Can positron emission mammography help to identify clinically significant breast cancer in women with suspicious calcifications on mammography?

OBJECTIVE: To evaluate the diagnostic accuracy of positron emission mammography (PEM) for identifying malignant lesions in patients with suspicious microcalcifications detected on mammography. METHODS: A prospective, single-centre study that evaluated 40 patients with suspicious calcifications at mammography and indication for percutaneous or surgical biopsy, with mean age of 56.4 years (range: 28-81 years). Patients who agreed to participate in the study underwent PEM with 18F-fluorodeoxyglucose before the final histological evaluation. PEM findings were compared with mammography and histological findings. RESULTS: Most calcifications (n = 34; 85.0 %) were classified as BIRADS 4. On histology, there were 25 (62.5 %) benign and 15 (37.5 %) malignant lesions, including 11 (27.5 %) ductal carcinoma in situ (DCIS) and 4 (10 %) invasive carcinomas. On subjective analysis, PEM was positive in 15 cases (37.5 %) and most of these cases (n = 14; 93.3 %) were confirmed as malignant on histology. There was one false-positive result, which corresponded to a fibroadenoma, and one false negative, which corresponded to an intermediate-grade DCIS. PEM had a sensitivity of 93.3 %, specificity of 96.0 % and accuracy of 95 %. CONCLUSION: PEM was able to identify all invasive carcinomas and high-grade DCIS (nuclear grade 3) in the presented sample, suggesting that this method may be useful for further evaluation of patients with suspected microcalcifications. KEY POINTS: • Many patients with suspicious microcalcifications at mammography have benign results at biopsy. • PEM may help to identify invasive carcinomas and high-grade DCIS. • Management of patients with suspicious calcifications can be improved.

Antioxidant activity and chemical composition of oleoresin from leaves and flowers of Brunfelsia uniflora.

In this study, the temperature and pressure of supercritical CO2 extraction were evaluated to obtain oleoresin of Brunfelsia uniflora leaves and flowers. The oleoresin compounds were identified by gas chromatography-mass spectrometry. The antioxidant activity was evaluated by three different methods. The highest oleoresin yields were 3.32% at 40°C and 200 bar for the leaves, and 1.03% at 60°C and 200 bar for the flowers. The main extracted compounds from leaves were phytol varying from 11.95 to 36.42% and α-tocopherol from 15.53 to 43.10%, and from flowers were geranyl linalool from 11.05 to 21.42% and α-amyrin from 9.66 to 22.12%. Oleoresin obtained at 60°C and 150 bar from leaves presented high antioxidant activity by DPPH (IC50 1.90 mg/mL) and by FRAP (1.8 µmol Fe2+/mg). ß-carotene/linoleic acid co-oxidation oleoresin from leaves at 0.25 mg/mL presented higher antioxidant activity than Trolox. The total phenolic content of the oleoresin from leaves ranged from 66.20 to 83.33 µg/mg and from flowers it was just up to 12.46 µg/mg. The extraction conditions affected yield, chemical composition, and antioxidant activity of oleoresin from leaves and flowers. This is the first report on the antioxidant activity of B. uniflora oleoresin from leaves and flowers and provides subsidies for potential applications in chemical, pharmaceutical, and food industries.

Antifungal and antibacterial activities of Petroselinum crispum essential oil.

Parsley [Petroselinum crispum (Mill.) Fuss] is regarded as an aromatic, culinary, and medicinal plant and is used in the cosmetic, food, and pharmaceutical industries. However, few studies with conflicting results have been conducted on the antimicrobial activity of parsley essential oil. In addition, there have been no reports of essential oil obtained from parsley aerial parts, except seeds, as an alternative natural antimicrobial agent. Also, microorganism resistance is still a challenge for health and food production. Based on the demand for natural products to control microorganisms, and the re-evaluation of potential medicinal plants for controlling diseases, the objective of this study was to determine the chemical composition and antibacterial and antifungal activities of parsley essential oil against foodborne diseases and opportunistic pathogens. Seven bacteria and eight fungi were tested. The essential oil major compounds were apiol, myristicin, and b-phellandrene. Parsley essential oil had bacteriostatic activity against all tested bacteria, mainly Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica, at similar or lower concentrations than at least one of the controls, and bactericidal activity against all tested bacteria, mainly S. aureus, at similar or lower concentrations than at least one of the controls. This essential oil also had fungistatic activity against all tested fungi, mainly, Penicillium ochrochloron and Trichoderma viride, at lower concentrations than the ketoconazole control and fungicidal activity against all tested fungi at higher concentrations than the controls. Parsley is used in cooking and medicine, and its essential oil is an effective antimicrobial agent.

Iron translocation in Pleurotus ostreatus basidiocarps: production, bioavailability, and antioxidant activity.

Translocation of minerals from substrate to mushrooms can change the medicinal characteristics, commercial value, and biological efficiency of mushroom. In the present study, we demonstrated that addition of iron to the substrate reduces the yield of Pleurotus ostreatus mushroom. The biological efficiency of the mushroom varied from 36.53% on the unsupplemented substrate to 2.08% for the substrate with 500 mg/kg iron added. The maximum iron concentration obtained for mushroom was 478.66 mg/kg (dry basis) and the maximum solubility in vitro was 293.70 mg/kg (dry basis). Iron translocation increased the ash and protein content, reduced antioxidant activity, and enhanced the aroma and flavor characteristics of the mushroom. However mushroom has higher amounts of iron than vegetables like collard greens, it is not feasible to use mushrooms as the only dietary source of iron. The study also indicated that because of more bioaccumulation of iron in mycelium than in the mushroom, mycelium and not mushroom, could be a better alternative as a non-animal iron source.

Debrisoquine polymorphism: novel CYP2D6 gene Bam HI restriction fragment length polymorphism in the Ngawbé Guaymí Indian of Panama.

Markedly decreased cytochrome P450-mediated metabolism of debrisoquine, sparteine, and more than two dozen additional commonly prescribed drugs is an autosomal recessive trait that has been associated with several RFLP patterns involving the CYP2D6 gene. In Caucasians there are at least six variant alleles known to be correlated with the 'poor metabolizer' (PM) phenotype. We examined debrisoquine and sparteine metabolism and CYP2D6 RFLP patterns in 22 Ngawbé Guaymí Indians of Panama. We studied a two-generation family, a three-generation family, and three other unrelated PM individuals. Digestion of all 22 DNA samples with Xba I or Hind III did not produce the same varying CYP2D6 RFLP patterns as those commonly seen in at least two-thirds of all Northern European Caucasians and Chinese so far screened. In contrast, we found a single heretofore undescribed Bam HI polymorphism that was correlated with the PM phenotype among all Ngawbé Guaymí individuals examined. It is possible that this novel RFLP might represent a recent founder effect that has occurred in this unadmixed Amerindian tribe within the past 20,000-30,000 years.

Comparative evolutionary pharmacogenetics of CYP2D6 in Ngawbe and Embera Amerindians of Panama and Colombia: role of selection versus drift in world populations.

The development of CYP2D6 has been attributed to the need of earth-dwelling animals to detoxify toxic xenobiotics (phytoalexins) present in plants. This hypothesis has been extrapolated to humans, but is yet unconfirmed. Therefore, we studied two Amerindian populations as the best available model to test the effect of selection through diet on human CYP2D6 evolution. The frequency of sparteine poor metabolizers in Ngawbe was 4.4% (n = 344), while the frequency in Embera was 2.2% (n = 153). Among Ngawbe and Embera, CYP2D6*4 (allelic frequencies for each tribe, respectively: 0.171; 0.14), CYP2D6*6 (0.005; 0.011) and CYP2D6*10 (0.175; 0.069) were detected, while CYP2D6*3, CYP2D6*5, CYP2D6*9 and CYP2D6*16 were absent. All poor metabolizers possessed either CYP2D6*4 or CYP2D6*6 and there were no disagreements between genotypic and phenotypic data. The total frequency of mutant alleles showed no difference among Amerindians or when compared to Caucasians. It was higher than in Chinese, since the frequency of CYP2D6*4 was higher in Amerindians. XbaI restriction fragment length polymorphisms haplotypes were very homogeneous in Amerindians, because the only fragment that hybridized with the CYP2D6 cDNA probe was the 29 kb (not 42/44 kb or 11.5/13 kb). This indicated no gene cluster recombinations that generate insertions or deletions. We propose that in earlier hominids and humans, CYP2D6 had increasingly become a vestigial characteristic unconstrained by dietary stressors, as a result of cultural survival strategies. Human CYP2D6 evolution was preferentially affected by random genetic drift, and not by adaptive or purifying selection.

Evolutionary pharmacogenetics of CYP2D6 in Ngawbe Guaymi of Panama: allele-specific PCR detection of the CYP2D6B allele and RFLP analysis.

Gene cluster CYP2D controls the biosynthesis of enzyme CYP2D6, which is responsible for the polymorphic oxidation of sparteine, debrisoquine and related drugs. This cluster consists of the functional gene D6 and of two pseudogenes, D7 and D8. RFLP Bam HI analysis of CYP2D in 37 unrelated and eight related Ngawbe Guaymi Amerindians of Panama showed a polymorphism characterized by the presence of two alleles: 4.7 + 7.9 and 2.3 + 6.0 (frequencies: 0.63 and 0.37, respectively, n = 35 unrelated subjects). The possible genotypes for these alleles follow the Hardy-Weinberg distribution (chi 2 = 1.76; 0.10 < p < 0.25). All PMs of sparteine or debrisoquine (n = 7) were homozygotes for the second allele, but not all homozygotes (n = 10) were PMs, so there was not an exclusive association between the Bam HI genotype and the observed phenotype. A similar analysis with the endonuclease Xba I proved to be non-informative in relation to phenotype, since all subjects (n = 40) showed only the 29 kb allele. Allele-specific PCR studies of selected subjects indicated the existence of the CYP2D6B allele (freq = 0.17; C.I.95% = 0.085, 0.29; n = 30 unrelated subjects), in addition to the wild-type. The mutant CYP2D6B allele was responsible for the enzyme deficiency present in PMs. Its presence in Amerindians suggests that this allele has a far more ancient evolutionary history than previously thought. The over-all RFLP and PCR analyses point to a diminished genetic diversity for the Ngawbe subjects, consistent with their demographic history and population genetics.

A preliminary note on the transient polymorphic oxidation of sparteine in the Ngawbé Guaymí Amerindians: a case of genetic divergence with tentative phylogenetic time frame for the pathway.

The oxidation of sparteine was studied in a total of 121 Ngawbé Guaymí volunteers in Panama, 97 of whom were unrelated. When presented in a frequency histogram, the results of the log10 of the metabolic ratios (LMR) indicated the existence of two modes, the largest of which exhibited a normal distribution (alpha = 0.05; chi 2 = 5.46). A preliminary assignment of an antimode for this population sample is proposed, located within the region of LMR 0.65 to 0.85 vs LMR of 1.3 for white subjects, and results in five poor metabolizers (PMs) (5.2%). This is in contrast to the absence of PMs (0/210) we have reported for the Cuna Amerindians. The microevolution of the sparteine route, corresponding to a tenfold change in the frequency of PMs, is likely to have occurred within their genetic divergence time. These observations of the divergence of a metabolic route of therapeutic importance and the proposal of a time frame for its microevolution constitute the first cases in the literature.

The oxidative metabolism of sparteine in the Cuna Amerindians of Panama: absence of evidence for deficient metabolizers.

Sparteine sulfate (50 mg) was administered to 170 Cuna Amerindians, 142 of whom were unrelated, and the drug and its dehydrometabolites were determined in the 0- to 12-hour urine samples. The log10 of the metabolic ratio was unimodally, but not normally, distributed and showed the following values: mean -0.21 +/- 0.26, median -0.24, limits -0.73 and 0.76, skewness 1.00, and kurtosis 4.95. On the basis of these results, it can be concluded that there are no deficient metabolizers in the Cuna sample population studied. However, the similarity of the skewness found between the Cuna sample population studied and the extensive Canadian white group, as well as an inflection point at 6.3 U in the former's probit plot, suggests the existence of at least two subgroups congregating within the same single mode in the frequency distribution curve. The use of the inflection point is discussed thoroughly, concluding that although it does not allow exclusion of the existence of genotypically different subgroups, the limitations of the data do not permit its use to determine the number of heterozygotes and thus the existence of polymorphism. The possibility of an isozyme variant, consistent with the general genetic structure of Amerindians, as suggested by the coexistence of two subgroups within the unimodal curve, is entertained.

Systemic chemotherapy-induced microsatellite instability in the mononuclear cell fraction of women with breast cancer can be reproduced in vitro and abrogated by amifostine.

OBJECTIVES: Microsatellite instability (MSI) induction by alkylating agent-based chemotherapy (ACHT) may underlie both tumor resistance to chemotherapy and secondary leukaemias in cancer patients. We investigated if ACHT could induce MSI in tumor-derived plasma-circulating DNA (pfDNA) and in normal peripheral blood mononuclear (PBMN) cells. We also evaluated if amifostine could interfere with this process in an in-vitro model. METHODS: MSI was determined in pfDNA, PBMN cells and urine cell-free DNA (ufDNA) of 33 breast cancer patients before and after ACHT. MCF-7 cells and PBMN from normal donors were exposed in vitro to melphalan, with or without amifostine. RESULTS: We observed at least one MSI event in PBMN cells, pfDNA or ufDNA of 87, 80 and 80% of patients, respectively. In vitro, melphalan induced MSI in both MCF-7 and normal PBMN cells. In PBMN cells, ACHT-induced MSI occurred together with a significant decrease in the expression of the DNA mismatch repair gene hMSH2. Amifostine decreased hMSH2 expression and also prevented MSI induction only in normal PBMN cells. CONCLUSIONS: ACHT induced MSI in PBMN cells and in tumour-derived pfDNA. Because of its protective effect against ACHT induction of MSI in normal PBMN cells in vitro, amifostine may be a potential agent for preventing secondary leukaemias in patients exposed to ACHT.

[Human biodiversity and its effects on the pharmacological variability: CYP2D6 and NAT2 enzymes in Amerind populations of Panama, Colombia and Costa Rica]. / La biodiversidad humana y sus efectos sobre la variabilidad farmacologica: enzimas CYP2D6 y NAT2 en poblaciones amerindias de Panama, Colombia y Costa Rica.

Human biodiversity originates partially from human microevolution, which have produced different populations. This biodiversity is responsible for most of the variability in drug response. We present the methodology employed in population pharmacology studies and general information about the CYP2D6 and NAT2 systems. We report results obtained in Embera and Ngawbe Amerindians, who are characterized by a low phenotypic and genotypic CYP2D6 diversity. In regard to NAT2, Amerindians are distinguished by a high allelic frequency of S3 and low ones of S1 and S2, situation which is reversed in Caucasians.

[Population pharmacology and ethnopharmacokinetics in 3 Amerindian groups from Panama: Cuna, Ngawbe Guaymi and Teribe]. / Farmacología poblacional y etnofarmacocinética de tres grupos amerindios de Panamá: Cuna, Ngawbe guaymi y Teribe.

We report on studies of the oxidative routes associated with the polymorphic metabolism of debrisoquine, sparteine and mephenytoin, as well as on the pathway catalyzed by N-acetyl-transferase. Normal, healthy non-related subjects were studied: 250 Cuna, 285 Ngawbé Guaymí and 20 Teribe. These studies were aimed at establishing differences or similarities among Amerindian tribes and between them and Caucasians, since certain abnormal or non-expected results in clinical response to drugs could be due to racial differences. In those cases, it was considered necessary to evaluate the degree of toxicity and danger of drugs administration, and their effective therapeutic actions.

Characterization of the urinary metabolites of primaquine in rats.

Following the synthesis of reference standards of the primaquine metabolites, a high-performance liquid chromatographic (HPLC) analytical method for carboxyprimaquine, its glycine conjugate, and its glucuronide conjugate in urine samples was developed. After the administration of primaquine, only trace quantities of primaquine and carboxyprimaquine (each less than 1% of dose) and no significant quantity of the two conjugates of carboxyprimaquine were excreted in the urine. When carboxyprimaquine was administered, only 0.3% of the dose was excreted in the urine. When carboxyprimaquine glycinate was administered, the compound was found in the 700- to 1300-µg/ml concentration range in the urine within the first few hours. Using (14)C-labeled primaquine, six new metabolites were found in the urine and partially characterized. The purported metabolites of primaquine (8-amino-6-methoxyquinoline, 5-hydroxyprimaquine, and 6-desmethyl-5-hydroxyprimaquine) were not found in the urine. A field screening test for the quantitation of primaquine metabolites in urine was also investigated. The inexpensive, but sensitive assay was found to give results that closely paralleled the more complex HPLC method and it was moderately well correlated with the total radioactivity in the urine samples.

Mephenytoin hydroxylation in the Cuna Amerindians of Panama.

1 Mephenytoin p(4')-hydroxylation, which is deficient in 3-5% of Caucasians, was examined in 96 Cuna Amerindians of Panama. 2 Attempts were made to exclude poor compliance with urine collection and ingestion of the drug dose since the assignment of phenotype was based upon urinary recovery of the metabolite. These involved the measurement of the urinary recovery of sparteine, added to the ingested capsule, and of the renal excretion of creatinine. 3 Of the 90 Cunas deemed to be reasonably complaint, none of them appeared to be deficient in p(4')-hydroxylation of mephenytoin.

Unimodal distribution of the metabolic ratio for debrisoquine in Cuna Amerindians of Panama.

1. The metabolic oxidation of debrisoquine (DB) was studied in 89 non-related Cuna Amerindian subjects. 2. Means and standard deviations for urinary recoveries of the intact drug and its 4-hydroxy metabolite (4-HD) were: %DB: 6.8 +/- 4.5; %4-HD: 16.0 +/- 9.1; %sum: 22.8 +/- 12.0. The log10 metabolic ratios for DB (LMRDB) were distributed within a single mode of insignificant skewness (-0.01, P greater than 0.10), which was unimodal (log kernel density and maximum likelihood methods) and normal (chi 2 = 22.5; d.f. = 15; P greater than 0.09; power of the test greater than 80%). 3. Therefore, no poor metabolizers (95% C.I.: 0.1%, 5.2%) were detected in the population sample studied.

["Cholos de Coclé": determination of their racial mixture and genetic origins]. / Estudio sobre los "cholos de Coclé": determinación de su mezcla racial y orígenes genéticos.

We have found, in this first genetic study of a supposedly admixed Panamanian population, that the cultural group known as "cholos of Coclé" constitute a trihybrid mixture, whose genetic pool has the following composition: 44% Amerindian, 38% Caucasoid and 18% Negroid. Similarly, we have detected Amerindian genes, such as LDHB--Gua and TFchi, in proportions that relate this population with the extant Ngawbé (Guaymí). Nevertheless, the very high frequency of variant PEPA--KUN seems to indicate the genetic contribution of Amerindian populations from Eastern Panama, possibly from the extinct indigenous group cueva. This variant is frequently found among the present-day Kuna, but has not been detected among Nagawbé and Buglé.