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Biomedical subjects

D A Mehregan

Publications and source records attributed to D A Mehregan.

At least 19 recordsLinked to original sources
PubMed2001

Utility of anti-bacillus Calmette-Guérin antibodies as a screen for organisms in sporotrichoid infections.

BACKGROUND: Sporotrichoid infections often present a diagnostic challenge for the dermatopathologist. Therefore an affordable, reliable method of easier recognition of organisms is desired. Recently, immunohistochemical staining with antibodies against Mycobacterium bovis (bacillus Calmette-Guérin, BCG) was found to be useful in identifying various fungi and mycobacteria with minimal background staining. OBJECTIVE: The purpose of this study was to demonstrate the usefulness of anti-BCG antibodies as a screen for organisms in sporotrichoid infections. METHODS: Thirteen specimens of suspected sporotrichosis were selected for staining with anti-BCG antibody. Sporotrichoid infection was confirmed by histochemical staining, biopsy, and follow-up results. RESULTS: Twelve of the 13 specimens stained positively using anti-BCG antibody. Of the 5 cultures done, 2 were positive for M. marinum, and 1 grew Sporothrix schenckii. CONCLUSION: Immunohistochemical staining with anti-BCG antibody offers another screening method to identify organisms in sporotrichoid infections because of its ease, cost-effectiveness, and simplicity.

Antibodies, Bacterial↗
PubMed2000

Cutaneous malakoplakia: a report of two cases with the use of anti-BCG for the detection for micro-organisms.

Malakoplakia is an uncommon granulomatous infectious disease that is found primarily in the genito-urinary tract, but may rarely involve the skin. Histologic findings are marked by the presence of foamy macrophages containing basophilic concentric spherules, the Michaelis-Gutman bodies. Micro-organisms are not readily identifiable. Immunostaining with polyclonal anti-mycobacterium bovis (BCG) has been described as a method of identifying bacterial and fungal organisms in situations where organisms may be sparse. We report 2 cases of cutaneous malakoplakia with demonstration of organisms by immunostaining with anti-BCG antibodies.

Aged↗
PubMed1998

Staining of eccrine and apocrine neoplasms and metastatic adenocarcinoma with IKH-4, a monoclonal antibody specific for the eccrine gland.

The histogenesis of apocrine and eccrine neoplasms has always interested dermatopathologists. In addition, the histologic differential diagnosis of eccrine carcinoma from metastatic adenocarcinoma is of practical importance. We describe a novel monoclonal antibody IKH-4 which stains the eccrine secretory coil, but not the apocrine secretory segment. Positive staining was observed in eccrine hidradenoma, eccrine poroma, eccrine spiradenoma, papillary eccrine adenoma, eccrine hidrocystoma, syringoma, eccrine carcinoma, and in 1 case of syringocystadenoma papilliferum. Negative staining was observed in apocrine adenocarcinoma, hidradenoma papilliferum, erosive adenomatosis of the nipple, and primary and metastatic adenocarcinomas. IKH-4 antibody was useful in differentiating eccrine from apocrine neoplasms and in differentiating eccrine carcinoma from metastatic adenocarcinomas.

Adenocarcinoma↗
PubMed1998

Cheilitis due to treatment with simvastatin.

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase are very common and effective treatments for hyperlipidemia. Epidermal cholesterol synthesis has been shown to be essential for maintaining the cutaneous barrier function. We present two patients who experienced cheilitis after beginning treatment of hyperlipidemia with simvastatin (Zocor). The rash resolved after discontinuation of medication and subsequent treatment with topical moisturizers and topical corticosteroids. We suspect that skin barrier dysfunction may occur in the mucosa from inhibitors of HMG-CoA reductase in a manner analogous to the epidermis.

Adult↗
PubMed1997

Onychomycosis.

Treatment options for onychomycosis are expanding, making accurate and prompt diagnosis of greater importance. Diagnosis of onychomycosis can be made by direct examination of potassium hydroxide-prepared nail clippings, culture, and histologic examination. We compared culture of nail clippings to histologic examination and show that histologic examination is a quick and reliable alternative.

Culture Media↗
PubMed1996

Amelanotic lentigo maligna melanoma: a diagnostic conundrum-- presentation of four new cases.

BACKGROUND: The clinical appearance of amelanotic lentigo maligna melanoma (ALMM) is quite confusing and usually is not diagnosed prior to histopathologic examination. METHODS: We have studied four new patients with ALMM whose correct diagnosis was not obtained from any one clinical finding. We arrived at the final diagnosis in an unexpected way, having had biopsied the lesions for diagnoses other than malignant melanoma. RESULTS: ALMM presents as a nonspecific skin lesion with no single indicative characteristic. A search of the literature confirmed our difficulty in making the diagnosis. CONCLUSIONS: To diagnose ALMM, one has to be cognizant of this condition and has to consider a constellation of findings that are unusual with melanocytic lesions. Questionable lesions must be biopsied for definitive histopathologic diagnosis.

Aged↗
PubMed1996

Chronic lupoid leishmaniasis. Evaluation by polymerase chain reaction.

BACKGROUND: The cutaneous lesions in chronic lupoid leishmaniasis resemble those of lupus vulgaris, both clinically and histologically. The differential diagnosis is difficult and may depend on the detection of a few Leishmania amastigotes in the histologic sections, the growth of the promastigotes in cultures, or the identification of amastigotes by other techniques. Polymerase chain reaction was used to detect Leishmania amastigote DNA in tissue samples obtained from 65 patients with chronic lupoid leismaniasis, and the results were confirmed by Southern blot analysis. OBSERVATIONS: The histologic findings of a predominantly epithelioid cell granuloma surrounded by lymphocytic infiltrate in chronic lupoid leishmaniasis are very similar to those observed in lupus vulgaris. Extensive histologic examination of the sections in this series revealed occasional macrophages containing a few amastigotes in only 12 cases. Cultures in NNN medium yielded Leishmania promastigotes in 20 cases. Polymerase chain reaction studies using a Leishmania-specific primer identified Leishmania DNA in 30 of 63 cases, and those using a Mycobacterium tuberculosis primer were found to be negative for mycobacteria in 47 cases tested, including 11 cases with a positive tuberculin skin reaction. CONCLUSIONS: The histologic findings in chronic lupoid leishmaniasis resemble those of lupus vulgaris. Polymerase chain reaction studies were useful in identifying amastigotes in 30 (47.6%) of 63 cases. This study confirms the presence of DNA molecules of Leishmania amastigotes in samples of formalin-fixed, paraffin-embedded granulomatous tissue obtained from patients with chronic lupoid leishmaniasis.

Adolescent↗
PubMed1996

Clinical and histologic evaluation of psoriatic plaques treated with a flashlamp pulsed dye laser.

BACKGROUND: Psoriatic plaques can be cleared by destruction of the dermal papillae. Dilated vessels, the major component of psoriatic dermal papillae, can be selectively destroyed with yellow light lasers. Previous investigators have demonstrated partial clearing of psoriatic plaques after treatment with a pulsed dye laser (PDL) (585 nm). OBJECTIVE: This study was designed to examine the clinical and histologic events of psoriasis treated with the PDL. METHODS: Psoriatic plaques were treated with a short (450 microseconds) and long (1500 microseconds) pulse-width PDL. Photographs of the plaques were used for clinical assessment. Biopsy specimens were examined microscopically. RESULTS: Significant clinical improvement was seen, and no significant difference between the long and short pulse-width lasers was found. Patients responding to treatment with the PDL remained in remission for up to 13 months. Histologic normalization occurred after treatment. Two pretreatment vascular patterns were seen: vertically oriented vessels with few horizontal vessels and numerous tortuous vessels. Tortuous vessels were associated with poor clinical results. CONCLUSION: The PDL can induce prolonged remission in chronic plaque psoriasis. The vascular pattern may help to distinguish those patients likely to respond to this treatment.

Adult↗
PubMed1995

Axillary granular parakeratosis.

We report two cases of axillary granular parakeratosis, which is a unique eruption involving the axilla that has distinctive histopathologic features. Both of our patients had slightly pruritic, hyperpigmented patches in the axilla. The biopsy specimens revealed severe compact parakeratosis with maintenance of the stratum granulosum and retention of keratohyalin granules throughout the stratum corneum, which was markedly thickened and measured between 90 to 185 microns. The exact etiology is not known, but this conditions is believed to represent a contact reaction to an antiperspirant or deodorant.

Aged↗
PubMed1995

Spindle cell lipomas. A report of two cases: one with multiple lesions.

BACKGROUND: Spindle cell lipoma is an unusual and histologically distinctive form of lipoma occurring primarily in older individuals. OBJECTIVE: The dermatologic surgeon and pathologist should be familiar with this variant of lipoma. METHODS: We are reporting two cases of spindle cell lipomas with the results of histologic examination with special stains and immunohistochemical studies. RESULTS: The neoplasms consisted of lobulated masses of mature adipose tissue with areas of spindle cell proliferation. There was strong positive staining with antibodies for vimentin within the areas of spindle cells proliferation. One of the cases is unusual in that multiple lesions are occurring in a young patient. CONCLUSION: Recognition of the histologic pattern is important in distinguishing the benign spindle cell lipoma from the malignant liposarcoma.

Adipose Tissue↗
PubMed1995

Epidermotropic metastatic malignant melanoma.

Epidermotropic metastatic malignant melanoma can simulate a primary malignant melanoma. However, since therapeutic management can be drastically different for these two lesions, care must be taken in evaluating them. We report a woman with forty-eight metastatic lesions of malignant melanoma, twenty-two of which were removed and found on histologic examination to be epidermotropic metastatic malignant melanoma.

Adenocarcinoma↗
PubMed1994

Clinical, histologic, and ultrastructural evaluation of tattoos treated with three laser systems.

We examined the response of tattoo pigments treated with three commercially available lasers: Q-switched ruby, Q-Switched neodynium:yttrium,aluminum,garnet (Nd:YAG), and the alexandrite. Tattoos applied to hairless guinea pigs and treated with the aforementioned lasers were evaluated clinically, histologically, and ultrastructurally. Clinical evaluation showed red brown, dark brown, and orange pigment responded best to the Nd:YAG laser (1064 nm). The alexandrite laser was most effective for removing blue and green pigment, the Q-switched ruby laser was most effective for removing purple and violet pigment, and the Nd:YAG laser (532 nm) removed red pigment the best. Black pigment was lightened equally with the Nd:YAG laser (1064 nm) and (532 nm) and the alexandrite laser (755 nm). No clinical scarring was observed; however, some colors turned black after treatment. Histologic and ultrastructural examination showed epidermal and dermal damage to be most evident after treatment with the Nd:YAG laser. Our study shows that certain tattoo pigments respond better to different laser systems.

Aluminum Oxide↗
PubMed1994

Basal cell epithelioma arising from epidermoid cyst.

BACKGROUND: Basal cell epithelioma is a tumor arising from a pluripotential cell found within the basal cell layer of the epidermis or various appendageal structures. OBJECTIVE: We report two cases of basal cell epithelioma arising from the wall of an epidermoid cyst. METHODS AND RESULTS: Review of our files produced two cases of basal cell epithelioma arising from a cyst wall. CONCLUSION: Basal cell epithelioma arising from the wall of an epidermoid cyst is rare. Examination of all cysts removed surgically is important as not to overlook this possibility and to allow close follow-up for potential recurrence.

Adult↗
PubMed1994

Subcutaneous T-cell lymphoma: a clinical, histopathologic, and immunohistochemical study of six cases.

Recently, T-cell lymphoma localized to the subcutaneous tissue has been reported. We report the clinical, histologic, immunohistochemical, and molecular genetic findings in 6 patients who we believe had this peculiar T-cell lymphoma with its unique morphologic and clinical features. All patients presented with deep-seated nodules, most frequently on the extremities, and with systemic complaints of low-grade fever, fatigue, myalgias, and weight loss. In all cases, the neoplastic lymphocytic infiltrate was confined to the subcutaneous tissue, predominantly in a lobular pattern. Hemorrhage, necrosis, and rare erythrophagocytosis were also seen. Immunohistochemical staining was predominantly T-cell reactive (CD43, CD3, and CD45RO). Clonal rearrangements of the beta and gamma chains of the T-cell antigen receptor genes were found in 1 case. Three of the 6 patients died within 22 months of the diagnosis of lymphoma. We believe that subcutaneous T-cell lymphomas are a distinctive group of peripheral T-cell lymphomas with unusual clinical and morphologic features and that they should be distinguished from other types of lymphoma.

Adult↗