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Hydroxychloroquine induced melanosis. REUMATOLOGIA CLINICA 2022; 18:377-378. [PMID: 35680368 DOI: 10.1016/j.reumae.2021.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 09/23/2021] [Indexed: 06/15/2023]
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Tumoral Melanosis in the Setting of Targeted Immunotherapy for Metastatic Melanoma-A Single Institutional Experience and Literature Review. Am J Dermatopathol 2021; 43:9-14. [PMID: 32149829 DOI: 10.1097/dad.0000000000001612] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Tumoral melanosis clinically resembles metastatic melanoma, occurs in the context of regressed disease, and requires evaluation to rule out underlying melanoma and metastatic disease. Histopathology demonstrates a nodular infiltrate of melanophages in the dermis, subcutaneous tissue, deep soft tissue, or lymph nodes in the absence of viable melanocytes. Recent limited reports of tumoral melanosis in the context of immunotherapy with ipilimumab (monoclonal antibody targeting CTLA-4) as well as nivolumab and pembrolizumab (humanized monoclonal antibodies against programmed death 1 receptor) highlight a unique presentation representative of treatment-related tumor regression and an association with a favorable clinical response. OBJECTIVE To describe our experience with tumoral melanosis in the setting of immunotherapy for metastatic melanoma and elucidate the clinical and histopathological features. METHODS Retrospective case series from a single tertiary care institution. RESULTS We describe 10 cases of patients with metastatic melanoma who received treatment with immunotherapy before the development of tumoral melanosis. Length of time between the initiation of therapy and the onset of tumoral melanosis ranged from 2 to 20 months with a mean time of 10 months. At the end of the follow-up period, 8 patients were classified as having a complete or partial response to treatment with immunotherapy. One patient had progression of visceral and cutaneous disease on ipilimumab despite developing tumoral melanosis, and 1 patient had yet to undergo repeat imaging. Furthermore, at the end of follow-up, 3 patients were alive with no evidence of active disease, 5 patients were alive with disease, and 1 patient was deceased, although this patient died of a cardiovascular event unrelated to his underlying melanoma. Of the patients who were classified as alive with disease, 2 patients had minimal remaining disease, and 2 patients had an almost complete response on immunotherapy with recurrence of visceral metastases after immunotherapy was discontinued. One patient developed new peritoneal and cutaneous metastases on pembrolizumab despite development of tumoral melanosis. CONCLUSIONS The underlying biologic mechanisms and prognostic implications of tumoral melanosis in the setting of immunotherapy remain to be elucidated. Further prospective studies with a larger cohort and prolonged follow-up are necessary to better understand the incidence, prevalence, and oncologic outcomes in patients with tumoral melanosis who receive immunotherapy.
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Granulomatous Tumoral Melanosis Associated With Pembrolizumab Therapy: A Mimicker of Disease Progression in Metastatic Melanoma. Am J Dermatopathol 2018; 40:523-526. [PMID: 29924748 DOI: 10.1097/dad.0000000000001066] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Immune checkpoint inhibitor therapy has revolutionized the treatment of advanced melanoma, with these agents significantly improving survival for patients with metastatic disease. With the increasing use of these agents, the number of adverse reactions secondary to their use has also increased. Sarcoidosis and sarcoid-like reactions are one such immune checkpoint inhibitor-related adverse event. We report a case of sarcoid-like granulomatous tumoral melanosis in a patient on the programmed cell death-1 (PD-1) receptor inhibitor pembrolizumab for metastatic melanoma. This is, to our knowledge, the first reported case of a sarcoidal form of tumoral melanosis in a patient on anti-PD-1 therapy. We postulate that this reflects tumor regression in response to pembrolizumab-induced immune activation, with concomitant therapy-triggered induction of a sarcoid-like reaction. These findings and the literature review presented herein should alert clinicians and pathologists to the possibility of regressed lesions with sarcoid-like features presenting as mimickers of disease progression in patients undergoing immunotherapy for advanced melanoma.
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A Prospective Study of Iridial Pigmentation and Eyelash Changes Due to Ophthalmic Treatment with Latanoprost. Jpn J Ophthalmol 2016; 48:141-7. [PMID: 15060793 DOI: 10.1007/s10384-003-0039-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2003] [Accepted: 08/15/2003] [Indexed: 11/26/2022]
Abstract
PURPOSE To conduct a 12-month prospective study on the occurrence of latanoprost-induced iridial pigmentation and eyelash change in Japanese patients with glaucoma METHODS Seventy-five patients (75 eyes) were enrolled in the study. Photographs of the iris and eyelashes were taken under identical conditions before and after treatment. Three glaucoma specialists assessed the iridial pigmentation/eyelash change independently with no knowledge of patient data. The effects of age, sex, concomitant medication, and type of glaucoma on iridial pigmentation/eyelash change were investigated, and intraocular pressure (IOP) reduction and iridocorneal angle pigmentation before and after latanoprost treatment were compared between patients with iridial pigmentation/eyelash change and patients without these changes. RESULTS The incidence of iridial pigmentation was 6.3% at 1 month, 15.7% at 3 months, 37.8% at 6 months, and 56.5% at 12 months. The incidence of eyelash change was 0% at 1 month, 33.8% at 3 months, 44.4% at 6 months, and 46.2% at 12 months. Latanoprost did not affect IOP reduction or iridocorneal angle pigmentation. No significant relationship between iridial pigmentation and eyelash change was observed. None of the investigated parameters except age affected the iridial pigmentation/eyelash change. CONCLUSION Iridial pigmentation and eyelash change occurred at a high frequency in long-term treatment with latanoprost in Japanese glaucoma patients.
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IN VIVO EVALUATION OF SKIN IRRITATION POTENTIAL, MELASMA AND SEBUM CONTENT FOLLOWING LONG TERM APPLICATION OF SKIN CARE CREAM IN HEALTHY ADULTS, USING NON-INVASIVE BIOMETROLOGICAL TECHNIQUES. ACTA POLONIAE PHARMACEUTICA 2016; 73:219-227. [PMID: 27008816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The present investigation was conducted to evaluate non-invasively, various functional skin parameters i.e., irritation potential, melasma and sebum contents following long term application of topical cream (w/o) loaded with 2% methanolic extract of Ananas comosus L. versus placebo control (base) in healthy adults. Healthy human volunteers (n = 11, aged 20-30 years) were recruited for investigation and written informed consent was taken from each volunteer. In this single blinded study every volunteer applied formulation on one side of face and placebo on the other side of face twice daily for a period of 12 weeks (three months). Different skin parameters i.e., skin irritancy, melasma, and sebum contents were measured on both sides of face at baseline and after two weeks interval, using photometric device Mexameter and Sebumeter in a draught free room with modulated conditions of temperature (22-25°C) and humidity (55-60%). It was evident from the results that no primary skin irritancy was observed with patch test. Besides, statistical interpretation indicates that treatment with formulation is superior to placebo because it significantly (p ≤ 0.05) reduced the skin irritancy, melasma and sebum secretions throughout the study and reaching maximum -20.76 ± 0.89, -54.2 ± 0.37 and -40.71 ± 0.75%, respectively, at the end of study period. Antioxidant activity of extract was 92% compared to standard antioxidant. Conclusively, active cream loaded with fruit extract was well tolerated by all the volunteers and suitable to treat contact dermatitis, greasy skin, acne and seborrheic dermatitis and augmenting beauty and attraction by depigmentation of human skin. So, in the future, there is need to clinically evaluate these formulations in patients with compromised skin functions i.e., contact dermatitis, melasma, and acne vulgaris in order to explore the actual potential of this fruit.
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Pollution as a risk factor for the development of melasma and other skin disorders of facial hyperpigmentation ‑ is there a case to be made? J Drugs Dermatol 2015; 14:337-341. [PMID: 25844605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Worldwide air pollution is a major health concern. There is accumulating scientific evidence that air pollution plays an important role in extrinsic aging. This article invites the reader to consider pollution as a possible emerging etiologic agent for the development of melasma. Pollution may be a risk factor for melasma and other facial pigmentary dyschromias. Air pollution in the form of airborne particulate matter (PM) and Polycyclic aromatic hydrocarbons (PAHs) enter the skin via nanoparticles and generate quinones, which are redox-cycling chemicals that produce reactive oxygen species (ROS). The PM increases the amount of ROS that triggers the increase of metalloproteinases that leads to extrinsic aging, which includes skin pigmentation. The incidence of disorders of facial hyperpigmentation specifically, melasma, is increased in persons of skin type III-VI living in India and South East Asia. Interestingly, these are also geographic regions with very heavy pollution. India, South East Asia, China, and United States lead the world in air pollution.
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Paclitaxel-associated melanonychia. Cutis 2015; 95:E12-E14. [PMID: 25671450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Imatinib-associated melanosis of the palate. Am J Hematol 2014; 89:564. [PMID: 24030927 DOI: 10.1002/ajh.23589] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/01/2013] [Indexed: 11/07/2022]
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Finasteride associated melasma in a Caucasian male. J Drugs Dermatol 2014; 13:484-486. [PMID: 24719069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Melasma is an acquired hypermelanosis that typically affects sun-exposed areas on the face and presents as symmetric brownish macules and patches. It is most commonly reported in women and thought to be related to the effects of estrogen and progesterone on melanocytes. Since the advent of finasteride 1mg daily tablets for the treatment of androgenic alopecia, we have noticed an increase in the number of men presenting with melasma. Here we present one of those cases. We hypothesize this could be related to the effects of finasteride on estrogen and progesterone concentrations in the skin.
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Abstract
An accumulation of pigment deposits on mucosa, called melanosis or pseudomelanosis, of the small bowel is observed infrequently during endoscopic examination. We describe 6 cases of small bowel pseudomelanosis; the possible etiology of which was chronic iron intake. We observed numerous brown spots in duodenum, jejunum, and terminal ileum during upper and lower endoscopy. Interestingly, all patients have been taking oral iron for several years. Histology showed pigment depositions within macrophages of the lamina propria and a positive Prussian blue stain indicating hemosiderin deposition. Herein, we demonstrate that long term iron therapy may result in pseudomelanosis of small bowel, such as duodenum, jejunum, and ileum.
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The extremes in orthopaedics! Whom to blame? Musculoskelet Surg 2012; 96:179-182. [PMID: 22736335 DOI: 10.1007/s12306-012-0208-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 06/11/2012] [Indexed: 06/01/2023]
Abstract
Traditional medicines especially the herbal paste is routinely prescribed by the herb sellers. The unsupervised combinations and preparations are easily available in our part of world. The demand and supply of such irrational combination is only based on the principle that anything natural is safe. Drugs and preparations made by the people who lack the scientific knowledge of traditional herbal medicines adversely affect the consumer. We put forward few complications that resulted after herbal paste application in those who already had visited the specialist but opted the easily available unsupervised herbal preparations.
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Arsenic-induced health crisis in peri-urban Moyna and Ardebok villages, West Bengal, India: an exposure assessment study. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2012; 34:563-74. [PMID: 22580621 DOI: 10.1007/s10653-012-9458-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 04/16/2012] [Indexed: 05/21/2023]
Abstract
Drinking of arsenic (As)-contaminated groundwater has adverse effects on health of millions of people worldwide. This study aimed to determine the degree of severity of As exposure from drinking water in peri-urban Moyna and Ardebok villages, West Bengal, India. Arsenic concentrations in hair, nail and urine samp les of the individuals were determined. Arsenical dermatosis, keratosis and melanosis were investigated through medical evaluation. We have evaluated the association between As exposure from drinking water, and keratosis and melanosis outcomes. The results showed that 82.7 % of the sampled tube wells contain As concentrations above 10 μg/L, while 57.7 % contain As concentrations above 50 μg/L. The hair, nail and urine As concentrations were positively correlated with As concentrations in drinking water. In our study population, we observed a strong association between As concentrations ranging 51-99 μg/L and keratosis and melanosis outcomes, although the probability decreases at higher concentration ranges perhaps due to switching away from the use of As-contaminated tube wells for drinking and cooking purposes. High As concentrations in hair, nail and urine were observed to be associated with the age of the study population. The level of As concentrations in hair, nail and urine samples of the study population indicated the degree of severity of As exposure in the study region.
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Oral and maxillofacial pathology case of the month. Palatal melanosis associated with imatinib mesylate therapy. TEXAS DENTAL JOURNAL 2012; 129:764-788. [PMID: 22988661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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NGF-p75 and neuropsin/KLK8 pathways stimulate each other to cause hyperkeratosis and acanthosis in inflamed skin. J Dermatol Sci 2012; 67:71-3. [PMID: 22520925 DOI: 10.1016/j.jdermsci.2012.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 02/26/2012] [Accepted: 03/16/2012] [Indexed: 11/18/2022]
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Response to case study on darkening of a facial skin graft after latanoprost. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2011; 129:964-965. [PMID: 21746996 DOI: 10.1001/archophthalmol.2011.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Oral melanosis after tyrosine kinase inhibition with Imatinib for chronic myelogenous leukemia: report of a case and review of the literature. Dermatol Online J 2011; 17:4. [PMID: 21635826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
Dermatologic manifestations from therapy with imatinib are well known and frequently include hypopigmentation, and less commonly, hyperpigmentation. There have been few reports of oral hyperpigmentation. We present a case of palatal melanosis related to imatinib therapy for chronic myelogenous leukemia. This case is reported to add to the sparse literature concerning mucosal reactions related to this medication.
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Nail changes in a patient with leukaemia. BMJ 2011; 342:c6439. [PMID: 21224311 DOI: 10.1136/bmj.c6439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Labial melanotic macule after application of topical tacrolimus: two case reports. Acta Derm Venereol 2010; 90:527. [PMID: 20814635 DOI: 10.2340/00015555-0878] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Diffuse pigmentation of the palate. JOURNAL - OKLAHOMA DENTAL ASSOCIATION 2009; 100:24-25. [PMID: 19998620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Doxorubicin-induced hyperpigmentation. Dermatol Online J 2008; 14:18. [PMID: 19061617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
A 39-year-old man with human immunodeficiency virus infection and Kaposi sarcoma on HAART therapy and doxorubicin presented in 2007 with a hyperpigmented tongue. Physical examination also showed hyperpigmented patches on the mucosal aspects of the lips and longitudinal dark bands on multiple nails. A skin biopsy specimen showed pigmentary alteration. Such hyperpigmentation has been described in numerous case reports and case series and has been reported to resolve within weeks to months of cessation of doxorubicin.
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[5-Fluorouracil-induced reticular hyperpigmentation]. ACTAS DERMO-SIFILIOGRAFICAS 2008; 99:573-574. [PMID: 18682175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
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Palmar and flagellate hyperpigmentation following low dose intralesional injection of bleomycin for cystic hygroma. Dermatol Online J 2008; 14:19. [PMID: 19061577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
A 1(1/2)-year-old boy developed hyperpigmentation of the palms and feet along with flagellate pigmentation over the trunk following intralesional injection of bleomycin for cystic hygroma. We present this case to highlight the possibility of cutaneous pigmentation being induced by bleomycin in low doses through non-intravenous administration.
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Abstract
OBJECTIVES To assess types and prevalence of HIV-related oral lesions among HIV-infected individuals in south India and to correlate common oral findings with co-morbidities, gender, age and medication. SUBJECTS AND METHODS One hundred and one patients with HIV infection or AIDS at infectious diseases units of Attavar Hospital, Mangalore, and medical wards of Kasturba Medical College, Manipal, were selected. Sociodemographic information was obtained using a structured questionnaire. Oral lesions were diagnosed according to the presumptive criteria of EEC-Clearinghouse Classification. Clinical history was retrieved from patient's medical records. RESULTS Erythematous candidiasis (44.5%), melanotic hyperpigmentaion (34.6%) and xerostomia (29.7%) were among the most common oral manifestations. A significant association was found between oral candidiasis and advanced immunosuppression (P < 0.05). Oral hairy leukoplakia (OHL) was predominant in individuals <35 years (P < 0.05). Melanotic hyperpigmentation was significantly associated with highly active antiretroviral therapy (P < 0.05). OHL was more frequent in patients with HIV-associated tuberculosis. Linear gingival erythema was more predominant in females. CONCLUSIONS Oral hairy leukoplakia showed a positive relationship with patients younger than 35 years. Oral candidiasis can act as a marker for immunosuppression. Angular cheilitis was predominant in the symptomatic stage.
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Abstract
This study aimed to define the smoking status and smoke-related gingival melanin pigmentation in army recruitments and was conducted with army recruitments in Sivas. Nine hundred eight subjects were examined. The oral and dental health of those subjects was checked and recorded. The smoking status of the subjects was self-reported and recorded on questionnaires by researchers. The chi2 test and Kruskal-Wallis test were used for statistical analysis. More than one-half of the subjects (54.3%) were primary school graduates and the mean age was 20.2 +/- 0.95 years. The response rate regarding smoking was 100%. Of the respondents, 596 (65.7%) were current smokers, 12 (1.3%) were former smokers, and 300 (33.0%) were never smokers. The gingival melanin pigmentation rate was 27.5% in current smokers and 8.6% in those who never smoked (p = 0.000). Smoking five to nine cigarettes a day appeared to be sufficient to cause gingival melanin pigmentation. The proportion of smokers who had melanin pigmentation did not change after 10 cigarettes a day. A rehabilitation project on smoking prevention and smoking cessation for army recruitments is urgently needed.
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Melanoniquia inducida por zidovudina. FARMACIA HOSPITALARIA 2007; 31:128-9. [PMID: 17590123 DOI: 10.1016/s1130-6343(07)75730-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Arsenic groundwater contamination and its health effects in the state of Uttar Pradesh (UP) in upper and middle Ganga plain, India: a severe danger. THE SCIENCE OF THE TOTAL ENVIRONMENT 2006; 370:310-22. [PMID: 16899281 DOI: 10.1016/j.scitotenv.2006.06.015] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 06/16/2006] [Accepted: 06/20/2006] [Indexed: 05/11/2023]
Abstract
This communication presents results of our 2-year survey on groundwater arsenic contamination in three districts Ballia, Varanasi and Gazipur of Uttar Pradesh (UP) in the upper and middle Ganga plain, India. Analyses of 4,780 tubewell water samples revealed that arsenic concentrations in 46.5% exceeded 10 microg/L, in 26.7%, 50 microg/L and in 10% 300 microg/L limits. Arsenic concentrations up to 3,192 microg//L were observed. The age of tubewells (n=1,881) ranged from less than a year to 32 years, with an average of 6.5 years. Our study shows that older tubewells had a greater chance of contamination. Depth of tubewells (n=3,810) varied from 6 to 60.5 m with a mean of 25.75 m. A detailed study in three administrative units within Ballia district, i.e. block, Gram Panchayet, and village was carried out to assess the magnitude of the contamination. Before our survey the affected villagers were not aware that they were suffering from arsenical toxicity through contaminated drinking water. A preliminary clinical examination in 11 affected villages (10 from Ballia and 1 from Gazipur district) revealed typical arsenical skin lesions ranging from melanosis, keratosis to Bowens (suspected). Out of 989 villagers (691 adults, and 298 children) screened, 137 (19.8%) of the adults and 17 (5.7%) of the children were diagnosed to have typical arsenical skin lesions. Arsenical neuropathy and adverse obstetric outcome were also observed, indicating severity of exposure. The range of arsenic concentrations in hair, nail and urine was 137-10,900, 764-19,700 microg/kg, and 23-4,030 microg/L, respectively. The urine, hair and nail concentrations of arsenic correlated significantly (r=0.76, 0.61, and 0.55, respectively) with drinking water arsenic concentrations. The similarity to previous studies on arsenic contamination in West Bengal, Bihar and Bangladesh indicates that people from a significant part of the surveyed areas in UP are suffering and this will spread unless drives to raise awareness of arsenic toxicity are undertaken and an arsenic safe water supply is immediately introduced.
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Melanosis coli. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2006; 54:548. [PMID: 17089904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
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Prevalence of arsenicosis in terai, Nepal. JOURNAL OF HEALTH, POPULATION, AND NUTRITION 2006; 24:246-52. [PMID: 17195566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This paper summarizes the findings of surveys on arsenicosis cases conducted during 2001-2004 in terai, Nepal, by governmental and non-governmental organizations in their respective project areas and by some national and international institutes. Studies were conducted in six arsenic-contaminated districts of terai, namely Nawalparasi, Bara, Parsa, Rautahat, Rupandehi, and Kapilvastu. In these districts, arsenic contamination in tubewells varied from 2.1% to 25.7%. The prevalence of arsenicosis was, on average, 2.2% and varied from 0.7% in Kapilavastu district to 3.6% in Nawalparasi district. In the community-based study, the highest prevalence (18.6%) of arsenicosis was found in Patkhouli village of Nawalparasi, where 95.8% of tubewells were contaminated with arsenic. The prevalence of arsenicosis was higher in older age-groups (>50 years) of both the sexes. Males suffered more from arsenicosis than females (odds ratio: 2.50, 95% confidence interval 1.80-3.47). Skin manifestations, such as melanosis and keratosis, were the common symptoms of arsenicosis. Most patients were identified in the early or mild stage of the disease. They are expected to recover if further exposure to arsenic could be avoided by providing arsenic-safe drinking-water through intervention measures.
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Abstract
OBJECTIVE To investigate light microscopic and ultrastructural changes in bimatoprost-induced skin hyperpigmentation. METHODS Eyelid biopsy specimens from bimatoprost-treated patients and matched controls were examined by light microscopy and transmission electron microscopy. Using an image analyzer, melanin granules were counted on Fontana-Masson-stained sections, and melanosomes were counted on electron micrographs. Immunohistochemical analysis was performed with antibodies against S100 and CD3. Positively labeled cells were counted. RESULTS By light microscopy, a marked increase in the number of melanin granules was noted in the bimatoprost-treated specimens. Electron microscopy demonstrated dermal melanocytes with prominent rough endoplasmic reticulum and abundant normal-sized melanosomes in different stages of maturation as compared with control specimens. Furthermore, the keratinocytes of the bimatoprost-treated specimens showed abundant mature melanosomes when compared with controls. Also of note, atypical melanocytes were absent in both specimens. The S100-positive melanocytes were comparable in bimatoprost-treated and control specimens. Few CD3- and CD68-positive cells in the bimatoprost-treated specimens were noted in both groups. CONCLUSION Bimatoprost-induced periocular hyperpigmentation is caused by increased melanogenesis. There was no evidence of melanocyte proliferation or prostaglandin-induced inflammation in the specimens that were examined.
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A Randomized, Double-Blind Placebo-Controlled Trial Evaluating the Effects of Vitamin E and Selenium on Arsenic-Induced Skin Lesions in Bangladesh. J Occup Environ Med 2005; 47:1026-35. [PMID: 16217243 DOI: 10.1097/01.jom.0000183095.45050.97] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We sought to determine whether supplementation of vitamin E (alpha-tocopherol), selenium (L-selenomethionine), or their combination improves arsenical skin lesions. METHODS A 2 x 2 randomized, placebo-controlled, double-blind trial among 121 men and women chronically exposed to arsenic in drinking water was conducted in rural Bangladesh. Participants were randomized to one of four treatment arms: vitamin E, selenium, vitamin E and selenium (combination), or placebo and were treated for 6 months. RESULTS At baseline, the average skin lesion scores were 2.23, 2.26, and 2.63 and at follow-up, the average skin lesion scores went down to 2.00, 2.06, and 2.47 in those receiving vitamin E, selenium, and the combination, respectively. CONCLUSIONS Supplementation with vitamin E and selenium, either alone or in combination, slightly improved skin lesion status, although the improvement was not statistically significant.
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Re: Martin TJM, Sharp I, Oral mucosal pigmentation secondary to treatment with mepacrine, with sparing of the denture bearing area (Br J Oral Maxillofac Surg 2004;42:351–3). Br J Oral Maxillofac Surg 2005; 43:268. [PMID: 15888372 DOI: 10.1016/j.bjoms.2004.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Minocycline-associated intra-oral soft-tissue pigmentation: clinicopathologic correlations and review. J Clin Periodontol 2005; 32:119-22. [PMID: 15691339 DOI: 10.1111/j.1600-051x.2005.00646.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Intra-oral minocycline staining of alveolar bone and teeth is well-described in the literature. Minocycline-induced discoloration of oral soft tissues is less common and has been often attributed to staining of the underlying bone. AIM This report documents the clinical and histopathologic features of a case of actual oral soft tissue minocycline-induced pigmentation. The patient, a 45-year-old Caucasian female, presented with pigmentation of the gingiva, lips, and nail beds of recent onset. The past medical history revealed initiation of minocycline therapy 6 months earlier for dermatological concerns. Histopathologic examination of biopsy specimens from the gingiva and lip showed evidence of increased melanin/melanocytes in the epithelium and melanin/melanophages in the connective tissue. A working diagnosis of drug-associated pigmentation was determined and the patient discontinued immediately minocycline therapy. Nine months after cessation of minocycline the patient exhibited a marked reduction in pigmentation. CONCLUSION Systemic minocycline treatment has the potential to induce significant and esthetically objectionable discoloration of the gingiva and oral mucosa. A brief review of the literature is presented to help understand this uncommon finding that should be included in the differential diagnosis of spontaneous discoloration of intra-oral soft tissues.
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A Study of Iridectomy Histopathologic Features of Latanoprost- andNon–Latanoprost-Treated Patients. ACTA ACUST UNITED AC 2004; 122:1680-5. [PMID: 15534130 DOI: 10.1001/archopht.122.11.1680] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVES To examine the histopathologic features of iridectomy specimens from patients undergoing glaucoma surgery and to compare histologic abnormalities in a group of patients with a history of latanoprost therapy with those in a group of patients who had no history of prostaglandin therapy (controls). METHODS Iridectomy specimens and patient history forms were submitted to the central Latanoprost Pathology Center. These were independently examined by 3 ophthalmic pathologists in a masked fashion. Specimens were evaluated for malignant, premalignant, and other changes including differences in levels of pigmentation, degrees of cellularity, inflammation, vascular abnormalities, and changes in the iris pigment epithelium. RESULTS Specimens were received from 449 patients with a history of latanoprost treatment and 142 patients who had no history of treatment with latanoprost or other prostaglandin analogues. No evidence of malignant or premalignant changes was found. In latanoprost-treated irides, the prevalence of iris freckles was higher (P = .001) than in control irides, as was the combined number of stromal fibroblasts and melanocytes (P<.001). In a subgroup of specimens received through June 2002, there was no significant difference in mean melanocyte counts (P=.35) obtained by immunohistochemical staining techniques between the latanoprost-treated and control groups. CONCLUSIONS These findings support previous studies indicating that latanoprost-induced eye color changes are due to an increased amount of melanin within the iris stromal melanocytes. The increased numbers of freckles may be a focal manifestation of this effect.
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Melanosis coli involving pericolonic lymph nodes associated with the herbal laxative Swiss Kriss: a rare and incidental finding in a patient with colonic adenocarcinoma. Arch Pathol Lab Med 2004; 128:565-7. [PMID: 15086301 DOI: 10.5858/2004-128-565-mcipln] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Melanosis coli is a well-known condition in which macrophages filled with a lipofuscin-like pigment are found in the colonic lamina propria. The condition has been associated with the ingestion of anthracene laxatives and is believed to be caused by increased epithelial apoptosis. Although melanosis coli is a frequent finding in colonic biopsies and resection specimens, to our knowledge the presence of identical pigment in macrophages of pericolonic lymph nodes has been reported in only 4 other patients in the English literature. We report the case of a patient who underwent a left hemicolectomy for colonic adenocarcinoma and was found incidentally to have melanosis coli associated with long-term use of the herbal laxative Swiss Kriss, not only in his colonic mucosa, but also in the colonic submucosa and in his pericolonic lymph nodes.
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Oral mucosal pigmentation secondary to treatment with mepacrine, with sparing of the denture bearing area. Br J Oral Maxillofac Surg 2004; 42:351-3. [PMID: 15225957 DOI: 10.1016/j.bjoms.2004.02.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2004] [Indexed: 10/26/2022]
Abstract
We report a case of oral mucosal pigmentation secondary treatment with mepacrine, with sparing of the denture bearing area. To our knowledge this phenomenon has not been reported since the association between antimalarial therapy and mucosal pigmentation was first described.
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Oral mucosal pigmentation secondary to minocycline therapy: report of two cases and a review of the literature. ACTA ACUST UNITED AC 2004; 97:718-25. [PMID: 15184854 DOI: 10.1016/j.tripleo.2003.11.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Minocycline is a semisynthetic broad-spectrum antimicrobial agent that was first introduced into clinical practice in 1967. The most common use of minocycline is for the long-term treatment of acne vulgaris. A well-recognized side effect of minocycline treatment is pigmentation, which has been reported in multiple tissues and fluids including thyroid, skin, nail beds, sclera, bone, and teeth. While there have been several reports of oral pigmentation following minocycline therapy, these have been, for the most part, pigmentation of the underlying bone with the overlying oral mucosa only appearing pigmented. We report two cases of actual pigmented oral mucosal lesions on the hard palate secondary to minocycline therapy with the accompanying histopathology, followed by a discussion of minocycline-induced oral pigmentation and a differential diagnosis of these lesions.
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Abstract
BACKGROUND Giving the immunosuppressive drug tacrolimus (FK506) to liver transplant patients has helped to considerably reduce oral side effects such as gingival hyperplasia. Patients taking cyclosporin who suffer from gingival hyperplasia are often switched to tacrolimus. METHODS We present here a pediatric liver transplantation case study. The patient has been followed for 5.5 years. She developed oral lesions that resulted in the immunosuppressive therapy being changed from tacrolimus to cyclosporin. In clinical terms, the atypical pathology consisted of hyperpigmented patches on the gingival margin, the internal surfaces of the cheeks, and the intraoral surfaces of the lips. When located on the lips, the hyperpigmented patches were associated with pruriginous and edematous lesions. RESULTS Optical and electronic microscopic examinations of a gingival tissue sample revealed the presence of melanin incontinence and lichenoid lesions with degenerated keratinocytes and a mild infiltrate of lymphocytes. This points to a chronic graft-versus-host disease (cGvHD)-like syndrome linked to tacrolimus. This diagnosis was given further credence by improvement in the lesions following the switch to cyclosporin. CONCLUSION To our knowledge, this is the first reported case of tacrolimus-associated chronic GvHD-like syndrome occurring in the oral mucosa.
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Diagnosis of arsenicosis. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2003; 38:255-272. [PMID: 12635831 DOI: 10.1081/ese-120016893] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Arsenicosis is chronic subclinical or clinical toxicity due to high level of arsenic in body. Diagnosis of arsenicosis was derived by chronological establishment of facts: (a) arsenic as the cause of malady, (b) drinking water (tubewell water) as the vehicle of arsenic, (c) soil as the source of arsenic, (d) mechanism of leaching of arsenic from soil, and (e) cause of prevalence in particular areas of the country. Arsenicosis has been classified by the author into 4 stages, 7 grades and 20 subgrades. Stage I is pre-clinical or grade 0. While clinical features were not found at this stage, high level of arsenic metabolites was observed in urine. As disease progressed to stable phase of grade 0, high level of arsenic was also found in nails, hair, and skin scales. Stage II or clinical stage is divided into 4 grades, (1) Melanosis, (2) Spotted keratosis in palms/soles, (3) Diffuse keratosis in palms/soles, and (4) Dorsal keratosis. Clinical complications are grouped in stage III and grade 5. Malignancy is considered in stage IV and grade 6. There is a concern of both underdiagnosis and overdiagnosis. Therefore, cases of arsenicosis should be cautiously evaluated. Melanosis was the earliest cutaneous sign of clinical arsenicosis. Mild cases of melanosis could only be revealed by a thorough comparison with normal palms. Similarly mild cases of keratosis might not be visible and could only be revealed by careful palpation of palms and soles. Combination of melanosis and keratosis in adults indicated clinical diagnosis of arsenical dermatosis (ASD) that should be confirmed by showing high arsenic concentration in body tissues e.g., nails, hair, skin scales. Isolated melanosis or keratosis in newborn or children below 2 years almost negated the diagnosis of arsenicosis. Genetic melanosis or keratosis is often present since birth. Isolated melanosis or keratosis in adults should be differentiated from non-arsenical dermatosis and proven by absence of high arsenic level in nails and hair. Non arsenical causes of diffuse melanosis, spotted melanosis or leucomelanosis and localized or generalized keratosis can be clinically differentiated from arsenicosis by absence of pigmentation and keratosis in palms/soles.
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Anthranoid self-medication causing rapid development of melanosis coli. Neth J Med 2003; 61:22-4. [PMID: 12688566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
It is widely known that long-term use of anthranoid-containing laxatives is the cause of melanosis coli. We describe a case of melanosis coli, which occurred in a 39-year-old liver transplant patient who took an over-the-counter product containing aloe, rheum and frangula. The typical brownish pigmentation of the colonic mucosa developed in a period of ten months. The anthranoid medication was stopped and follow-up colonoscopy one year later showed normal looking mucosa once more. However, in contrast to previous examinations, a sessile polypoid lesion was found in the transverse colon. Histology showed tubulovillous adenoma with extensive low-grade dysplasia. Since there have been preliminary reports suggesting a possible role of anthranoid-containing laxatives in the development of colorectal adenomas and cancer, their use should be discouraged.
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A comparison of cycle control, efficacy, and side effects among healthy Thai women between two low-dose oral contraceptives containing 20 microg ethinylestradio1/75 microg gestodene (Meliane) and 30 microg ethinylestradio1/75 microg gestodene (Gynera). Contraception 2002; 66:407-9. [PMID: 12499032 DOI: 10.1016/s0010-7824(02)00411-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to compare cycle control, efficacy and side effects of an oral contraceptive containing 20 microg ethinylestradiol and 75 microg gestodene, with a reference preparation containing 30 microg ethinylestradiol combined with 75 microg gestodene. From the study, it was demonstrated that the two regimens had no difference in cycle control, efficacy, and side effects. The occurrence of spotting and breakthrough bleeding was low and was not different between these two preparations. The most common adverse events in both treatment groups were nausea, vomiting, dizziness, and chloasma. There were no statistically significant change in body weight and blood pressure in both groups at the end of study. It is concluded that both preparations are good cycle control, reliable and low side effects oral contraceptives.
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Chronic arsenic toxicity in Bangladesh and West Bengal, India--a review and commentary. JOURNAL OF TOXICOLOGY. CLINICAL TOXICOLOGY 2002; 39:683-700. [PMID: 11778666 DOI: 10.1081/clt-100108509] [Citation(s) in RCA: 295] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Fifty districts of Bangladesh and 9 districts in West Bengal, India have arsenic levels in groundwater above the World Health Organization's maximum permissible limit of 50 microg/L. The area and population of 50 districts of Bangladesh and 9 districts in West Bengal are 118,849 km2 and 104.9 million and 38,865 km2 and 42.7 million, respectively. Our current data show arsenic levels above 50 microg/ L in 2000 villages, 178 police stations of 50 affected districts in Bangladesh and 2600 villages, 74 police stations/blocks of 9 affected districts in West Bengal. We have so far analyzed 34,000 and 101,934 hand tube-well water samples from Bangladesh and West Bengal respectively by FI-HG-AAS of which 56% and 52%, respectively, contained arsenic above 10 microg/L and 37% and 25% arsenic above 50 microg/L. In our preliminary study 18,000 persons in Bangladesh and 86,000 persons in West Bengal were clinically examined in arsenic-affected districts. Of them, 3695 (20.6% including 6.11% children) in Bangladesh and 8500 (9.8% including 1.7% children) in West Bengal had arsenical dermatological features. Symptoms of chronic arsenic toxicity developed insidiously after 6 months to 2 years or more of exposure. The time of onset depends on the concentration of arsenic in the drinking water, volume of intake, and the health and nutritional status of individuals. Major dermatological signs are diffuse or spotted melanosis, leucomelanosis, and keratosis. Chronic arsenicosis is a multisystem disorder. Apart from generalized weakness, appetite and weight loss, and anemia, our patients had symptoms relating to involvement of the lungs, gastrointestinal system, liver, spleen, genitourinary system, hemopoietic system, eyes, nervous system, and cardiovascular system. We found evidence of arsenic neuropathy in 37.3% (154 of 413 cases) in one group and 86.8% (33 of 38 cases) in another. Most of these cases had mild and predominantly sensory neuropathy. Central nervous system involvement was evident with and without neuropathy. Electrodiagnostic studies proved helpful for the diagnosis of neurological involvement. Advanced neglected cases with many years of exposure presented with cancer of skin and of the lung, liver, kidney, and bladder. The diagnosis of subclinical arsenicosis was made in 83%, 93%, and 95% of hair, nail and urine samples, respectively, in Bangladesh; and 57%, 83%, and 89% of hair, nail, and urine samples, respectively in West Bengal. Approximately 90% of children below 11 years of age living in the affected areas show hair and nail arsenic above the normal level. Children appear to have a higher body burden than adults despite fewer dermatological manifestations. Limited trials of 4 arsenic chelators in the treatment of chronic arsenic toxicity in West Bengal over the last 2 decades do not provide any clinical, biochemical, or histopathological benefit except for the accompanying preliminary report of clinical benefit with dimercaptopropanesulfonate therapy. Extensive efforts are needed in both countries to combat the arsenic crisis including control of tube-wells, watershed management with effective use of the prodigious supplies of surface water, traditional water management, public awareness programs, and education concerning the apparent benefits of optimal nutrition.
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Abstract
PURPOSE To report the histopathologic and immunohistochemical findings from the iridectomy specimen of a patient with acquired unilateral iris heterochromia due to latanoprost. PATIENT AND METHODS A 45-year-old woman with open-angle glaucoma and unilateral iris heterochromia was evaluated for uncontrolled intraocular pressure increase. Subsequently, the patient underwent trabeculectomy with mitomycin C and an iridectomy specimen was obtained for analysis. RESULTS The histopathologic analysis of the iridectomy specimen did not reveal any nuclear atypia, nuclear crowding, or mitotic figures. Immunohistochemical studies showed that the iris melanocytes were negative for HMB45 and S-100, and weakly positive for Melan A. CONCLUSION Latanoprost-associated iris color change may exhibit a diffuse, uniform, dark velvet-brown appearance, thereby simulating diffuse iris melanoma. Histopathologic and immunohistochemical analysis confirmed the benign characteristics of the affected iris melanocytes.
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Abstract
PURPOSE To investigate the incidence of iridial pigmentation induced by latanoprost ophthalmic solution in Japanese glaucoma patients by a prospective and observer-masked study. PATIENTS AND METHODS Sixty-nine eyes of 69 glaucoma patients were included. Patients who had undergone intraocular surgery, laser trabeculoplasty, and laser iridotomy within 12 months before enrollment, and patients with history of uveitis and any changes in antiglaucoma drugs within 6 months before enrollment were excluded. Iridial photographs were taken by one examiner under the same conditions at 1, 3, and 6 months after the initiation of latanoprost treatment. Three glaucoma specialists, masked of patient information, independently assessed the iridial pigmentation. Cases with iridial pigmentation diagnosed by three specialists were categorized as showing a definite increase in iridial pigmentation. RESULTS A definite increase in iridial pigmentation occurred in 3.5%, 9.7%, and 35.0% of eyes within 1, 3, and 6 months of treatment, respectively. Age, gender, or concomitantly used eyedrops did not significantly influence the incidence of iridial pigmentation within 6 months of instillation. A reduction of intraocular pressure by latanoprost did not differ significantly between patients with and without iridial pigmentation. CONCLUSION The incidence of iridial pigmentation by latanoprost ophthalmic solution in Japanese patients was higher than previously reported values in pigmented races.
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Abstract
Interspecific hybrid crosses between members of the fish genus Xiphophorus have been used for over 70 years to study the genetic aspects of melanoma formation. In the well-established "Gordon-Kosswig" cross, the platyfish X. maculatus is outcrossed to the swordtail X. helleri, and the resulting backcross segregants spontaneously develop melanoma. We recently produced a distinct cross between X. maculatus and another platyfish species, X. couchianus. X. maculatus strain Jp 163 A is homozygous for several X-linked pigment pattern genes, including the Spotted dorsal (Sd), Dorsal red (Dr), and Anal fin spot (Af). Af is a sex-limited trait, coding exclusively for melanophores distributed on the modified anal fin or "gonopodium" in the adult male fish. Within F1 and BC1 hybrids (to X. couchianus), the Sd pigment pattern is phenotypically suppressed, whereas Dr and Af are enhanced. We exposed BC1 hybrids to the direct-acting carcinogen N-methyl-N-nitrosourea (MNU). Treatment led to the development of schwannomas, fibrosarcomas, and retinoblastomas. In addition, numerous MNU-treated males that inherited Af developed a pronounced melanotic phenotype, with melanin-containing cells oftentimes totally covering the gonopodium and extending further to grow within the ventral regions of the fish. Genetic linkage analysis of the BC1 hybrids revealed a significant (p < 0.01) association between CDKN2X genotype and the phenotypic degree of melanization. Such an association is consistent with a locus within linkage group V playing a role in the development of melanosis and delineates three genetic preconditions and a carcinogenic scheme resulting in melanosis of the ventral regions of hybrid fish. The overall study further alludes to the potential of using Xiphophorus fish to study carcinogenic mechanisms for tumors other than melanoma (schwannoma, fibrosarcoma, and retinoblastoma) and should enable extensive pathologic and molecular genetic studies of derived neoplastic abnormalities.
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