Effect of Lincocin Treatment on the Greening Process in Bean (Phaseolus vulgaris) Leaves

The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –¹⁴CO₂ fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes.     

Lecithotrophic development and metamorphosis in the Indo-West Pacific brittle star Ophiomastix venosa (Echinodermata: Ophiuroidea)

Summary

The larval development of the ophiocomid ophiuroid Ophiomastix venosais described using SEM. The gastrula transforms into a uniformly ciliated early larva which progressively changes into a lecithotrophic late premetamorphic larva with a continuous bilateral ciliated band. This stage is short-lived and equivalent to a highly reduced ophiopluteus. Comparisons between O. venosa and other ophiuroid species whose development has been investigated suggest that, whatever the developmental mode (lecithotrophic or planktotrophic), a pluteus stage always occurs in ophiuroids with planktonic development. Two metamorphic stages were identified, the late metamorphic larva differing from the early one by the closure of the larval mouth. The appearance of the permanent mouth marks the end of the metamorphosis. The postlarva still possesses remnants of larval features. The transformation of the reduced ophiopluteus into a barrel-shaped metamorphic larva with transverse ciliated bands, a vitellaria larva, is followed. The possible occurrence of a unique type of metamorphic larva in non-brooding ophiuroids is discussed. Verification of this, however, needs further SEM investigations on metamorphic larva from species having “regular” planktotrophic development.     

Enantioselective pharmacokinetics of lercanidipine in healthy volunteers

OBJECTIVE: The enantioselective kinetic disposition of lercanidipine, a dihydropyridine type of third-generation calcium antagonist, was investigated in six healthy male volunteers following a single 20 mg racemic oral dose. METHODS: Serial plasma samples were obtained from 0 to 24 h after drug administration. Lercanidipine enantiomers were analysed using a chiral LC-MS-MS method. RESULTS: The following differences (p < 0.05, Wilcoxon test) between (S) and (R) enantiomers were found (median): C(max) 2.071 ng mL(-1) versus 1.681 ng mL(-1); AUC(0-24)12.352 ng h mL(-1) versus 10.063 ng h mL(-1) and Cl/f 732.16 L h(-1) versus 1891.84 L h(-1). The AUC(0-infinity) values for (S)-LER were 1.21-fold higher than those for (R)-LER. CONCLUSION: The pharmacokinetics of LER was enantioselective in healthy volunteers following a single dose of 20 mg of the unlabeled racemic drug.     

Nipple-areola reconstruction: satisfaction and clinical determinants

After performing a chart review, the authors identified 120 patients who underwent breast cancer-related reconstruction. All charts were evaluated with regard to breast mound reconstruction type, nipple-areola reconstruction type, the interval between breast mound and nipple-areola reconstruction, the number of procedures needed to achieve nipple-areola reconstruction, patient history of radiation therapy, and complications. A questionnaire was then developed and mailed to all of the patients who underwent both breast mound and nipple/areola reconstruction (n = 105) to evaluate their level of satisfaction. Of the 43 patients who returned the questionnaire, 41 completed all portions correctly. The questionnaire evaluated patient satisfaction with breast mound reconstruction; patient satisfaction with nipple-areola reconstruction; what the patient disliked most about the nipple-areola reconstruction; and whether or not the patient would choose to have breast reconstruction again. Several parameters were then tested statistically against the reported patient satisfaction.A review of all patients who underwent breast reconstruction revealed that their breast mound reconstructions were done using either a TRAM flap (59 percent), a latissimus dorsi flap and an implant (19 percent), an expander followed by an implant (9 percent), an implant only (4 percent), or other means (9 percent). The nipple-areola was reconstructed in these patients with either a star flap (36 percent), nipple sharing (10 percent), a keyhole flap (9 percent), a skate flap (9 percent), an S-flap (8 percent), a full-thickness skin graft (6 percent), or by another means (22 percent). The number of procedures needed to achieve nipple-areola reconstruction was either one (in 66 percent of the patients), two (in 32 percent of the patients), or three or more (2 percent of the patients). Eleven percent of the patients experienced the complication of nipple necrosis.Satisfaction with breast mound reconstruction was reported by 81 percent of patients to be excellent/good, by 14 percent of patients to be fair, and by 5 percent of patients to be poor. Reported satisfaction with nipple-areola reconstruction was excellent/good for 64 percent of patients, fair for 22 percent of patients, and poor for 14 percent of patients. The factors patients disliked most about their nipple-areola reconstruction were, in descending order, lack of projection, color match, shape, size, texture, and position. Statistical analysis of the data revealed inferior patient satisfaction when there was a longer interval between breast mound and nipple areola reconstruction (p = 0.003). No significant difference was observed in nipple/areola reconstruction satisfaction ratings when compared with breast mound reconstruction type (p = 0.46), nipple-areola reconstruction type (p = 0.98), and history of radiation therapy (p = 0.23). There was also no significant difference when breast mound reconstruction was compared with technique (p = 0.51) and history of radiation therapy (p = 0.079). Overall, there was a greater satisfaction with breast mound reconstruction than with nipple-areola reconstruction (p = 0.0001).     

Selective Cytotoxicity of 1,3,4-Thiadiazolium Mesoionic Derivatives on Hepatocarcinoma Cells (HepG2)

In this work, we evaluated the cytotoxicity of mesoionic 4-phenyl-5-(2-Y, 4-X or 4-X-cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chloride derivatives (MI-J: X=OH, Y=H; MI-D: X=NO₂, Y=H; MI-4F: X=F, Y=H; MI-2,4diF: X=Y=F) on human hepatocellular carcinoma (HepG2), and non-tumor cells (rat hepatocytes) for comparison. MI-J, M-4F and MI-2,4diF reduced HepG2 viability by ~ 50% at 25 μM after 24-h treatment, whereas MI-D required a 50 μM concentration, as shown by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. The cytotoxicity was confirmed with lactate dehydrogenase assay, of which activity was increased by 55, 24 and 16% for MI-J, MI-4F and MI-2,4diF respectively (at 25 μM after 24 h). To identify the death pathway related to cytotoxicity, the HepG2 cells treated by mesoionic compounds were labeled with both annexin V and PI, and analyzed by flow cytometry. All compounds increased the number of doubly-stained cells at 25 μM after 24 h: by 76% for MI-J, 25% for MI-4F and MI-2,4diF, and 11% for MI-D. It was also verified that increased DNA fragmentation occurred upon MI-J, MI-4F and MI-2,4diF treatments (by 12%, 9% and 8%, respectively, at 25 μM after 24 h). These compounds were only weakly, or not at all, transported by the main multidrug transporters, P-glycoprotein, ABCG2 and MRP1, and were able to slightly inhibit their drug-transport activity. It may be concluded that 1,3,4-thiadiazolium compounds, especially the hydroxy derivative MI-J, constitute promising candidates for future investigations on in-vivo treatment of hepatocellular carcinoma.     

Enantioselective analysis of praziquantel in plasma samples

A direct enantioselective high-performance liquid chromatography method is described for the quantitative determination of praziquantel enantiomers in plasma samples. The method involves two-step extraction of plasma with toluene, evaporation of the solvent and chromatography on a Chiralcel OD-H column using hexane-ethanol (85:15, v/v) as the mobile phase and detection at 220 nm. The assay satisfies all of the criteria required for use in clinical pharmacokinetic studies.