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Keeney DS, Skinner C, Travers JB, Capdevila JH, Nanney LB, King LE, Waterman MR. Differentiating keratinocytes express a novel cytochrome P450 enzyme, CYP2B19, having arachidonate monooxygenase activity. J Biol Chem 1998; 273:32071-9. [PMID: 9822682 DOI: 10.1074/jbc.273.48.32071] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The novel cytochrome P450, CYP2B19, is a specific cellular marker of late differentiation in skin keratinocytes. CYP2B19 was discovered in fetal mouse skin where its onset of expression coincides spatially (upper cell layer) and temporally (day 15.5) with the appearance of loricrin-expressing keratinocytes during the stratification stage of fetal epidermis. CYP2B19 is also present postnatally in the differentiated keratinocytes of the epidermis, sebaceous glands, and hair follicles. CYP2B19 mRNA is tightly coupled to the differentiated (granular cell) keratinocyte phenotype in vivo and in vitro. In primary mouse epidermal keratinocytes, it is specifically up-regulated and correlated temporally with calcium-induced differentiation and expression of the late differentiation genes loricrin and profilaggrin. Recombinant CYP2B19 metabolizes arachidonic acid and generates 14,15- and 11, 12-epoxyeicosatrienoic (EET) acids, and 11-, 12-, and 15-hydroxyeicosatetraenoic (HETE) acids (20, 35, 18, 7, and 7% of total metabolites, respectively). Arachidonic acid metabolism was stereoselective for 11S,12R- and 14S,15R-EET, and 11S-, 12R-, and 15R-HETE. The CYP2B19 metabolites 11,12- and 14,15-EET are endogenous constituents of murine epidermis and are present in similar proportions to that generated by the enzyme in vitro, suggesting that CYP2B19 might be the primary enzymatic source of these EETs in murine epidermis.
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McElwee KJ, Boggess D, King LE, Sundberg JP. Experimental induction of alopecia areata-like hair loss in C3H/HeJ mice using full-thickness skin grafts. J Invest Dermatol 1998; 111:797-803. [PMID: 9804341 DOI: 10.1046/j.1523-1747.1998.00380.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Alopecia areata (AA)-like hair loss in C3H/HeJ mice provides an excellent model for human AA disease research. The potential to induce mouse AA in normal haired C3H/HeJ mice at an early age or serially passage the AA phenotype was investigated by exchange of full-thickness skin grafts. Skin grafts from normal male and female C3H/HeJ, or severe combined immunodeficient C3H/SmnC Prkdc(scid)/J, mice onto AA-affected C3H/HeJ mice became inflamed and lost hair (28 of 28). Successful grafts from AA-affected C3H/HeJ mice induced hair loss in histocompatible C3H/OuJ mice (four of 13) and normal C3H/HeJ mice dependent on age (four of 17 at <31 d and 15 of 15 at >70 d). The AA phenotype was serially transmitted from induced AA mice to normal C3H/HeJ mice (nine of nine). Grafts from AA-affected C3H/HeJ mice onto C3H/SmnC Prkd(scid)/J mice resulted in depigmented hair fiber regrowth and perifollicular neutrophil and eosinophil infiltrates but no hair loss (15 of 15). Sham grafting did not induce AA (none of 10). The finding that AA can be serially transferred from AA-affected C3H/HeJ mice to normal littermates and C3H/ OuJ mice, indicates that an immune response against hair follicles can be induced with suitable stimuli. Conversely, skin grafts from normal C3H/HeJ, or C3H/SmnC Prkd(scid)/J, mice rapidly lose hair due to lymphocyte, but not neutrophil and eosinophil, mediated inflammation. This AA induction method reproducibly provides large numbers of AA-affected mice to study the pathogenesis and treatment of human AA.
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Frank J, Poh-Fitzpatrick MB, King LE, Christiano AM. The genetic basis of "Scarsdale Gourmet Diet" variegate porphyria: a missense mutation in the protoporphyrinogen oxidase gene. Arch Dermatol Res 1998; 290:441-5. [PMID: 9763307 DOI: 10.1007/s004030050333] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The porphyrias are disorders of porphyrin or porphyrin-precursor metabolism that result from inherited or acquired aberrations in the control of the porphyrin-heme biosynthetic pathway. Variegate porphyria (VP), one of the acute hepatic porphyrias, is characterized by a partial reduction in the activity of protoporphyrinogen oxidase (PPO), and recently, mutations in the PPO gene on chromosome 1q22-23 have been described. Our purpose was to identify the underlying genetic lesion in a severely affected patient with VP and to detect the silent mutation carriers in her family. The disease in this patient was precipitated by carbohydrate restriction as outlined in the "Scarsdale Gourmet Diet". Our mutation detection and confirmation strategy included PCR, automated sequencing, and restriction enzyme digestion. We identified a missense mutation in the patient and five family members. The mutation consisted of a previously unreported C-to-T transition in exon 5 of the PPO gene, resulting in the substitution of arginine by cysteine, designated R152C. This arginine residue is evolutionarily highly conserved in humans, mice, bacteria, yeast, and plants, indicating the importance of this residue in PPO. Our study established that a missense mutation in the PPO gene was the underlying mutation in this patient with VP and explained the occurrence of the phenotype in this family.
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Abstract
BACKGROUND Osteoma cutis, the presence of lamellar bone in the skin, is relatively common. This process is divided into two categories: primary osteoma cutis and secondary osteoma cutis. OBJECTIVE The purpose of this study was to describe the clinical and histopathologic features of patients in whom lamellar bone developed in cutaneous basal cell carcinoma. METHODS We evaluated the features of five cases of osteoma cutis associated with basal cell carcinoma and obtained detailed clinical information from those patients. RESULTS All five patients had significant underlying medical conditions, including two patients who were receiving interferon alfa-2b therapy. Three patients had been previously treated with electrodesiccation and curettage. The amount of sun exposure experienced by these patients varied. Histologically, the basal cell carcinomas were of the nodular or micronodular variety. Bone was found both in the stroma and intratumorally. CONCLUSION The presence of bone within basal cell carcinomas is not uncommon and may be more prevalent in patients with an underlying medical disorder.
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McElwee KJ, Boggess D, Burgett B, Bates R, Bedigan HG, Sundberg JP, King LE. Murine cytomegalovirus is not associated with alopecia areata in C3H/HeJ mice. J Invest Dermatol 1998; 110:986-7. [PMID: 9620311 DOI: 10.1046/j.1523-1747.1998.00207.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Park JH, Kari S, King LE, Olsen NJ. Analysis of 31P MR spectroscopy data using artificial neural networks for longitudinal evaluation of muscle diseases: dermatomyositis. NMR IN BIOMEDICINE 1998; 11:245-256. [PMID: 9719579 DOI: 10.1002/(sici)1099-1492(199806/08)11:4/5<245::aid-nbm513>3.0.co;2-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Classical myopathic dermatomyositis (DM) is a chronic autoimmune disease characterized by an erythematous rash and severe, proximal muscle weakness. A disease variant, amyopathic DM, presents with the typical rash but without clinical evidence of muscle weakness. Prednisone and immunosuppressive drugs alleviate symptoms in many patients. Accurate longitudinal evaluations of patients are important to limit serious side effects of these drugs, including osteoporosis, cataracts, and growth inhibition. Metabolic abnormalities detected with 31P magnetic resonance spectroscopy (MRS) provide the best quantitative data for evaluating these patients. With 31P MRS, the levels of inorganic phosphate (Pi), phosphocreatine (PCr), ATP, and phosphodiesters (PDE) were determined in the quadricep muscles of patients during rest and exercise. Artificial neural network (ANN) analyses of these data were previously used for accurate classification of patients with myopathic or amyopathic DM and normal controls. In the present investigation, an artificial neural network was employed for further analysis of the 31P metabolite levels in quantitative, longitudinal evaluations of the extent (percent) of clinical improvement or deterioration during treatment with prednisone and immunosuppressive drugs. The ANN results showed that adult patients in a severe myopathic state could improve with treatment to a clinical status of amyopathic DM. In contrast, severely weak juvenile patients in the myopathic state recovered to normal status. One juvenile patient did not improve and remained in the myopathic state. Additionally, a serious clinical relapse in an amyopathic patient was predicted with serial ANN analyses well in advance of the actual clinical event. These network analyses show potential utility for clinical applications in muscle diseases.
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Lappin PB, Ross KL, King LE, Fraker PJ, Roth RA. The response of pulmonary vascular endothelial cells to monocrotaline pyrrole: cell proliferation and DNA synthesis in vitro and in vivo. Toxicol Appl Pharmacol 1998; 150:37-48. [PMID: 9630451 DOI: 10.1006/taap.1998.8398] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Monocrotaline pyrrole (MCTP) causes pulmonary vascular endothelial cell (EC) injury followed by progressive pulmonary vascular leak in vivo and the inhibition of EC proliferation in vitro. It was hypothesized that MCTP inhibits cell proliferation in vitro by interfering with cell cycle progression in a cycle phase-specific manner. Furthermore, it was proposed that early alterations in MCTP-induced lung injury leading to hypertension were associated with a similar inhibition of EC proliferation. Subconfluent cultures of bovine pulmonary artery endothelial cells (BECs) were synchronized with aphidicolin (APH), a reversible G1-S phase inhibitor. Upon removal of APH, BECs were exposed to MCTP (5 micrograms/ml) or its vehicle for a 4-h interval corresponding to either the G1-S, S-G2, or G2 through mitosis (M) phases of the cell cycle. Fluorescence-activated cell sorting (FACS) was used to identify MCTP-induced changes in cell cycle progression in BECs, and the transit of S phase cells through the cycle was characterized through the incorporation of bromodeoxyuridine (BrdU). Synchronized BECs exposed to MCTP between mid-S-G2 or G2 through M were briefly delayed in G2-M at 12 h but underwent cell division by 24 h. By contrast, BECs treated with MCTP immediately after release from APH block became arrested in G2-M at 24 h and showed evidence of continued DNA synthesis and hypertetraploidy, but they did not divide. In vivo, MCTP (3.5 mg/kg i.v.) administration caused an increase in arterial EC BrdU incorporation between Days 3 and 7, but no increase in EC density. During this same interval, pulmonary vascular permeability increased and persisted. In summary, MCTP inhibits cell proliferation in a cell cycle phase-dependent manner in vitro. The results suggest that a similar mechanism could occur in vivo and may be associated with delayed EC repair, a process that could contribute to persistent pulmonary vascular leak.
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Osati-Ashtiani F, King LE, Fraker PJ. Variance in the resistance of murine early bone marrow B cells to a deficiency in zinc. Immunology 1998; 94:94-100. [PMID: 9708192 PMCID: PMC1364336 DOI: 10.1046/j.1365-2567.1998.00076.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Little is known of the effects of nutritional deficiencies on lymphopoietic processes. Nevertheless, deficiencies in zinc adversely affect immune function causing thymic atrophy and lymphopenia in both humans and animals. Previous studies of the effects of zinc deficiency (ZD) on lymphopoiesis in adult mice indicated that a suboptimal intake of zinc caused a 50% or more depletion of the marrow of developing B cells. Thus, interference in the production of lymphocytes by ZD appeared to be a significant factor in the loss of host defence capacity. In the current study three-colour immunofluorescence phenotyping of early bone marrow B lymphocytes (B220+ immunoglobulin-) using flow cytometry demonstrated that a 27-day period of ZD caused a 50-70% decline in pre-B cells (B220+ CD43- immunoglobulin M (IgM)-) for moderate and severely zinc-deficient mice, respectively. Conversely, early pro-B cells (B220+ CD43+ 6C3-) and late pro-B cells (B220+ CD43+ 6C3+) exhibited little or no change in their distribution within the marrow. Indeed, the greater resistance of pro-B cells resulted in a 50% increase in the proportion of this subset within the B-cell compartment of the marrow as the deficiency in zinc advanced. Collectively, the data indicate that the B-cell compartment of the marrow is substantially altered by ZD and the stage specific sensitivity noted among early B cells may be related to chronically elevated levels of glucocorticoids present during ZD or other parameters that affect their survival and resistance to apoptosis.
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Abstract
BACKGROUND Lichen planus is a papulosquamous dermatosis which has recently been linked to infection with hepatitis C virus. It is unclear whether or not viral antigens may be present in the cutaneous lesions of lichen planus. MATERIALS AND METHODS Twenty-five paraffin-embedded samples of glabrous lichen planus were evaluated using immunoperoxidase staining for the presence of hepatitis C virions. Control tissues consisted of hepatitis C-infected hepatic tissue (n = 2), normal hepatic tissue (n = 2), normal human skin (n = 1), and two cutaneous biopsies of lichen planus from persons known to be infected with hepatitis C. RESULTS The sections of hepatitis C-infected liver tissue stained positive for hepatitis C virions. The 25 biopsies of glabrous lichen planus, the two biopsies of lichen planus from hepatitis C patients, the two sections of normal liver, and the one normal skin sample all failed to take up the stain. CONCLUSIONS Cutaneous lesions of lichen planus are more probably reactive to the underlying infection than a manifestation of skin involvement by this disease. This theory is supported by the histologic findings in a lichenoid drug eruption, which are virtually identical to those of idiopathic lichen planus. Insufficient sensitivity by the immunoperoxidase procedure used is a possible explanation for our results; however, it appears more probable that no virus exists at the sites of cutaneous involvement.
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Nanney LB, Davidson MK, Gates RE, Kano M, King LE. Altered distribution and expression of protein tyrosine phosphatases in normal human skin as compared to squamous cell carcinomas. J Cutan Pathol 1997; 24:521-32. [PMID: 9404849 DOI: 10.1111/j.1600-0560.1997.tb01456.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Amounts and subcellular localizations of 4 protein tyrosine phosphatases (PTPs) were compared in cultured normal human keratinocytes, an immortalized keratinocyte cell line, and 2 squamous cell carcinoma (SCC) lines. Cellular localizations for PTPs were determined in biopsies of normal human skin and SCCs. Compared to normal keratinocytes, SCC cell lines had higher levels of PTP-1B and T-cell PTP and comparable levels of PTP-1C or PTP-1D. The subcellular localization of each PTP was similar in the 3 types of keratinocytes with PTP-1B localizing to the endoplasmic reticulum, T-cell PTP exclusively found in the nucleus, PTP-1C localized to the plasma membrane, cytosol and nucleus, and PTP-1D present in both cytosol and nucleus. Compared to normal skin, immunoreactive PTP-1B was markedly increased in the invasive margins of SCCs while T-cell PTP was generally increased in tumors. PTP-1C immunostaining varied between cells with no obvious difference between normal and neoplastic tissues. The intensity and distribution of immunoreactive PTP-1D varied greatly between cells within tumors. These differences in amounts and in cellular and subcellular localization of these PTPs, especially those differences in invasive margins of SCCs, may reflect the diverse roles these PTPs play in the proliferation and invasive potential of neoplastic keratinocytes.
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Tobin DJ, Sundberg JP, King LE, Boggess D, Bystryn JC. Autoantibodies to hair follicles in C3H/HeJ mice with alopecia areata-like hair loss. J Invest Dermatol 1997; 109:329-33. [PMID: 9284100 DOI: 10.1111/1523-1747.ep12335848] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have previously described spontaneous but reversible hair loss that clinically and histologically resembles human alopecia areata in a colony of C3H/HeJ mice. Alopecia areata in humans is associated with antibodies to hair follicles. This study was conducted to determine whether C3H/HeJ mice with hair loss have a similar abnormal antibody response to hair follicles. Eighteen C3H/HeJ mice with alopecia, 12 unaffected littermates, and 15 control mice were examined for circulating antibodies to C3H/HeJ anagen hair follicles by indirect immunofluorescence and against extracts of isolated C3H/HeJ and human anagen hair follicles by immunoblotting. Using both procedures, antibodies to anagen hair follicles were present in all C3H/HeJ mice with alopecia but in none of the control mice. The antibodies were also present in some unaffected C3H/HeJ littermates but were absent in mice of an unrelated strain with inflammatory skin disease and alopecia, indicating that their appearance did not result from the hair loss. These antibodies reacted to hair follicle-specific antigens of 40-60 kDa present in murine and human anagen hair follicles. These antigens were also reactive with human alopecia areata antibodies. Some of the antibodies in both C3H/HeJ mice and humans with alopecia areata reacted to antigens of 44 and 46 kDa, which were identified as hair follicle-specific keratins. This study indicates that C3H/HeJ mice with hair loss have circulating antibodies to hair follicles similar to those present in humans with alopecia areata. These findings confirm that these mice are an appropriate model for human alopecia areata and support the hypothesis that alopecia areata results from an abnormal autoimmune response to hair follicles.
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King LE, Grynpas MD, Tomlinson G, Vieth R. Pamidronate content and turnover in sternum, vertebral body, and iliac bones of dogs. Bone 1997; 20:405-11. [PMID: 9145237 DOI: 10.1016/s8756-3282(97)00017-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Therapeutic efficacy of bisphosphonates depends on how much drug is present in bone. Therefore, it is important to measure the amount of bone bisphosphonate in toxicological and pharmacological studies. We analyzed pamidronate content of bone samples from two previously published long-term dose studies. In the first study, mature beagle dogs were given oral pamidronate at doses of 0, 2.5, 12.5 and 25 mg/kg per day for 1 year. The dogs in the second study received the same dosages for 1 year followed by 1 year without drug. In both studies, the amount of pamidronate measured was dependent upon dose in bone samples of ilium, sternum, and vertebral body. After 1 year of treatment, vertebral bone had more pamidronate than sternum or iliac bone on a permilligram basis. After 2 years, there was significantly less pamidronate in the vertebral body, sternum, and ilium than there had been at 1 year. The fall in pamidronate content was largest in vertebral body and least in the ilium. The higher uptake of pamidronate by the vertebral body during the 1 year study, and its greater loss of pamidronate after a year without drug treatment, would reflect the higher turnover of trabecular bone in the vertebral body vs. cortical bone in the ilium. The percent difference in bone pamidronate content between the 1 and 2 year dogs varied with dose. The largest percent loss occurred in the intermediate-dose group. These data suggest that, after 1 year without the drug, bone turnover rates in dogs treated with the highest dose of pamidronate were lower than at the intermediate dose. Thus, the time required for bone turnover rates to return to pretreatment levels is probably dose-dependent.
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Russell MA, Langley M, Truett AP, King LE, Boyd AS. Lichenoid dermatitis after consumption of gold-containing liquor. J Am Acad Dermatol 1997; 36:841-4. [PMID: 9146563 DOI: 10.1016/s0190-9622(97)70036-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Medicinal gold has a well-known side effect profile that includes mucocutaneous eruptions. We describe three patients with a pruritic dermatitis that began after consumption of a gold-containing alcoholic beverage. Blood and urine gold levels, chemistry panels, hepatitis screens, skin biopsies, and patch tests were performed. The gold-containing liquor was analyzed for the presence and quantity of gold. The liquor consumed by all of the patients was a cinnamon schnapps with free-floating gold-colored flakes. Gold is present in the liquid portion of this liquor and in the solid flakes. Elevated levels of gold in the urine and blood were present in one patient 3 months after last drinking this beverage. Another patient had a positive patch test to gold sodium thiosulfate. All patients experienced improvement of their dermatitis after they stopped drinking the gold-containing liquor.
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Zic JA, Stricklin GP, Greer JP, Kinney MC, Shyr Y, Wilson DC, King LE. Long-term follow-up of patients with cutaneous T-cell lymphoma treated with extracorporeal photochemotherapy. J Am Acad Dermatol 1996; 35:935-45. [PMID: 8959953 DOI: 10.1016/s0190-9622(96)90118-8] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Few studies have assessed the long-term outcome of patients with cutaneous T-cell lymphoma (CTCL) treated with extracorporeal photochemotherapy (ECP). OBJECTIVE Our objective was to assess the efficacy, safety, and survival of a cohort of patients with refractory T-cell lymphoma in various stages of cutaneous involvement who were treated with ECP. METHODS Twenty patients who had received at least 6 months of ECP between September 1988 and April 1991 were reevaluated and the data analyzed statistically to obtain outcome data through December 1995. RESULTS A complete response (disappearance of all lesions) was obtained in five patients (25%) and a partial response (disappearance of at least 50% of lesions) in five patients (25%). Of the 10 responders, seven (70%) were weaned from ECP. Two of seven patients had a relapse. Ten patients (50%) showed no response to ECP. No statistically significant differences between responders and nonresponders were found with respect to demographic, clinical, or laboratory variables. Seven patients died of causes directly related to CTCL and two patients died of unrelated causes. Median survival time for the entire cohort was 96 months (range, 16 to 152 months). An assessment of early response after 6 to 8 months of ECP had a sensitivity of 100% and a specificity of 90% for predicting long-term (> 4 years) outcome. Adverse effects were minimal. CONCLUSION ECP is a safe effective alternative therapy for CTCL that is refractory to other therapies; it can induce a long-term, disease-free remission in a minority of patients. Response in the first 6 to 8 months of treatment predicts long-term outcome.
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Abstract
Weakness and fatigue are common symptoms in patients with scleroderma and may be due at least in part to underlying abnormalities of muscle. Various modalities, including electromyography, histologic examination of biopsy specimens, MR imaging, and MR spectroscopy are useful in defining muscle abnormalities in these patients. Recent studies using P-31 MR spectroscopy and near infrared spectroscopy demonstrate the presence of underlying metabolic abnormalities that may contribute to the clinical findings of weakness and fatigue.
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Boyd AS, Hook M, King LE. An evaluation of the accuracy of residency applicants' curricula vitae: are the claims of publications erroneous? J Am Acad Dermatol 1996; 35:606-8. [PMID: 8859291 DOI: 10.1016/s0190-9622(96)90688-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Competition for residency positions in dermatology is intense. Training programs in other disciplines have described significant misrepresentation among their applicants in claims of research and publication. An evaluation was made of the curricula vitae for the 138 applicants with completed applications for our 1994 residency match. Cited articles were placed in four categories: "published," "in print/in press," "submitted for publication," and "in preparation/in progress." We found significantly less misrepresentation than has been described in other specialty training programs. Simplification of the way in which applicants verify their bibliography may reduce erroneous citations and remove implications of willful misrepresentation of academic achievements.
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Abstract
A comparison has been presented to illustrate many of the similarities in patterns of disease between mouse and human hair follicle diseases and how various mouse mutations can be used as research tools to investigate these observations. The powerful genetic tools available for investigating mouse mutations and human homologues will continue to result in many breakthroughs in the understanding of hair follicle biology and pathology. Many more mouse mutations are available than are described here. Information on these mutations fills books and computer databases, providing an unlimited resource.
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Montagutelli X, Hogan ME, Aubin G, Lalouette A, Guénet JL, King LE, Sundberg JP. Lanceolate hair (lah): a recessive mouse mutation with alopecia and abnormal hair. J Invest Dermatol 1996; 107:20-5. [PMID: 8752833 DOI: 10.1111/1523-1747.ep12297438] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A new autosomal recessive mutation of the house mouse developed generalized alopecia associated with breakage of abnormal hair shafts. This mutation, named 'lanceolate hair' (symbol: lah), arose in a mutagenesis experiment using ethylnitrosourea. Hair shafts were short with a focal degeneration at the breakpoint characterized by a pronounced enlargement at the apex, resembling a lance head. Plucked hair fibers were 2.0 to 3.5 mm in length with a normal base, suggesting that there was a synchronized developmental defect. Histologic examination of anagen follicles revealed abnormal cornification of the matrix region with degeneration resulting in the focal hair shaft deformity. Catagen follicles showed pronounced follicular dystrophy but telogen follicles were almost normal. There was a marked, persistent thickening of the epidermis associated with a non-scarring, relatively non-inflammatory ichthyosiform dermatitis. These features are found in the Netherton's syndrome of the human, for which this mouse mutation may represent a model. The lah mutation has been localized to the centromeric end of mouse Chromosome 18.
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Gates RE, Miller JL, King LE. Activity and molecular weight of protein tyrosine phosphatases in cell lysates determined by renaturation after gel electrophoresis. Anal Biochem 1996; 237:208-15. [PMID: 8660568 DOI: 10.1006/abio.1996.0231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A procedure for renaturing and detecting the activity of protein tyrosine phosphatases (PTPases) after sodium dodecyl sulfate (SDS)-gel electrophoresis with greatly improved sensitivity and resolution is described. Epidermal growth factor receptor-kinase, c-src kinase, and focal adhesion kinase were phosphorylated on tyrosine with 32PO4 and incorporated into gels prior to electrophoresis. These proteins are dephosphorylated when cellular proteins are electrophoresed and the separated PTPases are renatured in the gel by removing SDS with extensive washing. With whole cell lysates, at least eight separate bands of decreased radioactivity corresponding to PTPase activity with molecular weights between 110 and 34 kDa are seen in autoradiographs of the dried gels. PTPases detected are similar with different cell types and with the three 32P-labeled protein substrates, although they are different in cytosolic and membrane-associated fractions. A PTPase detected above 200 kDa in wheat germ agglutinin eluates from solubilized cells suggests that some receptor PTPases can be renatured. While microgram levels of recombinant PTP-1C are required for detection, nanogram levels of recombinant PTP-1B are easily detected. Assaying the activity of renatured PTPases after they have been separated by molecular weight in SDS gel electrophoresis provides a simple and rapid means of determining the activity of individual PTPases in cell fractions.
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Abstract
Epidermal growth factor receptors (EGF-Rs) are elevated in active human psoriatic lesions, but decrease in resolving lesions. Similar biologic responses in EGF-R levels have been demonstrated within human psoriatic skin grafted onto mice. We tested the hypothesis that flaky-skin mice (fsn/fsn), one proposed genetic animal model of psoriasis, would display EGF-R levels comparable to human psoriatic epidermis and show similar biologic responses. EGF-R levels were characterized in unperturbed sites in fsn/fsn skin and +/? skin by enzyme-linked immunosorbent assay, 125I-EGF binding, and immunostaining. Altered EGF-R levels were noted after mild trauma (tape stripping) or under resolving conditions (30 doses of 50 mJ/CM2 ultraviolet B, 2.5 mg/kg oral cyclosporin A, or daily 30 microg/ml topical EGF). Increased EGF-R immunostaining was observed in involved flaky epidermal sites before treatment. To determine whether a hyperproliferative (Koebner) reaction could be induced, we tape stripped fsn/fsn tail and non-flaky dorsal sites. EGF-R levels in dorsal epidermis increased by days 3-4 after injury by enzyme-linked immunoabsorbent assay methods. When fsn/fsn mice received one of three different treatments for 6 weeks, the skin returned to a normal phenotype both grossly and microscopically. Immunoreactive EGF-R in treated, but not untreated, sites decreased to either normal or nondetectable levels. These data indicate that fsn/fsn mice exhibit an EGF-R profile identical to that of lesional and nonlesional human psoriatic epidermis. Modulations of the flaky phenotype in response to injury and three different treatments suggest that fsn/fsn is a useful in vivo model for examining new treatment modalities for psoriasiform skin diseases.
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King LE. Less than human, more than human. The use of mouse models in dermatologic research. ARCHIVES OF DERMATOLOGY 1996; 132:508-10. [PMID: 8624146 DOI: 10.1001/archderm.132.5.508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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King LE, Vieth R. Extraction and measurement of pamidronate from bone samples using automated pre-column derivatization, high-performance liquid chromatography and fluorescence detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 678:325-30. [PMID: 8738038 DOI: 10.1016/0378-4347(95)00531-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A method for the determination of 3-amino-1-hydroxylpropylidene-1, 1-bisphosphonic acid (pamidronate) in bone samples is described. This method combines and modifies parts of previous procedures. Pamidronate is extracted from finely ground bone with dilute hydrochloric acid. Amine-containing contaminants are removed by co-precipitation of pamidronate with calcium. Excess calcium is removed with EDTA and an ion-exchange resin. Pamidronate is automatically derivatized at the primary amine and quantified by high-performance liquid chromatography with fluorescence detection. The method assay was linear in the concentration range 7.5-600 ng/mg bone (20-100 pmol/mg). The imprecision for repeat analyses were 16.5 and 7.8%, at pamidronate levels of 7.5 and 600 ng/mg bone, respectively. The method has been used to analyze bone samples from pharmacokinetic animal studies involving both acute and chronic dosages.
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Dellasega C, King LE. The psychogeriatric nurse in home health care: use of research to develop the role. CLIN NURSE SPEC 1996; 10:64-8. [PMID: 8705946 DOI: 10.1097/00002800-199603000-00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
IN THIS ARTICLE, how one home health agency developed services for a high-risk group of clients based on a research study conducted on-site is described. Part of that study compared the cost of home care for cognitively impaired and cognitively intact persons over the age of 65. Although care for older adults with cognitive impairment was less expensive in terms of actual dollars, hospital and agency readmissions were significantly greater for those who were cognitively impaired, which led to greater total costs. Study results document that cognitively impaired older adults have special home care needs. Results were used to develop a special psychogeriatric program within the home health agency where data were collected. A CNS is now the key feature of this program; the CNS role in addressing the special needs of cognitively impaired home health clients is outlined.
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Adams-Gandhi LB, Boyd AS, King LE. Diagnosis and management of dermatomyositis. COMPREHENSIVE THERAPY 1996; 22:156-64. [PMID: 8706385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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