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Biomedical subjects

A Arens

Publications and source records attributed to A Arens.

10 recordsLinked to original sources
PubMed2003

[Sentinel lymph node dissection in patients with malignant melanoma. Diagnostic and therapeutic standards].

INTRODUCTION: In patients with cutaneous malignant melanoma, the sentinel lymph node (SLN) reflects the histopathological features of the lymphatic basin with high accuracy. MATERIAL AND METHODS: Three hundred eighty-one melanoma patients at the Hornheide clinic with an overall follow-up of 36 months (November 1998 to October 2001) underwent sentinel lymph node dissection (SLND). RESULTS: The SLNs were successfully found in 93% of truncal melanoma ( n=136), 97% of melanoma of the extremities ( n=184), and 86% of melanoma of the head and neck region ( n=61). Of truncal midline melanomas, 84% ( n=43) showed two or more regional basins, in contrast to 18% of nonmidline melanoma ( n=93). Histopathological analysis revealed occult nodal disease in 25% of all patients. Completion lymphadenectomy revealed residual nodal disease in 8% of all patients with low risk melanoma with a tumor thickness of 0-1.5 mm (two of 26 patients with positive SLN) and in 11% of all patients with high risk melanoma with tumor thickness above 1.5 mm (eight of 70 patients with positive SLN). Tumor relapse was noted in 5% of negative SLN patients and 14% of positive SLN patients. The results of the method were false negative in 2% with a sensitivity of 98%. CONCLUSION: Sentinel lymph node dissection is a reliable and accurate method of staging regional lymph nodes for all primary tumor sites. It can localize occult metastases in unexpected lymphatic basins and provides critical indications for completion lymphadenectomy. It represents an essential method of establishing stratification criteria for future adjuvant trials. Further long-term follow-up is needed to investigate its prognostic relevance to recurrence and overall survival.

Adolescent↗
PubMed1998

Colorimetric method for quantifying human Stratum corneum removed by adhesive-tape stripping.

Tape-stripping of the skin is a useful method for removing the stratum corneum and obtaining more information about the function of this skill layer as the main barrier for skin penetration. The amount of stratum corneum removed is of relevance in establishing the concentration profile of chemicals within the stratum corneum after topical application. Weighing is the preferred method for measuring the amount stripped, but because it is often subject to artifacts, alternative methods are sought. We present a simple, colorimetric method for determining the amount stratum corneum removed by sequential adhesive-tape-stripping of human skin in vivo. The method is based on quantification of the sodium hydroxide soluble protein fraction using a commercially available protein assay similar to the Lowry assay. The method is shown to be an accurate and reproducible alternative to weighing, also demonstrating uniform removal of stratum corneum layers following the very initial strips.

Adhesives↗
PubMed1987

Pyroglutamyl-aprotinin, a new aprotinin homologue from bovine lungs--isolation, properties, sequence analysis and characterization using 1H nuclear magnetic resonance in solution.

A new Kunitz-inhibitor, which is different from aprotinin was extracted from bovine lungs with methanol, further purified by affinity chromatography on trypsin-Sepharose CL-6B and by repeated cation exchange chromatography on CM-Sephadex C-25. The inhibitor, which is less basic than aprotinin was characterized by polyacrylamide gel electrophoresis and ion-exchange HPLC. The N-terminus is blocked by pyroglutamic acid (Glu-1). After enzymatic removal of this residue with pyroglutamate aminopeptidase, complete identity with the primary structure of aprotinin was established by sequencing the inhibitor, which had been oxidized with performic acid, and by sequencing a tryptic fragment. The occurrence of the inhibitor, which can be denoted as pyroglutamyl-aprotinin or Glu-1-aprotinin, but which cannot be distinguished from aprotinin regarding its inhibitory specificity, is obviously the result of a different proteolytic processing of the bovine aprotinin precursor. By using CD and NMR-techniques it was shown that the N-terminus of the inhibitor is blocked, and that the conformation and the internal mobility correspond with those of aprotinin.

Amino Acid Sequence↗