PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Mucus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed1979

Human cervical mucus. V. Oral contraceptives and mucus rheologic properties.

Mucus viscoelasticity on individual samples obtained from patients using combination oral contraceptives was quantitated by microrheometry. These results, in conjunction with mucus chemical characterization, indicate that combination oral contraceptive use eliminates the cyclic variations in mucus chemical, physicochemical, and rheologic properties associated with the ovulatory menstrual cycle. A correlation was demonstrated between the mucus elastic modulus and mucus nondialyzable dry weight, and the mucins produced during oral contraceptive therapy were shown to be similar to those recovered from ovulatory donors. Differences in mucus properties were noted when donors using estrogenic contraceptives were contrasted with those using androgenic contraceptives. On the basis of established relationships between sperm penetrability and mucus solids content, it was concluded that the use of contraceptives, as examined in this study, provided a secondary degree of fertility control at the cervical level.

Cervix Mucus↗
PubMed1977

Immunoglobulins, proteinase inhibitors, albumin, and lysozyme in human cervical mucus. I. Communication: hormonal profiles and cervical mucus changes--methods and results.

The serum levels of luteinizing hormone (LH), estradiol-17beta, and progesterone were determined simultaneously with the concentrations of immunoglobulin (Ig) G, IgA, C'3, alpha1-antitrypsin, inter-alpha-trypsin inhibitor, alpha1x-antichymotrypsin, albumin, and lysozyme in cervical mucus during nine ovulatory cycles. Spinnbarkeit and ferning were also assessed, and the basal body temperature was measured and recorded during these cycles. The profiles were synchronized according to the LH peak. The midcycle period, characterized by the rapid increase and decline of estrogen and the beginning rise of progesterone, shows a prounced minimum of immunoglobulins, C'3, proteinase inhibitors, albumin, and lysozyme in cervical mucus, which is known to be most receptive to sperm penetration at this time. Although the variation of cervical mucus values is considerable during the early proliferative and the luteal phases, the midcycle values appear to be constantly low, showing slight differences among the profiles of the different parameters. The statistical evaluation and the assessment of the significance of parameters for ovulation detection and the assessment of the fertile period as well as the correlation of these parameters with basal body temperature will be the subject of the second communication of this series.

Adult↗
PubMed1975

Results of in vitro sperm penetration tests in cervical mucus in the normal cycle and in mucus under the influence of the contraceptive pill.

Women who are either menstruating normally or taking a combined or sequential preparation for hormonal contraception were examined at intervals of 2 days with reference to the day of the cycle. The parameter studied was the in-vitro penetrability of the cervical mucus for sperms. Whilst the combined preparation completely blocked the cervical canal for the spermatozoa, the distance travelled by the spermatozoa under the influence of the sequential preparation was approximately the same as in the normal cycle. This study of the depth of penetration of the spermatozoa in relation to the hormonal situation was prompted not by contraceptive but rather by epidemiological considerations of cervical carcinoma.

Cervix Mucus↗
PubMed1979

Mechanisms of mucus release in exposed canine gastric mucosa.

Mucus release was studied in the exposed gastric mucosa of anesthetized fasted dogs using scanning and transmission microscopy as well as histochemical and autoradiographic techniques. Under unstimulated conditions, the gastric epithelium was composed of both nonsecreting and mucus-secreting epithelial cells, with the former being predominant. Nonsecreting cells were characterized by an intact apical mucus package of granules and a continuous plasma membrane. The secreting mucus cell population was found in the foveolar (pit region) as well as interfoveolar areas. Three mechanisms of mucus release were observed: (a) exocytosis, (b) apical expulsion, and (c) cell exfoliation. Evidence for exocytosis was found in all mucus cells, especially in the sulfated glycoprotein-rich foveolar cells. Exocytosis involved only a few granules at a time; this mode of secretion is likely slow and continuous. In contrast, apical expulsion resulted in an explosive release of the entire apical mucus package followed by in situ degeneration of the cell itself. This occurred in the oldest cells forming mucosal crests in the interfoveolar area, whose mucus predominantly stains for neutral glycoproteins. Cell exfoliation, in which the entire cell was extruded into the lumen, was rarely observed and may provide, in addition to apical expulsion, a second mechanism to rid the mucosa of senescent epithelial cells. Mucus secretion is a complex function of the gastric epithelium. The mechanism of secretion and the histochemically defined type of mucus secreted are variables which are dependent on the age of the cell, its position on the foveolae, and the microenvironment within the gastric lumen. The mucus-containing surface and pit cells of gastric epithelium have been described morphologically and ultrastructurally in a number of studies. These cells are highly differentiated, forming a layer which is dynamic and responsive to conditions present in the gastric lumen. Mucus cells arise from multipotent progenitor cells which differentiate in the course of migration up the gastric pits and are involved in the complex macromolecular synthesis of glycoproteins. Although mucus release occurs throughout cell life, very little attention has been given to the cellular ultrastructural changes that deal with mucus secretion. As a result, the mucus-containing surface and pit cells have been described primarily in terms of their nonsecreting functional state. Exceptions to this are a few transmission and scanning electron microscopy studies which describe loss of intact mucus granules, cell extrusion, and in situ degeneration. These previous ultrastructural studies describe cellular patterns, in both normal and injured mucosa, which we fell are related to mucus release. Because of a paucity of knowledge concerning the normal mechanisms of mucus secretion, it was the purpose of this study to define the ultrastructural changes which result in and accompany the production of mucus in canine gastric epithelium.

Animals↗
PubMed2026

Physical, chemical, and structural properties of human gastric organoid-derived mucus.

The gastric mucus layer protects the epithelium from gastric acid and ingested pathogens. However, studies of human gastric mucus have been limited due to poor accessibility of native human mucus and the abundance of contaminants in these samples. Here, we explored the potential of human gastric organoids as models for mucus production. Immunofluorescence staining confirmed that the organoids produced mucus containing MUC5AC and MUC6. The luminal mucus had viscoelastic properties similar to those of native human gastric mucus, as determined by particle tracking microrheology. To collect organoid-produced gastric mucus, termed bioengineered gastric mucus (BGM), organoids were cultured as monolayers at the air-liquid interface (ALI), and apically secreted mucus was harvested and analyzed by MUC5AC ELISA, proteomics, cryo-field emission scanning electron microscopy (CryoFE-SE), and rheometry. BGM contained high-molecular weight molecules also found in native gastric mucus. Proteomic analysis confirmed that BGM contained MUC5AC, MUC6, MUC1, and other stomach-specific molecules such as pepsin C, trefoil factor 2, and gastrokine. CryoFE-SE showed that both BGM and native mucus had a porous structure and a characteristic honeycomb scaffold. However, the viscosity of the BGM was generally lower than that of native human gastric mucus, and BGM failed to exhibit gelation at low pH. Collectively, these findings demonstrate the potential as well as some limitations of BGM as an accessible model system for human gastric mucus.NEW & NOTEWORTHY We demonstrate the structural and functional similarities of organoid-derived gastric mucus and native mucus collected from human patients. The bioengineered gastric mucus mimics its native counterpart in its proteomic profile and physical architecture. This work highlights the translational potential of organoid-derived mucus for functional investigations of the human gastric mucus layer.

Humans↗
PubMed1979

Effect of pentobarbital anesthesia on rheology and transport of canine tracheal mucus.

Tracheal mucus samples were collected from six tracheostomized dogs before and after induction of pentobarbital anesthesia. The dynamic mechanical properties of the mucus were determined by the magnetic microrheometer technique. In 15 experiments, the mean value of elasticity at 1 rad/s rose from 67 dyn/cm2 before anesthesia to 212 dyn/cm2 in the period 15-90 min after induction. At the same time, mean viscosity at 1 rad/s rose from 24 to 79 P. The mucociliary transportability of some of the mucus samples was assayed by means of in vitro frog palate technique. In 10 experiments, the relative transport rate for dog tracheal mucus went from 98% of frog palate control befor anesthesia to 79% during pentobarbital anesthesia. A negative relationship between from palate transport rate and mucus elasticity was found. A negative correlation between transport and mucus viscosity at constant elasticity was also discovered. Finally, the mucus collection rate was reduced by a factor of about 8 during anesthesia, suggesting a reduction in the average depth of mucus.

Animals↗
PubMed1977

Human cervical mucus. I. Rheologic characteristics.

The viscoelastic properties of human cervical mucus were subjected to detailed characterization by microrheometry. An introduced to the range of parameters that can be measured and the sensitivity of microroheometry to variations in mucus viscoelasticity was presented, along with an interpretation of results obtained by this approach. Fresh cervical mucus samples were shown to be rheologically heterogeneous, reflecting compositional differences in situ. Mucas viscoelasticity was stable for several hours when samples were stored at ambient temperature in the microrheometer sample holder. Mucus viscoelasticity was strongly dependent upon nondialyzable solids (NDS) concentration. In order to eliminate (NDS) as a variable in comparative studies of mucus, procedures were developed for reconstitution of mucus at identical (NDS) or for normalization of viscoelasticity data derived from fresh samples to 2.5% NDS. The validity of this approach was then examined by applying these procedures to mucus collected during the follicular, ovulatory, and luteal phases of the normal menstrual cycle.

Animals↗
PubMed1977

Human cervical mucus. III. Isolation and characterization of rheologically active mucin.

Several common mucolytic agents were screened for their ability to solubilize cervical mucus without incurring irreversible losses in mucus viscoelasticity. Sodium thiocyanate was selected on the basis of its effectiveness and handling convenience, and solubilized mucus was fractionated by gel filtration on Sepharose columns. The excluded mucin fraction was characterized by a high neutral hexose to protein ratio and contained all of the elasticity of thiocyanate-treated whole mucus. The concentration of mucin in individual mucus samples collected throughout the ovulatory menstrual cycle was determined from column elution profiles. An increased relative amount of mucin was associated with samples collected during the ovulatory phase of the cycle, and a strong correlation was obtained when the percentage of mucin in individual samples was plotted against their respective storage moduli. These results indicate that the cyclic fluctuations in mucus viscoelasticity seen previously at constant concentrations of nondialyzable solids can be attributed to variations in mucin concentration. Evidence was also obtained, however, for compositional differences in mucus derived from different patients.

Cervix Mucus↗
PubMed1979

Effects of bile acids on mucus secretion in the dog colon.

The effects of unconjugated bile acids on colonic mucus production have been studied in the dog. Isolated segments of both ascending and descending colon were simultaneously perfused with either chenodeoxycholic, deoxycholic or cholic acid and the mucus production estimated from the total hexose output. Each bile acid produced a significant increase in mucus output in both the right and left colonic segments. There were no differences between the right and left colon in terms of mucus output for any of the bile acids studied. Deoxycholic had a greater effect than chenodeoxycholic which had a greater effect than cholic acid in colonic mucus production. Further, these effects on mucus secretion were completely reversible. In diarrhoea associated with disease or resection of the ileum, the effect of bile acids on mucus secretion may be as important as their effects on the inhibition of water and electrolyte absorption.

Animals↗
PubMed1977

Molecular arrangement of cervical mucus: a reevaluation based on laser light-scattering spectroscopy.

Evidence obtained from laser light-scattering spectroscopy suggests that the molecular arrangement of cow estrous cervical mucus is an ensemble of entangled random-coiled macromolecules rather than a cross-linked macromolecular network, the model heretofore widely accepted. This new model can account for the following phenomena: (1) The viscoelastic properties of the estrous mucus and human mid-cycle cervical mucus are the result of the way in which the glycoproteins are entangled. Variations of these properties during the reproductive cycle may simply be due to changes in the water content of the cervical mucus. (2) Penetration of spermatozoa in mucus may be entirely mechanical without involving any kind of enzymatic lysis of cross-links (this is supported by changes in the pattern of spermatozoa flagellation during sperm penetration of cervical mucus as shown in motion picture films). (3) The orientation of spermatozoa in the cervical muscus need not be due to the presence of 'channels' between micelles but simply to an artifact, the stretching or flow of the mucus, which orients the entangled macromolecules and thus facilitates the penetration of spermatozoa in an axis parallel to them.

Animals↗
PubMed1976

Cervical mucus changes in infertile ewes previously exposed to oestrogenic subterranean clover.

Characteristics of cervical mucus were compared between groups of ewes which had previously grazed for long periods on either potently oestrogenic clover pasture (group A), mildly oestrogenic pasture (group B) or non-oestrogenic pasture (group C). No phytooestrogens were fed at the time of the study. The chloride content of mucus from group A ewes was significantly decreased, on a dry weight basis. The motility and survival of ram spermatozoa appeared similar in cervical mucus from groups A and B. There was no statistically significant difference between groups of ewes in either the total wet weight of mucus, the proportion of dry weight, or the degree of arborisation of mucus, at the time of oestrus. Mucus from group A ewes had a significantly decreased spinbarkheit, and a decreased ability to orientate sperum migration, when compared with group B. The group B ewes had a significantly smaller spinbarkheit than group C. Measurement of cervical mucus spinbarkheit offers promise as a diagnostic test for permanent clover infertility.

Animal Feed↗
PubMed1977

Human cervical mucus. II. Changes in viscoelasticity during the ovulatory menstrual cycle.

Quantitative viscoelasticity measurements were made on individual human cervical mucus samples by microrheometry. Increases in mean values for mucus spinnbarkeit, ferning, and wet weight were associated with the ovulatory phase of the menstrual cycle, while no significant differences versus time were noted for mean values for sample pH or nondialyzable dry weight. A nadir in mucus nondialyzable solids (NDS) concentration and in visoelasticity was seen at or near midcycle. Substantial, highly reproducible, variations in mucus viscoelasticity were observed when mucus from different donors was compared. When the contribution of (NDS) to viscoelasticity was minimized by data normalization or by sample reconstitution, a significant increase in viscoelasticity was associated with the ovulatory phase of the cycle, suggesting the occurrence of a relative increase in mucin concentration or a compositional change in the mucus.

Cervix Mucus↗