The role of endoscopic ultrasound for portal hypertension in liver cirrhosis

Journal of Medical Ultrasonics - Chronic liver disease is still a major problem because disease progression will ultimately lead to liver cirrhosis. Portal hypertension is the hallmark in advanced...     

Reproducibility of 18F-FDG microPET studies in mouse tumor xenografts.

(18)F-FDG has been used to image mouse xenograft models with small-animal PET for therapy response. However, the reproducibility of serial scans has not been determined. The purpose of this study was to determine the reproducibility of (18)F-FDG small-animal PET studies. METHODS: Mouse tumor xenografts were formed with B16F10 murine melanoma cells. A 7-min small-animal PET scan was performed 1 h after a 3.7- to 7.4-MBq (18)F-FDG injection via the tail vein. A second small-animal PET scan was performed 6 h later after reinjection of (18)F-FDG. Twenty-five sets of studies were performed. Mean injected dose per gram (%ID/g) values were calculated from tumor regions of interest. The coefficient of variation (COV) from studies performed on the same day was calculated to determine the reproducibility. Activity from the second scans performed after 6 h were adjusted by subtracting the estimated residual activity from the first (18)F-FDG injection. For 7 datasets, an additional scan immediately before the second injection was performed, and residual activity from this additional delayed scan was subtracted from the activity of the second injection. COVs of both subtraction methods were compared. Blood glucose values were measured at the time of injection and used to correct the %ID/g values. RESULTS: The COV for the mean %ID/g between (18)F-FDG small-animal PET scans performed on the same day 6 h apart was 15.4% +/- 12.6%. The delayed scan subtraction method did not produce any significant change in the COV. Blood glucose correction increased the COV. The injected dose, tumor size, and body weight did not appear to contribute to the variability of the scans. CONCLUSION: (18)F-FDG small-animal PET mouse xenograft studies were reproducible with moderately low variability. Therefore, serial small-animal PET studies may be performed with reasonable accuracy to measure tumor response to therapy.     

Maturation of immature oocytes by coculture with granulosa cells

To increase the number of embryos available for transfer, immature human oocytes were cocultured with granulosa cells from preovulatory follicles. Greater numbers of immature oocytes incubated with granulosa cells had dispersion of the cumulus and corona cells compared with immature oocytes cultured in media alone. Fifty-four percent of immature oocytes were fertilized after coculture with granulosa cells compared with 20% fertilization of immature oocytes cultured without granulosa cells. There were no cases in which only embryos developed from immature oocytes were transferred, and thus we could not determine if the immature oocytes could contribute to a pregnancy.     

Metastatic mammary carcinoma of the middle ear

Malignancies of the middle ear and mastoid are rare and secondaries in the ear are extremely rare. A rare case of metastic adenocarcinoma from the breast is presented herewith.     

Neonatal exposure to estradiol prevents the expression of ovarian hormone-induced luteinizing hormone and prolactin surges in adulthood but not antecedent changes in neuropeptide Y or adrenergic transmitter activity: Implications for sexual differentiation of gonadotropin secretion

Sex differences in adult patterns of mating behavior and gonadotropin secretion in rats are determined in part by the presence or absence of gonadal steroids during a perinatal critical period. For example, male rats and female rats exposed neonatally to androgen do not exhibit LH surge patterns when treated appropriately with ovarian hormones in adulthood, and there is evidence that this may be due to a failure of ovarian hormones to activate the hypothalamic neuronal systems that stimulate LH secretion in such animals. Because considerable evidence suggests that estradiol formed centrally from testosterone is responsible for the permanent defeminization of mating behavior and gonadotropin secretion, the present studies compared normal females with normal males and with females treated neonatally with estradiol on the ability of ovarian hormones to induce several important neurochemical changes antecedent to the LH surge, including changes in neuropeptide Y (NPY) and LH-releasing hormone (LHRH) concentrations in the median eminence, as well as changes in turnover rates for catecholamine transmitters in the medial basal hypothalamus and medial preoptic area. Normal ovariectomized female rats responded to sequential treatment with estradiol followed by progesterone with afternoon LH and prolactin (PRL) surges, and with sequential accumulation followed by decline in concentrations of LHRH and NPY in the median eminence prior to the LH surge. In addition, administration of progesterone increased the turnover rates of norepinephrine (NE) and epinephrine (EPI) in the arcuate-median eminence region of normal females. Gonadectomized male rats receiving the same ovarian hormone treatment failed to exhibit LH or PRL surges and displayed none of the changes in neurotransmitter turnover or peptide concentrations characteristically seen in the normal female. Unexpectedly however, when females that were treated with estradiol benzoate on days 1–3 postpartum were ovariectomized and treated with ovarian hormones in adulthood, they showed the same accumulation/decline in median eminence NPY concentrations and the same activation of NE and EPI turnover in the arcuate-median eminence region as normal females, even though they showed no LH or PRL surges or changes in median eminence LHRH concentrations. These results suggest that estradiol may not mediate all of the defeminizing actions of androgen exerted during the early neonatal period, and particularly those actions that result in a lack of responsiveness in central noradrenergic, adrenergic and NPY systems in adulthood. However, an action of neonatal estradiol may result in uncoupling of the LHRH neurosecretory system from normal excitatory neurochemical influences.     

Hyper-recombination and mutator effects of the mms9-1, mms13-1, and mms21-1 mutations in Saccharomyces cerevisiae

Summary Spontaneous mitotic intragenic and intergenic recombination at various sites is enhanced 10 to 100 fold in the methyl methanesulfonate (MMS)-sensitive mutants mms9-1, mms13-1, and mms21-1 of Saccharomyces cerevisiae. All three mutants show elevated rates of spontaneous mutation. Sporulation is reduced in diploids homozygous for any of the three mutations, and a deficiency in meiotic recombination and meiotic chromosome segregation is observed. Pleiotropic effects on cell viability, growth rate, and radiation sensitivity, in combination with the alterations in recombination and mutagenesis displayed by mutant strains, suggest that the MMS9, MMS13, and MMS21 genes play important roles in DNA replication and/or genetic recombination.     

Reaction of chitosan with genipin and its fluorogenic attributes for potential microcapsule membrane characterization

This study investigates the fluorogenic characteristics of the chitosan-genipin reaction for applications in microencapsulation research. Results showed that the chitosan-genipin reaction generated a colored and fluorescent product, with optimal excitation and emission wavelengths at 369 and 470 nm, respectively. Furthermore, it was found that reaction conditions affected the fluorescence intensity of the product. Mixture at the ratio of 4:1 (chitosan: genipin by weight) fluoresced the most. It also fluoresced stronger if the reaction occurred at higher temperature, with the intensity of 10.4 x 10(5) CPS at 37 degrees C, 5.9 x 10(5) CPS at 20 degrees C, and 2.5 x 10(5) CPS at 4 degrees C. As well, the fluorescence of the mixture developed gradually over time, attaining the emission maxima of 2.9 x 10(5), 7.6 x 10(5), and 10.0 x 10(5) CPS in 1, 6, and 18 h, respectively. Chitosan-coated alginate microcapsules were prepared without prior labeling, to which subsequent genipin treatment was applied in order to examine the potential of using genipin in microcapsule characterization. Chitosan bound to the alginate beads interacted with genipin, from which the resultant fluorescent signals allowed for clear visualization of the chitosan coating under confocal laser scanning microscopy. The relative fluorescence intensity across the chitosan membrane was found to be considerably higher than the controls (175 vs. 50). The membrane thickness measured was 29.2 +/- 7.3 microm. These findings demonstrate a convenient and effective way of characterizing chitosan-based microcapsules using genipin as a fluorogenic marker, a technique that will be useful in microcapsule research and other biomedical applications.