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Biomedical subjects

J R Stanley

Publications and source records attributed to J R Stanley.

At least 19 recordsLinked to original sources

Down syndrome with pure partial trisomy 21q22 due to a paternal insertion (4;21) uncovered by uncultured amniotic fluid interphase FISH.

OBJECTIVE: To emphasize the usefulness and reliability of fluorescence in situ hybridization (FISH) on uncultured amniotic fluid cells in the prenatal diagnosis of common chromosomal aneuploidies. METHODS: FISH analyses utilizing centromeric, locus-specific or whole chromosome paint DNA probes specific for chromosomes X, Y, 13, 18, 21, and 4 were performed on uncultured amniotic fluid cells or the peripheral blood specimen from the father. Routine chromosome analysis was carried out as well. RESULTS: A prenatal case with partial trisomy 21 due to a paternal cryptic insertion (4;21) was ascertained by a rapid overnight FISH on uncultured amniotic fluid cells. The fetus was delivered at term and had classical features of Down syndrome. CONCLUSION: Our results stress the importance of FISH on uncultured amniotic fluid cells to supplement routine cytogenetics, especially in cases with abnormal ultrasound findings.

Adult↗

Desmoglein isoform distribution affects stratum corneum structure and function.

Desmogleins are desmosomal cadherins that mediate cell-cell adhesion. In stratified squamous epithelia there are two major isoforms of desmoglein, 1 and 3, with different distributions in epidermis and mucous membrane. Since either desmoglein isoform alone can mediate adhesion, the reason for their differential distribution is not known. To address this issue, we engineered transgenic mice with desmoglein 3 under the control of the involucrin promoter. These mice expressed desmoglein 3 with the same distribution in epidermis as found in normal oral mucous membranes, while expression of other major differentiation molecules was unchanged. Although the nucleated epidermis appeared normal, the epidermal stratum corneum was abnormal with gross scaling, and a lamellar histology resembling that of normal mucous membrane. The mice died shortly after birth with severe dehydration, suggesting excessive transepidermal water loss, which was confirmed by in vitro and in vivo measurement. Ultrastructure of the stratum corneum showed premature loss of cohesion of corneocytes. This dysadhesion of corneocytes and its contribution to increased transepidermal water loss was confirmed by tape stripping. These data demonstrate that differential expression of desmoglein isoforms affects the major function of epidermis, the permeability barrier, by altering the structure of the stratum corneum.

Animals↗

Central role of the plakoglobin-binding domain for desmoglein 3 incorporation into desmosomes.

The carboxy-termini of classical cadherins and desmocollins have been shown to play an important role in initiating desmosome assembly. In this study we wanted to determine whether the carboxy- terminal cytoplasmic domains of desmoglein 3 are important for targeting it to the desmosome. By generating stably transfected A431 cell lines with chimeric constructs encoding for the extracellular domain of E-cadherin and the transmembrane and intracellular region of human desmoglein 3, we could show that the cytoplasmic tail is sufficient to target the protein to the desmosome. By generating truncations of the carboxy-terminus we investigated the importance of the various intracellular subdomains. Whereas the construct encoding the intracellular cadherin-type segment domain still allowed its incorporation into the desmosome, further truncation, leaving only the intracellular anchor domain, did not. Deletion of the 87 amino acid long plakoglobin-binding site within the intracellular cadherin-type segment domain demonstrated that this region is essential for targeting desmoglein 3 to the desmosome. Absent the plakoglobin-binding site the chimeric molecule colocalizes with beta-catenin rather than desmoplakin. We conclude that binding of plakoglobin to desmoglein 3 is an important step in desmosome assembly and leads to the incorporation of desmoglein 3 into the desmosome.

Adherens Junctions↗

Description of ciliary body anatomy and identification of sites for transscleral cyclophotocoagulation in the equine eye.

OBJECTIVE: To determine the most appropriate anatomical location for diode laser probe placement to accurately photoablate the equine ciliary body using a contact, transscleral approach. DESIGN: Original research. PROCEDURES: Forty-two freshly enucleated adult equine eyes were evaluated. The horizontal, medial vertical, central vertical, and lateral vertical lengths of the cornea were measured from limbus to limbus. Needles were inserted perpendicular to the sclera at specific distances posterior to the external limbus at the 1, 2, 4, 5, 6, 7, 8, 10, 11 and 12 o'clock positions. The per cent frequency that needles penetrated internal anatomical regions (lens, lens zonules, pars plicata, anterior, middle, and posterior pars plana, ora ciliaris retinae, or retina), when inserted at 2, 4, 6, and 8 mm posterior to the limbus, were calculated for all eyes combined, for right vs. left, for males vs. females, and for three age groups. The internal distance from the limbus to the anterior pars plana, and from the anterior pars plana to the ora ciliaris retinae were also measured in six of the horses (12 eyes). Mean distances and standard deviations were computed for all parameters. RESULTS: Average corneal sizes and standard deviations were: 30.24 mm +/- 1.53 (horizontal); 24.69 mm +/- 1.52 (central vertical); 22.79 mm +/- 1.49 (medial vertical); and 19.79 mm +/- 1.55 (lateral vertical). Internal distances of the pars plicatas ranged from 5.33 mm +/- 0.49 to 10.67 mm +/- 1.15. Internal distances of the pars planas ranged from 0.33 mm +/- 0.49 to 3.17 mm +/- 0.39. High probabilities of penetrating the pars plicata correspond to positions 4 mm posterior to the external limbus dorsotemporal 10, 11 o'clock (OD), and 1, 2 o'clock (OS), dorsonasal 1 o'clock (OD) and 11 o'clock (OS), and ventrotemporal 5-7 o'clock (OU). Low probabilities of penetrating the pars plicata correspond to positions ventronasal 4 o'clock (OD), 8 o'clock (OS) and dorsonasal 2 o'clock (OD), 10 o'clock (OS) at 4 and 6 mm posterior to the external limbus as well as ventrotemporal 4 o'clock (OS), 8 o'clock (OD) at 6 mm posterior to the external limbus. CONCLUSIONS: Transscleral cyclophotocoagulation may be a viable alternative to medical therapy for control of intraocular pressure in horses with glaucoma. Overall, the most accurate anatomical position on the sclera for cyclophotocoagulation of the equine eye is 4-6 mm posterior to the limbus, avoiding the nasal quadrants. Accurate transscleral cyclophotocoagulation should optimize the therapeutic outcome and minimize potential side-effects such as retinal detachment and cataract formation.

Animals↗

Endoplasmic reticulum and cis-Golgi localization of human T-lymphotropic virus type 1 p12(I): association with calreticulin and calnexin.

Human T-lymphotropic virus type 1 (HTLV-1) is a complex retrovirus encoding regulatory and accessory genes in four open reading frames (ORF I to IV) of the pX region. We have demonstrated an important role of pX ORF I expression, which encodes p12(I), in establishment of HTLV-1 infection in a rabbit model and for optimal viral infectivity in quiescent primary lymphocytes. These data indicated that p12(I) may enhance lymphocyte activation and thereby promote virus infection. To further define the role of p12(I) in cell activation, we characterized the subcellular localization of p12(I) in transfected 293T cells and HeLa-Tat cells by multiple methods, including immunofluorescence confocal microscopy, electron microscopy, and subcellular fractionation. Herein, we demonstrate that p12(I) accumulates in the endoplasmic reticulum (ER) and cis-Golgi apparatus. The location of p12(I) was unchanged following treatments with both cycloheximide (blocking de novo protein synthesis) and brefeldin A (disrupting ER-to-Golgi protein transport), indicating that the protein is retained in the ER and cis-Golgi. Moreover, using coimmunoprecipitation assays, we identify the direct binding of p12(I) with both calreticulin and calnexin, resident ER proteins which regulate calcium storage. Our results indicate that p12(I) directly binds key regulatory proteins involved in calcium-mediated cell signaling and suggest a role of p12(I) in the establishment of HTLV-1 infection by activation of host cells.

Biological Transport↗

Early postpartum discharge at a university hospital. Outcome analysis.

OBJECTIVE: To determine whether implementation of an early hospital discharge policy was effective in safely reducing hospital stay and acceptable to patients. STUDY DESIGN: The study was a prospective, observational trial. Early discharge was defined as discharge from the hospital either on the first day after vaginal delivery or on the second day after delivery by cesarean section. A "stayover mom" policy was subsequently implemented to allow a mother the option to remain in the hospital overnight after discharge. This prospective study was divided into three consecutive three-month periods: (1) routine care (n = 576), (2) early discharge (n = 622), and (3) early discharge with stay-over mom (n = 574). Primary outcome measurements were length of hospital stay and patient willingness. RESULTS: With proper review of written instructions, all eligible patients were willing to be discharged early. As compared with the routine care group, the length of hospital stay was shorter by 0.8 days (95% CI, 0.4-1.2 days) in the early discharge group (P < .01) and by 1.1 days (95% CI, 0.5-1.7 days) in the early discharge with stayover mom group (P < .005). The stayover mom policy was more desirable because of limitations in obtaining timely transportation and concern about the infant warranting continued observation. The need for maternal readmission was rare (15 cases, 0.8% of total), with endometritis equally common (n = 3 in each group). CONCLUSION: Early postpartum discharge, especially including a stayover mom policy, was acceptable to our predominantly Medicaid population. The reduced hospital stay was not associated with increased maternal morbidity.

Female↗

Squamous epithelial proliferation induced by walleye dermal sarcoma retrovirus cyclin in transgenic mice.

Walleye dermal sarcoma (WDS) is a common disease of walleye fish in the United States and Canada. These proliferative lesions are present autumn through winter and regress in the spring. Walleye dermal sarcoma virus (WDSV), a retrovirus distantly related to other members of the family Retroviridae, has been etiologically linked to the development of WDS. We have reported that the D-cyclin homologue [retroviral (rv) cyclin] encoded by WDSV rescues yeast conditionally deficient for cyclin synthesis from growth arrest and that WDSV-cyclin mRNA is present in developing tumors. These data strongly suggest that the rv-cyclin plays a central role in the development of WDS. To test the ability of the WDSV rv-cyclin to induce cell proliferation, we have generated transgenic mice expressing the rv-cyclin in squamous epithelia from the bovine keratin-5 promoter. The transgenic animals were smaller than littermates, had reduced numbers of hair follicles, and transgenic females did not lactate properly. Following injury the transgenic animals developed severe squamous epithelial hyperplasia and dysplasia with ultrastructural characteristics of neoplastic squamous epithelium. Immunocytochemistry studies demonstrated that the hyperplastic epithelium stained positive for cytokeratin and were abnormally differentiated. Furthermore, the rv-cyclin protein was detected in the thickened basal cell layers of the proliferating lesions. These data are the first to indicate that the highly divergent WDSV rv-cyclin is a very potent stimulator of eukaryotic cell proliferation and to demonstrate the potential of a cyclin homologue encoded by a retrovirus to induce hyperplastic skin lesions.

Alopecia↗

Toxin in bullous impetigo and staphylococcal scalded-skin syndrome targets desmoglein 1.

Exfoliative toxin A, produced by Staphylococcus aureus, causes blisters in bullous impetigo and its more generalized form, staphylococcal scalded-skin syndrome. The toxin shows exquisite specificity in causing loss of cell adhesion only in the superficial epidermis. Although exfoliative toxin A has the structure of a serine protease, a target protein has not been identified. Desmoglein (Dsg) 1, a desmosomal cadherin that mediates cell-cell adhesion, may be the target of exfoliative toxin A, because it is the target of autoantibodies in pemphigus foliaceus, in which blisters form with identical tissue specificity and histology. We show here that exfoliative toxin A cleaved mouse and human Dsg1, but not closely related cadherins such as Dsg3. We demonstrate this specific cleavage in cell culture, in neonatal mouse skin and with recombinant Dsg1, and conclude that Dsg1 is the specific receptor for exfoliative toxin A cleavage. This unique proteolytic attack on the desmosome causes a blister just below the stratum corneum, which forms the epidermal barrier, presumably allowing the bacteria in bullous impetigo to proliferate and spread beneath this barrier.

Animals↗

Postnatal lethality of P-cadherin/desmoglein 3 double knockout mice: demonstration of a cooperative effect of these cell adhesion molecules in tissue homeostasis of stratified squamous epithelia.

To investigate the cooperativity of different cell adhesion molecules in maintaining the structural integrity of the epidermis, we have generated mice deficient for both a classical cadherin, P-cadherin, and a desmosomal cadherin, desmoglein 3. In epithelial cells, P-cadherin is localized to the adherens junction, whereas desmoglein 3 is found in desmosomes. Previous studies have shown that these two junctional complexes are important for keratinocyte cell-cell adhesion. Both P-cadherin and desmoglein 3 expression are restricted to the basal and most immediate suprabasal cells of the epidermis, whereas both proteins are found throughout the oral mucosal epithelium. Although P-cadherin mutant mice have no apparent defect in epithelial cell adhesion, the desmoglein 3 mutant phenotype resembles that of patients with the autoimmune disease pemphigus vulgaris, in that the mice develop spontaneous mucous membrane blisters and trauma-induced skin blisters. The oral lesions in DSG3-/- mice reduce their food intake, resulting in a runted phenotype; however, most animals recover and live past weaning age. In contrast, animals mutant for both P-cadherin and desmoglein 3 die before weaning. The majority of the double mutant animals die around 1 wk after birth, apparently due to malnutrition. These studies suggest that loss of P-cadherin leads to a more severe desmoglein 3 mutant phenotype in the double knockout mice. This is the first in vivo evidence of possible synergism between a classical and desmosomal cadherin.

Animals↗

Indications for labor induction. Differences between university and community hospitals.

OBJECTIVE: To compare the rates of and indications for labor induction between a university hospital and two community hospitals and to examine the risk of cesarean delivery among labor induction cases. STUDY DESIGN: Labor induction cases over a six-month period were included (N = 536). Medical records were reviewed by a trained abstractor using a standardized form to determine maternal characteristics, reason for induction and perinatal outcomes. RESULTS: Rates of labor induction were significantly different between the three hospitals: university, 18.2%; community hospital A, 21.4%; community hospital B, 33.7% (P < .001). At the university hospital, 95% of labor inductions were medically indicated using American College of Obstetricians and Gynecologists (ACOG) criteria. Forty-four percent of labor inductions at community hospital A and 57% at community hospital B were for elective reasons. Cesarean rates among induction cases were highest at the university hospital (19%) as compared to community hospital A (15%) and community hospital B (11%), although the difference was not statistically significant. Parity, race and cervical status, but not elective induction, were significantly associated with cesarean delivery. CONCLUSION: Labor induction was more frequent in community hospitals but more likely to meet ACOG-approved indications at the university hospital. The more-frequent inductions at the community hospitals did not result in higher cesarean rates.

Adult↗