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Biomedical subjects

V G Prieto

Publications and source records attributed to V G Prieto.

At least 19 recordsLinked to original sources
PubMed2005

Proven pulmonary cryptococcosis due to capsule-deficient Cryptococcus neoformans does not differ clinically from proven pulmonary cryptococcosis due to capsule-intact Cr. neoformans.

We compared the clinical manifestations, laboratory and radiologic findings, and outcomes of eight patients with proven pulmonary cryptococcosis (PC) caused by capsule-deficient Cryptococcus neoformans with those of six patients with PC caused by capsule-intact Cr. neoformans. The presentations and outcomes did not differ significantly between the groups.

Adult↗
PubMed2001

Down-regulated melanoma differentiation associated gene (mda-7) expression in human melanomas.

The melanoma differentiation associated gene-7 (mda-7) has a potential inhibitory role in melanoma progression, although the mechanisms underlying this effect are still unknown. mda-7 mRNA has been found to be present at higher levels in cultured normal melanocytes compared with metastatic melanoma cell lines. Furthermore, levels of mda-7 message have shown an inverse correlation with melanoma progression in human tumor samples, suggesting that mda-7 may be a novel tumor suppressor gene. We have designed this study to investigate MDA-7 protein expression in different stages of melanoma progression and to examine its antiproliferative effects in vitro. Our data demonstrate that MDA-7 protein can be found in normal melanocytes and early stage melanomas. It is also observed in smooth muscle cells in the skin. However, in keeping with a possible role as a tumor suppressor, MDA-7 expression is decreased in more advanced melanomas, with nearly undetectable levels in metastatic disease. We also investigated antitumor effects of overexpressed MDA-7 on human melanoma cells in vitro. Our results demonstrate that Ad-mda-7 induces apoptosis and G2/M cell cycle arrest in melanoma cells, but not in normal human melanocytes.

Apoptosis↗
PubMed2001

Recurrent melanocytic nevus: a histologic and immunohistochemical evaluation.

BACKGROUND: Recurrent melanocytic lesions may histologically resemble malignant melanoma. METHODS: We evaluated the original nevi (ON) and recurrent nevi (RN) of 15 patients by routine histology and immunohistochemistry (IHC), examining expression of S-100 protein, gp100 (with HMB-45), MART-1, tyrosinase, and the Ki-67 proliferation marker. RESULTS: Compared with ON, RN had a dermal scar, a significantly greater number of melanophages, and a greater extent of cellular atypia including prominent nucleoli and larger cell size. Architecturally, RN showed significantly less symmetry than ON; however, the percentage of junctional cohesive nests, the presence of suprabasal spread, and the degree of confluence were similar between ON and RN. Both ON and RN showed a decrease in expression of gp100 and tyrosinase with increasing depth ("maturation gradient") and low proliferative activity in both the junctional (4.6% for ON vs. 4.13% for RN) and the dermal components (0.93% for ON vs. 1.45% for RN). CONCLUSIONS: RN exhibit a dermal scar, a greater number of melanophages, cytologic atypia, and asymmetry than ON, features that may raise concern about the possibility of malignant melanoma. However, the area with the irregular architectural pattern is restricted to the epidermis and dermis immediately above the scar. In addition, IHC helps to distinguish RN from malignant melanoma; specifically, RN demonstrate an immunohistochemical "maturation pattern" (with HMB-45 and anti-tyrosinase) and a low proliferative index (with Ki-67).

Adolescent↗
PubMed2001

Primary chondroid melanoma.

BACKGROUND: Malignant melanoma is notorious for the wide range of histologic patterns it can assume, among the least frequent of which is chondroid melamona. METHODS: Two cases of primary chondroid melanoma of the distal lower extremity were studied. Tissue for light microscopy was fixed in formalin, embedded in paraffin, and processed routinely. In one case, transmission electron microscopy and immunohistochemical evaluation were performed. RESULTS: Both cases exhibited melanoma in-situ, a conventional (non-chondroid) invasive component, and areas of chondroid differentiation, as confirmed by strongly positive staining with Alcian blue at pH 2.5 and Safranin O. Immunohistochemically, one case expressed S-100 protein and vimentin, and did not express gp100 (HMB-45), tyrosinase, MART-1, the Mel-5 antigen, the NKI/C3 antigen, CD45Ro, cytokeratin, or desmin. Electron microscopy of the chondroid component revealed occasional tumor cells with rare, membrane-bound, electron-dense organelles; the extracellular compartment showed amorphous ground substance consistent with cartilaginous differentiation. CONCLUSIONS: Chondroid change in the absence of osteogenic differentiation is extremely rare in malignant melanoma. Melanoma should be considered in the differential diagnosis of primary cutaneous neoplasms exhibiting cartilaginous differentiation.

Aged↗
PubMed2001

Intrauterine epidermal necrosis.

BACKGROUND: Epidermal necrosis in a neonate is an uncommon event with a variety of potential cases. RESULT: We report a case of intrauterine epidermal necrosis in a preterm infant, with death occurring soon after birth. The histopathology of the denuded skin revealed full-thickness epidermal necrosis and calcification within both the epidermis and follicular structures. CONCLUSION: We believe this represents the fourth reported case of lethal intrauterine epidermal necrosis and follicular calcification.

Epidermis↗
PubMed2001

Reassessment of lymphocytic atypia in the diagnosis of mycosis fungoides.

The manifestations of mycosis fungoides in its early stage may mimic clinically and histologically those of many benign inflammatory dermatoses. Therefore, the diagnosis of mycosis fungoides remains a major challenge for dermatologists and dermatopathologists. For many years, it has been proposed that atypical lymphocytes within the epidermis constitute one of the diagnostic features in mycosis fungoides. Presence of dermal atypical lymphocytes remains controversial as a diagnostic criterion. We reassessed the feasibility of applying lymphocytic atypia within epidermis and dermis as diagnostic criteria discriminating between mycosis fungoides and spongiotic dermatitis. Thirty cases of mycosis fungoides and 30 cases of spongiotic dermatitis were retrieved from archival hematoxylin and eosin-stained histologic sections. Punch biopsy sections were examined by light microscopy; epidermal and dermal lymphocytes were photographed at 1000x (oil immersion). A total of 92 ektachrome slides (35 mM) were developed, coded, and ordered randomly. For each slide, cells were interpreted as typical or atypical lymphocytes by seven pathologists. Atypical epidermal lymphocytes were judged to be present in 9 +/- 2 out of 16 (56%) cases of mycosis fungoides photographed as compared with 8 +/- 3 out of 16 (50%) in spongiotic dermatitis. Dermal lymphocytic atypia was thought to be present in 14 +/- 6 out of 30 (47%) patients with mycosis fungoides. Thirteen +/- 6 out of 30 (43%) patients with non-mycosis fungoides also displayed dermal lymphocytic atypia. No statistical significance was observed in these comparisons (t test, P >.05). Furthermore, atypia of lymphocytes was deemed to be present in 41, 38, 59, 70, 23, 47, and 40 out of 92 slides examined by the investigators, suggesting that observer variation is a very significant factor in our present study. We conclude that it is not possible to distinguish mycosis fungoides from spongiotic dermatitis merely based on lymphocytic atypia within epidermis or dermis.

Dermatitis↗
PubMed2001

A comparative clinical and histologic study of hair transplantation using Er:YAG, Er:YAG/CO2, and standard punch techniques.

BACKGROUND: This study compares the effects of Er:YAG laser alone, Er:YAG/CO2 laser at 5 W (low power), Er:YAG/CO2 at 10 W (high power), and standard punch techniques in 10 men with androgenetic alopecia. OBJECTIVE: To study the clinical and histologic features of hair transplantation with recipient graft defects created by a new hybrid Er:YAG and CO2 laser. METHODS: Ten male patients (mean age 34 y) with Norwood IV-VI androgenetic alopecia had hair replacement surgery with the recipient sites divided into four quadrants comparing cold stell, erbium, combined erbium low-power CO2, and combined erbium high-power CO2 technologies. Hair growth, intraoperative procedure, lateral thermal damage, and patient satisfaction were compared, utilizing each of the four stated technologies. RESULTS: The addition of CO2 laser at both low and high power settings resulted in improved hemostasis when compared with standard punch or Er:YAG laser alone. The mean hair counts were similar for the Er:YAG laser, Er:YAG/CO2 (5 W) laser, and standard punch at both 3 and 6 months after treatment. Lateral thermal damage was not significantly increased by the addition of low-power CO2 to Er:YAG. The addition of high-power CO2 (10 W) laser resulted in slightly lower mean hair counts at 3 months, but significantly decreased at 6 months (P =.05). Also, high-power CO2 laser caused significantly increased lateral damage. There were no detectable differences in hsp70 expression among the groups. CONCLUSION: The addition of 5 W CO2 laser to Er:YAG laser results in better hemostasis than Er:YAG laser alone, while not significantly diminishing mean hair counts or inducing increased lateral thermal damage.

Adult↗
PubMed2001

Evaluation and surgical resection of adrenal masses in patients with a history of extra-adrenal malignancy.

BACKGROUND: Adrenal abnormalities are often identified on imaging studies performed during the staging of patients presenting with a new malignancy or restaging of patients with a history of a malignancy. METHODS: We reviewed the records of patients who underwent surgical resection of an adrenal mass identified in the setting of previously or newly diagnosed extra-adrenal malignancy. RESULTS: Eighty-one patients with an adrenal mass and recently diagnosed malignancy (n = 24) or history of a malignancy (n = 57) underwent adrenalectomy. In 42 patients (52%) the adrenal mass was a metastasis. In 39 patients (48%) the adrenal mass was an additional primary adrenal tumor process: 19 pheochromocytomas, (14 syndrome-associated, 5 sporadic), 13 cortical adenomas, 3 adrenocortical carcinomas, 2 ganglioneuromas, and 2 cases of nodular hyperplasia. CONCLUSIONS: In this series nearly half of the patients with cancer and an adrenal mass had adrenal pathologic condition independent of their primary malignancy. Despite the presence of a newly diagnosed malignancy or history of malignancy, all patients with an adrenal mass should undergo a standard hormone evaluation to confirm that the mass is not a functional neoplasm. An assumption that the adrenal mass is metastatic disease will be wrong in up to 50% of such patients.

Adrenal Gland Neoplasms↗
PubMed2001

Sentinel lymph node biopsy for conjunctival melanoma.

OBJECTIVE: To investigate the feasibility and safety of preoperative lymphoscintigraphy and sentinel lymph node (SLN) biopsy for conjunctival melanoma. METHODS: A 49-year-old man with a biopsy-proven malignant melanoma of the conjunctiva (caruncle) underwent preoperative lymphoscintigraphy and SLN biopsy using a technique in which both isosulfan blue dye and technetium Tc 99 m sulfur colloid were injected in the subconjunctival space around the primary lesion. The conjunctival melanoma was excised just before identification and removal of the SLNs. The SLNs were excised along with concomitant dissection of their associated lymph node basins. The SLNs were evaluated histologically using serial sectioning and immunohistochemical staining with antisera against the S-100 protein and the melanoma antigen HMB-45. RESULTS: Three SLNs were identified in the left submandibular and the left upper and middle jugular lymph node basins during the preoperative lymphoscintigraphy. The same three SLNs were successfully identified in the operating room. The SLNs were histologically negative, and the immunohistochemical staining against S-100 and HMB-45 was also negative. We did not observe any immediate adverse effects on the globe or the periocular structures from lymphatic mapping and SLN biopsy. By 24 hours after injection of blue dye, only a faint trace of blue was visible on the ocular surface. CONCLUSIONS: Preoperative lymphoscintigraphy and SLN biopsy can be performed safely in patients with conjunctival melanoma. A larger study is planned to determine the sensitivity of this technique for the detection of occult regional nodal disease in patients with conjunctival melanoma.

Antigens, Neoplasm↗
PubMed2001

A novel preclinical model of human malignant melanoma utilizing bioreactor rotating-wall vessels.

Malignant melanoma poses a serious health risk which is becoming more crucial as the incidence of this disease steadily increases. The development of appropriate in vitro models that reflect the in vivo tumor environment is a key factor for the study of this malignancy. The local tumor microenvironment plays a critical role in the ability of tumor cells to proliferate and metastasize. While interactions among various cell types are known to be important for tumor growth, most in vitro models utilize only tumor cells, ignoring the importance of tumor-stroma interactions, as well as the contribution of immune cells, which may be important for potential therapies. In addition, the cellular architecture found in vivo, known to be involved in changes in gene expression, is not reflected in standard two-dimensional culture systems. In this study, we have utilized rotating-vessel bioreactors to culture minced human melanoma specimens, allowing the culture of three-dimensional structures which reflect the cellular architecture and heterogeneous composition of the tumor site in vivo. The viability of the pieces in culture can be maintained for 1-2 wk. Immunohistochemical analysis shows multiple cellular types similar to the in vivo situation. Therefore, this system provides a unique model of human melanoma that mimics the in vivo tumor environment much more closely than current culture methods. This novel system may be utilized to determine the mechanism of action of current therapy protocols, as well as to develop new treatment regimens.

Antigens, CD↗
PubMed2001

Clinical and pathophysiologic correlates of 1064-nm Nd:Yag laser treatment of reticular veins and venulectasias.

BACKGROUND: The goal of sclerotherapy, laser therapy, and intense pulsed-light therapy is to produce long-term, cosmetically significant elimination of disfiguring leg veins. This study examines the histologic and clinical effects of using a 1064-nm Nd:YAG laser system on lower extremity vessels. DESIGN: A single treatment using the following parameters: wavelength, 1064 nm (multiple synchronized pulsing); spot size, 6 mm; pulse duration, 14 milliseconds (single pulse); and fluence, 130 J/cm(2). SETTING: Private dermatology practice. PATIENTS: Thirteen women (mean age, 38.5 years) with blue venulectasia, 0.5 to 1.5 mm in diameter (class 2), and reticular veins, 1.5 to 3.0 mm in diameter (class 3), on the thighs. MAIN OUTCOME MEASURES: Examination of treated and untreated areas by 2 masked observers using macrophotography (1, 2, 3, and 6 months after treatment), Doppler, and optical chromatographic changes. Findings from three 2-mm punch biopsies from treated (immediately and 4 weeks after treatment) and untreated sites. Routine histologic examination; special stains (for elastic and connective tissue and for mucopolysaccharides); and immunohistochemical analysis for expression of the heat shock protein hsp70, tie2 (an endothelial cell-specific receptor tyrosine kinase), and transforming growth factors beta1 and beta2. RESULTS: Eight patients (62%) manifested 75% to 100% clearing of treated vessel surface area. Treated areas revealed perivascular hemorrhage, thrombi, fragmentation and homogenization of elastic fibers, and eosinophilia of vessel walls. Expression of hsp70 and transforming growth factor beta was increased in treated vessels. CONCLUSIONS: Our data confirm the effectiveness of 1064-nm Nd:YAG laser treatment in clearing dilated lower extremity veins, probably by heat-induced vessel damage and subsequent fibrosis. Maintenance of clearing was achieved for up to 6 months. However, the presence of recanalized thrombi in some of the specimens suggests the potential for long-term vessel reappearance.

Adult↗
PubMed2000

Long-term photoepilation using a broad-spectrum intense pulsed light source.

BACKGROUND: The goal of laser or flashlamp photoepilation is to produce long-term, cosmetically significant hair removal. We document the long-term efficacy achieved with an intense pulsed light source for photoepilation. DESIGN: Prospective study comparing long-term results of single vs multiple treatments, and effects of anatomic site and skin type on efficacy of photoepilation with a device emitting broad-spectrum, noncoherent (nonlaser) radiation from 550- to 1200-nm wavelengths, in macropulses divided into 2 to 5 minipulses. SETTING: Private dermatology practice. PATIENTS: Thirty-four patients (8 men, 26 women) with hirsutism. INTERVENTIONS: Parameters for the study were wavelength of 615 to 695 nm, pulse duration of 2.6 to 3.3 milliseconds, fluence of 34 to 42 J/cm(2), 10 x 45-mm exposure field, and application of 1 degrees C cooling gel. MAIN OUTCOME MEASURES: Hair removal efficiency, calculated as percentage ratio of the number of hairs present compared with baseline counts, and patient satisfaction questionnaire completed at last follow-up. RESULTS: The mean hair removal efficiency achieved was 76% after a mean of 3.7 treatments. More than 94% of the sites reached mean hair removal efficiency values greater than 50%. Hair removal efficiency was not significantly related to skin type, hair color, anatomic site, or number of treatments. Side effects were mild and reversible and occurred in a minority of patients (hyperpigmentation in 3 and superficial crusting in 2). CONCLUSIONS: Our data document the long-term clinical efficacy of intense pulsed light source-induced hair removal in light and dark skin phenotypes. Maximal photoepilation was achieved from the initial 1 to 3 treatments; only a small added benefit was seen after more treatments.

Adolescent↗
PubMed2000

Utility of step sections: demonstration of additional pathological findings in biopsy samples initially diagnosed as actinic keratosis.

OBJECTIVES: To discover additional diagnostic findings on step sections of biopsy samples showing features of actinic keratosis on the initial section and to correlate such findings with clinical and histological variables. DESIGN: Prospective study comparing initial histological findings with those noted on deeper tissue levels. SETTING: University-based dermatopathology practice. PATIENTS: Fifty-seven patients (36 men and 21 women) with biopsy samples from 69 skin lesions. MAIN OUTCOME MEASURES: Identification of additional pathological diagnoses in step sections and correlation with clinical diagnosis, size and location of lesion, history of skin cancer or immunosuppression, size and handling of specimen, and presence of ulceration on the initial level. RESULTS: Additional diagnostic findings were present on step sections in 23 specimens (33%), including 9 (13%) with squamous cell carcinoma in situ, 3 (4%) with basal cell carcinoma, and 2 (3%) with invasive squamous cell carcinoma. Three variables were significantly correlated with the discovery of cancer on step sections: (1) ulceration on the first level, (2) clinical diagnosis of skin cancer, and (3) history of skin cancer diagnosed by biopsy examination. The latter 2 variables were also correlated with the discovery of any additional finding, whether benign or malignant, on step sections. CONCLUSIONS: In biopsy samples initially diagnostic of actinic keratosis, examination of step sections contributes clinically important information. Step sections are particularly useful when a clinical diagnosis of skin cancer is present. The results of this study confirm the pathogenetic importance of actinic keratosis as a precursor to fully evolved malignant neoplasia and suggest that such lesions merit thorough histological study.

Adult↗
PubMed2000

Expression of the intermediate filament peripherin in extraskeletal myxoid chondrosarcoma.

The embryologic histogenesis of cartilage is not well characterized. While cranial cartilage is believed to be derived from pluripotential precursor cells of the neural crest, chondrocytes found elsewhere in the body are thought to be derived from mesoderm. As such, soft tissue tumors with cartilaginous differentiation may be related to neural crest or mesoderm. Peripherin is an intermediate filament encoded on chromosome 12, involved in growth and development of the peripheral nervous system. Peripherin is apparently expressed exclusively in cells derived from the neural crest and neural tube. A group of six soft tissue tumor types was selected because they are either of controversial differentiation or cytogenetically related to chromosome 12. A total of 41 cases was evaluated with antibodies against the intermediate filament peripherin. A panel of neural and neuroendocrine differentiation markers was used in selected cases. Three of five extraskeletal myxoid chondrosarcomas showed strong cytoplasmic reactivity with anti-peripherin. No peripherin expression was noted in any of eleven epithelioid sarcomas, eight liposarcomas, seven conventional chondrosarcomas, four neurothekeomas, three alveolar soft part sarcomas, or three clear cell sarcomas. The finding of peripherin expression in some extraskeletal myxoid chondrosarcomas may suggest the ability of some tumors to demonstrate both neural and chondroid differentiation.

Adolescent↗