Phytate technetium-99m versus dextran 500 technetium-99m in the sentinel lymph node biopsy.

PURPOSE: To study which of the two most used radiopharmaceutical drugs for the sentinel lymph node (SLN) biopsy procedure (dextran 500 99mTc and phytate 99mTc) best defines the SLN and migrates less to other lymph nodes. MATERIAL AND METHODS: Thirty-two rats, separated into two groups, underwent lymphoscintigraphy examination with either dextran or phytate followed by sentinel (popliteal), lumbar, and inguinal lymph node biopsy. Radiation was detected with a gamma probe. RESULTS: The statistical study indicated count rates significantly higher in the SLN than in the other basins for both the dextran (P<0.01) and phytate groups (P<0.001). There was no statistically significant difference concerning SLN absorption in either group (P=0.2981). In the dextran group, migration occurred to 1.5 lymphatic basins with counting higher than 10% of that found in the SLN versus 0.8 in the phytate group (P=0.0023). Migration was thus higher in the dextran group (P=0.0207). CONCLUSION: There was no statistically significant difference between dextran and phytate in the SLN identification, but the phytate migrated to fewer lymphatic basins beyond the SLN and with less intensity.

Vertical growth phase and positive sentinel node in thin melanoma.

Sentinel node (SN) status is the most important prognostic factor for localized melanoma. Usually, patients with Breslow thickness of less than 1.0 mm are not included in SN protocols. However, the literature presents a rate ranging from 3 to 7% of nodal recurrence in thin melanoma. Ulceration, regression and high mitotic rate have been considered to be indications for an SN biopsy. The metastatic potential of the vertical growth phase is uncertain. To correlate pathological features in thin melanoma with SN metastasis, we reviewed 358 patients submitted to SN biopsy. Seventy-seven patients with lesions of 1 mm or smaller were included in the study group. Histological evaluation of the primary tumor included thickness, Clark level, mitotic rate, ulceration, regression, and growth phase. Lymphoscintigraphy was performed on all patients. Lymphatic mapping and gamma probe detection were both used for SN biopsy. Histological examination of SN consisted of hematoxylin-eosin and immunohistochemical staining. Median follow-up was 37 months. Six patients had micrometastases. Statistical analysis by the Fisher test showed that ulceration (P = 0.019), high mitotic rate (P = 0.008) and vertical growth phase (P = 0.002) were positively correlated with micrometastases. If other studies confirm these results, more melanoma patients must be submitted to SN biopsy.

Vertical growth phase and positive sentinel node in thin melanoma

Sentinel node (SN) status is the most important prognostic factor for localized melanoma. Usually, patients with Breslow thickness of less than 1.0 mm are not included in SN protocols. However, the literature presents a rate ranging from 3 to 7 percent of nodal recurrence in thin melanoma. Ulceration, regression and high mitotic rate have been considered to be indications for an SN biopsy. The metastatic potential of the vertical growth phase is uncertain. To correlate pathological features in thin melanoma with SN metastasis, we reviewed 358 patients submitted to SN biopsy. Seventy-seven patients with lesions of 1 mm or smaller were included in the study group. Histological evaluation of the primary tumor included thickness, Clark level, mitotic rate, ulceration, regression, and growth phase. Lymphoscintigraphy was performed on all patients. Lymphatic mapping and gamma probe detection were both used for SN biopsy. Histological examination of SN consisted of hematoxylin-eosin and immunohistochemical staining. Median follow-up was 37 months. Six patients had micrometastases. Statistical analysis by the Fisher test showed that ulceration (P = 0.019), high mitotic rate (P = 0.008) and vertical growth phase (P = 0.002) were positively correlated with micrometastases. If other studies confirm these results, more melanoma patients must be submitted to SN biopsy

Antimicrobial peptides from the Brazilian frog Phyllomedusa distincta.

Different peptides were purified by chromatographic procedures from the skin-secretory glands of the frog Phyllomedusa distincta. These are the first peptides reported from this frog species. Their primary structure was determined by a combination of automated Edman degradation and mass spectrometry. Peptide Q2 contains 25 amino acid residues, peptide Q1 and L have 28 each, peptide M contains 31, and peptide K has 33 amino acid residues. They all showed potent antimicrobial activity against Gram-negative and Gram-positive bacteria, presenting minimal inhibitory concentrations from 0.6 to 40 microM, when tested against Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Peptides K, L, and Q1 were chemically synthesized and shown to be active.

Spatial and temporal gene expression patterns occur during corm development.

We investigated gene expression patterns that occur during taro corm development. Two-dimensional gel electrophoresis identified several different prevalent proteins that accumulate during corm development. Microsequencing studies indicated that some of these proteins are related to taste-modifying proteins, such as curculin and miraculin, and proteins found in other storage organs, such as sporamin and the Kunitz trypsin inhibitor. A curculin-encoding cDNA clone, designated as TC1, was identified that corresponds to a highly prevalent 1-kb corm mRNA. The TC1 mRNA accumulates during corm development, is more prevalent in corm apical than basal regions, and is either absent, or present at low concentrations, in other vegetative organs such as the leaf and root. In situ hybridization experiments showed that the TC1 mRNA is highly concentrated in corm storage parenchyma cells and is absent, or present in reduced concentrations, in other corm cells and tissues. Our results show that corm development is associated with the differentiation of specialized cells and tissues, and that these differentiation events are coupled with the temporal and spatial expression of corm-specific genes.

Isolation, characterization and expression of a gene coding for a 2S albumin from Bertholletia excelsa (Brazil nut).

Two genes, BE2S1 and BE2S2, coding for methionine-rich albumins of Brazil nut (Bertholletia excelsa H.B.K.) have been cloned and their sequence determined. The genes are members of a multigene family and one of them, i.e. BE2S1, codes for one of the dominant 2S isoforms. Its expression is highly regulated during seed development and with respect to tissue specificity. Sequence analysis has shown that the genes contain one intron and that the promoter of BE2S1 shows a canonical TATA motif. The transcription initiation site is located 26 nucleotides downstream from the TATA box. Sequence comparison of the promoter regions of 2S genes from Brassica napus, Arabidopsis thaliana and B. excelsa revealed the presence of TGCA palindromic sequence that appear to be arranged in a 2S-specific manner.