Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Suspensions”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

Reproducibility of yields of foot--and--mouth disease virus from BHK monolayer and suspension cells.

The production of FMD virus from BHK 21 C13 monolayer and suspension cells was examined under standardized conditions and in different systems. The yields of virus from suspension cells did not significantly exceed the yield from monolayer cells, whereas the monolayer cell was capable of producing virus from some strains of FMD virus which would not grow in suspension cells. When different production systems were examined, the scale of operation did not significantly influence the yield of virus from suspension cells, while the plastic spiral film propagator produced significantly less virus than the other monolayer systems examined. The use of unit monolayer systems on the large scale is discussed.

Aphthovirus↗

The use of suspension cultures for FMD vaccine production. Criteria for the evaluation of cells, virus and vaccine.

A survey of problems connected with the cell suspension culture for the production of FMD vaccine is presented, in order to stimulate a discussion. Introductory remarks are made on the following topics: 1) suspension cell lines used for FMD vaccine production, 2) terminology, 3) criteria for the characterization of a cell culture, 4) evaluation of FMD virus produced according to the cell suspension technique and correlation existing between in vitro tests and antigenicity in domestic animals, 5) criteria which must be met by FMD vaccine produced from virus cultivated on cell suspension.

Antigens, Viral↗

[The determination of the bacterial effectiveness of surface disinfectants using suspension tests].

The results of the testing of 38 preparations intended for surface disinfection are compared in order to evaluate the value of the suspension tests. The studied testing methods are: the in vitro test (IVT) with the disinfectant diluted in distilled water (AD), in standard hard water (WSH) and in 0.2% albumin; the European Suspension Test (EST) under clean and under dirty conditions; the French AFNOR test NF T 72-190; the practical test of the German Society for Hygiene and Microbiology (DGHM); and the Quantitative Surface Disinfection Test (QSDT). The suspension tests yield comparable results (Table 1). These results correlate very well with these of the AFNOR test, to a lesser extent with those of the DGHM test and hardly with the results of the QSDT, which is the most real-life mimicking practical test (Table 2). Suspension tests are not able to exclude only inactive preparations from further testing in practical tests: they are not specific (Tables 3 and 4). Therefore, it is necessary to include practical tests in the testing schedule for the evaluation of the bactericidal activity of surface disinfectants.

Bacteria↗

Effects of plasma proteins on the adhesion, spreading, polarization in suspension, random motility and chemotaxis of neutrophil leukocytes on polycarbonate (Nuclepore) filtration membrane.

The effects on adhesion, spreading, polarization in suspension, random motility and chemotaxis to N-formyl-methionyl-leucyl-phenyl-alanine (FMLP) of neutrophil leukocytes on polycarbonate (Nuclepore) membrane in the Boyden chamber of purified serum albumin, gamma globulin and fibrinogen, as well as of the Hanks'-soluble components of Cohn fractions III (beta and gamma globulins) and IV (albumin, alpha globulins and transferrin) of plasma proteins were tested in comparison to the corresponding effects of dilute fresh heparinized plasma. Serum albumin, fibrinogen and fibronectin inhibited adhesion of neutrophils, so that the spreading, random motility and chemotaxis of these cells could not be assessed in the presence of these proteins alone. These plasma proteins induced little or no polarization of the cells in suspension. Of the remaining preparations, gamma globulin promoted adhesion and excessive spreading and caused corresponding reduction of random motility and chemotaxis to FMLP of these cells. This plasma protein, even in low concentration, induced marked polarization of neutrophils in suspension. Both Cohn fractions III and IV supported adhesion and permitted random motility and chemotaxis to FMLP approximating that which occurs in dilute plasma. These fractions induced moderate polarization of cells in suspension. Addition of serum albumin or fibronection to the preparations of gamma globulin, or Cohn fractions III or IV did not alter the adhesion, random motility or chemotaxis of the neutrophils in these preparations. These results suggest that alpha and beta globulins, as well as gamma globulins are factors in plasma affecting adhesiveness and polarization of neutrophils and which provide for optimal motility and chemotaxis of these cells on solid substrata.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Proteins↗

Sex differences in blood constituents of rats following tail suspension.

Tail suspension was utilized to study sex differences in the effects of hypokinesia on blood constituents of rats. Twelve male and twelve female rats were used. After four weeks of exposure to tail suspension or non-treatment, the rats were laparotomized under ether anesthesia and blood samples were obtained. Biochemical tests on the blood samples were then performed immediately. Hematocrit and serum iron were also estimated. The results were as follows: 1) The same tendencies were noted in blood constituents between male and female rats in the control group and the tail suspension group. 2) The average levels of blood albumin, creatinine, uric acid, glucose, triglyceride, serum iron and hemoglobin in the tail suspension group were lower than those in the control group, especially in male rats.

Animals↗

Influence of the elimination of lymphocytes from tumor cell suspensions on the calculation of S-phase fractions by flow cytometry.

Contaminating lymphocytes were eliminated from enzymatically obtained cell suspensions of 260 surgical biopsy specimens by density gradient centrifugation using lymphocyte separation medium (LSM) in an attempt to improve the determination of S-phase fractions by flow cytometry. The elimination of lymphocytes from the cell suspensions was ascertained on cytologic smears prepared from the suspensions before and after LSM centrifugation. Following the elimination of lymphocytes, the calculated S-phase fractions increased significantly in DNA-diploid tumors, but not in DNA-aneuploid ones. The increase of the S-phase fraction was correlated to the numbers of lymphocytes in the tumor cell suspensions before LSM centrifugation. Furthermore, in 12 tumors originally classified as diploid, an aneuploid cell line was detected after LSM centrifugation. These results indicate that samples from diploid tumors containing large numbers of lymphocytes should have the lymphocytes eliminated by methods such as LSM centrifugation in order to obtain reliable results for the calculations of the S-phase fractions.

Breast Neoplasms↗

Use of hepatocytes in adhesion and suspension cultures for liver support bioreactors.

Hepatocyte cultivation in bioreactors for hybrid liver support systems is possible under two conditions: attached to a substrate like membranes or microcarriers or in suspension culture. To compare the ammonia metabolism of hepatocytes cultivated under these two conditions, cultures of primary seeded rat hepatocytes were cultivated either attached to collagen coated tissue culture plastic or as a suspension culture. During the time course of culture, the ability of hepatocytes to reduce the ammonia content of the medium decreased in both adhesion and suspension cultures, though to different extents. In suspension cultures, ammonia content was reduced from 350 microM to about 100 microM (day 4) and to about 180 microM (day 6). No significant reduction was seen on day 8 of culture. In contrast, hepatocytes attached to collagen coated dishes remained viable and functional for at least 8 days after plating, reducing ammonia content from 350 microM to 70 microM (day 4), 90 microM (day 6) and 180 microM (day 8). The period of useful metabolism of hepatocytes in bioreactors for hybrid liver support systems appears to depend on the culture conditions.

Ammonia↗

[A simple technic for vaginal suspension using multiple approaches. Study of a series of 50 cases].

Fifty patients underwent vaginal suspension using a new technique based on Stamey's procedure. The method of operation is described with illustrations. This procedure can be carried out with the patient in the lithotomy position when special indications are present: when prolapse has to be cured by the vaginal route and a vaginal suspension has to be carried out; when a vaginal hysterectomy has to be carried out together with a vaginal suspension; when an upper approach vaginal suspension using a Marshall-Marchetti technique has failed. The advantages of this technique seem to the authors to be: the simplicity of the procedure: only the lithotomy position is needed. It is easy and quick to carry out, it is safe: dissecting out the bladder from the vaginal approach and passing threads from below to above practically completely avoids the risk of damaging the bladder. The preliminary clinical and uro-dynamic results are given.

Adult↗

Organization of the vimentin system and its spatial relationship to the microtubule complex during the division of mammalian cells growing attached and in suspension.

We have used immunofluorescence staining with antibodies that detect vimentin, tubulin and the centrioles to compare the distributions of these respective antigens during the division of several suspension and attached cultured cells. Our observations demonstrate that 1) from distinct interphase organizations in suspension and attached cells, the vimentin system consistently rearranges with the onset of mitosis into a filamentous cage-like structure enclosing the spindle, 2) during cytokinesis, the polar centrosomes relocalize near the midbody in suspension cells while they remain at the pole opposite to it in attached cells, and 3) the vimentin cage is disintegrated and aggregated on each side of the midbody during cytokinesis in lymphoid cells but may be retained in other suspension cells.

Animals↗

Short-term cardiovascular adaptations to vertical head-down suspension.

Inversion devices have been advocated as means of therapy for patients with low back pain. The present investigation was undertaken to determine the cardiovascular responses to vertical head-down suspension with such a device. Eight men were monitored for three minutes in the upright and supine position, and for ten minutes in the vertical head-down position. Stroke volume (SV), heart rate (HR), cardiac output (QT), segmental arm blood flow (ABF), and segmental leg blood flow (LBF) were measured by impedance plethysmography. Moving from the upright to the supine positions resulted in an SV increase from 93.1 +/- 18.8 to 138.2 +/- 28.2 ml.beat-1 (p less than 0.01). During the first minute of suspension a further increase in SV to a maximum of 178.6 +/- 45.0 ml.beat-1 was noted. By the end of the suspension period, SV had declined to 159.6 +/- 34.2 ml.beat-1. Resumption of the upright position was associated with a reduction in SV to 94.3 +/- 15.8 ml.beat-1. Changes in QT across the supine and vertical head-down positions reflected the changes in SV. The vertical head-down position was also associated with a gradual reduction in both ABF and LBF. These data suggest that the primary effect of inverted suspension was a transient increase in venous return, which requires an effective ventricular response. An element of caution should be exercised in using these devices to avoid aggravating concurrent pathologic conditions.

Adaptation, Physiological↗

Controlled air suspension: an advantage in burn care.

The clinical uses of the air-fluidized Clinitron therapy system and the air suspension KinAir bed are discussed based on a review of 31 patients. The risks of infection and high evaporative water loss on the air-fluidized bed are problems not associated with the air suspension bed. The clinical use of the air suspension bed is much simpler and safer for nursing personnel. The air suspension bed is indicated for patients with massive burn injuries, patients with deep burns of the back, obese burn patients, heavily infected burn patients, and debilitated patients.

Adult↗

Acute inflammatory effects of intratracheally instilled Escherichia coli endotoxin and sonicated suspension of Haemophilus pleuropneumoniae in swine.

A single bolus of either Escherichia coli endotoxin, sonicated suspension of Haemophilus pleuropneumoniae, or pyrogen-free normal saline was intratracheally instilled in six week old specific-pathogen-free pigs. Pigs exposed to E. coli endotoxin developed fever, leukopenia followed by leukocytosis, and endotoxemia. Leukocytosis was the only clinical abnormality noted in pigs receiving the sonicated suspension of H. pleuropneumoniae. At one day postexposure, focal areas of atelectasis and consolidation were observed in the caudal lung lobes of animals receiving either E. coli endotoxin or the sonicated suspension of H. pleuropneumoniae. Lesions were characterized by a neutrophilic bronchitis and bronchiolitis with alveolitis in the surrounding tissue. Increased numbers of alveolar macrophages and evidence of phagocytosis were observed by light and electron microscopy. No clinical abnormalities or lesions were observed in animals receiving normal saline. Lesions typical of acute porcine Haemophilus pleuropneumonia were not produced by either E. coli endotoxin or sonicated suspension of H. pleuropneumoniae, indicating that multiple virulence factors are probably involved in lesion development.

Animals↗

Skeletal suspension in the management of severe burns in children. A sixteen-year experience.

From 1966 to 1983, skeletal suspension was used at the Shriners Burns Institute, Galveston, Texas, for the treatment of 626 burned pediatric patients who had 1128 affected extremities. Skeletal suspension was used for 863 acutely burned extremities (76.5 per cent) to facilitate skin-grafting and in 265 extremities (23.5 per cent) for functional positioning in the surgical correction of burn-acquired deformities. In a retrospective examination of these patients, there were fifty complications (4.4 per cent) related to the skeletal suspension, of which forty-five (4.0 per cent) were infections. All infections resolved with removal of the pins or the administration of antibiotics, or both. With this established low rate of complications, skeletal suspension continues to be a useful adjunct in the care of the severely burned pediatric patient.

Acute Disease↗

Skeletal response to simulated weightlessness: a comparison of suspension techniques.

The skeletal response to simulated weightlessness was studied in rats subjected to two different methods of suspension. Skeletal unloading of the hind limbs for a two week period was achieved by use of either a back harness or tail traction. In comparison to pair-fed control rats, back-suspended rats failed to gain weight whereas tail-suspended rats exhibited normal weight gain. Quantitative bone histomorphometry revealed marked skeletal abnormalities in the proximal tibial metaphysis of back-suspended rats. Loss of trabecular bone mass in these animals was due to a combination of depressed longitudinal bone growth, decreased bone formation, and increased bone resorption. In contrast, the proximal tibia of tail-suspended rats was relatively normal by these histologic criteria. However, a significant reduction in trabecular bone volume occurred during 2 weeks of tail suspension, possibly due to a transient inhibition of bone formation during the early stages of skeletal unloading. Lack of weight gain in back-suspended rats may be indicative of a pronounced stress response during which corticosteroids adversely affected the skeleton. Maintenance of normal weight gain by tail-suspended rats provides evidence for the less traumatic nature of this method of suspension. Our findings indicate that tail suspension may be a more appropriate model for evaluating the effects of simulated weightlessness on skeletal homeostasis.

Adipose Tissue↗

Transvaginal needle bladder neck suspension.

Like the transabdominal bladder neck suspension, the aim of the transvaginal needle suspension of the bladder neck is to suspend the bladder neck and urethra in a fixed retropubic position. Because the transvaginal technique does not require the splitting of the abdominal wall fascia, postoperative discomfort and convalescence may be lessened. Different techniques of transvaginal needle bladder neck suspension, including suspension of the bladder neck with a fascial sling, are discussed in detail.

Fasciotomy↗

A suspension model for hypokinetic/hypodynamic and antiorthostatic responses in the mouse.

Hypokinetic/hypodynamic and antiorthostatic responses to weightlessness and bedrest were simulated in mice using a suspension technique. Animals were suspended for 1 or 2 weeks in an antiorthostatic posture and positioned to permit freedom of movement but eliminate load bearing by the hindlimbs. Suspended mice exhibited reduced food and water intakes and rapid 10% decrease in body weight to a level which was maintained for the remainder of the suspension period. Diuresis was evident in suspended mice, but the natriuresis and kaliuresis previously observed in the suspended rat were not evident. Differential hindlimb muscle atrophy (soleus greater than plantaris = gastrocnemius greater than EDL) and increased excretion of urea and ammonia were also noted in suspended mice. Postsuspension recovery studies indicated that the recovery process was highly effective. These results document specific responses to hypokinesia/hypodynamia and antiorthostasis in the mouse and demonstrate similarities in the responses of mice and rats to suspension. These studies expand the utility of the suspension model and suggest that the mouse may be useful in future studies simulating both weightlessness and bedrest.

Adrenal Glands↗

High pressure liquid chromatographic method for probenecid in flavored oral suspensions containing ampicillin: collaborative studies.

A high pressure liquid chromatographic method for determining probenecid in oral suspensions of amoxicillin was applied to the determination of probenecid in oral suspensions of ampicillin. Three preparations containing various known amounts of probenecid in synthetic mixtures of ampicillin oral suspensions were analyzed by 5 chemists in an intralaboratory study, with satisfactory results. Blind duplicates of 3 prepared oral suspensions were sent to 12 collaborators, who were instructed to analyze the samples in a fixed random order. The standards showed a satisfactory linear response. Average recoveries of probenecid in the interlaboratory study for the 6 mixtures ranged from 95.2 to 99.1%, and the coefficients of variation ranged from 1.63 to 4.9%.

Ampicillin↗

Alloimmunization against the MHC antigens after platelet transfusions is due to contaminating leukocytes in the platelet suspension.

Repeated platelet transfusion to thrombocytopenic patients frequently induce anti HLA antibodies, which are responsible for transfusion refractoriness. As the transfused platelet suspensions usually contain 15-30% of the leukocytes originally present in the blood, it is not known whether these antibodies are raised by the platelets or by the contaminating leukocytes in the platelet suspensions. In the mouse, pure platelet suspensions are not able to induce a primary antibody response, as measured by the NIH test and the indirect immunofluorescence test on platelets and leukocytes, despite repeated injections. However, when the platelet suspensions are contaminated with leukocytes (10(3) or more/injection) an antibody response is induced. This response is higher than the response indiced by an equal amount of leukocytes alone. As in man the use of leukocyte poor platelets postpones the development of refractoriness to random platelets it is concluded that transfusions with leukocyte free platelets will probably prevent immunization against the HLA antigens.

Animals↗