Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cheek”

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 199 records · Page 11Linked to original sources
PubMed1990

Changes in keratin expression during 7,12-dimethylbenz[a]anthracene-induced hamster cheek pouch carcinogenesis.

This study was undertaken to explore the expression of keratins in the hamster cheek pouch carcinogenesis model, using monospecific keratin antibodies and a technique that allows immunoblotting analysis of tissues embedded in paraffin. Changes in keratin expression were correlated with histopathological changes and with the expression of the enzyme gamma-glutamyl transpeptidase. The right cheek pouch of 20 male golden Syrian hamsters was treated with 0.5% 7,12-dimethylbenz[a]anthracene for 16 weeks. As previously described by other laboratories, this treatment resulted in hyperplastic and dysplastic lesions and benign and malignant tumors. The keratins assayed in this study were K14 (Mr 55,000), K1 (Mr 67,000), and K13 (Mr 47,000). The normal hamster cheek pouch epithelium expressed K14 in the basal layer and K13 in the suprabasal and differentiated layers, whereas K1 was not detected by either immunohistochemistry or immunoblotting. Concomitant with 7,12-dimethylbenz[a]anthracene-induced hyperplasia, there were some topographical alterations in the distribution of K14. In this case, K14 was no longer restricted to the basal layer but was also expressed in differentiated cells. The same pattern was also observed in dysplastic lesions and in squamous cell carcinoma. Furthermore, expression of the K13 differentiation-associated keratin was preserved in this hyperplastic epithelium during all the stages of carcinogenesis, including either anaplastic or differentiated areas. In contrast, after 2 weeks of 7,12-dimethylbenz[a]anthracene treatment, K1 expression started as a weak and patchy pattern in suprabasal cells, becoming stronger and more homogeneous at 8 and 16 weeks of treatment. However, K1 was almost absent in squamous cell carcinoma, where only small very well differentiated areas were stained. We also observed gamma-glutamyl transpeptidase-positive foci in earlier stages of carcinogenesis, concomitant with the expression of the K1 keratin. However, it was not possible to find a perfect topographical correspondence between the two events. Alterations in the pattern of keratin expression appear to be a common feature during the development of squamous cell carcinoma in different systems and could be an excellent tool to study carcinogenesis and chemoprevention.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1977

[Epitheliomas of the retro-molar trigone and of the inside surface of the cheeks (author's transl)].

The authors have made a study of 53 cases of tumours of the retro-molar trigone and of the internal surface of the cheeks which were treated between 1959 and 1972; these were malphigian epitheliomas except for one case of cylindroma. The research is concerned with the choice of methods and the therapeutic indications. Retro-molar trigones call for combined telecobaltherapy-electrontherapy;--curie-therapy is too difficult in this area. Electrontherapy may be used on alternate days with telecobaltherapy or as a booster dose after external irradiation by cobaltherapy. In cases of epitheliomas of the cheek, curietherapy or electrontherapy may be used after external irradiation or in isolation for tumours which are small in size. Therapeutic results are satisfactory in lesions at the outset (7/8 and 7/9), for T1-T2. For advanced lesions T3 of the trigone (6/16) and especially for those of the internal surface of the cheeks (2/9), the success rate is considerably lower; in lesions of the T4 type, a palliative effect was obtained but without any definite improvement.

Adult↗
PubMed1990

[Vascular reflex in microcirculation of hamster cheek pouch model].

The vascular reflex in hamster cheek pouch model was studied. When temperature of the superfusing solution was changed from 37 degrees C, diameter of small artery was increased up to 45 degrees C; instead, the diameter was decreased at the temperature below 37 degrees C to 14 degrees C. These responses of small artery were temperature-dependent. The dilatation of small artery by increasing or decreasing pH from 7.35 was demonstrated. The pH-dependent response of the small artery was found over the pH range of 7.0-8.5 or of 7.0-5.85. By the temperature (45 degrees C and 14 degrees C) or pH (8.5 and 5.85) stimulation of the cheek pouch preparations, the small artery in opposite preparation superfused at 37 degrees C or at pH 7.35 was responded after a few minute latency in a manner analogous to that seen in the stimulated cheek pouch preparations. The reflex dilatation produced by the stimulation with pH 5.85 was significantly inhibited by the treatment of hamster with atropine, suggesting that the vascular reflex are from the stimulated preparations to opposite non-stimulated preparations may be the long path reflex at least in part via parasympathetic nerves. It is also demonstrated that the potency of the sensitivity of the microvessels to pH and temperature changes is in following orders: small artery (A1) greater than arteriole (A2) greater than terminal arteriole (A3) and A2 = A3 greater than A2, respectively.

Animals↗
PubMed1990

[Neoplasms intrinsic to the cheek. Diagnostic and surgical approach].

In the light of nineteen personal observations during the past ten years, the Authors remember at first the anatomy of the cheek then the diagnostic approach and the surgery management of this complex region. They specify the variety of cheek space lesions and the possibility of rare or malignant masses involving the cheek. They emphasize the aesthetic results with the different surgery approaches.

Cheek↗
PubMed1989

Light and electron microscopic study of hamster cheek pouch treated with 9,10 dimethyl 1,2 benzanthracene and retinoic acid.

The present study reports light and electron microscopic observations of hamster cheek pouch epithelium exposed to 25 micrograms DMBA (DMBA = 9,10 Dimethyl, 1,2 Benz(a)-nthracene, RA = Retinoic Acid) and 25 micrograms DMBA along with 25 micrograms, 50 micrograms and 100 micrograms retinoic acid. Significant delay in tumour induction was observed in the animals treated with DMBA + retinoic acid. DMBA + retinoic acid treated cheek pouch developed papillary epidermoid carcinomas which were less invasive and less keratinized than only DMBA treated animals. At cellular level DMBA treated animals showed keratinized cells with thick bundles of tonofilaments, broken basement membrane, wide intercellular spaces and loss of desmosomal attachments, whereas animals treated with DMBA + retinoic acid showed decrease in the intercellular spaces, maintenance of basement membrane and intracellular organelles with suppression of keratinization, indicating the differentiating effect of retinoic acid on DMBA transformed cells of hamster cheek pouch.

9,10-Dimethyl-1,2-benzanthracene↗
PubMedDate not supplied

A simple lavage method for the cytologic sampling of DMBA-induced carcinomas of the hamster cheek pouch.

An effective, simple sampling device was developed to obtain improved cytologic specimens from the cheek pouches of hamsters; it was tested in the sampling of squamous-cell carcinomas induced with 9,10-dimethyl-1,2-benzanthracene (DMBA). Cellular samples collected by this modified syringe lavage-aspirator using Hanks' balanced salt solution contained an average of 1.3 X 10(5) cells per milliliter. Of the heterogeneous contents of the cheek pouch (food, debris, erythrocytes, leukocytes, macrophages, squamous cells, atypical cells and cancer cells), the cells of diagnostic significance from cancer and dysplasia were increased by this procedure to 3.7% of the cells recovered, as compared to 2.5% of the cells obtained by direct scraping of the same pouches. The inexpensive, disposable device allowed repeated sampling of cheek pouches without causing injury to the animals.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1994

Possible mechanisms for the inhibitory effect of Ruscus extract on increased microvascular permeability induced by histamine in hamster cheek pouch.

Extract of Ruscus aculeatus is used in treatment of venous insufficiency. In the present study, we used the hamster cheek pouch preparation and investigated in vivo the effects of an alpha 1 and alpha 2 adrenoceptor antagonists, a calcium blocker, Ruscus extract, and their combination on increased microvascular permeability induced by histamine. Experiments were performed on male hamsters; 30 min after completion of the cheek pouch preparation, fluorescein-labeled dextran (molecular weight 150,000) was given intravenously (i.v.). Histamine, applied topically, increased the number of fluorescent vascular leakage sites from postcapillary venules, evidence of an increase in macromolecular permeability, which was quantified by ultraviolet light microscopy as the number of leaky sites in the prepared area. Prazosin (alpha 1-adrenoceptor antagonist), diltiazem (calcium blocker), and Ruscus extract applied topically dose-dependently inhibited the macromolecular permeability-increasing effect of histamine. Rauwolscine (alpha 2-adrenoceptor antagonist), also applied topically, had no effect on histamine-induced permeability increase. Inhibition of the histamine-induced permeability increase evoked by Ruscus extract could be blocked by prazosin and by diltiazem but not by rauwolscine. These results indicate that any variation in the transmembrane flux of calcium impairs formation of microvascular leaky sites by histamine. Our results show that Ruscus extract has a protective effect against the leakage of FITC-dextran in hamster cheek pouch after administration of histamine that is modulated by calcium and selectively by alpha 1-adrenoceptors.

Animals↗
PubMed1995

EMG studies of lip and cheek activity in sucking habits.

Pronounced lip and mentalis (perioral) muscle activity was developed during thumb and dummy sucking. Cheek (Buccinator) activity was less evident, showing light to moderate activity. Lip and cheek activity was more noticeable during dummy sucking than thumb sucking. Sucking water through a straw and swallowing produced similar functional patterns to thumb sucking: strong lip and mentalis activity but comparatively low buccinator activity. Activity at rest in perioral muscles was pronounced among thumb and dummy suckers, while buccinator activity was negligible. Lip and cheek activity was substantially less, both at rest and during sucking, in a control group of children who were not thumb suckers.

Adolescent↗
PubMed1994

[Adhesion of Acinetobacter calcoaceticus to cheek epithelial cells].

Adhesive properties of 309 strains of Acinetobacter calcoaceticus were determined toward cells of cheek epithelium obtained from 13 healthy women. Most of strains adhered in number of > 0-20 bacterial cells for one epithelial cell. Adherence of A. calcoaceticus to cheek epithelium was dependent not only of variety, strain and temperature of bacterial culture, but also of individual properties of epithelial cells obtained from donors. Relation between hydrophobic properties and adherence to cheek epithelial cells in tested bacteria was observed. Strains with very strong hydrophobic properties (auto-aggregating strains) were exhibiting weaker adhesive abilities when compared with strains with lower hydrophobic properties (strains causing no aggregation).

Acinetobacter calcoaceticus↗
PubMed1996

Melatonin prevents ischemia reperfusion injury in hamster cheek pouch microcirculation.

OBJECTIVE: We used the hamster cheek pouch microcirculation to investigate the effects of melatonin (ME) on ischemia reperfusion (I-R) injury by in vivo microscopy. ME is a hormone produced by the pineal gland and is the most powerful and effective hydroxyl radical scavenger detected to date in vitro. The second aim was to determine the scavenger effect of ME in cheek pouch microcirculation when topically applying an oxygen-derived free radical generating system. METHODS: Ischemia was induced by clamping the cheek pouch for 30 min followed by 30 min of reperfusion. We quantified the increase in permeability, the perfused capillary length and leukocyte adhesion by computerized methods. Microcirculation was also exposed to a hypoxanthine-xanthine oxidase (H-X) system. RESULTS: In control hamsters I-R was associated with increased permeability, increased number of leukocytes sticking to venules, and decreased perfused capillary length. Treatment with ME completely inhibited microvascular edema formation and reduced the number of leukocytes sticking to venules after reperfusion. Moreover, ME prevented the marked decrease in perfused capillary length, preserving microvascular perfusion. ME topically applied reduced significantly the permeability increase due to H-X exposure. CONCLUSIONS: The beneficial effect of ME may be related to its antioxidant properties. These protect the endothelial barrier integrity as well as preserve microvascular blood perfusion by dysfunctions after I-R.

Animals↗
PubMed1997

An evaluation of the role of nuclear cytoplasmic ratios and nuclear volume densities as diagnostic indicators in metaplastic, dysplastic and neoplastic lesions of the human cheek.

The increase in nuclear cytoplasmic (N/C) ratio is one of the features of cellular atypia which is used in the histopathological assessment of premalignant lesions of the oral mucosa. Since this feature is readily quantifiable using morphometry, we have analysed both N/C and nuclear volume densities in basal and spinous cells from human cheek lesions with and without malignant potential in order to ascertain the validity of this parameter as a predictor. Using a strictly standardised sampling procedure, measurements of cellular and nuclear areas of basal and spinous cells from normal and pathological human cheek mucosa were made on haematoxylin and eosin-stained sections using a VIDAS image analyser. Cases examined comprised fibrous hyperplasia (FH), traumatic inflammation (IF), benign hyperkeratosis (HK), lichen planus (LI), leukoplakia with dysplasia (DYS), squamous cell papilloma (PP), dysplastic epithelium from the edges adjacent to invasive carcinoma (CE) and islands from invasive squamous cell carcinoma (CI). In basal cells, N/C ratios and nuclear volume densities were lower than values obtained for the normal controls. In spinous cells, these parameters were elevated in the potentially premalignant lesions (DYS, CE) as well as in CI but values were similarly elevated in FH, IF, HK and PP, lesions which appear to have no malignant potential. The N/C ratio is of no value as a predictor of malignant potential in basal or spinous cells from cheek lesions. The putative increase in N/C which has been previously described qualitatively is probably due to increased nuclear hyperchromatism, which may provide an illusory increase in relative nuclear size at the expense of the cytoplasm.

Carcinoma, Squamous Cell↗
PubMed1997

[A simple method for improvement of the measurement of respiratory impedance in humans by increasing oropharyngeal impedance using cheek and mouth floor clamps].

It is known, that the upper airway (oropharyngeal) impedance (Z(op)) influences the measured input impedance of the respiratory system (Zrs). This investigation deals with simple methods reducing the artefact caused by Z(op). The following methods have been examined: (1) Supporting the cheeks with fingers, (2) supporting the cheeks and the floor of the mouth with fingers and (3) using a new mechanical clamp for the cheeks and the floor of the mouth. The effect of these procedures on Zrs, were investigated on two subjects. Also Z(op) has been estimated during a voluntary closure of the glottis (VALSALVA manoeuvre). The impedance has been assessed as well with forced sine shaped oscillations as with the pulsatile technique. All three procedures show, compared to measurements without any support, an increase of the Zrs, especially at high values. The highest increase has been obtained while using the clamp (up to 50%). The varied impedance must be placed in parallel to Zrs, because Z(op) increases even more than Zrs. So, by applying the clamp the subjects is better coupled to the measuring system. The clamp is easy to handle, leads to more exact values, and increases the inter- and intra-individual reproducibility.

Airway Resistance↗
PubMed1996

Zinc deficiency produces time-related ultrastructural changes in rat cheek epithelium.

The subject of this study was whether the ultrastructural changes in cheek epithelium of zinc-deficient rats are time related. Weanling male Sprague Dawley rats were fed a zinc-deficient diet containing 0.4 ppm zinc (ZD) ad libitum and controls were pair-fed zinc adequate diet containing 40 ppm zinc. After 9, 18, and 27 days of zinc deficiency, specimens from cheek epithelium of both groups were processed for transmission electron microscopy. Partial conversion of the orthokeratinized cheek epithelium to parakeratinized was seen as early 9 days. An electron-lucent band surrounding the nucleus was observed in ZD cells. Mitochondria, tonofilaments, keratohyalin granules and ribosomes seemed to be increased with the increase in time of zinc deficiency. There was a thickening of the stratum corneum as well as hyperplasia and widening of the intercellular spaces of the spinous layer cells. Retention of a few membrane coating granules (MCGs) in the parakeratinized layer was seen after 9 days. Parakeratinization was further increased after 18 days of zinc deficiency, and the number of MCG profiles also increased. The epithelium was fully parakeratinized following 27 days of zinc deficiency, and the number of MCG profiles was increased. It was concluded that zinc deficiency affected cell proliferation and differentiation of the epithelium as early as 9 days, and caused a delay in loss of nuclei and MCGs in parakeratinized cells.

Animals↗
PubMed1992

Activating mutation of the Ha-ras gene in chemically induced tumors of the hamster cheek pouch.

The presence of an activating mutation in the Ha-ras gene in hamster cheek pouch tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) complete carcinogenesis was investigated. The normal sequence of a fragment of genomic DNA encompassing codon 61 of the Ha-ras gene was amplified by the polymerase chain reaction using primers designed for a highly conserved region of the mouse Ha-ras-1 gene. The sequence of the amplified fragment was determined by a direct sequencing technique and exhibited 83.3% and 87.5% homology with the corresponding human and mouse sequences, respectively. At the amino acid level, the sequence was identical among the three species. Paraffin sections of 11 squamous cell carcinomas of the cheek pouch were used to detect mutated Ha-ras alleles. DNA sequencing of the tumors showed that six of 11 tumors presented an A----T transversion in the second position of codon 61, resulting in an amino acid change from glycine to leucine. As has been demonstrated in other systems, we have shown a specific mutation of the Ha-ras gene in chemically induced tumors of the hamster cheek pouch, further supporting the role of this oncogene in chemical carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1992

A scanning electron microscopic study on the distribution of peritubular dentine in cheek teeth of Cervidae and Suidae (Mammalia, Artiodactyla).

Distribution of peritubular dentine was studied in cheek teeth of fallow deer (Dama dama), roe deer (Capreolus capreolus) and wild boar (Sus scrofa). In the two cervid species, especially intense peritubular dentine formation was found in the outer regions of mid and cuspal coronal dentine. In these areas a marked asymmetry occurred, peritubular dentine being predominantly secreted onto the side of the dentinal tubule walls nearest to the dentinoenamel junction. Intensity and asymmetry of peritubular dentine formation decreased cervically. In root dentine, the walls of the dentinal tubules were covered with only a thin peritubular dentine layer of even thickness. Here, in contrast to peripheral coronal dentine, the volume of intertubular dentine far exceeded that of peritubular dentine. In porcine coronal dentine, PTD asymmetry, being of lesser extent than in cervids, was observed only in peripheral areas of cuspal and flank regions of the cheek teeth. Because peritubular is more highly mineralized than intertubular dentine, the relative volume of dentine made up from the two components has an important influence on dentinal wear resistance. The significance of variations in volume and distribution of peritubular dentine between different dentinal regions for achieving and maintaining a functional occlusal surface is shown for cervid cheek teeth. Our results suggest that dentinal structure (in addition to enamel structure) should be taken more into consideration when discussing occlusal surface morphology in herbi- and omnivores from a functional point of view.

Animals↗
PubMedDate not supplied

Augmentation of cheek bone contour using malar osteotomy.

Patients with a narrow face have often a defect in expansion of the maxillary-malar complex. A malar osteotomy, separating the malar-zygomatic complex from the orbit and the maxilla, allows an anterolateral cheek projection when performing an external rotation. This technique changes facial contour and improves facial aesthetics. During the past 5 years, 18 malar osteotomies have been performed; the external rotation was stabilized with interposed coral graft in six patients and with interposed bone graft fixed by a miniplate or with a stainless steel wire in 12 patients. Simultaneously septoplasty was performed in five patients, rhinoplasty in 13 patients, and genioplasty in two patients. Six patients had a face and neck lift, one patient had a forehead lift, and one patient had onlay iliac crest bone graft to treat atrophic maxillary alveolar ridges prior to implant placement. Stability was defined after 1 year follow-up. The increase in projection was correlated to the size of the graft. At least 5 mm were necessary to have cheek modification. Mucous inflammation, maxillary sinusitis, and relapse were observed with the use of interposed coral graft, but no complications were observed with bone graft. Malar osteotomy is a simple and safe procedure; it allows an anterolateral cheek projection and seems to be effective for treating transverse midface deficiency.

Adult↗
PubMed1995

Detection of squamous neoplasia by fluorescence imaging comparing porfimer sodium fluorescence to tissue autofluorescence in the hamster cheek-pouch model.

BACKGROUND: Early neoplastic changes in the oral cavity may be difficult to detect. Fluorescence imaging using porphyrin-derived drugs has been used to enhance detection of neoplasia. Autofluorescence has also been used for this purpose. This paper compares autofluorescence to porfimer sodium-induced fluorescence in the detection of neoplasia in the hamster cheek-pouch model. MATERIALS AND METHODS: Neoplasia was induced in the hamster cheek pouch by the application of 9,10-dimethyl-1,2-benzanthracene. Animals were imaged either with injection of drug (porfimer sodium) or without drug (autofluorescence). Imaging was carried out using a laser-induced fluorescence detection system. Biopsies were performed on imaged sections and histologic grades were assigned. RESULTS: Porfimer sodium fluorescence provided 100% sensitivity and specificity in detection of neoplasia. The sensitivity and specificity with autofluorescence was 76% and 83%, respectively. CONCLUSIONS: Autofluorescence provides an accurate means of detecting early neoplastic changes in the hamster cheek-pouch model; however, porfimer sodium imaging does improve detection rates.

9,10-Dimethyl-1,2-benzanthracene↗