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M W Lee

Publications and source records attributed to M W Lee.

At least 37 records · Page 2Linked to original sources
PubMed2001

Histologic and histochemical characterization of seminal vesicle intraluminal secretions.

CONTEXT: We have observed intraluminal crystalloid morphology in seminal vesicles that is superficially similar to that seen in prostate neoplasia, but found little information on such morphology in the literature. DESIGN: Two hundred fifty-three prostate specimens (163 needle biopsies, 75 radical prostatectomies with prostate carcinoma, 11 prostates from autopsy, and 4 cystoprostatectomies without prostate carcinoma) were examined for seminal vesicle secretions, which were categorized as (a) dense platelike inspissated, (b) fluidlike, (c) crystalloid morphology, and (d) absent. Histochemical stains (periodic acid-Schiff with and without diastase, Alcian blue at pH 2.5, and mucicarmine) were performed to characterize the nature of secretions. RESULTS: Proteinaceous secretions were identified in 82% of seminal vesicles examined. Of these, 61% had predominantly dense, platelike, inspissated secretions, 15% had predominantly fluidlike secretions, and 24% had predominantly crystalloid morphology. Although in some cases the crystalloid morphology resembled that of prostatic intraluminal crystalloids, the seminal vesicle crystalloids differed in that they were invariably multiple, had curved edges, and had varied forms (elliptical, cylindrical, rodlike, and rectangular). Seventy-one percent of seminal vesicle crystalloids were associated with dense, platelike, inspissated secretions and appeared to be created by fracturing within platelike secretions. There was no relationship between seminal vesicle crystalloid morphology and associated malignancy in the prostate gland, as it was seen in 24% of cases with prostate carcinoma and 25% of cases without prostate carcinoma (P = 1.0000). Fluidlike secretions were positive for Alcian blue (pH 2.5) and mucicarmine, whereas dense platelike secretions and crystalloid morphology were negative for Alcian blue (pH 2.5) and mucicarmine. CONCLUSIONS: Seminal vesicle secretions are fairly common and, when fluidlike, are composed of acid mucopolysaccharides. Inspissation of secretions appears to be associated with loss of acidity, presumably resulting in dense platelike secretions and crystallization. Awareness of both the crystalloid morphology in seminal vesicle tissue and the distinguishing features from prostatic crystalloids may be important while interpreting prostate needle biopsies in which seminal vesicle epithelium may be confused for prostate carcinoma because of a small acinar morphology with accompanying cytologic atypia and crystalloid morphology.

Biopsy, Needle↗
PubMed2001

Renal angiomyolipoma: further immunophenotypic characterization of an expanding morphologic spectrum.

BACKGROUND: Renal angiomyolipoma is a benign tumor histologically characterized by proliferation of spindle cells, epithelioid cells, and adipocytic cells in concert with many thick-walled blood vessels. To add further diagnostic confusion, an epithelioid cell-predominant variant of renal angiomyolipoma has recently been described. HMB-45 immunoreactivity correlates with ultrastructural striated organelles that closely resemble premelanosomes, although no evidence of melanogenesis has been documented in this tumor. OBJECTIVE: To further characterize the immunophenotypic and ultrastructural profile of renal angiomyolipoma based on phenotypic cell type (epithelioid, spindle, and adipocytic cell). DESIGN: Formalin-fixed, paraffin-embedded tissues from 27 renal angiomyolipomas and 8 renal cell carcinomas were immunostained with monoclonal antibodies to the melanoma-associated antigens HMB-45, HMB-50, NKI/C3 (CD63), and tyrosinase; the smooth muscle-related antigens calponin and muscle-specific actin (HHF-35); S100; and cytokeratin (CK). All renal angiomyolipomas were also immunostained with a polyclonal antibody to renin. Ultrastructural examination was performed on 9 selected cases. RESULTS: All renal angiomyolipomas stained positive for HMB-45, HMB-50, NKI/C3, muscle-specific actin (HHF-35), and calponin. Overall, HMB-45, HMB-50, and NKI/C3 preferentially stained the epithelioid cells. Tyrosinase staining was present in 50% of the renal angiomyolipomas with adequate tissue for staining (12 of 24 cases); positive staining and intensity paralleled HMB-45, HMB-50, and NKI/C3. Muscle-specific actin (HHF-35) and calponin preferentially stained the spindle cells. The adipocytic cells stained positive for both melanoma-associated antigens and smooth muscle antigens. Epithelioid cells, spindle cells, and adipocytic cells were CK, S100, and renin negative. Ultrastructural findings paralleled immunohistochemical staining patterns. Premelanosome-like organelles and electron dense granules were more readily detected in the epithelioid cells within the tumor, whereas ultrastructural characteristics of smooth muscle cells were more easily found in the spindle cells. All renal cell carcinomas stained positive for CK, NKI/C3 staining was variable, and all were negative for HMB-45, HMB-50, smooth muscle actin (HHF-35), and calponin. CONCLUSION: In renal angiomyolipoma, the epithelioid and spindle cells have preferential staining patterns for melanoma-associated antigens versus smooth muscle antigens, respectively. Positivity in renal angiomyolipoma for HMB-50, NKI/C3, and tyrosinase, in addition to HMB-45, provides evidence for the presence of different melanoma-associated gene products. Immunophenotypic overlap of the 3 histologically distinct renal angiomyolipoma cell populations suggests a common cell line, supporting a unitarian concept for renal angiomyolipoma. Ultrastructural characteristics of the 3 renal angiomyolipoma cell phenotypes parallel the immunophenotype, giving further support to a common cell line. Our study lends further credence to the perivascular epithelioid cell concept as proposed by Bonetti and colleagues.

Actins↗
PubMed2001

Diltiazem-associated photodistributed hyperpigmentation: a review of 4 cases.

BACKGROUND: Diltiazem hydrochloride is a widely used calcium channel blocking agent. While a few cases of diltiazem-associated photosensitivity have been reported, no cases of photodistributed hyperpigmentation are known. OBSERVATION: Four cases of photodistributed hyperpigmentation associated with the long-acting formulation of diltiazem hydrochloride (Cardizem CD) are presented. All patients were African American women, with a mean age of 62 years. The mean duration of diltiazem administration prior to the development of hyperpigmentation was 8 months. The hyperpigmentation was slate-gray and reticulated. Phototesting during diltiazem therapy revealed a decreased minimal erythema dose to UV-A in 1 patient. Histopathologic examination showed lichenoid dermatitis with prominent pigmentary incontinence. Electron microscopic examination of the tissue revealed multiple melanosome complexes. Discontinuation of diltiazem therapy resulted in the gradual resolution of the hyperpigmentation. CONCLUSIONS: Long-term administration of diltiazem may be associated with characteristic reticulated, slate-gray hyperpigmentation on sun-exposed areas. Discontinuation of the therapy results in resolution of the eruption.

Aged↗
PubMed2001

Patterns of chemotherapy administration in patients with intermediate-grade non-Hodgkin's lymphoma.

Records from 653 patients treated between 1991 and 1998 in the Oncology Practice Patterns Study (OPPS) were analyzed to determine contemporary chemotherapy delivery patterns in patients with intermediate-grade non-Hodgkin's lymphoma (NHL). Of the 653 patient records reviewed, 90 (14%) omitted an anthracycline or mitoxantrone (Novantrone) from primary therapy. Among patients receiving CHOP (cyclophosphamide [Cytoxan, Neosar], doxorubicin HCl, vincristine [Oncovin], prednisone) or CNOP (cyclophosphamide, mitoxantrone, vincristine, prednisone), 134 (27%) of 492 received an average relative dose intensity of less than 80% of the literature-referenced dose, due either to an inadequate planned or delivered dose. Of 181 advanced-stage patients with responsive disease, 28 (15%) failed to receive at least six treatment cycles. Overall, 283 (43%) of 653 patients potentially received suboptimal chemotherapy due either to choice of regimen or chemotherapy delivered. Patient age > or = 65 years and cardiac comorbidity appeared to have the greatest influence on a physician's decision regarding chemotherapy administration. Among the 492 patients who received CHOP or CNOP, 235 (48%) experienced a delay or reduction in chemotherapy dose (usually neutropenia-related), 100 (20%) developed mucositis, and 116 (24%) were hospitalized for febrile neutropenia. Growth factor was administered to 261 patients (53%), and its primary prophylactic use was associated with a significant reduction in the incidence of hospitalizations for febrile neutropenia in all patient subgroups receiving appropriate chemotherapeutic dose intensity (P = .02). This assessment of chemotherapy delivery to patients with intermediate-grade NHL showed significant variation from current standards. Further analysis of factors influencing chemotherapy delivery might improve therapeutic outcomes.

Adolescent↗
PubMed2000

Diarylheptanoids from the leaves of Alnus hirsuta Turcz.

Diarylheptanoids, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane-3-one (1, hirsutanonol), (5S)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-one-5-O-beta-D-xylopyranosi de (2, oregonin), (5R)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-beta-D-xylopyranoside (3), and (5R)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-beta-D-glucopyranoside (4) were isolated from the leaves of Alnus hirsuta Turcz. The structures of these compounds were identified based on the spectral and physicochemical data.

Korea↗
PubMed2000

Antioxidative phenolic compounds from the roots of Rhodiola sachalinensis A. Bor.

The acetone extract of the roots of Rhodiola sachalinensis has furnished six phenolic compounds which exhibited significant scavenging effects against DPPH free radical. The structures of these compounds were identified and determined as gallic acid (1), (-)-epigallocatechin 3-O-gallate (2), kaempferol (3), kaempferol 7-O-alpha-L-rhamnopyranoside (4), herbacetin 7-O-alpha-L-rhamnopyranoside, (5) and rhodiolinin (6) by physico-chemical and spectral evidences.

Antioxidants↗
PubMed2000

Genetic changes in sweat gland carcinomas.

The molecular pathogenesis of malignant appendageal tumors is poorly understood. Immunohistochemical staining, polymerase chain reaction (PCR)-based loss of heterozygosity (LOH) and sequencing analyses were performed in a mixed group of 21 sweat gland carcinomas. LOH was mostly confined to the chromosome arm 17p. None of the remaining 17 tumors showed LOH at any loci. Nuclear accumulation of p53 protein was observed in 3 tumors, all of which also showed LOH of 17p. One eccrine gland adenocarcinoma showed allelic loss of 17p and a Cys 176 Arg mutation in the p53 gene. The other three tumors that showed LOH of 17p, however, had wild-type p53 genes. A clear transition from benign eccrine poroma to porocarcinoma that was associated with p53 protein stabilization and allelic loss was observed in one tumor. One eccrine porocarcinoma/undifferentiated adnexal carcinoma showed prominent microsatellite instability, probably reflecting an underlying defect in DNA mismatch repair. Overexpression of erbB-2 was observed in three tumors. The low frequencies of LOH and p53 alterations in sweat gland carcinomas contrasted with the multiple genetic defects normally observed in cutaneous squamous cell carcinomas, and may be partly explained by the relative protection of cutaneous appendages from ultraviolet light and other environmental mutagens.

Adenocarcinoma↗
PubMed2000

Linear eruptions of the nose in childhood: a form of lichen striatus?

We report four children with linear eruptions on the nose, with overlapping features of lichen striatus and linear cutaneous lupus erythematosus. However, linear lupus erythematosus has rarely been reported, and lichen striatus, although classically linear, rarely affects the face. The linear distribution of lesions from the glabella to the ala nasi may represent distribution following Blaschko's lines.

Adolescent↗
PubMed2000

Diarylheptanoids with in vitro inducible nitric oxide synthesis inhibitory activity from Alnus hirsuta.

Four diarylheptanoids were isolated from the leaf of Alnus hirsuta (Betulaceae) and have been assessed for nitric oxide (NO) production inhibitory effects in vitro. Oregonin (1) and hirsutanonol (2) were found to be potent inducible nitric oxide synthase (iNOS) inhibitors. Compounds 1 and 2 showed inhibition of NO synthesis in dose-dependent manners by murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). Their 50% inhibitory concentrations (IC50) were 3.8 and 14.3 microM, respectively. The inhibitory effects of these compounds on NO synthesis were due to suppression of iNOS mRNA expression as determined by Northern blotting.

Animals↗
PubMed2000

New paradigm, new market and new theatre in ergonomics.

Change is the only constant in today's technology-driven world. As industry moves towards an unprecedented revolution, the momentum and impact of the change are both rapid and profound. This will affect our profession drastically. We will need to redefine our goals and strategies to cope with these new challenges. In this paper, a new paradigm of thinking, a new market for our discipline and a new theatre of ergonomics in the future are proposed and explained.

Ergonomics↗
PubMed2000

Phakomatous choristoma: a case report and review of the literature.

Phakomatous choristoma is a rare congenital lesion of the eyelid that can be clinically and/or histologically mistaken for a cyst, cutaneous adnexal neoplasm, or an ocular adnexal oncocytoma. Only 13 such cases have been previously described, mostly in the English language ophthalmic literature. Zimmerman reported the first case in 1971 and proposed the lesion to be of lenticular anlage origin, a theory that has been widely accepted. We report an additional case occurring in an 8-week-old male infant with a firm nodule of the right lower eyelid that was present since birth. A 15 x 12 x 2 mm circumscribed solid nodule with a homogenously white cut surface was surgically excised. Histologically, this lesion was comprised of cuboidal cells forming cystically dilated and irregularly branched ducts and cords within a densely fibrotic stroma. Also present were eosinophilic basement membranelike material, psammoma body-like calcifications and intraluminal degenerated ghost cells. The immunohistochemical profile of the epithelial cells included strong immunoreactivity for vimentin, focal weak staining for S-100, and negative staining for cytokeratin, epithelial membrane antigen, synaptophysin, and chromogranin. The irregularity of the ducts and cords of epithelial cells within the densely fibrotic stroma resembled an infiltrative neoplasm of cutaneous adnexal or lacrimal duct origin. However, the site of involvement, the peculiar basement membrane material, ghost cells, and immunohistochemical profile were features that helped to distinguish phakomatous choristoma from an infiltrative carcinoma. The correct identification of this lesion is essential to avoid an aggressive surgical excision, thus sparing the eyelid and lacrimal system. The purpose of this article is to bring attention to this rare entity, because it has not been described in either the dermatology or dermatopathology literature and furthermore, is not mentioned in any of the major dermatopathology texts.

Choristoma↗
PubMed2000

Ultrastructural observations on mitochondria and microvesicles in renal oncocytoma, chromophobe renal cell carcinoma, and eosinophilic variant of conventional (clear cell) renal cell carcinoma.

On light microscopic examination, the morphologically overlapping features of granular eosinophilic cytoplasm in renal oncocytoma and the eosinophilic variants of chromophobe renal cell carcinoma and conventional (clear cell) renal cell carcinoma may pose difficulties in diagnosis. We investigated the ultrastructure of 5 renal oncocytomas, 7 eosinophilic variants of chromophobe renal cell carcinoma, and 5 eosinophilic variants of conventional (clear cell) renal cell carcinoma. Special attention was paid to mitochondria and microvesicles and interrelations thereof. The electron microscopic features were correlated with the light microscopic findings. All of the tumors had abundant mitochondria. Although abundant microvesicles were present in all of the chromophobe renal cell carcinomas, scant numbers of microvesicles were also sometimes present in renal oncocytomas (2 of 5) and in the eosinophilic variant of conventional (clear cell) renal cell carcinoma (1 of 5). The mitochondria in all three types of renal neoplasms studied differed in morphology, being predominantly uniform and round with predominantly lamellar cristae in renal oncocytoma, variable in shape and size with predominantly tubulocystic cristae in chromophobe renal cell carcinoma, and swollen and pleomorphic with rarefied matrix and attenuated cristae in the eosinophilic variant of conventional (clear cell) renal cell carcinoma. Variable numbers of mitochondria in all of the chromophobe renal cell carcinomas had outpouchings of the outer membranes, some of which carried parts of inner membrane within them. These outpouchings closely resembled the nearby cytoplasmic microvesicles, as did the tubulocystic cristae of the mitochondria. Some microvesicles contained homogeneous, electron-dense, finely granular matrix, similar to that seen in mitochondria. In one of seven chromophobe renal cell carcinomas, microvesicles were present in rough endoplasmic reticulum, and in two others, mitochondria were present within some vesicles. These features strongly suggest a close relationship between the microvesicles and mitochondria. Based on the role of vesicle formation in normal mitochondriogenesis, and some of our observations, we propose that defective mitochondriogenesis may be the source of microvesicles in chromophobe renal cell carcinomas.

Adenocarcinoma, Clear Cell↗
PubMed2000

Hyalinizing Spitz nevus.

A seventeen-year-old Korean girl had a reddish-brown papular lesion on the nose. Histopathologically, it proved to be a "hyalinizing Spitz nevus" with the characteristic features of a discohesive growth pattern of nevus cells and hyalinized stroma. Immunohistochemical stains showed positive reactivity of nevus cells with S-100 protein and Vimentin and negative stainings with HMB45, CD68, CEA and low molecular weight cytokeratin. Hyalinizing Spitz nevus may represent a variant in the spectrum of Spitz nevus.

Adolescent↗
PubMed2000

Effect of vitamin D nutrition on parathyroid adenoma weight: pathogenetic and clinical implications.

In primary hyperparathyroidism, adenoma size is a major determinant of disease severity and manner of presentation, but the reason for the large variation in size (>100-fold) is unknown. One factor could be the level of vitamin D nutrition, because in India, where vitamin D deficiency is endemic, adenomas are larger and the disease more severe than in the U.S. Accordingly, we determined the relationship between vitamin D nutrition, as measured by serum levels of 25-hydroxyvitamin D (25OHD), and parathyroid gland weight, expressed on a logarithmic scale, in 148 U.S. patients with primary hyperparathyroidism. A significant inverse relationship was found between log gland weight as dependent variable and serum 25OHD as independent variable (r = -0.365; P < 0.0001). The only other influence on gland weight was a weak inverse correlation with age. Log gland weight as an independent variable was significantly related to adjusted calcium, PTH, and alkaline phosphatase (AP) as dependent variables. In 51 patients with serum 25OHD levels less than 15 ng/mL, gland weight, PTH, AP, and adjusted calcium were each significantly higher than in 97 patients with 25OHD levels of 15 ng/mL or more, but 1,25-dihydroxyvitamin D levels were similarly increased in both groups. In the former group the response of adjusted calcium to PTH was blunted, and the response of AP was enhanced, based on significant differences in regression slopes (P = 0.0004 and 0.0022, respectively). Suboptimal vitamin D nutrition stimulates parathyroid adenoma growth by a mechanism unrelated to hypocalcemia or 1,25-dihydroxyvitamin D deficiency and reduces the calcemic response to PTH, so that a higher PTH level and more parathyroid cells are needed to raise the patient's serum calcium to the level corresponding to the increased set-point that is characteristic of the disease. Improved vitamin D nutrition in the population is partly, perhaps largely, responsible for the historical changes in disease severity and manner of presentation that have occurred over the last 50 yr.

Adenoma↗
PubMed2000

Inhibition of cyclooxygenase-2 expression by diarylheptanoids from the bark of Alnus hirsuta var. sibirica.

Two known diarylheptanoids, oregonin (1), (5S)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-one-5-O-beta-D-xylopyranosi de and hirsutanonol (2), (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane-3-one isolated from the bark of Alnus hirsuta var. sibirica, showed significant inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cyclooxygenase-2 (COX-2) expression in immortalized human breast epithelial MCF10A cells.

Cell Line, Transformed↗
PubMed1999

Cutaneous extravascular necrotizing granuloma (Churg Strauss granuloma).

Churg Strauss granuloma (cutaneous extravascular necrotizing granuloma) is a distinct entity which is associated with systemic immunoreactive or autoimmune diseases in a majority of cases. Typically, Churg Strauss granuloma presents as symmetrical papules or nodules on the extremities. There are two histological patterns: the classic pattern reveals palisading granuloma with central degenerated collagen, interspersed polymorphonuclear leukocytes, and leukocytoclastic debris; the focal basophilic necrosis pattern does not show palisading granuloma. We report two cases of Churg Strauss granuloma with different histopathological patterns.

Adult↗