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Biomedical subjects

R S Redman

Publications and source records attributed to R S Redman.

At least 73 records · Page 4Linked to original sources
PubMed1990

Botryoid odontogenic cyst. Report of a case with histologic evidence of multicentric origin.

Histologic examination of an excisionally biopsied botryoid odontogenic cyst (BOC) documented that it was composed of at least 2 separate cysts, the location of which suggested that both originated within the alveolar bone rather than from within the periodontal ligament. These observations provide evidence for a multicentric origin of this example of BOC, and are consistent with a previous suggestion that lateral periodontal cysts of non-inflammatory origin arise from remnants of the dental lamina.

Aged↗
PubMed1989

Hemodialysis-associated amyloidosis presenting as lingual nodules.

Hemodialysis has permitted long-term survival of patients with kidney failure, but not without many complications, such as mineral loss from bones, secondary hyperparathyroidism, and increased risk of infection. Recently a new form of amyloidosis, AB2M, has been characterized that is specifically associated with long-term dialysis. The tissues and organs affected by deposits of AB2M appear to differ from those affected by the other major types of amyloidosis; AB2M affects mainly the carpal ligament, synovia of large joints, juxtaarticular bone, and intervetebral disks, while involvement of the oral tissues has been rare. We present here a case in which the biopsy of superficial lingual deposits of AB2M led to the recognition that the patient had developed hemodialysis-associated amyloidosis. It is suggested that periodic inspection of the oral soft tissues for signs or symptoms of amyloidosis should become a part of the dental care of patients undergoing dialysis.

Amyloidosis↗
PubMed1989

Respiratory epithelium in an apical periodontal cyst of the mandible.

A cyst attached to the apex of a mandibular canine was partly lined with respiratory epithelium. This is an interesting observation for two reasons: (1) The few well-documented instances of this type of epithelium in apical periodontal cysts have been in the maxilla, where a plausible source for the respiratory epithelium for most of them was a breach in the floor of the maxillary sinus. (2) The mandibular location of the cyst reported here indicates that the respiratory epithelium within it was derived through proliferation and metaplasia of the rests of Malassez.

Adolescent↗
PubMed1988

Effects of dexamethasone, epidermal growth factor, and retinoic acid on rat submandibular acinar-intercalated duct complexes in primary culture.

Mature acini with attached segments of intercalated ducts were dissociated from the submandibular glands of rats and grown in primary culture on gels of reconstituted rat tail collagen. Screening evaluations indicated that the following new conditions promoted a substantial improvement in the survival of the cells as compared with our previously reported results: a) adding dexamethasone, epidermal growth factor, and retinoic acid to the medium, b) decreasing the fetal bovine serum in the medium to 1%; and c) adjusting the oxygen in the gas phase to 50%. A detailed evaluation, including light and electron microscopy and biochemical analysis, then provided the following observations. The acinar-ductal complexes enlarged throughout the 22-d culture period, and after 4 d sheets comprised of a one- to two-cell thick layer of acinar cells spread among the complexes. Synthesis of mucin, and its secretion in response to norepinephrine or cAMP, dropped precipitously to very low levels after 2 d. However, synthesis of DNA, general proteins, and glycoproteins dropped only transiently after 2 d, rising to levels approaching those of freshly dissociated complexes by 22 d. These data indicate that a shift occurred from the synthesis of large quantities of secretory proteins and glycoproteins, especially mucins, during the first 2 d in culture, to other materials thereafter. Overall, the new culture conditions resulted in substantial growth and survival of acinar cells through 22 d in primary culture, but the important acinar characteristic of the synthesis and secretion of mucins was essentially lost after 4 d.

Animals↗
PubMed1988

Dietary fructose exacerbates the cardiac abnormalities of copper deficiency in rats.

Copper deficiency has been shown to result in severe cardiovascular lesions in several species of animals. The principal carbohydrate in the copper-deficient diet most often used with rats is sucrose, which is known to have adverse effects on carbohydrate and lipid metabolism and thus may contribute to cardiovascular disorders. These observations prompted experiments in which starch and fructose were substituted for sucrose in a copper-deficient diet, to see if the effects of the copper deficiency might be modified. In the hearts from rats fed copper-deficient diets with fructose or sucrose, there was marked, mostly ventricular hypertrophy, and mild to severe myocardial inflammation, degeneration, and fibrosis. Aneurysm of the left ventricle and pericarditis also were common. Hearts from the starch, copper-deficient groups were much less hypertrophic, and very few were affected by myocardial inflammation, degeneration, or fibrosis. Defects of elastin or other structures were not observed in the aortas or pulmonary or coronary arteries of any specimens.

Animals↗
PubMed1987

Effect of clonidine on secretion of fluid and ions by the parotid and submandibular glands of the rat.

Secretion in response to this alpha 2-adrenergic agonist was evaluated in the presence and absence of several adrenergic antagonists, reserpine and sympathectomy (Sx). In both glands, the response was qualitatively but not quantitatively similar to that induced by the alpha 1-adrenergic agonist, phenylephrine, in the presence of propranolol. With clonidine, the volume of submandibular saliva was much higher but the Ca concentration was 3-4 times lower than that of the parotid; both salivas had low Na but high K concentrations. Clonidine-induced secretion was almost completely blocked by the alpha 1-adrenergic antagonist, prazosin and a mixed alpha-adrenergic antagonist, phentolamine, and markedly reduced by the alpha 2-adrenergic antagonist, yohimbine, but unaffected by the beta-adrenergic antagonist, propranolol. Reserpine reduced the parotid, but enhanced the submandibular secretory response to clonidine. Results in Sx glands were similar. Thus, in the rat glands clonidine may activate alpha 1-rather than alpha 2-adrenoceptors, which appear to play a part similar to alpha 1-adrenoceptors only after reserpine or Sx.

Animals↗
PubMed1986

Short-term primary culture of acinar-intercalated duct complexes from rat submandibular glands.

Acinar-intercalated duct complexes dissociated from rat submandibular glands have been shown to be an excellent model for studying secretory responses of salivary gland components. However, they are functionally normal for only a few hours. We undertook a systematic manipulation of primary culture conditions in an attempt to extend the useful life of the complexes. The major modifications that were tested were increased oxygenation in increments to 95%; substitution of norepinephrine or carbamylcholine or both for isoproterenol in the medium; different sources of collagen for and addition of laminin, fibronectin and/or type IV collagen to the matrix gel; and varying the thickness of the collagen gel, richness of the cell suspension inoculate, and sources and concentrations of sera in the medium. Progress was monitored by light microscopic evaluation of routine sections of specimens until improved maintenance of acinar and other cells warranted carrying parallel cultures for biochemical, histochemical, and ultrastructural analyses. Best results were obtained with 90% O2, laminin in rat tail collagen gel, 10% fetal bovine serum, and 3 microM isoproterenol. Morphologically, there was good survival of acini and intercalated ducts after 1 d, with decreased acinar size being correlated with secretory response to the isoproterenol. Reorganization and considerable mitotic activity were seen at 2, 3, and 4 d, with most clusters of cells becoming much larger than the original complexes. During this period acinar cells steadily became less differentiated and their numbers decreased in proportion to intercalated duct or undifferentiated cells. However, there was good overall survival through 7 d. Biochemical analysis indicated that the cells were able to maintain significant biosynthetic activity for 4 d, with DNA, RNA, protein, and glycoprotein synthetic rates increasing over the culture period, but the secretory capacity of the cells diminished during the primary culture period, with mucin biosynthesis and secretion decreasing significantly after 1 d in culture.

Animals↗
PubMed1986

Canalicular adenoma of the buccal mucosa. An ultrastructural and histochemical study.

A canalicular adenoma that occurred in the minor salivary glands of the buccal mucosa in a 62-year-old black man was examined by electron microscopy and histochemistry. The ulcerated bowl-shaped tumor consisted mostly of ductlike tubules of columnar and cuboidal epithelial tumor cells which resembled intercalated duct cells ultrastructurally. Tumor cells resembling myoepithelial cells were not associated with these tubules. Less frequently, there were narrow tubules and cords adjacent to the capsule. Occasional cells in these cords contained variable amounts of microfilaments, often associated with focal densities, and thus resembled myoepithelial cells in varying stages of differentiation. Other noteworthy ultrastructural findings in this neoplasm included marked replication of the basal lamina of capillaries and the presence of a single, luminally oriented cilium in a tumor cell lining a tubule.

Adenoma↗
PubMed1985

Ultrastructure of the anterior buccal gland of the rat.

The anterior buccal gland of the rat is a mucous salivary gland which develops as a branch of the main (Stensen's) duct of the serous parotid gland, a few mm from its oral orifice. The purpose of the present study was to further characterize the mature gland by means of electron microscopy and the histochemical demonstration of myoepithelial cells. The tubuloacini were found to have intercellular extensions (canaliculi) of the lumina, prominent Golgi complexes, and mucous secretory granules with a biphasic substructure. Discharge was by exocytosis of individual granules. The tubuloacini joined directly to striated ducts; no intercalated ducts were seen. First-order excretory ducts had larger lumina and shorter columnar cells, with fewer mitochondria and basal infoldings, than the striated ducts. Myoepithelial cells invested the tubuloacini but not the ducts. The anterior buccal gland has several features that are unusual for a minor salivary gland of mucous type, and which are usually associated with serous glands such as the parotid. It should provide a particularly interesting model for investigating factors which control the differentiation of secretory and myoepithelial cells, and the glycosylation of polypeptides to form mucous secretory products.

Alcian Blue↗
PubMed1985

Focus of epithelial dysplasia arising in hereditary gingival fibromatosis.

The gingiva of a 32-year-old black male was biopsied for evidence of vasculitis, but instead an area of epithelial dysplasia was found. Further investigation revealed that the patient and several members of his family had hereditary gingival fibromatosis. Treatment included four quadrants of gingivectomy plus inverse bevel incisions for trimming those areas which were too thick for simple gingivectomy. Histopathologic examination of the excised tissues supported the diagnosis of gingival fibromatosis, but no other areas of epithelial dysplasia were seen. To our knowledge, this is the only reported instance of a premalignancy or malignancy arising in gingival fibromatosis, and thus there is no reason to regard the gingival disorder as predisposing to carcinoma. However, the pedigree reported here supports a previous suggestion that hereditary gingival fibromatosis is not as rare among blacks as the literature has indicated.

Adult↗
PubMed1984

Two independently regulated secretory systems within the acini of the submandibular gland of the perinatal rat.

Rat submandibular glands undergo a transient stage of differentiation in the perinatal acini. Two morphologically distinct cell types (Type I and Type III) appear and secrete several electrophoretically identifiable proteins. To examine the regulation of the secretion of these proteins and their association with secretion by the two cell types, 4-day-old glands were incubated with secretory agonists and antagonists, and the cultures were evaluated for secreted proteins in the medium and morphologically assayed degranulation of the cells. Stimulation of glands with beta-adrenergic agonists resulted in the secretion of three proteins, A, B1, and B2, at Rf 0.26, 0.36, and 0.40 in native, anionic gels at pH 8.3. Cholinergic stimulation caused the appearance of a different protein, C, at Rf 0.12, but only slight secretion of A, B1, and B2. With both beta-adrenergic and cholinergic stimulation, another protein, D, was seen near the origin. Partial purification of the proteins was effected by gel chromatography followed by preparative IEF (Isoelectric point focusing). Proteins A, B1, and B2 were recovered at isoelectric pH 4.5, 5.4, and 5.1 respectively. SDS gels of IEF fractions and secretion medium indicate Mr 25K, 26K, 27K, 97K, and greater than 150K for A, B1, B2, C, and D respectively. beta-Adrenergic stimulation caused degranulation only of Type I cells and cholinergic stimulation only of Type III cells. We propose the existence of two independently regulated secretory systems in the perinatal acini, with Type I cells secreting protein C on stimulation of cholinergic receptors, and Type III cells secreting A, B1, and B2 through beta-adrenergic receptors. With either stimulation, protein D is secreted, and thus it may serve a general function in the secretion process.

Animals↗
PubMed1981

Identification of human mononuclear leukocytes bearing receptors for somatostatin and glucagon.

Mononuclear leukocytes (MNL) were isolated from human blood by Ficoll-Hypaque. These cells were further separated into lymphocyte (L) and monocyte (M) enriched fractions. L contained 99% lymphocytes and M contained 74% monocytes, a threefold enrichment over MNL. Specific binding to somatostatin, glucagon, and insulin was measured in the three fractions. Binding of all three hormones in the M fraction was increased by a factor of 3 compared with MNL and was linear with cell number. Binding of glucagon and insulin to the L fraction was very low while, in contrast, somatostatin binding was substantial and linear with lymphocyte number. Autoradiography confirmed the binding of glucagon to monocytes and of somatostatin to both monocytes and lymphocytes. Somatostatin is the first of the peptide hormones shown to bind to both types of circulating mononuclear cells, perhaps complicating quantification of somatostatin binding in disease states in which differential alteration of binding of lymphocytes or monocytes might occur.

Autoradiography↗
PubMed1981

Cicatricial pemphigoid in a patient with systemic lupus erythematosus.

Three years after the onset of lupus erythematosus, blisters, erosions, and erythema of the gingivae developed in a 31-year-old man. A diagnosis of cicatricial pemphigoid was established by routine and immunofluorescence microscopy studies. An association between cictricial pemphigoid and other autoimmune disorders seems to be rare. This case demonstrates the importance of performing immunofluorescence microscopy studies, as well as routine histologic assessments, of conditions that resemble desquamative gingivitis.

Adult↗
PubMed1980

Differentiation of myoepithelial cells in the developing rat parotid gland.

Parotid glands of rats were prepared for light and electron microscopy and for the histochemical demonstration of myofibrils and alkaline phosphatase (AkPase) activity. Through 18 days in utero, the epithelial cells of the developing gland remain relatively undifferentiated. At 20 days in utero, a few cells in the outer layer of the terminal buds and adjacent segments of ducts acquire a cilium, the initial indication that they are differentiating into myoepithelial cells (MEC). Up until the time of birth, the only additional characteristics of MEC that the outer cells develop are to flatten against the underlying cells, begin to send out processes, and produce a few dilated cisternae of rough endoplasmic reticulum. Myofibrils and AkPase activity are first detected at the light microscopic level at five days after birth, around both the developing acini and intercalated ducts. Progressive increases in AkPase activity and in the size and number of myofibrils continue until the acini and intercalated ducts are invested with well-differentiated MEC at 15 days. Subsequently, as the acini undergo maturation during the weaning period (18-25 days), the MEC cease to surround the acini and assume the adult pattern of investing only the intercalated ducts. The pattern of MEC differentiation in the parotid gland differs from those in the sublingual and submandibular glands of the rat in several important respects. They begin to differentiate last, yet mature almost as early as do the MEC of the sublingual gland; they begin to differentiate prior to, rather than simultaneously with, the secretory cells; and their distribution changes as the acinar cells become mature.

Animals↗