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Biomedical subjects

I Leigh

Publications and source records attributed to I Leigh.

At least 37 records · Page 2Linked to original sources
PubMed1994

An association between psoriasis and hereditary multiple exostoses. A clue for the mapping of a psoriasis susceptibility gene?

Chronic plaque psoriasis affects approximately 1.6% of the U.K. population. Population, family and twin studies all strongly suggest an important genetic component in the pathogenesis of the disease, although genetic linkage studies have, so far, failed to identify susceptibility genes. We describe a family in which psoriasis cosegregates through three generations with a known autosomal dominant disorder, hereditary multiple exostoses (HME). A major locus for HME has recently been mapped to chromosome 8q. Observations in this family may provide a mapping clue for a psoriasis susceptibility gene.

Adult↗
PubMed1993

Synthesis of preparative amounts of biologically active interleukin-6 using a continuous-flow cell-free translation system.

Cell-free synthesis of preparative amounts of interleukin-6 (IL-6) in a wheat germ extract is described. Following transcription of uncapped mRNA by SP6 polymerase, protein was synthesized in a continuous flow of translation components. The system remained active for at least 50 h, producing 1.25 x 10(6) units of IL-6. Recovered IL-6 was > 80% pure, reacted with anti-IL-6 polyclonal antiserum in Western blots, and had a specific activity comparable to recombinant IL-6 purified from Escherichia coli. This is the first time biologically active IL-6 has been prepared in preparative amounts using a continuous-flow cell-free translation system and confirms the feasibility of using enhanced in vitro translation for rapid synthesis of proteins from cloned templates.

Animals↗
PubMed1993

Expression of distinct desmocollin isoforms in human epidermis.

Previous evidence suggested the presence of two distinct desmocollin isoforms in human epidermis. These isoforms have now been distinguished at the protein level using monoclonal and polyclonal antibodies against N-terminal fragments of desmosomal glycoprotein (DG) IV/V isolated from plantar callus and antibodies against a fusion protein containing the extracellular domain of DGII/III. Immune blotting of glycoprotein fractions from whole epidermis, plantar callus, psoriatic scales and cultured keratinocytes showed that intact DGIV/V and its proteolytic fragments consistently migrated faster than DGII/III during SDS-PAGE. The apparent Mr difference between the two isoforms was in the range 2-5 kD. DGIV/V was the predominant species in epidermal tissue but was much less prominent in cultured cells by immune-blotting and immune precipitation. This is consistent with the differentiation-related expression of desmocollins revealed by immunofluorescence. DGIV/V was strongly expressed in the upper spinous/granular layer of the epidermis whereas DGII/III was more prominent in the basal layers of the tissue. The DGIV/V monoclonal (LH50) recognized an N-terminal, Ca(++)-sensitive epitope, because its staining of unfixed epidermal tissue was markedly influenced by Ca++ levels. Ca++ inhibition was observed at concentrations as low as 50 microM, suggesting its possible physiologic significance. Ca++ inhibition of LH50 binding was also observed in an enzyme-linked immunosorbent assay system using denatured glycoproteins although higher concentrations were required. It remains to be seen whether direct effects of Ca++ on desmocollin conformation are involved in the regulation of keratinization by extracellular Ca++.

Antibodies, Monoclonal↗
PubMed1992

Dermatomyositis pemphigoides: a case with coexistent dermatomyositis and bullous pemphigoid.

We describe a patient with coexistent dermatomyositis and bullous pemphigoid; both appeared within a few weeks. Protein blotting showed binding of the patient's serum to the classic 220 kd bullous pemphigoid antigen. Because of the close temporal association of the two disorders, we believe that they are almost certainly etiologically linked. One possibility is that exposure of basement membrane antigens by dermatomyositis led to exposure of bullous pemphigoid antigen and subsequent antibody formation.

Aged↗
PubMed1992

Foetal antigen 2 (FA2) in relation to wound healing and fibroblast proliferation.

During wound healing of human skin the deposition of foetal antigen 2 (FA2) and basement membrane (BM) components collagen type IV and collagen VII was followed. FA2 appeared on day 8 in the cytoplasm of proliferating fibroblasts and around newly formed blood vessels. As granulation tissue was formed, FA2 was seen diffusely in the loose matrix and in proliferating fibroblasts. Re-establishment of FA2 as a broad diffuse band along the BM at the dermo-epidermal junction was seen on day 22. In contrast, type IV and VII collagen were found along the BM and in the basal cells of the newly formed epithelium and a continuous linear BM distribution of these two components were re-established by days 12 and 14, respectively. The molecular weight (Mr) analysis of FA2, isolated from human skin fibroblast culture supernatants using SDS-PAGE, revealed a Mr of 27 kDa, corresponding to that of FA2 isolated from amniotic fluid. The presence of FA2 in proliferating fibroblasts and diffusely in the newly formed matrix of granulation tissue, as well as its late appearance at the BM after this had become established, suggests that FA2 takes part in connective tissue metabolism and perhaps tissue morphogenesis.

Amniotic Fluid↗
PubMed1992

Immunohistochemical analysis of the cytokeratin expression in middle ear cholesteatoma and related epithelial tissues.

Immunohistochemical investigations were carried out to determine the pattern of cytokeratin (CK) expression in middle ear cholesteatoma and related epithelia. Using monoclonal antibodies specific for CK chains and the indirect immunoperoxidase technique, we examined 10 CK polypeptides for expression. The external stratified squamous epithelium of the tympanic membrane generally expressed CKs 5, 10, and 14. In addition, basal keratinocytes in the annular region of the pars tensa expressed CK 19 (a simple epithelium marker), while suprabasally the hyperproliferative marker CK 16 was expressed. These data reflect the unusual proliferative nature of this region. The unexpected appearance of CK 16 (known to have a limited distribution in healthy epidermis) clearly relates to its expression in the neighboring deep meatus. The medial simple epithelium of the eardrum revealed mucosal CKs 7, 8, 14, 18, and 19. Acquired cholesteatoma lesions, besides CKs 5, 10, and 14, consistently expressed CK 16 in suprabasal layers. These results constitute the first direct molecular evidence for the hyperproliferative nature of the cholesteatoma matrix. Overall, our CK data suggest that aural cholesteatoma lesions and epidermal tissue in this area are related. However, they do not explain the mechanism(s) by which the eardrum or meatal epithelia might invade the middle ear cavity. Congenital cholesteatomas expressed CKs 5, 10, 14, and 16 equally. These CK data do not support the idea of a metaplastic origin from middle ear mucosa; instead, they suggest activation of an ectodermal rest in the middle ear cavity.

Adult↗
PubMed1992

Basal-cell keratins in cervical reserve cells and a comparison to their expression in cervical intraepithelial neoplasia.

Expression of keratins 5, 14 and 17 in endocervical subcolumnar reserve cells was detected by means of immunohistochemical studies using polypeptide specific monoclonal antibodies. These particular keratins that were found among others in basal cells could also be detected to a variable extent in metaplastic and dysplastic cervical lesions. In some cases of immature squamous metaplasia all three keratin subtypes were expressed throughout the full thickness of the epithelium. In contrast, in mature squamous metaplasia a compartmentalization of these keratins was observed. Mature squamous metaplastic epithelium showed a keratin distribution pattern comparable to ectocervical squamous epithelium, with the exception of keratin 17, which was only sporadically found in the basal layer of ectocervical epithelium and was always present in the basal cells of mature squamous metaplastic epithelium. During progression of cervical intraepithelial neoplasia a clear increase in the expression of keratin 17 was observed. However, also keratins 5 and 14 were expressed. Our results demonstrate that a considerable number of premalignant lesions of the uterine cervix express the same keratins as found in the progenitor reserve cells. Lesions that lack expression of keratin 17 may form a distinct group, which are regressive in nature and do not progress into cervical cancer.

Cervix Uteri↗
PubMed1992

Keratin expression in cervical cancer.

Using a panel of 21 monoclonal and 2 polyclonal keratin antibodies, capable of detecting separately 11 subtypes of their epithelial intermediate filament proteins at the single cell level, we investigated keratin expression in 16 squamous cell carcinomas, 9 adenocarcinomas, and 3 adenosquamous carcinomas of the human uterine cervix. The keratin phenotype of the keratinizing squamous cell carcinoma was found to be most complex comprising keratins 4, 5, 6, 8, 13, 14, 16, 17, 18, 19, and usually keratin 10. The nonkeratinizing variety of the squamous cell carcinoma expressed keratins 6, 14, 17, and 19 in all cases, usually 4, 5, 7, 8, and 18, and sometimes keratins 10, 13, and 16. Adenocarcinomas displayed a less complex keratin expression pattern comprising keratins 7, 8, 17, 18, and 19, while keratin 14 was often present and keratins 4, 5, 10 and 13 were sporadically found in individual cells in a few cases. These keratin phenotypes may be useful in differential diagnostic considerations when distinguishing between keratinizing and nonkeratinizing carcinomas (using keratin 10, 13, and 16 antibodies), and also in the distinction between nonkeratinizing carcinomas and poorly differentiated adenocarcinomas, which do not express keratins 5 and 6. Keratin 17 may also be useful in distinguishing carcinomas of the cervix from those of the colon and also from mesotheliomas. Furthermore the presence of keratin 17 in a CIN I, II, or III lesion may indicate progressive potential while its absence could be indicative of a regressive behavior. Because most carcinomas express keratins 8, 14, 17, 18, and 19, we propose that this expression pattern reflects the origin of cervical cancer from a common progenitor cell, i.e., the endocervical reserve cell that has been shown to express keratins 5, 8, 14, 17, 18, and 19.

Adenocarcinoma↗
PubMed1991

Basal cell glycoprotein in pig epidermis closely resembles the beta 1 subunit of the integrin family of cell adhesion molecules.

A 135-kD conA-binding glycoprotein isolated from pig epidermis was previously localized to the surface of basal cells in stratified epithelia using affinity-purified antibodies. Preembedding immunoperoxidase electron microscopy has now shown that this glycoprotein is concentrated on the lateral surfaces of basal cells but is not detectable on those surfaces adjacent to the basement membrane indicating a role in cell-cell rather than cell-substrate interactions. The basal cell glycoprotein was shown to resemble the beta 1 subunit of the integrin family following the generation of a specific monoclonal antibody (M5.25). The epidermal glycoprotein recognized by M5.25 and by antibodies against the beta 1 fibronectin receptor from human placenta co-migrated on SDS gels under both reducing and non-reducing conditions. Its response to disulphide reducing agents was characteristic of beta 1 integrin subunits. In addition, the basal cell glycoprotein was shown to bind to the 120-kD cell-binding fragment of fibronectin in a RGD-dependent manner. It was readily detected by immunoblotting whole cell lysates of cultured pig keratinocytes suggesting increased expression in cultured cells compared to fresh epithelial tissue. The results suggest that beta 1 integrin subunits may be involved in cell-cell interactions between basal keratinocytes in pig epidermis and that these receptors are lost from the cell surface during terminal differentiation. Thus modulation of beta 1 integrin subunit expression may play an important role in regulating differentiation in pig epidermis.

Animals↗
PubMed1991

Immunohistochemical studies on the localization of fetal antigen 2 (FA2), laminin, and collagen type 4 in basal cell carcinoma.

The localization of fetal antigen 2 (FA2), a recently described basement membrane (BM) associated antigen, was studied by immunohistochemical techniques in 21 basal cell carcinomas (BCC). In both superficial and infiltrating BCC, FA2 was located in a broad diffuse band around the tumor elements and in close contact with the BM. Compared to normal skin, a more extensive distribution of FA2 was seen in BCC. In the infiltrating BCC, FA2 staining was also present in the interstitial stroma between the tumor islands. FA2 was absent in areas with inflammatory cell infiltrates and elastoid degeneration. Epithelial and tumor cells were FA2 negative. The distribution of FA2 was clearly different from that of laminin and collagen type 4. Collagen type 4 and laminin were present as a continuous linear band corresponding to the BM surrounding the tumors. The close contact to the BM and the increased content of FA2 in the reactive stroma around BCC suggest that FA2 is involved in the matrix and/or BM changes taking place during tumor growth and invasion.

Antigens↗
PubMed1991

Patterns of cytokeratin expression in human gingival epithelia.

Specimens of human gingiva were collected from teenage and adult subjects and frozen sections were stained with an extensive panel of monoclonal antibodies with defined specificities for individual cytokeratins. The results indicated different and distinctive patterns of keratin expression by the oral gingival, oral sulcular and the junctional epithelia. It was observed that epithelium with staining characteristics of sulcular epithelium extended over the gingival crest onto the oral surface of the gingiva. Junctional epithelium showed the unusual pattern of co-expression of keratins typical of the stratifying and of the simple epithelial phenotypes. The patterns of gingival keratin expression are compared with those of other mucosal epithelia. The findings are discussed in relation to mechanisms that may determine or influence the junctional epithelial phenotype.

Adolescent↗
PubMed1991

Relation between antinuclear antibodies and the autoimmune rheumatic diseases and disease type and activity in systemic lupus erythematosus using a variety of cultured cell lines.

Antinuclear activity was assessed in serum samples from a series of 40 patients with differing clinical subsets (including renal and neurological disease) of systemic lupus erythematosus (SLE) against a transformed keratinocyte line (SvK14)* and normal human keratinocytes. Paired serum samples were studied during disease activity and inactivity, and the effects of ultraviolet radiation on the availability of nuclear antigens in the cell substrates were assessed. Serum samples from 20 healthy controls and 40 disease controls, comprising 10 patients each with rheumatoid arthritis, Sjögren's syndrome, scleroderma, and myositis, were also studied. The keratinocytes all provided sensitive substrates for the detection of antinuclear antibodies (ANAs), and in normal keratinocytes treated with ultraviolet radiation nuclear antigens were exposed on the cell surface. There was no correlation between ANAs and disease activity or patterns so, apart from assisting diagnosis, the detection of ANAs is of little relevance to predicting disease activity.

Antibodies↗
PubMed1990

Expression of beta human chorionic gonadotrophin by non-trophoblastic non-endocrine 'normal' and malignant epithelial cells.

Expression of hCG and its free subunits by non-trophoblastic tumours is well recognised. Previously we reported hCG secretion by normal and malignant bladder epithelial cells in vitro. Here we examined culture medium from 83 different cell lines derived mainly from common epithelial tumours. Thirty-two of the cell lines were found to secrete hCG-like material into their culture media. Partial immunochemical characterisation showed that of these only choriocarcinoma and fetal tissue cell lines produced intact hCG and alpha subunit. The remaining 28 hCG-expressing epithelial cell lines, which are of mucosal origin, only secreted free beta subunit. Expression of free beta hCG by non-trophoblastic nonendocrine cells would appear to be especially characteristic of mucosal epithelia from the genitourinary and oral/respiratory tracts. Furthermore, this phenomenon may be characteristic of epithelium with transitional and/or squamous cell-like properties.

Carcinoma↗
PubMed1990

Changing patterns of keratin expression during progression of cervical intraepithelial neoplasia.

The expression of keratins in normal cervical epithelia, metaplastic epithelium, and cervical intraepithelial neoplasia (CIN) grades I, II, and III is investigated with a panel of keratin polypeptide-specific monoclonal antibodies. This approach allowed the detection of individual keratins 4, 7, 8, 10, 13, 14, 18, and 19 at the single-cell level. By using an antibody recognizing keratins 5 and 8 (RCK 102) and two antibodies specific for keratin 8 (CAM 5.2 and M 20), it was also possible to derive information on the distribution of keratin 5. Our results show that during immature squamous metaplasia there is an acquisition of keratins typical of squamous epithelium, ie, keratins 4, 5, 13, and 14. This process continues during further differentiation to mature squamous metaplasia. In premalignant lesions the expression pattern of the progenitor reserve cells and immature squamous metaplastic epithelium is partly conserved. However, in most cases an induction in the expression of the keratins 4, 13, and 14 was observed. Furthermore, CIN III shows a more extensive expression of keratins typical of simple epithelia, ie, keratins 8 and 18, as compared to CIN I and CIN II.

Adult↗
PubMed1990

Keratins 1 and 10 or homologues as regular constituents of inner root sheath and cuticle cells in the human hair follicle.

Morphological maturation of the inner root sheath (IRS) and cuticle of the human hair follicle reveals analogies to differentiation processes in other keratinizing epithelia. Detailed biochemical analysis of respective differentiation products, however, has been largely restricted by their low solubility. Herein we provide further evidence for the existence of K1 and K10-derivatives in IRS and hair cuticle based on protein analysis of isolated fractions and immunofluorescence in situ, substantiating our earlier data (Stark, H. J., et al. Differentiation 35, 236-248 (1987)). Extracts from both compartments showed on two-dimensional (2D)-polyacrylamide gels a group of presumptive K1 and K10-turnover products in a wide pI (basic to acidic) and Mr range (56,000-65,000), named IC-I to III and IC-IV, respectively. These components (also found in nail plate) reacted with specific antibodies (to K1 and K10) on Western blots. Weak but distinctive radiolabeling of presumptive precursor spots close to authentic K1 and K10, respectively, and their presence in lower follicle fractions (distant from infundibulum) largely precluded epidermal contamination. Two-dimensional tryptic peptide maps of excised 2D spots from the IC-I to III series revealed high homology to K1, and those from IC-IV components to K10. Immunodetection in frozen sections was improved by trypsin pretreatment and showed distinguished staining for K1 and K10 in IRS ranging from the lower bulbus region up to the "keratinizing zone" of the follicle. Above, the reaction was abruptly abolished which coincides with ultrastructural "melting" of distinct filaments in the intracellular matrix. Thus, our data suggest that differentiation in these follicular compartments (IRS and cuticle) might follow common principles of keratinization.

Fluorescent Antibody Technique↗
PubMed1989

Survival of cultured allogeneic keratinocytes transplanted to deep dermal bed assessed with probe specific for Y chromosome.

To determine the survival of cultured allogeneic keratinocytes transplanted to a deep dermal bed 24 tattoos that had been removed by deep shave excision in 19 patients were grafted with sheets of cultured allogeneic keratinocytes from donors of the opposite sex. Cells carrying the Y chromosome were identified in biopsy specimens taken from the graft site by in situ DNA hybridisation with a biotinylated Y probe (pHY 2.1) and visualised with a technique using immunoperoxidase. The cultured allograft sites were biopsied one, two, and three weeks after transplantation. No male cells were identified in any biopsy specimen from female patients who were given transplants of male cultured keratinocytes, and all biopsy specimens from male patients, who received female cultured keratinocytes, showed percentages of male cells within the normal range for male skin. The beneficial effects of cultivated allogeneic keratinocytes result from effects on wound healing other than forming a successful graft that "takes."

Bandages↗
PubMed1989

Cytokeratin expression of the odontogenic epithelia in dental follicles and developmental cysts.

The patterns of cytokeratin expression in the epithelium of 5 dental follicles, 7 dentigerous cysts, 5 odontogenic keratocysts, 3 nasopalatine cysts and an epidermoid cyst have been studies using a panel of monoclonal antibodies. The epithelium of dental follicles and of developmental odontogenic cysts strongly expressed keratins 5 and 19 and showed weaker expression of keratins typical of stratified non-cornified and of simple epithelia. Staining with mAbs against the latter keratins varied with the degree of epithelial differentiation. Nasopalatine cysts strongly expressed simple epithelial keratins and the epidermoid cyst strongly expressed a marker of cornification. Odontogenic cysts thus appear to differ in their pattern of keratin expression from other oral developmental cysts and all derivatives of odontogenic epithelia appear to share similar basic patterns of cytokeratin expression.

Antibodies, Monoclonal↗