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Biomedical subjects

B R Nelson

Publications and source records attributed to B R Nelson.

At least 19 recordsLinked to original sources
PubMed1996

A comparison of wire brush and diamond fraise superficial dermabrasion for photoaged skin. A clinical, immunohistologic, and biochemical study.

BACKGROUND: Superficial dermabrasion has a proven beneficial effect on photoaged skin, but little is known about the differences between the two major modalities used in dermabrasion, the diamond fraise (DF) and the wire brush (WB). OBJECTIVE: We compared the clinical, immunohistologic, and biochemical changes after superficial dermabrasion with DF and WB. METHODS: Eight photoaged patients (mean age, 68 years; range, 49 to 80 years) underwent facial dermabrasion to the level of the papillary dermis. Clinical assessments were performed at baseline and at 3 and 12 weeks after dermabrasion. Biopsy specimens were taken from both dermabraded halves at the same time points and assessed by routine histologic and immunohistologic examinations, western blot analysis, and radioimmunoassay. Scoring of intracellular and extracellular transforming growth factor-beta 1 was based on a semiquantitative ordinal scale (0 = no staining to 4 = maximum staining) in half-unit increments. The score for each specimen represents the average of values obtained from four high-power fields. RESULTS: Both methods of dermabrasion resulted in significant resolution of actinic keratoses, lentigines, and wrinkling. No statistical significance was noted between the two methods in regard to clinical efficacy. Significantly fewer milia occurred after DF than after WB. Solar elastosis decreased with both the WB and DF. Immunohistologic examination demonstrated a highly significant increase in papillary dermal fibroblast staining for amino terminal procollagen I (type I pN-collagen) at 3 weeks for both DF and WB compared to baseline. Staining at 12 weeks had decreased from the peak noted at week 3, but was still significantly increased from baseline. Western blotting of type I pN-collagen demonstrated a 5.4-fold (p = 0.01) increase from baseline at 3 weeks and a 4.9-fold (p = 0.002) increase at 12 weeks after dermabrasion with the WB. Similarly, the DF produced a 4.9-fold (p = 0.006) increase at 3 weeks and a 5.1-fold (p = 0.008) increase at 12 weeks after dermabrasion. Western blotting of amino terminal procollagen III (type III pN-collagen) showed a 6.1-fold (p = 0.07) increase from baseline at 3 weeks and a 3.9-fold (p = 0.04) increase at 12 weeks after dermabrasion with the DF. The WB showed a 3.8-fold (p = 0.07) increase from baseline at 3 weeks and a 5.1-fold (p = 0.05) increase at 12 weeks. Transforming growth factor-beta 1 demonstrated a significant increase in extracellular staining with DF (3.3 +/- 0.2) and WB (3.7 +/- 0.2) from baseline (1.2 +/- 0.2, p < 0.001) at 3 weeks. CONCLUSION: Superficial dermabrasion with DF and WP appears to be similarly efficacious in the treatment of photoaged skin. Significant increases in type I pN-collagen, type III pN-collagen, and TGF-beta 1 occurred in the papillary dermis after both types of dermabrasion. These results suggest that increased fibroblast activity and consequent collagen I and III synthesis underlie the clinical improvement.

Aged↗
PubMed1995

The importance of maintaining the alar-facial sulcus in nasal reconstruction.

The alar-facial sulcus is an important topographical region because it represents a junctional zone of three cosmetic units: the nasal base, the medial aspect of the cheek, and the upper lip. Too often, the sulcus is violated by transposition flaps that have been harvested from the cheek to reconstruct defects of the nasal-alar lobule. When the sulcus is violated by surgery, it is difficult to restore a completely natural appearance. For this reason, we suggest an alternative method of reconstructing the alar lobule through the use of an interpolated flap. When defects extend into the alar-facial sulcus, reconstruction of the sulcus is necessary and should be accomplished with a separate skin flap from that used to repair the nasal component of the defect. When a single flap is used to reconstruct both lobule and sulcus, restoration of a completely natural-appearing sulcus is rarely achieved and usually involves multiple surgical procedures often facilitated by aggressive flap contouring, secondary intention healing, and Z-plasty. We describe our methodology in restoring the alar-facial sulcus after nasal reconstruction.

Female↗
PubMed1995

The Rieger flap for nasal reconstruction.

OBJECTIVE: To repair surgical defects of the middle and distal third of the nose. DESIGN: The anatomic and technical design of the Rieger (dorsonasal) flap is described. CONCLUSION: When performed on properly selected patients, the Rieger flap is an aesthetically predictable, one-stage procedure.

Humans↗
PubMed1995

Sebaceous carcinoma.

Sebaceous carcinoma is a rare, aggressive, malignant tumor derived from the adnexal epithelium of sebaceous glands. It may arise in ocular or extraocular sites and exhibits such a variety of histologic growth patterns and diverse clinical presentations that the diagnosis is often delayed for months to years. We discuss incidence as well as clinical, histologic, diagnostic, prognostic, and management issues of this aggressive neoplasm.

Adenocarcinoma, Sebaceous↗
PubMed1995

Pilot histologic and ultrastructural study of the effects of medium-depth chemical facial peels on dermal collagen in patients with actinically damaged skin.

BACKGROUND: Chemical peels are employed for a variety of benign and premalignant skin disorders. OBJECTIVE: We compared clinical and histologic features with ultrastructural changes that occur after medium-depth chemical facial peel. METHODS: Three men with actinically damaged facial skin underwent a single 35% trichloroacetic acid peel. Biopsy specimens were taken before the peel, and 2 weeks and 3 months after the peel, for histologic examination, electron microscopy, and gel electrophoresis to assess total collagen type I content. RESULTS: Clinical resolution of actinic damage corresponded with restoration of epidermal polarity. Collagen type I was markedly increased after the peel. Characteristic ultrastructural features of skin after peeling include markedly decreased epidermal intracytoplasmic vacuoles, decreased elastic fibers, and increased activated fibroblasts. CONCLUSION: Electron microscopic studies after a medium-depth chemical peel of photodamaged skin reveal more profound changes than those seen histologically.

Aged↗
PubMed1995

The role of dermabrasion and chemical peels in the treatment of patients with xeroderma pigmentosum.

We describe our experience with two patients with xeroderma pigmentosum who underwent periodic trichloroacetic acid chemical peels. One also received a full-face dermabrasion. The effect of chemical peeling was more transient than dermabrasion but was associated with less morbidity. Both chemical peeling and dermabrasion provided a prophylactic effect against the development of skin malignancies; the latter had a more pronounced effect.

Adolescent↗
PubMed1995

Current therapy for cutaneous melanoma.

We review the current therapy for melanoma. The diagnosis, prognostic variables, staging, treatment, and follow-up guidelines for cutaneous melanoma are reviewed from the earliest to the most advanced stages. New guidelines for margins are discussed. A new, evolving, innovative radiographic technique, positron emission tomography using 2-fluorine-18-fluoro-2-deoxy-D-glucose, may be useful to identify subclinical nodal and visceral disease. Recent advances with respect to tumor vaccines, gene therapy, immunotherapy, and interleukin 2 as well as current concepts regarding lymph node dissection are discussed.

Humans↗
PubMed1994

Technical aspects of prolonged scalp expansion.

Tissue expansion offers the reconstructive surgeon a better option than the conventional methods of skin grafts or the transfer for non-hair-bearing, regional or microsurgical flaps for reconstructing large defects that cannot be repaired with adjacent hair-bearing flaps. Aspects of preoperative planning and technical factors of scalp expansion are presented to assist the clinician in managing these difficult reconstructive challenges.

Adolescent↗
PubMed1994

Increased expression of stromelysin-3 in basal cell carcinomas.

We examined the expression of two groups of matrix metalloproteinases (MMPs), stromelysin and interstitial collagenase, in human skin cancer by northern blot analysis and in situ hybridization. Stromelysin-3 (ST-3) mRNA was overexpressed more than tenfold in 17 of 19 (89%) specimens of basal cell carcinoma (BCC) but in only three of 13 (23%) cutaneous squamous cell carcinomas (SCCs). Stromelysin-1 and -2 (ST-1/2) mRNA was overexpressed in three of 19 (16%) BCC and three of 13 (23%) SCC. Collagenase mRNA was overexpressed in nine of 19 (47%) BCC and three of 13 (23%) SCC. No mRNA for ST-3, ST-1/2, or collagenase was detected by northern analysis in 21 specimens of adjacent normal skin. Because of these findings, we examined the specific location of the ST-3 mRNA in BCC specimens by in situ hybridization. ST-3 mRNA was particularly abundant in the characteristic stroma adjacent to the invasive basaloid tumor islands of the BCC and absent in the malignant cells. Moreover, ST-3 mRNA was expressed and induced by phorbol ester treatment in adult dermal fibroblasts but not in keratinocytes. In vitro studies have shown that MMPs are involved in the degradation of extracellular matrix molecules. Our finding of ST-3 mRNA overexpression in 17 of 19 (89%) BCC specimens is consistent with a role for this molecule in local invasion of stroma by BCC. Our in situ hybridization data suggested that while ST-3 is not expressed by malignant basal cells themselves, these tumor cells may induce the expression of ST-3 in adjacent nonmalignant stromal elements such as fibroblasts.

Blotting, Northern↗
PubMed1994

Increased expression of matrix metalloproteinase-3 (stromelysin-1) in cultured fibroblasts and basal cell carcinomas of nevoid basal cell carcinoma syndrome.

Nevoid basal cell carcinoma syndrome (NBCCS), an autosomal dominant disorder, is characterized by the development of numerous cutaneous basal cell carcinomas (BCCs). To better characterize this disorder, we examined the expression of matrix metalloproteinase-3 (MMP-3; also known as stromelysin-1) in BCC tumor specimens, adjacent normal skin, and fibroblasts isolated from the normal-appearing skin of NBCCS patients. Three of three BCC tumors obtained from NBCCS patients overexpressed MMP-3 mRNA. In contrast, only 25% of BCC specimens in patients without NBCCS demonstrated overexpression of MMP-3 mRNA. Moreover, fibroblasts isolated and cultured from all nine uninvolved skin specimens of NBCCS patients overexpressed MMP-3 mRNA. MMP-3 mRNA was not detected or was detected at very low levels in normal skin and fibroblast cultures isolated from normal skin in nonsyndrome patients.

Amino Acid Isomerases↗
PubMed1994

Unusual basal cell carcinomas.

The typical features of basal cell carcinoma are well recognized. However, manifestations of uncommon and unusual basal cell carcinomas are less well known. In this review, unusual basal cell carcinomas are described based on their clinical characteristics, histologic appearance, behavior, and treatment.

Age Factors↗
PubMed1994

Clinical improvement following dermabrasion of photoaged skin correlates with synthesis of collagen I.

BACKGROUND AND DESIGN: The ability of superficial dermabrasion to improve clinical features of photoaged skin is well known, but the specific biological mechanisms involved are poorly understood. The so-called repair zone, as visualized by routine histologic examination, has been attributed to new collagen formation within the papillary dermis and may be responsible for clinical improvement following dermabrasion. We investigated molecular and histologic events occurring in dermabraded skin and correlated them with clinical improvement. Ten photoaged patients (mean age, 59 years) underwent facial dermabrasion to the level of the papillary dermis. Clinical severity of photoaging was graded in a blinded manner at baseline and 12 weeks after dermabrasion. Biopsy specimens obtained at baseline and 3 and 12 weeks after dermabrasion were analyzed histologically and by in situ hybridization for fibroblast procollagen I mRNA, immunohistologically and by Western blotting with a monoclonal antibody specific for the aminoterminal cleavage site of procollagen I. RESULTS: Masson's trichrome staining demonstrated an increase in collagen from baseline (as an upper dermal band in the dermabrasion "repair zone") at 3 and 12 weeks' postdermabrasion. Immunohistologic examination demonstrated papillary dermal fibroblast staining for procollagen I at baseline that increased by threefold at 3 weeks' postdermabrasion and by 1.5-fold at 12 weeks' postdermabrasion. Western blotting demonstrated an average-fold increase in pN collagen I of 4.2 +/- 1.5 at 3 weeks and of 2.7 +/- 0.7 at 12 weeks. By in situ hybridization, baseline levels of procollagen I mRNA in papillary dermal fibroblasts increased sixfold at weeks 3 and 12 postdermabrasion. Increase in procollagen I mRNA correlated with clinical improvement, ie, reduction in wrinkling. CONCLUSION: Superficial dermabrasion clinically improves photoaged skin, and this improvement correlates strongly with increased collagen I gene expression.

Aged↗
PubMed1994

Basic suture materials and suturing techniques.

There is a need for surgeons to be able to make a logical decision regarding which suture materials to use in a given clinical situation because the choice of wound-closure materials may make a difference in wound healing and the ultimate functional and cosmetic result obtained. This article will review the basic physical, handling, and tissue-reaction characteristics of commonly used suture materials. Basic suturing techniques are also reviewed. Knowledge of multiple suturing techniques provides versatility, individuality, and optimal closure of surgical wounds.

Absorption↗
PubMed1993

Merkel cell carcinoma.

Merkel cell carcinoma is a malignant neuroendocrine tumor with features of epithelial differentiation. Biologically aggressive, it may be difficult to diagnose and, particularly in its late stages, even more difficult to treat effectively. This article addresses what is known and what is still controversial about the histogenesis, diagnosis, and management of Merkel cell carcinoma and the structure and function of the Merkel cell from which it is believed to be derived. The incidence, clinical presentation and diagnosis, ultrastructure, immunocytochemistry, treatment, and prognosis of this tumor will be discussed.

Carcinoma, Merkel Cell↗
PubMed1993

Microcystic adnexal carcinoma.

Microcystic adnexal carcinoma is a rare cutaneous neoplasm characterized by invasive, relentless, and destructive local growth. The incidence of perineural invasion and tumor recurrence is high. We report two cases of microcystic adnexal carcinoma with typical clinical features. The use of formalin-fixed, paraffin-embedded horizontal Mohs sections is described in one case. We also review the current concepts and management of microcystic adnexal carcinoma.

Aged↗