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PubMed2000

Synthesis, control of substitution pattern and phase transitions of 2,3-di-O-methylcellulose.

An improved heterogeneous procedure has been found for the regioselective introduction of trityl and 4-methoxytrityl groups at the primary positions of cellulose. The 6-O-tritylcelluloses produced were completely methylated by MeI-NaOH in Me2SO solution. The trityl groups were then completely removed to afford 2,3-di-O-methylcellulose without significant degradation of the polymer. 1H and 13C NMR spectroscopy and degradation analysis showed less than 5% deviation from the regular substitution pattern. Under optimum reaction conditions, almost perfectly regular cellulose derivatives could be obtained. Small changes in the substitution pattern had a strong effect on the phase transitions of the O-methylcelluloses in water. It was shown by DSC for the first time that perfect 2,3-di-O-methylcellulose does not undergo phase separation at elevated temperatures.

Magnetic Resonance Spectroscopy↗
PubMed2000

Growth of rainbow trout hemopoietic cells in methylcellulose and methods of monitoring their proliferative response in this matrix.

A technique for the clonal culture of rainbow trout leukocytes in a methylcellulose matrix can be used to identify growth factors and other substances affecting cell proliferation and development in fish. Methylcellulose supports colony formation by rainbow trout leukocytes isolated from the major hemopoietic organ, the pronephros. The addition of rainbow trout serum dramatically increased the number of colonies formed, scored by counting colonies. As an alternative measure of cell proliferation, 3H-thymidine incorporation by cells can be easily measured in methylcellulose cultures. This method requires only small amounts of test substances, is rapid, and is superior for assessing the growth-stimulating ability of some substances, such as bacterial lipopolysaccharide, which stimulated growth but not the formation of discreet colonies by rainbow trout cells.

Animals↗
PubMed1995

Collagen matrix: an attractive alternative to agar and methylcellulose for the culture of hematopoietic progenitors in autologous transplantation products.

Autografts using untreated or in vitro manipulated bone marrow and peripheral blood stem cells represent promising approaches to the treatment of malignant diseases. In this work, the collagen gel culture technique was compared with agar and methylcellulose for its capacity to permit the growth of human granulomonocytic (day 14 CFU-GM; collagen vs agar or MTC) or erythroblastic (day 7 CFU-E and day 14 BFU-E; collagen versus methylcellulose) colonies in autologous transplantation products. Our results show that the collagen culture system always gave as many or more colonies than the other techniques. It also allowed harvesting of gels onto glass slides and subsequent May-Grünwald-Giemsa, cytochemical or immunocytochemical staining. We suggest that the collagen assay represents an interesting alternative to the widely used agar or methylcellulose systems for the culture of hematopoietic progenitors because of the equal or higher number of colonies detected, the easy phenotypical identification of colonies in stained gels, and the ability to store high-quality documentation. This technique is particularly attractive for use in the quality control of autologous bone marrow transplantation procedures.

Agar↗
PubMed2002

Critical evaluation of methylcellulose as an alternative medium in sperm migration tests.

BACKGROUND: The aim of this study was to evaluate the ability of human spermatozoa to penetrate methylcellulose (MC) and to compare this with penetration in hyaluronic acid. METHODS: Spermatozoa from normal (>or=20 x 10(6) sperm/ml, >or=50% progressive motility, >or=5% normal forms) and oligozoospermic (<20 x 10(6) sperm/ml) semen samples were allowed to swim into glass capillary tubes containing methylcellulose with a viscosity of 15 centipoise (cp) (MC15) and 4000 cp (MC4000), hyaluronic acid (rooster comb) or Sperm Select. Penetration of the spermatozoa at 1, 2, 3 and 4 cm were correlated with basic semen parameters (concentration, motility and morphology). The effects of temperature on penetration into MC4000 were explored at 17-37 degrees C. RESULTS: Higher numbers of spermatozoa penetrated MC4000 (10 mg/ml) compared with MC15 and the hyaluronic acid preparations. There was a highly significant correlation between the number of spermatozoa at all migration distances in MC4000 (10 mg/ml) and semen parameters. Increases in temperature from 17-37 degrees C were accompanied by significantly higher numbers of spermatozoa at each penetration distance. MC4000 at 10 mg/ml was at least as favourable to sperm penetration as human cervical mucus. Effective discrimination between normal and abnormal samples was achieved using MC4000 (10 mg/ml). CONCLUSION: Our results suggest the potential use of methylcellulose (MC4000, 10 mg/ml) as a reproducible and effective alternative to hyaluronic acid in sperm migration tests.

Cervix Mucus↗
PubMed1983

Methylcellulose and lens implantation.

Methylcellulose has been used since 1976 to prevent damage to the corneal endothelium during operations for implantation of intraocular lenses. Originally one drop of a 1% solution was placed on the artificial lens just before its insertion. Later the anterior chamber was completely filled with a 2% solution of methylcellulose before implantation. In this way it is possible to maintain a space between the cornea and iris even if vitreous pressure is present and to operate without risk to the corneal endothelium. This paper demonstrates the safety of the intraocular use of methylcellulose on the basis of over 400 operations. The substance is cheap, universally available, and can be easily prepared for intraocular use.

Corneal Diseases↗
PubMed1972

Effect of methylcellulose on rectal and colonic pressures in treatment of diverticular disease.

Six patients with diverticular disorder confirmed by barium-enema examination were given a six-month course of methylcellulose (Celevac) tablets; their rectal and rectosigmoid colonic pressures were measured before and afterwards. Open-tipped, fluid-filled, narrow-bore polyethylene tubes were used for pressure measurements and care was taken to site the tubes similarly in all patients before and after treatment. After methylcellulose treatment the mean rectosigmoid pressures had fallen to the same range as the mean rectal pressures, a highly significant reduction. Methylcellulose significantly reduces rectosigmoid pressures in diverticular disease.

Aged↗
PubMed2004

A methylcellulose microculture assay for the in vitro assessment of drug toxicity on granulocyte/macrophage progenitors (CFU-GM).

In a recent prevalidation study, the use of a methylcellulose colony-forming unit-granulocyte/macrophage (CFU-GM) macroassay for two independent in vitro tests (human and murine cell based) was suggested for quantifying the potential haematotoxicity of xenobiotics. In this paper, we describe the transfer of the macroassay to a 96-well plate microassay, in which the linearity of the response was studied (both in terms of CFU-GM and optical density [OD] versus the number of cells cultured), and the inhibitory concentration (IC) values for doxorubicin, 5-fluorouracil and taxol were determined and compared with those obtained by using the original macroassay. Fresh murine bone marrow and human umbilical cord blood mononuclear cells were used as a source of myeloid progenitors. The cells were cultured in methylcellulose containing granulocyte/macrophage-colony-stimulating factor, and in the presence of increasing drug concentrations. The cloning capacity of the progenitors was measured both as the number of colonies counted manually (CFU-GM), and as OD evaluated with an automated plate reader in an MTT test. Our results show that, in the microassay, up to 20 colonies/well could be easily counted, and that this range (20 to zero) gave a regression line from which IC values were calculated, which were very close to those obtained by using the macroassay (where the range of colony numbers was from 100 to zero). The test did not give good results when the OD (instead of the colony count) was used as the endpoint, because, although a high coefficient of determination was obtained, the OD values ranged from 0.6 to zero and the IC values determined were not comparable to those obtained by manual counts. The use of the microassay dramatically reduces the quantity of methylcellulose needed, and permits hundreds of cultures to be processed in the same experiment, contributing to significant reductions in both the work involved and the cost. A further important benefit is a reduction of the amount of drug needed for testing, which is crucial for screening new molecules, when many different toxicological tests have to be carried out. The microassay is therefore a useful and reproducible tool for screening compounds (chemicals, drugs and xenobiotics) for potential haematotoxicity directly on human myeloid progenitors, and could contribute significantly to reducing the use of animals in toxicity testing.

Animal Use Alternatives↗
PubMed1990

[Endothelium protective effect of the high viscosity substances hyaluronic acid and methylcellulose in mechanical damage].

We investigated the protective effect of the high-viscosity substances sodium hyaluronate (1%) and methylcellulose (2%) on corneal endothelium in the face of severe mechanical insult. An intraocular lens was drawn across the endothelium of porcine corneas with standardized conditions. We used different compression forces. Methylcellulose and sodium hyaluronate were used as lubricating substances in the experimental groups, while balanced salt solution (BSS PLUS) was used in the control group. In this study no significant protective effect of high-viscosity substances against strong direct mechanical damage was generally demonstrable. Only one group in which a moderately strong compression force was applied showed significantly less smaller endothelial cell loss when methylcellulose was used. The most important function of viscous substances is therefore to prevent a collapse of the anterior chamber and to prevent any contact of the intraocular lens or of instruments with the endothelium. Any mechanical contact with the endothelium means an irreversible endothelial cell loss.

Animals↗
PubMedDate not supplied

Methylcellulose--a better viscosurgical alternative for intraocular lens implantation.

The authors have used 2% methylcellulose in 8,000 cases of intraocular lens implant surgery during the last five and a half years. Their surgical experience and investigations have convinced them that methylcellulose is safe and effective besides being convenient and economical. It is easily autoclavable, has very low particulate matter when prepared by the author's technique, and causes minimal secondary rise of intraocular pressure. The endothelial protective function and breakdown of the blood aqueous barrier are comparable to that of Healon. The authors consider methylcellulose to be the better alternative for IOL implant surgery.

Glaucoma↗
PubMed1988

Comparison of 2% hydroxypropyl methylcellulose and 1% sodium hyaluronate in implant surgery.

We conducted a prospective randomized clinical trial of 2% hydroxypropyl methylcellulose and 1% sodium hyaluronate (Healon) in routine extracapsular cataract surgery with implantation of a posterior chamber intraocular lens. Of the 84 patients 40 received methylcellulose and 44 received sodium hyaluronate. There was no statistically significant difference in endothelial-cell loss or induced cellular polymegathism between the two groups. The intraocular pressure before and after surgery was similar in the two groups, as was the visual acuity 8 weeks after surgery. The results suggest that 2% hydroxypropyl methylcellulose is a safe and effective alternative to 1% sodium hyaluronate in routine implant surgery.

Cataract Extraction↗
PubMed1987

Cellulase slide preparation of methylcellulose cultures of hemopoietic cells.

A technique is described for making slides of colonies grown in methylcellulose semisolid medium. The entire contents of a 0.5-ml culture in a 24-well plate is digested using 0.25 ml of a 1.08-mg/ml solution of cellulase dissolved in fetal calf serum. The methylcellulose is digested overnight, and the well contents are transferred to slides and are stained. Adherent colonies are recovered using a fetal calf serum solution containing trypsin and EDTA to flush any residue from the well; the recovered cells are transferred to slides and then stained. This method produces slides free of the darkly stained methylcellulose background that interferes with viewing colonies and studying individual cells.

Animals↗
PubMed1980

Agglutinating phenomenon in the rat sera after administration of methylcellulose.

In the serum of Wistar rats following intraperitoneal application of methylcellulose (Kabi) the presence of the aggregation factor was confirmed. Using the more sensitive immunohaematological method-enzyme tests-we proved the agglutination phenomenon, which can be of antibody nature and cannot be induced under the test conditions in vitro by action of methylcellulose on blood cells and serum of normal rats. The described phenomenon will only occur if methylcellulose "passes" the organism of the experimental animal.

Animals↗
PubMed1983

Methylcellulose, a viscous cushioning material in ophthalmic surgery.

Methylcellulose has been used since 1976 to prevent damage to the corneal endothelium during operations for implantation of intraocular lenses. With a 2 per cent solution of methylcellulose it is possible to maintain a space between the cornea and iris even if vitreous pressure is present to operate without risk to the corneal endothelium. This paper demonstrates the safety of the intraocular use of methylcellulose based on the results of over 700 operations. The substance is cheap, universally available, and can be easily prepared for intraocular use.

Acetazolamide↗
PubMed1982

Comparison of agar and methylcellulose culture methods for human erythroid colony formation.

An agar culture method to permit human erythroid colony growth was described and was compared with the standard methylcellulose culture method. Although the cloning efficiency was greater and the colonies were larger in size in methylcellulose, the relative number of colonies was indistinguishable in the two culture systems after short-term exposure to cytosine arabinoside, adriamycin, tritiated thymidine, or busulfan. Thus, the agar culture system permits the growth of erythroid progenitor cells, which are at the same stage of differentiation as erythroid progenitor cells which can grow in methylcellulose. Since cultures in which agar is used as the semisolid matrix can be fixed and counted at the convenience of the investigator, the cloning of erythroid progenitor cells in agar will greatly facilitate investigation of the proliferative properties and drug sensitivity of erythroid progenitor cells obtained from normal individuals as well as from patients with hematologic neoplasms.

Agar↗
PubMed1997

Effects of hydroxypropyl methylcellulose and other gelling agents on the handling properties of calcium phosphate cement.

The calcium phosphate cement (CPC) used in this study was formed by combining equimolar amounts of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA). This powder, when mixed with water, sets to a hard cement in about 30 min. However, the water-based CPC paste is not highly cohesive and is vulnerable to washout until hardening occurs. The objectives of this study were to investigate the effects on handling properties, washout resistance, cement hardening behavior, and mechanical properties of adding several gelling agents to CPC paste. Aqueous solutions that contained a mass fraction of 2-4% of hydroxypropyl methylcellulose (HPMC), carboxyl methylcellulose (CMC), chitosan acetate, and chitosan lactate were used as cement liquids. Hardening time was measured by the Gilmore needle test; resistance to washout was evaluated by the disintegration of the cement specimen in water with agitation; and mechanical strength was evaluated by the measurement of diametral tensile strength and compressive strength. Handling properties were greatly improved by the addition of HPMC, CMC, chitosan acetate, and chitosan lactate. Hardening time was retarded by the additions of HPMC and CMC, and mechanical strength was weakened by the addition of either the chitosan lactate or the chitosan acetate.

Biocompatible Materials↗
PubMed1984

Methodological studies on growth of mouse granulocyte/macrophage colonies in methylcellulose-containing media.

We studied the influence of various physicochemical parameters on colony development and total cell numbers in 7-day methylcellulose cultures of mouse bone marrow cells. Colony growth was markedly retarded by an increase of PO2 from approximately 6.7 kPa towards that in ambient air and by a decrease of incubator temperature from 37 degrees C to 33 degrees C. Medium osmolality above approximately 340 mosm/kg inhibited formation of granulocytes (in cultures containing growth factors from pokeweed mitogen-stimulated spleen cells), but not macrophages (L cell-produced growth factors). At most, colony growth was affected slightly by moderate changes in pH (7.17-7.47) or concentration of methylcellulose (0.77-1.02%), or by the presence of 2-mercaptoethanol (50 mumol/1), Hepes buffer (25 mmol/1), or erythropoietin (0.1-1 units/ml). The culture trays could be stored for one day at 4 degrees C in the incubation boxes before colonies or cells were counted.

Animals↗
PubMed2003

Methylcellulose gel is a superior contrast agent for ultrasound examination of the cervix in obstetric patients.

OBJECTIVE: To determine the superior contrast agent for cervical sonography: water-soluble methylcellulose gel vs. normal saline. METHODS: Women with an indication for cervical sonography underwent placement of 10 mL water-soluble methylcellulose gel or normal saline. Assessment of cervical dimensions and contour was performed via transperineal sonography prior to and after contrast placement. RESULTS: Twenty-five patients with similar demographic characteristics and indications for ultrasonography were enrolled into each group. Administration of contrast improved the ability to visualize the external os or vaginal fornices in 18 women in the gel group vs. six in the saline group (P = 0.002). In the gel group, 17 patients had easier identification of the external os and visualization of the fornices was enhanced in 13 patients. The assessment of cervical length prior to and after contrast administration was not statistically different with the use of either of these agents. CONCLUSION: Intravaginal soluble gel is superior to normal saline as a cervical contrast agent. Intravaginal contrast may allow for easier identification of cervical anatomy during ultrasonographic examination in selected patients.

Adult↗