Cytodiagnosis of endometrial carcinoma.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to W Liu.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Abnormal cytologic findings in gynecologic smears were more common among patients using oral contraceptives than among control patients. Cytologic examination should be routinely performed before oral contraceptives are prescribed. The exfoliation of endometrial cells was essentially the same between control and oral contraceptive patients. No evidence of excessive stimulation of epithelial element in endometrium accompanied the continued use of hormonal contraceptives. In general, the cytohormonal effect associated with oral contraceptives showed a depressed superficial cell count in the vaginal smears. Teenagers using oral contraceptives constituted 2 to 3% of the surveyed group. Long-term effects of antiovulatory drugs in young females are yet to be observed.
Explore the source record for details and available documents.
Cytokine-induced expression of inducible nitric oxide synthase (iNOS) and concomitant production of nitric oxide (NO) involve activation of mitogen-activated protein (MAP) kinases and are in most cases mediated by the transcription factor NF-kappaB. We investigated the role of p38 MAP kinase activation and IkappaB phosphorylation in iNOS expression in a novel iNOS-inducing model in mouse macrophages. Deprivation of serum from the culture medium of RAW 264.7 cells up-regulated iNOS and NO production, which were inhibited by 4-hydroxy-2-nonenal (HNE), a component of oxidatively modified low-density lipoprotein (oxLDL). Serum withdrawal induced phosphorylation of Akt, IkappaB, and p38 MAP kinase. Pretreatment with the potent PI3 kinase inhibitor wortmannin, the NF-kappaB inhibitor PDTC or the specific p38 MAP kinase inhibitor SB203580 each partially attenuated the induction of iNOS and NO production, demonstrating that both p38 activation and IkappaB phosphorylation are required for iNOS expression. SB203580, however, did not prevent the phosphorylation of Akt and IkappaB, suggesting that the p38 MAP kinase signal contributes to iNOS gene expression through an IkappaB-phosphorylation-independent pathway. HNE, which markedly inhibited iNOS expression and NO production, prevented the serum withdrawal-triggered IkappaB phosphorylation but not that of Akt or p38 MAP kinase. A high concentration of HNE stimulated dephosphorylation of IkappaB but promoted activation of p38 MAP kinase. Taken together, these results suggest that NF-kappaB and p38 MAP kinase lie in separate signal pathways for serum deprivation-stimulated iNOS expression and NO production. HNE selectively suppresses the former pathway, targeting a site downstream of Akt.
An immunocomplex of the 4 x 6-meric hemocyanin of the scorpion Androctonus australis with the monoclonal Fab fragment L104 was reconstructed from electron micrographs of a negatively stained specimen, using the double-carbon-layer technique. The resulting structure enables a clear visualization of the Fab fragments bound to the four copies of the Aa6 subunit and directly confirms a previous localization of the L104 epitope deduced from two-dimensional image processing. Despite a strong flattening effect produced by the negative-staining technique the orientations of the Fab fragments are well characterized. Moreover, the observation of a central hole within the elbow bends of the Fab fragments provides information about the disposition of the Fabs around their main axis.
Electron tomography is a powerful tool in elucidating the three-dimensional architecture of large biological complexes and subcellular organelles. Its use can be expanded through the simplification of the tomographic procedure by automation of its tasks. In this paper, we describe our EMACT/EMCAT system, which automates both tomographic data collection and reconstruction.
Explore the source record for details and available documents.
Apoptosis is an important process, both for normal development of the inner ear and for removal of oxidative-stress damaged sensory cells from the cochlea. Oxidative-stressors of auditory sensory cells include: loss of trophic factor support, ischemia-reperfusion, and ototoxins. Loss of trophic factor support and cisplatin ototoxicity, both initiate the intracellular production of reactive oxygen species and free radicals. The interaction of reactive oxygen species and free radicals with membrane phospholipids of auditory sensory cells creates aldehydic lipid peroxidation products. One of these aldehydes, 4-hydroxynonenal, functions as a mediator of apoptosis for both auditory neurons and hair cells. We present several approaches for the prevention of auditory sensory loss from reactive oxygen species-induced apoptosis: 1) preventing the formation of reactive oxygen species; (2) neutralizing the toxic products of membrane lipid peroxidation; and 3) blocking the damaged sensory cells' apoptotic pathway.
The innervation of the rat pineal gland from the sphenopalatine, otic, superior cervical and trigeminal ganglia was investigated in animals by use of in vivo retrograde tracings. A solution of 2% Fluorogold was iontophoretically injected into the superficial pineal gland in a series of Wistar rats. After a survival time of 4-10 days, the animals were fixed by perfusion and the brains, sphenopalatine, otic, superior cervical and trigeminal ganglia were investigated with a fluorescence microscope. Many retrogradely labelled perikarya were found in the superior cervical ganglia, but a smaller number of neurones were also labelled in the sphenopalatine, otic and trigeminal ganglia. Injections of the tracer into the subarachnoidal space were used as the control for unspecific uptake and transport of the tracer. The input to the pineal gland from the parasympathetic sphenopalatine and otic ganglia might be involved in the regulation of the annual rhythms of the pineal gland. The projections from the sensory trigeminal ganglion could be involved in the control of the blood flow of the gland.
This preliminary study collected data from 326 heroin users in Guangxi Province, China, in 1997. Logistic regression analysis was performed to identify the risk factors for injection. Survival analysis identified factors independently associated with time from initiation of heroin use to adoption of injection. Four factors were independently associated with injection: number of friends who used heroin in the last year, duration of heroin use, dose of heroin consumed, and total number of times detoxified in drug treatment and rehabilitation centers. Only gender and duration of heroin use were independently associated with time to first injection. Median time to first injection was 11 months for males and 22 months for females. Median time to first injection varied by age. Median time to injection for those who used heroin for more than one year was 8.1 months; it was 19.1 months for on to five years of use, and 40.5 months for more than five years of use. This study's preliminary findings suggest that younger, more recent heroin users, and males are at increased risk of becoming injectors, a major risk behavior for HIV acquisition.
Understanding the developmental and genetic basis for evolutionarily significant morphological variation in complex phenotypes such as the mammalian skull is a challenge because of the sheer complexity of the factors involved. We hypothesize that even in this complex system, the expression of phenotypic variation is structured by the interaction of a few key developmental processes. To test this hypothesis, we created a highly variable sample of crania using four mouse mutants and their wild-type controls from similar genetic backgrounds with developmental perturbations to particular cranial regions. Using geometric morphometric methods we compared patterns of size, shape, and integration in the sample within and between the basicranium, neurocranium, and face. The results highlight regular and predictable patterns of covariation among regions of the skull that presumably reflect the epigenetic influences of the genetic perturbations in the sample. Covariation between relative widths of adjoining regions is the most dominant factor, but there are other significant axes of covariation such as the relationship between neurocranial size and basicranial flexion. Although there are other sources of variation related to developmental perturbations not analyzed in this study, the patterns of covariation created by the epigenetic interactions evident in this sample may underlie larger scale evolutionary patterns in mammalian craniofacial form.
The effects of large doses of fentanyl (0.05 to 2 mg/kg) and fentanyl plus N2O on cardiovascular dynamics were determined in 10 unpremedicated dogs breathing 100% O2. Using computer analysis of the central aortic pulsepressure curve, stroke volume (SV), cardiac output, heart rate (HR), peripheral vascular resistance (PVR), and systolic, diastolic, and mean arterial blood pressures (BP) were determined while fentanyl was being given at a rate of 0.3 to 0.44 mg/min. Fentanyl caused a dose-related decrease in HR, which was significant at 0.05 mg/kg. Cardiac output, PVR, and systolic, diastolic, and mean arterial BP were also decreased and SV increased. The latter changes became significant at 0.1 mg/kg for diastolic BP; 0.15 mg/kg for cardiac output and mean BP; 0.25 mg/kg for sv and systolic BP; and at 1.25 mg/kg for peripheral vascular resistance. Addition of N2O after fentanyl did not significantly change any parameter, although SV, cardiac output, and HR were usually increased and PVR decreased. These data demonstrate that, while large doses of fentanyl or fentanyl plus N2O do alter cardiovascular dynamics in dogs, the changes appear to be less profound than those produced by equianalgesic doses of morphine. Our findings suggest that large doses of fentanyl-O2 may be an attractive alternative to morphine-O2 anethesia in critically ill patients.
Bladder smooth muscle differentiation is dependent on the presence of bladder epithelium. Previously, we have shown that direct contact between the epithelium and bladder mesenchyme (BLM) is necessary for this interaction. In this study, we tested the hypothesis that bladder smooth muscle can be induced via diffusable growth factors. Fourteen-day embryonic rat bladders were separated into bladder mesenchyme (prior to smooth muscle differentiation) and epithelium by enzymatic digestion and microdissection. Six in vitro experiments were performed with either direct cellular contact or no contact (1) 14-d embryonic bladder mesenchyme (BLM) alone (control), (Contact) (2) 14-d embryonic bladders intact (control), (3) 14-d embryonic bladder mesenchyme combined with BPH-1 cells (an epithelial prostate cell line) in direct contact, (4) 14-d embryonic bladder mesenchyme with recombined bladder epithelium (BLE) in direct contact, (No Contact) (5) 14-d embryonic bladder mesenchyme with BPH-1 prostatic epithelial cells cocultured in type 1 collagen gel on the bottom of the well, and (6) 14-d embryonic bladder mesenchyme with BPH-1 epithelium cultured in a monolayer on a transwell filter. In each case the bladder tissue was cultured on Millicell-CM 0.4-microm membranes for 7 d in plastic wells using serum free medium. Growth was assessed by observing the size of the bladder organoids in histologic cross section as well as the vertical height obtained in vitro. Immunohistochemical analysis of the tissue explants was performed to assess cellular differentiation with markers for smooth muscle alpha-actin and pancytokeratin to detect epithelial cells. Control (1) bladder mesenchyme grown alone did not exhibit growth or smooth muscle and epithelial differentiation. Contact experiments (2) intact embryonic bladder, (3) embryonic bladder mesenchyme recombined with BPH-1 cells, and (4) embryonic bladder mesenchyme recombined with urothelium each exhibited excellent growth and bladder smooth muscle and epithelial differentiation. Both noncontact experiments (5) and (6) exhibited growth as well as bladder smooth muscle and epithelial differentiation but to a subjectively lesser degree than the contact experiments. Direct contact of the epithelium with bladder mesenchyme provides the optimal environment for growth and smooth muscle differentiation. Smooth muscle growth and differentiation can also occur without direct cell to cell contact and is not specific to urothelium. This data supports the hypothesis that epithelium produces diffusable growth factors that induce bladder smooth muscle.
The removal and recovery of chromium(III) (Cr3+) from aqueous solutions with a spheroidal cellulose adsorbent containing the carboxyl anionic group was investigated. The adsorption of Cr3+ ion on the adsorbent has been found to be time, concentration, pH, and temperature dependent. The adsorption process follows both the Freundlich and Langmuir adsorption isotherms, and has been found to be endothermic (enthalpy change, deltaH = 31.35 kJ/mol). The Cr3+ ion adsorbed on the adsorbent can be recovered by treating with a sodium hydroxide (NaOH) or hydrochloric acid (HCl) solution in one of two methods, static desorption or mobile desorption (column operation). A 1.2 mol/L HCl aqueous solution was finally chosen to recover the Cr3+ ion using column operation. The recovery percentage is approximately 85.2%. The exhausted column can be chemically regenerated by treatment with 1 mol/L NaOH aqueous solution and no dismantling is required. The adsorption mechanism is explained on the basis of complexation and ion exchange, between which the complexation adsorption is predominant.
A stable recombinant fowl poxvirus (rFPV) expressing the C-terminal region (119 amino acids) of the nucleocapsid (N) protein of an infectious bronchitis virus (IBV) strain Ch3 was constructed by inserting the coding sequence within the thymidine kinase gene of fowl poxvirus (FPV) by homologous recombination. The N protein was expressed under control of the vaccinia virus promoter P7.5 in chicken embryo fibroblast cell cultures as seen in immunofluorescence assay and in rFPV-inoculated specific-pathogen-free (SPF) chickens by detecting antibodies with enzyme-linked immunosorbent assay (ELISA). A homologous IBV strain (Ch3) and two heterologous IBV strains (Ch5 and H4) were used to inoculate SPF chickens in a challenge to examine the protective efficacy of the rFPV. When the chickens were challenged with IBV Ch3 or Ch5, the control birds had respiratory signs of infections bronchitis, whereas all the vaccinated birds were clinically normal although low levels of the IBV infection were detected by a differential ELISA. In contrast, in the chickens challenged with IBV H4, all control birds and vaccinated birds suffered from the highly lethal IBV H4 infection. Our results suggest that the C-terminal 119 amino acid of the nucleocapsid expressed by FPV is a host-protective antigen and may induce cross-protective immunity against illness among some IBV strains.