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Biomedical subjects

B A Dale

Publications and source records attributed to B A Dale.

At least 91 records · Page 5Linked to original sources
PubMed1987

Arrested epidermal morphogenesis in three newborn infants with a fatal genetic disorder (restrictive dermopathy).

Two sibs and one unrelated infant were born prematurely with taut, shiny, restrictive skin that was abnormal in structure, organization, biochemistry, and state of differentiation. Prominent abnormalities in all regions of the skin were recognized by light and electron microscopy, immunohistochemistry, and biochemistry. The epidermis was hyperplastic, hyperkeratotic, and parakeratotic. Keratohyaline granules were abnormal in structure, but the keratohyalin-derived protein filaggrin was apparently normal in quantity and biochemistry. The epidermal cells contained less than the expected quantity of high-molecular-weight, differentiation-specific keratins and the tissue stained with antikeratin antibodies in an aberrant pattern. Additional 48 and 56 kD keratin polypeptides, indicative of a hyperproliferative state, were expressed. The dermal-epidermal junction was remarkably flat and the dermis was thinner than normal. The connective tissue appeared stretched and was oriented like tendon rather than dermis. Collagen fiber bundles and fibrils were smaller in diameter than normal. The nails were normal but other epidermal appendages such as the pilosebaceous structures and the eccrine sweat glands were underdeveloped, suggesting that morphogenesis of these structures was arrested at an early stage in utero. The subcutaneous fat was at least twice the thickness of the dermis. The skin abnormalities appeared to be the cause of the flexion contractions, characteristic facies, and inability to survive because of restricted respiratory movements. The structural and biochemical abnormalities in the skin of affected infants may serve as markers for prenatal and postnatal diagnosis of the disorder, and may provide insight into the basic mechanism of the disease.

Filaggrin Proteins↗
PubMed1987

Keratinocytes cultured from subjects with ichthyosis vulgaris are phenotypically abnormal.

Ichthyosis vulgaris (IV) is an autosomal dominant, scaling disorder in which keratohyaline granules and filaggrin are reduced in or absent from the epidermis of affected individuals. Morphologic and biochemical markers of epidermal differentiation were studied in keratinocytes cultured from clinically unaffected skin of patients with IV, from clinically unaffected skin of an obligate gene carrier, and from normal skin of unaffected family members and an adult volunteer. Cultured keratinocytes from affected subjects formed thickened layers of scaly cells that failed to react with monoclonal antibody to filaggrin. In contrast, normal cells contained many large, immunoreactive granules. Electron microscopy confirmed the absence of keratohyaline granules in affected cells and the presence of large keratohyaline granules in normal cells. Immunoblot analysis of keratinocyte extracts from subjects with ichthyosis showed that profilaggrin was absent, but no differences in keratins were detected between affected and control cells. For all parameters, findings in cells of the clinically unaffected obligate gene carrier were intermediate between those from affected patients and controls. We conclude that keratinocytes cultured from patients with IV maintain structural and biochemical phenotypic characteristics of the disease in vitro.

Biopsy↗
PubMed1987

Localization of profilaggrin mRNA in newborn rat skin by in situ hybridization.

Profilaggrin mRNA has been localized in newborn rat skin by in situ hybridization. The granular layer and the hair canals of the epidermis are strongly positive for profilaggrin mRNA, while the basal and spinous cell layers are negative. These results suggest that profilaggrin gene expression is under transcriptional regulation since profilaggrin protein detected by immunohistochemistry closely corresponds to the distribution of profilaggrin mRNA. In addition, our results suggest that the profilaggrin gene is not coordinately expressed with the genes specifying the differentiation-specific keratins.

Animals↗
PubMed1987

Acute beta-adrenoreceptor blockade and induced hypotension.

Thirty patients scheduled for major middle ear surgery and induced hypotension, with a trimetaphan/sodium nitroprusside infusion, were randomly allocated to receive a single oral dose of beta-adrenoreceptor antagonist 2 hours before surgery. In group 1 ten patients received metoprolol 50 mg, in group 2 ten patients received metoprolol 25 mg and in group 3 ten patients received oxprenolol 20 mg. There were ten controls for each group. The nitroprusside infusion rate was significantly reduced in groups 1 and 3. However, there was an unacceptably high incidence of profound bradycardia after induction of anaesthesia in those patients who had received beta-adrenoreceptor antagonists pre-operatively and this technique is not recommended for routine use.

Adolescent↗
PubMed1987

Identification of Merkel cells in oral epithelium using antikeratin and antineuroendocrine monoclonal antibodies.

Merkel cells are a rare cell type located at or near the basal lamina of oral epithelia and epidermis. They are associated with nerves, and may function as touch receptors. Merkel cells are difficult to identify by routine light microscopy, but have been identified by electron microscopy and specific antibodies. We demonstrate here that Merkel cells can be identified by immunohistochemistry, using a monoclonal antibody (LK2H11, Lloyd and Wilson, 1983) to neuroendocrine granules, and a monoclonal antibody (35 beta H11, Gown and Vogel, 1982) to a 54-kD keratin generally located in simple epithelia but not in stratified epithelia. Human oral tissue was fixed in Carnoy's fixative, and adjacent serial sections were stained with the two antibodies. Individual positively-stained cells were generally located at the bases of rete ridges. Cells in the same position in adjacent sections stained with both antibodies. Essentially all cells (94%) staining for neuroendocrine granules also gave a positive reaction for the 54-kD keratin, evidence that a single Merkel cell contains neuroendocrine granules and the 54-kD keratin. Staining of epithelial sheets of human oral tissues revealed a linear distribution of Merkel cells along the bases of rete ridges. We concluded that antibodies to simple epithelial keratins and neuroendocrine granules may be excellent immunohistochemical markers for Merkel cells, thus facilitating future studies to examine changes in Merkel cells and their distribution in pathologic conditions. The observation that Merkel cells can be stained with an antikeratin antibody strongly supports the epithelial origin of these cells.

Antibodies, Monoclonal↗
PubMed1986

The repetitive structure of the profilaggrin gene as demonstrated using epidermal profilaggrin cDNA.

Filaggrin is the histidine-rich basic protein that aggregates keratin filaments in fully differentiated cells of the epidermis. Filaggrin is synthesized in the granular cell layer as a high molecular weight precursor protein (profilaggrin) that consists of multiple repeated copies of filaggrin. cDNA clones for rat and mouse epidermal profilaggrin have been constructed from sucrose gradient-enriched RNA in order to study the repetitive structure of profilaggrin. These clones hybridize to high molecular weight epidermal mRNA (23 kilobase pairs, rat and 19 kilobase pairs, mouse) and exhibit limited cross-hybridization between species. Several rat clones direct the synthesis of a portion of rat profilaggrin in bacteria. One of these, rat profilaggrin cDNA clone R4D6, is 2400 base pairs in length. The R4D6 cDNA is shown to contain repetitive sequence by restriction mapping and southern hybridization analysis of restriction digests of this plasmid, using subfragments of the plasmid as hybridization probes. Southern hybridization analysis of rat genomic DNA, digested to completion with several restriction enzymes, reveals a simple hybridization pattern of fragments equal in size to those of the cDNA. Partial digestion of rat genomic DNA results in a ladder of bands based on a 1200-base pair repeat, equal to the size of the repeating unit of the cDNA clone, and consistent with the expected repeating size of profilaggrin. Together, these results show that the profilaggrin mRNA and gene have repetitive structure and that the gene apparently lacks introns in the coding region.

Amino Acid Sequence↗
PubMed1986

Restrictive dermopathy: a newly recognized autosomal recessive skin dysplasia.

A brother and sister from consecutive pregnancies had rigid and tightly adherent skin in association with generalized contractures, unusual facies, pulmonary hypoplasia, an abnormal placenta, and a short umbilical cord. Both died shortly after birth. Pathologic examination of the skin by light and electron microscopy showed structural abnormalities of the epidermis, dermis, and subcutaneous fat. An abnormal pattern of keratin proteins was determined biochemically using extracted epidermal proteins. Autopsy showed a normal spinal cord and muscle histology. It is postulated that the defective skin severely restricted movement and secondarily led to the other abnormalities. Familial occurrence is most consistent with autosomal recessive transmission. These patients and the primary skin defect are discussed within the framework of the Fetal Akinesia or Hypokinesia Deformation Sequence.

Abnormalities, Multiple↗
PubMed1986

Beneficial response to pituitary ablation following aminoglutethimide.

Twenty-five postmenopausal women with advanced carcinoma of the breast, who were treated initially with aminoglutethimide alone (14 patients) or combined with tamoxifen (11 patients) had, on relapse or failure of treatment, a pituitary ablation performed. Initial therapy had produced a complete response in one patient, a partial response in 7, disease stasis in 6 but was without benefit in 8 patients. A further three patients were intolerant of aminoglutethimide therapy. Ten of these 25 patients benefited from subsequent pituitary ablation (1 complete response, 4 partial responses and 5 disease stasis), both local and distant sites of disease being influenced by this further therapy. Experience is also reported of 10 patients with advanced breast cancer who were treated initially by pituitary ablation and then subsequently received aminoglutethimide therapy. None responded. It is concluded that pituitary ablation should be considered for patients with progressive disease following aminoglutethimide therapy, irrespective of the therapeutic response to aminoglutethimide.

Adult↗
PubMed1986

Immunologic localization of filaggrin in human oral epithelia and correlation with keratinization.

Localization of filaggrin, a human epithelial structural protein, was investigated by indirect-immunofluorescence microscopy of oral mucosa. Thirty specimens were tested, 10 each of palate, gingiva, and buccal mucosa. Orthokeratinized and parakeratinized specimens displayed immunofluorescence within the stratum corneum, stratum granulosum, and upper stratum spinosum. Within the stratum corneum, the reaction was diffuse. Within the stratum granulosum and spinosum, the reaction was in a granular pattern, in a perinuclear position. Several of the nonkeratinized specimens had a negative reaction; however, most displayed a very weak, scattered reaction in a granular pattern within the most superficial cells. The presence of filaggrin in keratinized palate was confirmed by immunoblot studies with the same antibody. Profilaggrin was detectable in representative nonkeratinized and parakeratinized oral tissues, as well as in keratinized palatal epithelium. The localization of filaggrin is consistent with its possible function as the interfilamentous matrix protein within cells of the stratum corneum, and with its derivation from a cross-reactive precursor protein stored in keratohyaline granules. A strong positive correlation was found between the degree of keratinization and the amount of immunofluorescence; therefore, filaggrin and related antigens may be useful and sensitive marker proteins for epithelial keratinization.

Animals↗
PubMed1986

Histochemical and morphological studies on mammalian epidermal peridermal granules.

We performed morphological studies on the epidermal peridermal granules (PG) of newborn mice using histological, fluorescent and electron microscopic methods. PG appeared during the 17th to 18th day of foetal life, and remained in the outermost epidermal layers until 5 days after birth. PG were evenly distributed over the entire cutaneous surface of the mouse, except the tail. PG were found to contain protein and corresponded to sites of transglutaminase activity, but they were devoid of lipids and nucleic acids. They could be differentiated clearly from keratohyalin granules. Together, these studies suggest that PG represent a unique epidermal protein product that serves as a marker of late foetal development.

Animals↗
PubMed1986

Immunohistochemical study of structural proteins in developing junctional epithelium.

The objective of this study was to investigate structural proteins of ameloblasts, reduced enamel epithelium and junctional epithelium using antikeratin antibodies to determine if keratin expression changes as ameloblasts differentiate to cells of junctional epithelium. Block sections of fully erupted, partially erupted and unerupted molar and incisor teeth were removed at necropsy from monkeys age 2, 5, 6 and 7 years. Tissues were fixed in Carnoy's fixative, decalcified in Kristensen's solution for 4 to 8 weeks, embedded in paraffin and sectioned at 5 mu. Representative sections were stained with hematoxylin and eosin. Remaining sections were stained with antikeratin antibodies AE1, AE3, 34 beta E12, 35 beta H11 and anti-40kD using the avidin-biotin-conjugated immunoperoxidase method. Results were analyzed qualitatively for presence or absence of staining products. Antibody 35 beta H11 reacted with ameloblasts and reduced enamel epithelium during the early maturation phase of tooth development but not with the reduced enamel epithelium of erupting teeth or with junctional epithelium. The anti-40kD antibody stained ameloblasts and reduced enamel epithelium of unerupted teeth and teeth erupting through oral epithelium; however, junctional epithelium of partially erupted and fully erupted teeth were unstained. Antibodies AE1, AE3 and 34 beta E12 stained ameloblasts and all layers of reduced enamel epithelium and junctional epithelium in all stages of development. These results suggest a relationship between expression of structural proteins and changes during development and differentiation of ameloblasts to junctional epithelial cells.

Ameloblasts↗
PubMed1985

Multiple copies of phosphorylated filaggrin in epidermal profilaggrin demonstrated by analysis of tryptic peptides.

The precursor of mouse (c57/B16) epidermal filaggrin (profilaggrin) is a very large (ca. 500 000 daltons), highly phosphorylated protein containing multiple copies of filaggrin (26 000 daltons). The conversion of profilaggrin to filaggrin late in epidermal cell differentiation involves dephosphorylation and proteolysis to yield the unphosphorylated filaggrin, which polymerizes with keratin filaments into macrofibrils. In order to gain insight in the nature of these processes, we compared tryptic digests of profilaggrin with those of filaggrin by reverse-phase liquid chromatography. Approximately 80% of the profilaggrin mass consists of multiple copies of filaggrin. Twenty peptides purified in good yield from both profilaggrin and filaggrin accounted for most of the filaggrin sequence. A detailed analysis of the yield of several peptides provided an estimate of the size and frequency of the repeat unit within profilaggrin. These data indicate that the repeating substructure of profilaggrin contains about 265 amino acids and that about 50 residues are removed per filaggrin domain as the precursor is processed to filaggrin. Assuming a molecular weight of 500 000 (as estimated from sodium dodecyl sulfate-polyacrylamide gel electrophoresis), this indicates there are 16 repeats. Analysis of phosphopeptides isolated from profilaggrin showed that 66% of the phosphate was located on peptides that are unphosphorylated in filaggrin. Analysis of peptide recoveries confirmed the repeat size and showed that every copy of filaggrin was phosphorylated in profilaggrin.

Amino Acid Sequence↗