The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses. 相似文献
In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture
environment differs from in-vivo conditions in that the oxygen
concentration is higher, and in such conditions the mouse embryos show a
higher concentration of reactive oxygen species (ROS) in simple culture
media. ROS are believed to cause damage to cell membranes and DNA
fragmentation in somatic cells. This study was conducted to ascertain the
level of H2O2 concentration within embryos and the morphological features
of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31
fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was
obtained from the IVF-embryo transfer programme. The relative intensity of
H2O2 concentrations within embryos was measured using
2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence
imaging and DNA fragmentation was observed with transmission electron
microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations
were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/-
SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and
unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed
only in fragmented embryos, and was absent in non-fragmented embryos.
Electron microscopic findings confirmed apoptotic bodies and cytoplasmic
condensation in the fragmented blastomeres. We conclude that there is a
direct relationship between increased H2O2 concentration and apoptosis, and
that further studies should be undertaken to confirm these findings.
相似文献
Of the many changes in daily life brought about by the COVID-19 pandemic, social distancing efforts and governmentally mandated lockdowns were among the most drastic. Coinciding with these changes, popular pornography websites made some previously premium content available for free, spurring dramatic increases in traffic to these websites. This increase in time spent at home and reported increases in traffic to specific pornographic websites led to some speculation that pornography use might generally increase over the course of the pandemic and that problematic use might also increase. To test these speculations and quantify the effects of the pandemic and its associated restrictions on social behaviors on pornography use, we analyzed data from a longitudinal sample of American adults. Baseline, nationally representative data were collected in August 2019 via YouGov (N?=?2518). Subsequent data were collected in February 2020 (n?=?1677), May 2020 (n?=?1533), August 2020 (n?=?1470), and October 2020 (n?=?1269). Results indicated that, in May 2020, immediately following the height of the first wave of pandemic-related lockdowns, more people reported past-month pornography use than at other follow-up time points, but less did so than at baseline. Among those who reported use in May 2020, only 14% reported increases in use since the start of the pandemic, and their use returned to levels similar to all other users by August 2020. In general, pornography use trended downward over the pandemic, for both men and women. Problematic pornography use trended downward for men and remained low and unchanged in women. Collectively, these results suggest that many fears about pornography use during pandemic-related lockdowns were largely not supported by available data.
Experimental autoimmune uveoretinitis (EAU) in rodents is a widely used model of ocular autoimmunity. EAU has traditionally been elicited by injecting the uveitogenic protein in complete Freund's adjuvant (CFA) into the footpad(s) (FP). Because this route of immunization causes severe arthritis and inflammation, it is being banned by many institutions and investigators are switching to the subcutaneous (SC) route. However, there are no studies that systematically compare the outcome of these two immunization routes using defined clinical, histopathological and immunological criteria. We therefore undertook to compare the FP and SC routes of immunization in the Lewis rat and in the B 10. A mouse models of EAU. Animals were immunized with interphotoreceptor retinoid-binding protein (IRBP) or the retinal soluble antigen (S-Ag) in CFA, either by the traditional FP route or by the SC route. The parameters studied were kinetics and severity of EAU by clinical observation and by histopathology, respectively, as well as immunological responses by delayed-type hypersensitivity (DTH), serum antibody titers and lymphocyte proliferation to the uveitogen. In mice immunized with graded doses of IRBP, development of disease induced by the FP and SC methods had essentially identical kinetics. However, the SC method resulted in a somewhat higher incidence and severity of disease as well as higher DTH at the lower antigen doses. Antibody titers tended to be higher with FP immunization. In rats immunized with S-Ag, kinetics and severity of disease, DTH, proliferative responses of draining lymph node cells to the immunizing antigen, and serum antibody titers induced by FP and SC methods were similar. In rats immunized with IRBP, SC immunization resulted in somewhat higher responses across the board than FP. We conclude that at higher doses of antigen disease scores and immunological responses in animals immunized SC are comparable to those of FP-immunized animals. At limiting doses of antigen, however, the SC route appears to result in more severe disease than the traditional FP method. 相似文献
The role of hyperthermia during regional alkylating agent chemotherapy is controversial. The aim of this study was to determine the exact contribution of hyperthermia to tumor response during isolated limb infusion with l-phenylalanine mustard. Rats bearing rodent fibrosarcoma on the hindlimb underwent isolated limb infusion with saline, saline plus heat, l-phenylalanine mustard, l-phenylalanine mustard under conditions of normothermia, or l-phenylalanine mustard plus hyperthermia. Heat was administered locally using an in-line hot water circulation loop. Treatment with l-phenylalanine mustard at a concentration of 15 or 50 micrograms/mL was ineffective at producing tumor growth delay (P = 0.24 and 0.41, respectively). Furthermore, thermal enhancement of l-phenylalanine mustard activity was not seen at 15 micrograms/mL. However, administration of high-dose l-phenylalanine mustard, 50 micrograms/mL, with increasing amounts of heat yielded increasing tumor growth delay, increased regressions, and decreased proliferative index. Although l-phenylalanine mustard infusion under normothermia yielded a tumor growth delay of 7.1 days, combination l-phenylalanine mustard + hyperthermia treatment produced tumor growth delay of 27.0 days (P < 0.01; with two of five animals showing a complete response). Four hours after isolated limb infusion, 50.9% of cells in tumor treated with l-phenylalanine mustard + hyperthermia experienced apoptosis, whereas only 18.1, 16, and 4.4% of cells underwent apoptosis after treatment with l-phenylalanine mustard, saline + hyperthermia, or saline. The mean concentration of l-phenylalanine mustard within tumor relative to perfusate following isolated limb infusion was found to be similar among all groups at 0.023, 0.025, and 0.032 in animals undergoing isolated limb infusion with l-phenylalanine mustard, l-phenylalanine mustard + normothermia, and l-phenylalanine mustard + hyperthermia, respectively. These data indicate a synergistic cytotoxic effect of l-phenylalanine mustard + hyperthermia in isolated limb infusion, which is not attributable to enhanced tumor drug uptake. 相似文献