation was repaired by laparoscopic suture ligation. The mean urethral catheterization and hospitalization time was 2.1 and 2.3 days, respectively. Urethral recatheterization because of temporary urinary retention was required in 11.4% of the patients. Symptoms of bladder instability were experienced by 13.5% of the patients in the early postoperative period. A total of 28 patients (80.0%) reported that they were totally dry after a mean of 23.2 months. CONCLUSIONS: Extraperitoneal bladder neck suspension using hernia mesh and a stapler seems to be an effective and safe procedure, with a shorter operative time, in selected patient groups.

Adult↗
PubMed1997

Role of the four-corner bladder neck suspension to correct stress incontinence with a mild to moderate cystocele.

OBJECTIVES: Women undergoing four-corner bladder neck suspension were evaluated for subjective and objective results of the procedure. Patients were evaluated for continence, prolapse, and symptomatic status postoperatively. METHODS: Forty-seven women underwent four-corner bladder neck suspension for moderate cystocele with (44) or without (3) stress urinary incontinence. Mean and median follow-up were 37 months (range 15 to 80). To assess results of the four-corner bladder neck suspension, two sets of outcome measures were used (subjective questionnaire, including patient satisfaction, and objective physical examination, with standing voiding cystourethrogram) to compare pre- and postoperative data. RESULTS: At the time of follow-up, 25 patients (53%) reported no incontinence, 14 (30%) reported one incontinent episode per week, and 8 (17%) reported daily loss of urine. Twenty-seven (57%) had grade I or grade II cystoceles on follow-up examination and voiding cystourethrogram; however, only 12 (26%) experienced recurrent prolapse symptomatology. Overall patient acceptance of the procedure was high (70%). CONCLUSIONS: The four-corner bladder neck suspension is an effective option in the management of moderate cystocele.

Adult↗
PubMed2000

Modified Pereyra bladder neck suspension in patients with intrinsic sphincter deficiency and bladder neck hypermobility: patient satisfaction with a mean follow-up of 4 years.

OBJECTIVES: To determine the long-term success rate for the modified Pereyra bladder neck suspension and to identify preoperative characteristics that create differences in surgical outcome. We attempted retrospectively to separate those patients with what we now recognize was significant intrinsic sphincter deficiency (ISD) before routine use of Valsalva leak point pressures (VLPPs) was available. METHODS: The charts and videourodynamic reports of 208 patients who underwent a modified Pereyra bladder neck suspension from June 1988 to June 1996 were reviewed, and survey questionnaires were mailed to all patients. All videourodynamic study reports and charts were reviewed to identify those with what we now recognize was significant ISD and compare them with a group that we believed had more pure descent problems. RESULTS: A total of 135 patients or 65% of the population responded. The mean time after surgery was 4.14 years. At the follow-up survey, 14% reported no leakage at all, 42% reported very little or mild leakage, 38% reported moderate leakage, and 6% reported severe leakage. Fifty-three percent of patients continued to wear pads. Seventy-nine percent reported improvement in their leakage compared with the preoperative state, and 69% were satisfied with the results. When patients with preoperative ISD were compared with patients with pure bladder neck hypermobility, the ISD group had more leakage and less improvement after surgery than patients with bladder neck hypermobility. CONCLUSIONS: With an average follow-up of greater than 4 years, most women continued to leak with symptoms of stress urinary incontinence. Even though 79% reported improvement over their preoperative condition and 69% were satisfied, the results were disappointing. Patients with significant ISD had a worse outcome (2.6% dry) than patients with pure bladder neck hypermobility (20% dry). Given the above data, significant ISD is a contraindication for a modified Pereyra transvaginal needle suspension, and these data cast further doubt on the ability of the modified Pereyra needle suspension to consistently cure even anatomic incontinence.

Female↗
PubMed1998

Efficacy and safety of budesonide inhalation suspension (Pulmicort Respules) in young children with inhaled steroid-dependent, persistent asthma.

BACKGROUND: Inhaled glucocorticosteroids are indicated for the treatment of persistent asthma; however, many young children are unable to effectively use currently available inhalers. OBJECTIVE: We sought to evaluate the efficacy and safety of 3 different twice daily doses of budesonide inhalation suspension (Pulmicort Respules) in inhaled steroid-dependent asthmatic children. METHODS: This was a 12-week, randomized, double-blind, placebo-controlled, parallel-group study involving 178 children (age range, 4 to 8 years) at 17 centers in the United States. Budesonide inhalation suspension doses of 0.25 mg, 0.50 mg, or 1.0 mg twice daily were administered by means of a jet nebulizer and air compressor system. Efficacy was assessed by recording at home nighttime and daytime asthma symptom scores, use of rescue medication, pulmonary function tests, and treatment discontinuation because of worsening symptoms. Safety was assessed by reported adverse events and changes in baseline and adrenocorticotrophic hormone-stimulated plasma cortisol levels in a subset of patients. RESULTS: Baseline demographics, symptom scores, and pulmonary function data were similar across treatment groups. All doses of budesonide inhalation suspension were superior to placebo in improving nighttime and daytime asthma symptom scores (P </=.026), reducing use of breakthrough medication (P </=.032), and improving morning peak expiratory flow (P </=.030). The number of dropouts because of worsening asthma was also significantly fewer in the budesonide groups (P </=.015). There were no differences between doses of budesonide. Adverse events and basal and adrenocorticotrophic hormone-stimulated cortisol responses were not different between budesonide and placebo groups. CONCLUSION: Budesonide inhalation suspension, 0.25 mg, 0.50 mg, and 1.0 mg twice daily, is an effective and safe treatment for young children with inhaled steroid-dependent, persistent asthma.

Administration, Inhalation↗
PubMed2002

Distribution of talc suspension during treatment of malignant pleural effusion with talc pleurodesis.

Talc pleurodesis is an effective technique for the management of symptomatic malignant pleural effusions. It is assumed that a good dispersion of talc suspension contributes to the final success of this treatment. For this purpose, guidelines often advise to rotate the patient after intra-pleural instillation of the sclerosant. This prospective, randomized study analyses the dispersion of talc suspension and the overall success rate in patients with malignant effusions. After instillation of 99mTc-sestamibi-labeled talc suspension ten subjects were rotated for 1 h, while the ten other patients remained in a stable supine body position. Scintigraphic imaging was done in two directions immediately after instillation and after 1 h with a clamped drain. The overall success of the treatment was assessed 1 month after the pleurodesis. The dispersion of talc was limited and unequal in 75% of the subjects. In two patients with apparently good distribution on anterior views, the lateral views of the scintigraphy showed only limited distribution. Rotation of the patients did not influence the dispersion of sludge after 1 min or 1 h. Pleurodesis was successful in 85% of the patients after 1-month follow-up. Standard rotation protocols for patients with malignant pleural effusion do not affect the overall dispersion of talc suspension and should be abolished because of the discomfort caused to the patients.

Adult↗
PubMed2001

Patient notification and follow-up after suspension of treatment protocols. experience from four clinical trials of treatments for AIDS-related CMV retinitis.

We reviewed procedures for and data about patient notification of the suspension of the treatment protocol for four clinical trials. We also examined how data collected after the suspensions were used. All four trials were designed to evaluate treatments for cytomegalovirus retinitis in patients with AIDS and were conducted by the Studies of Ocular Complications of AIDS Research Group. Documentation that patients were notified of the results varied from 62--100% with three of the four studies documenting the process for > or =92% of patients. The median time between the recommendation for protocol suspension and patient notification varied from 7--49 days with three of the four trials at 12 days or fewer. Most of the analyses of data collected after the suspension of the treatment protocol did not focus on comparisons among treatment groups. Although they provided useful information about the long-term outcomes and the nature of the disease, they did not alter the conclusions about safety and efficacy from the randomized portion of the trial. Control Clin Trials 2001;22:62-68

AIDS-Related Opportunistic Infections↗
PubMed1996

Early effects of basic fibroblast growth factor on foetal rat mesencephalic cell suspensions.

Mesencephalic cell suspensions are used, experimentally but also clinically, to compensate for neurological deficiencies, by implantation into the striatum. Here, we have studied the metabolism of mesencephalic cell suspensions obtained from rat embryos by measuring heat dissipation, oxygen consumption, ATP and lactate production. The effect of basic fibroblast growth factor (bFGF) at a 50 ng/ml concentration on these parameters was studied in order to assess the effect of in vitro exposure of cell suspensions to this trophic factor. Heat production and oxygen consumption were low, as could be expected from an immature nervous tissue, and they further decreased after addition of bFGF. This trophic factor decreased the total ATP concentration and increased the lactate production. The viability of the cell suspensions was reduced by nearly a half, 2 h after the addition of bFGF, and numerous fragmented nuclei were observed. It seems that, in contrast to the neuroprotective effect of bFGF on mesencephalic cultures and nigrostriatal neurons, this factor could have an initial sorting effect in the development of mesencephalic structures.

Acridine Orange↗
PubMed1998

Comparative study of budesonide as a nebulized suspension vs pressurized metered-dose inhaler in adult asthmatics.

The study objective was to compare the effect of budesonide administered as a nebulized suspension as compared to a spray with a spacer in adult asthmatics. In a double-blind, double-dummy crossover study, 26 adult patients with moderately severe unstable asthma were randomized to three 4-week treatment periods with budesonide 0.8 mg b.i.d. administered by a pressurized metered-dose inhaler (pMDI) with spacer (Nebuhaler) and budesonide 1 mg and 4 mg b.i.d. administered by a Pari Inhalier Boy jet nebulizer. The nebulizer was activated only during inspiration. The total mass output was similar from the two devices but their fraction of small particles differed by a factor of 2 in favour of pMDI. Effect was evaluated from daily home measurements of peak expiratory flow (PEF), need of beta 2-agonist and symptom scores. Plasma cortisol and budesonide levels were measured in a subgroup of 10 patients. A consistent trend showed the nebulizer treatment to be at least as efficient as the pMDI plus spacer treatment. In actual fact, the apparent order of effect was: 4 mg nebulized suspension treatment > or = 1 mg nebulized suspension treatment > or = 0.8 mg pMDI with spacer treatment. Plasma budesonide and plasma cortisol also exhibited dose-related levels independent of device. The adverse effects reported appeared to be related to the dose rather than delivery device. Accordingly, the effect was related to total mass output, rather than to the small particle fraction of the budesonide aerosol. These results attest to the efficiency of jet-nebulized budesonide suspension, and indicate nebulized budesonide to be equipotent to standard budesonide therapy delivered by pMDI with Nebuhaler, provided nebulization is synchronized with inspiration and no loss of aerosol occurs during expiration.

Adult↗
PubMedDate not supplied

Measurement of UV radiation using suspensions of microorganisms.

The measurement of solar UV radiation is usually performed using physical devices like photodiodes or photomultipliers or with chemical substances (actinometry). The application of biological material such as microorganisms for this purpose has gained increasing importance in the last few years. The microorganisms may be dried and spread on a flat surface or they may be in aqueous suspensions contained in UV-transparent vessels. If the measurements are done on flat surfaces, the irradiance weighted by the action spectrum of the dried microorganism used is the result of the measurement. If aqueous suspensions of microorganisms are used, contained for instance in spherical vessels, the fluence weighted by the action spectrum of the microorganisms in the aqueous suspension is the result. A problem of this method of measurement can be that inside the vessel the distribution of UV radiation is usually not homogeneous, causing distributions of fluences among the irradiated microorganisms, which may result in variation of the results depending on the mixing characteristics of the suspension during irradiation.

Bacillus subtilis↗
PubMedDate not supplied

Production of podophyllotoxin using cross-species coculture of Linum flavum hairy roots and Podophyllum hexandrum cell suspensions.

Novel cross-species coculture systems using Linum flavum hairy roots and Podophyllum hexandrum cell suspensions were applied for in vitro production of podophyllotoxin. The hairy roots and suspensions were cocultured in Linsmaier and Skoog medium in dual shake flasks and dual bioreactors. In separate experiments, coniferin feeding was shown to be an effective strategy for increasing the accumulation of podophyllotoxin in P. hexandrum suspensions. Because roots of L. flavum are a natural source of coniferin, hairy roots of this species were used in coculture with P. hexandrum to provide an in situ supply of coniferin. Compared with P. hexandrum suspensions cultured alone in shake flasks or bioreactors, podophyllotoxin concentrations in cocultured P. hexandrum cells were increased by 240% and 72% in dual shake flask and dual bioreactor systems, respectively. The availability and stability of coniferin in the medium are the most likely factors limiting podophyllotoxin synthesis in coculture. Intensification of the coculture process is required to further improve total podophyllotoxin accumulation on a volumetric basis.

Bioreactors↗
PubMedDate not supplied

Large-scale expansion of mammary epithelial stem cell aggregates in suspension bioreactors.

Mutations in the pathways regulating mammary epithelial stem cell (MESC) self-renewal and differentiation are currently hypothesized to result in uncontrolled cell division and, in turn, breast tumor formation. Although research is aggressively being pursued to understand how such pathways result in breast cancer formation, current studies have been greatly limited by MESC scarcity. To address this issue, this study has successfully developed large-scale expansion protocols for MESC through the subculture of murine mammary epithelial tissue aggregates, called mammospheres, in suspension bioreactors. Growth kinetics of mammospheres cultured in 125 mL suspension bioreactors and T-flasks were found to be comparable, achieving cell densities of 3.10 x 10(5) and 2.75 x 10(5) cells/mL, respectively. This corresponded to a 4-fold expansion over 8 days. Yields were also found to be strongly affected by liquid shear forces, where high agitation rates reduced overall cell numbers. Bioreactor cultures were scaled up to 1000 mL operating volumes, resulting in the production of 4.21 x 10(8) total cells (5.6-fold expansion) from a single passage. Furthermore, intermittent replacement of culture medium with fresh medium dramatically improved maximum cell densities, resulting in an 11-fold expansion, thereby enabling the generation of stem cells in quantities sufficient for standard biochemical and genetic analyses. After being cultured in suspension bioreactors for several passages, analysis by flow cytometry of Ki-67 revealed that 85% of the population was composed of proliferating cells. The successful development of expansion protocols for MESC aggregates in suspension bioreactors makes available experimental avenues that were not previously accessible for breast cancer research, thereby facilitating future investigations into elucidating the role of MESCs in breast cancer tumorigenesis.

Animals↗
PubMed2005

Comparison of centrifugation and filtration techniques for the size fractionation of colloidal material in soil suspensions using sedimentation field-flow fractionation.

Sedimentation field-flow fractionation (SdFFF) with UV detection is used to systematically investigate the effect of traditional membrane filtration and centrifugation procedures on the isolation of specific size fractions from soil suspensions. Both procedures were used to isolate the nominal <0.45 and <0.2 microm fractions from a clay soil suspension. Results showed that the membrane filtration approach seriously underestimated the total mass of particulate matter present as compared to the centrifugation approach. This has serious implications forthe interpretation of results for "colloidal" and "soluble" fractions from soil suspensions and other environmental matrices obtained using the standard membrane approach. The results also show that sedimentation FFF has great potential as a robust and relatively mild technology for studying size distributions in the "colloidal" range for soil suspensions and other aquatic matrices.

Centrifugation↗
PubMed2005

Surface behavior of nickel powders in aqueous suspensions.

The colloidal behavior of nickel aqueous suspensions is studied and compared to that of NiO suspensions. Under acidic conditions, nickel readily dissolves, but no dissolution takes place at basic pH. Zeta potential is studied as a function of pH, showing that the isoelectric point (IEP) occurs at pH 3.5-4. Above the IEP there is a zeta potential plateau, which is associated to the predominance of NiO(OH) species. At pH 9 a new decrease in zeta potential is associated to NiO predominance. XPS studies support that suspensions prepared at pH >9 lead to NiO-enriched species, while suspensions prepared at lower pH form NiO(OH) species.

Journal Article↗