PubMed Health⌕ Search

Biomedical subjects

C Liu

Publications and source records attributed to C Liu.

At least 973 records · Page 54Linked to original sources
PubMedDate not supplied

Multicenter study of the clinical efficacy of imipenem/cilastatin for treatment of serious infections.

The efficacy and safety of imipenem/cilastatin was evaluated in a multicenter study. For 49 of the 78 patients with 79 infections entered into the study, the clinical and bacteriologic efficacy of therapy could be evaluated. Toxicity data were analyzed for all 79 infections. Overall, 35 of 49 infections were cured or improved: 10 of 11 cases of pneumonia; 8 of 15 cases of pyelonephritis; 4 of 5 cases of osteomyelitis; 3 of 4 intravascular infections; 6 of 9 soft tissue infections; and 4 of 5 miscellaneous infections. There were 13 bacteriologic failures; superinfections with resistant organisms (i.e., Candida albicans, methicillin-resistant Staphylococcus epidermidis, and Pseudomonas maltophilia) occurred in three patients; reinfection with sensitive pathogens complicated one urinary tract infection; relapses developed of five urinary tract infections and of one case of endarteritis; and bacteriologic persistence occurred in three soft tissue infections. Infections with Pseudomonas aeruginosa were the most difficult to treat. In only six of 11 P. aeruginosa infections was both bacteriologic and clinical cure achieved. Adverse effects were minimal; no serious hematologic or hepatic toxicity and no adverse renal effects were noted.

Adult↗
PubMedDate not supplied

Near-infrared frequency-domain optical spectroscopy and magnetic resonance imaging: a combined approach to studying cerebral maturation in neonatal rabbits.

The neonatal rabbit brain shows prolonged postnatal development both structurally and physiologically. We use noninvasive near-IR frequency-domain optical spectroscopy (NIRS) and magnetic resonance imaging (MRI) to follow early developmental changes in cerebral oxygenation and anatomy, respectively. Four groups of animals are measured: NIRS in normals, MRI in normals, and both NIRS and MRI with hypoxia-ischemia (HI) (diffusion MRI staging). NIRS and/or MRI are performed from P3 (postnatal day=P) up to P76. NIRS is performed on awake animals with a frequency-domain tissue photometer. Absolute values of oxyhemoglobin concentration ([HbO2]), deoxyhemoglobin concentration ([HbR]), total hemoglobin concentration (HbT), and hemoglobin saturation (StO2) are calculated. The brains of all animals appeared to be maturing as shown in the diffusion tensor MRI. Mean optical coefficients (reduced scattering) remained unchanged in all animals throughout. StO2 increased in all animals (40% at P9 to 65% at P43) and there are no differences between normal, HI controls, and HI brains. The measured increase in StO2 is in agreement with the reported increase in blood flow during the first 2 months of life in rabbits. HbT, which reflects blood volume, peaked at postnatal day P17, as expected since the capillary density increases up to P17 when the microvasculature matures.

Animals↗
PubMedDate not supplied

A simple intraductal aspiration method for cytodiagnosis in nipple discharge.

OBJECTIVE: To increase cytodiagnostic accuracy for women with spontaneous nipple discharge using a simple intraductal aspiration method. STUDY DESIGN: We compared the cytodiagnostic accuracy of the conventional squeezing collection method and intraductal aspiration by intravenous catheter in a total of 146 women with spontaneous nipple discharge in a single duct without a mass; they had been pathologically identified at Kaohsiung Medical University Hospital. RESULTS: Adequate specimens were collected in 96.6% (141/146 cases) of the sample by the intraductal aspiration method as compared to 76.0% collected by the conventional squeezing method (P < .05). An adequate specimen should consist, at a minimum, of six cohesive clusters of well-preserved epithelial cells, with each cluster composed of at least five cells other than foam cells. The cytologic diagnosis was divided into five categories: positive in 9 cases, suspicious in 10, negative with atypical findings in 59, negative in 33 and inadequate specimens in 35 cases that employed the squeezing method. These results were less satisfactory than with the intraductal aspiration method: the smears were positive in 17 cases, suspicious in 14, negative with atypical findings in 78, negative in 32 and inadequate specimens in 5. Our results showed a sensitivity of 92.3% and specificity of 93.9% for the intraductal aspiration method as compared to a sensitivity of 52.9% and specificity of 89.3% for the squeezing method. Among the 27 cancers in this series, correct cytodiagnosis, including suspicious cases, was made in 24 cases by intraductal aspiration, with an accuracy of 88.9%, as compared to the 33.3% (9/27) accuracy of the squeezing method (P < 0.5). CONCLUSION: For patients with spontaneous nipple discharge, the intraductal aspiration method provides much more accurate cytodiagnosis than does the conventional squeezing method.

Adolescent↗
PubMedDate not supplied

Histopathology of neurosensory deafness in sarcoidosis.

Sarcoidosis is an idiopathic systemic granulomatous disease which occasionally causes fluctuating auditory and vestibular dysfunction. The temporal bones from a 32-year-old man deaf for 5 years from CNS sarcoidosis were examined histologically and compared with other nervous system tissues. It was found that the acoustic, vestibular, and facial nerves were involved in a striking perivascular lymphocytic infiltration resulting in myelin and axonal degeneration. The cochlear and labyrinthine neuroepithelium and stria vascularis had degenerated. It is hypothesized that neurosensory deafness and vestibular dysfunction in sarcoidosis starts as a reversible neuropathy. In some patients, an ischemia secondary to the vasculitis results in irreversible damage to the inner ear neuroepithelium.

Adult↗
PubMedDate not supplied

Imbrication reconstruction following partial laryngectomy.

Experience over a 16-year period with 38 patients who underwent partial laryngectomy with imbrication reconstruction is reviewed. We have found this technique to be an expeditious and highly successful means of eradicating T1 or T2 glottic cancer. The use of the patient's own full-thickness, adjacent normal tissue with imbrication of cartilage produces an adequate airway, an almost normal-appearing larynx, and a remarkable posttreatment voice quality, better results than from most cordectomies or vertical hemilaryngectomies. It is valuable as a salvage procedure after full-course radiation. Imbrication laryngoplasty is an alternative and a preferred modality for treatment of young people with early glottic carcinoma for whom the possible carcinogenic properties of radiation must be considered. The survival results are comparable with the more extensive vertical laryngectomies.

Glottis↗
PubMedDate not supplied

Determination of the osmotic characteristics of hamster pancreatic islets and isolated pancreatic islet cells.

The ability to store pancreatic islets using cryopreservation methodology would greatly assist the application of clinical islet transplantation to Type 1 (insulin-dependent) diabetics. It is our working thesis that the illumination of fundamental biophysical characteristics of these cells will lead to increased cryosurvival rates through theoretically predicted and experimental testing of optimal freezing protocol; as has been found for cells and tissues such as mammalian and Drosophila embryos. Pancreatic islets were isolated from Golden hamsters and their osmometric behavior, including inactive cell volume (Vb), was determined for either whole islets or isolated individual islet cells. When islets or islet cells were exposed to various concentrations of NaCl, they were found to exhibit a "classic" "Boyle-Van't Hoff" osmometric response. The Boyle-Van't Hoff representation of the volume curve (relative cell volume vs. 1/osmolality) yields a linear response with r values of .99 for each curve. Extrapolations to the normalized osmotically inactive volumes (Vb) were .43 and .22 for whole islets and individual islet cells, respectively. These data regarding the fundamental cryobiological characteristics of islets and islet cells should provide the foundation upon which to further the investigation of osmotic parameters of these cells and eventually lead to the determination of optimal freezing protocols.

Animals↗
PubMedDate not supplied

Osmotic separation of pancreatic exocrine cells from crude islet cell preparations.

A novel approach is introduced here to selectively lyse exocrine cells in an islet preparation by hypo-osmotic treatment. Time to hypotonic cell lysis required for the islet cells was much longer than that for the exocrine cells, which permits a possibility of selectively killing the exocrine cells by hypotonic treatment. The first set of experiments was designed to select an appropriate osmolality for the hypotonic treatment. Kinetic changes in cell volume in response to extracellular anisosmolalities (30 to 90 mOsm/kg) were recorded using an electronic particle counter. The results indicated that, when exposed to a 30 mOsm/kg solution, islet cells swelled slowly to reach volumetric equilibrium in approximately 3 min. There was no significant hypotonic cell lysis observed even at the end of 4 min (n = 4). In contrast, pancreatic exocrine cells, when exposed to the same solution, expanded rapidly to the lytic volume and burst within 30 s. Significant exocrine cell lysis was invariably achieved within 30 s when cells were exposed to the osmolalities below 60 mOsm/kg. For osmolalities between 70 to 80 mOsm/kg, exocrine cell lysis was highly variable. When cells were exposed to 80 to 90 mOsm/kg, no significant cell lysis was observed. Thus, an osmolality of 50 mOsm/kg is recommended for hypotonic treatment, as it maximizes the lysis of exocrine cells without unnecessarily stressing (osmotically) the islet cells. The second set of experiments (time-course experiments, 20 to 120 s) was designed to determine the length of exposure time for which the exocrine cells were irreversibly damaged but the islet cells had only swollen to such a degree that cell function is restored upon returning to an isotonic condition. Viability of the hypotonic treated cells was evaluated at two different levels: membrane integrity, measured by combined fluorescent dye staining with propidium iodide (PI) and carboxyfluorescein diacetate (CFDA), and mitochondrial function, measured by colorimetric MTT assay. The results showed that hypotonic treatment in a 50 mOsm/kg solution for 30 s resulted in over 85% loss of the membrane integrity for the exocrine cells. About 90% of these membrane lysed cells lost mitochondrial function (n = 3). By contrast, under the same treatment, less than 15% of the islet cells lost membrane integrity and mitochondrial function (n = 3). In conclusion, hypotonic treatment with a 50 mOsm/kg solution for 20 to 30 s at room temperature is sufficient to lyse the majority of the contaminating exocrine cells in an islet cell preparation, while maintaining function in the islet cells.

Animals↗
PubMedDate not supplied

Annulate lamellae in a large cell lung carcinoma cell line with high expression of tyrosine kinase receptor and proto-oncogenes.

The morphology, karyotype, in vitro growth properties, and expression of tyrosine kinase receptors and proto-oncogenes are reported for a newly established large cell undifferentiated lung carcinoma cell line (RVH-6849). The results were analyzed concomitantly with those for two well-established cell lines from an adenocarcinoma of the lung (A549) and a squamous cell carcinoma (A431). All three cell lines demonstrated common ultrastructural features of epithelial cells, but only RVH-6849 had frequent aggregates of centrioles and annulate lamellae (AL) and was polyploid, having five to seven copies of chromosome 7 by karyotype analysis. All three cell lines expressed transforming growth factor alpha (TGF-alpha), epidermal growth factor receptor (EGFR), c-erb B-2, and c-met genes. RVH-6849 cells, however, expressed the most messenger RNA (mRNA) for TGF-alpha, c-erb B-2, and c-met. Only EGFR mRNA was expressed more in the other two cell lines, especially in A431 cells. AL represent an exaggerated form of the nuclear membrane-pore complex that is found in actively proliferating cells such as germ and some neoplastic cells. AL are suspected to be involved in the deposition or processing of mRNA: The enhanced coexpression of AL and mRNAs of three tyrosine kinase-containing receptors in RVH-6849 cells may represent such a relationship.

Blotting, Northern↗
PubMedDate not supplied

Expression analysis of multidrug resistance associated genes in neuroblastomas.

In a series of 40 neuroblastomas we analyzed the relative mRNA levels of the MDR associated genes encoding MDR1/P-glycoprotein (MDR1), multidrug resistance associated protein (MRP), lung cancer resistance related protein (LRP) and topoisomerase IIalpha (TOPO IIalpha) by cDNA-PCR. Cyclin A (CYCA) was included to examine cellular proliferation activity. MYCN gene expression was analyzed as it was recently shown to be associated with enhanced MRP gene expression in neuroblastomas. We found that tumors with MYCN gene amplification exhibit significantly increased MYCN and MRP gene expression levels. Tumors with an allelic loss of the chromosomal 1p region showed significant (P<0.05) lower MDR1 gene expression (MDR1: 50+/-29, n=4) than tumors without (MDR1: 117+/-81, P<0.05, n=36). Moreover, significant positive correlations were found for MYCN/TOPO IIalpha (P<0.0001), MYCN/CYCA (P<0.05), TOPO IIalpha/CYCA (P<0.01), MRP/CYCA (P<0.0001) and MRP/LRP (P<0.05). Our results give evidence that MDR in neuroblastomas might be caused by multiple resistance factors and that a higher proliferation rate of neuroblastoma cells possibly based on altered MYCN gene expression is associated with enhanced MRP, CYCA and TOPO IIalpha gene expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Livistona extract inhibits angiogenesis and cancer growth.

In a screen for naturally occurring angiogenic inhibitors, we have identified an extract from the seed of the plant Livistona chinensis, which has potent anti-angiogenic and anti-tumor activity. The aqueous extract inhibits the in vitro proliferation of endothelial cells and multiple tumor cell lines including mouse fibrosarcoma and human breast and colon cancer. In mouse experiments, this extract suppresses the growth of the subcutaneous fibrosarcoma tumors. When the seed is separated into different components, the shell including the seed skin appears more potent than the inner kernel in tumor suppression. Our results suggest that the extract from the shell of Livistona chinensis may be a potential supplemental source for cancer treatment.

Angiogenesis Inhibitors↗
PubMedDate not supplied

Chinese herbal medicines in the treatment of acute respiratory infections: a review of randomised and controlled clinical trials.

OBJECTIVE: To review clinical trials of Chinese herbal medicines (CHMs) in the management of acute respiratory infections (ARIs). DATA SOURCES: MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, the Cochrane Library and three Chinese medical journals available in Australia. STUDY SELECTION: Studies in which a control group was used in comparing CHMs with a placebo or "Western medicine" (usually antibiotics) for treating ARIs were included. DATA SYNTHESIS: 27 of 46 studies identified in the search of the databases and the Chinese journals fulfilled the inclusion criteria. Twenty-six of these were published in Chinese, and one in English. Twenty were randomised controlled trials and seven were "controlled clinical trials". Although most of the studies reported that CHMs are better than antibiotics for the treatment of ARIs, the quality of the studies was generally poor when evaluated for patient allocation, treatment description, outcome measurement and data analysis. CONCLUSIONS: Because the trial methodology of these studies was often inadequate or insufficiently documented, it is difficult to recommend the use of CHMs in ARIs. However, Shuang Huang Lian does appear to be useful for treating lower respiratory tract infections. More rigorous evaluation of CHMs is needed, as they are becoming popular treatments in many countries, including Australia.

Acute Disease↗
PubMedDate not supplied

[Concepts of development of the neurosurgical operative environment in the 21st century].

The operative environment has to a large extent defines the "state of the art and science" of neurosurgery, which is now undergoing rapid reinvention. In order to remain current, each neurosurgeon should periodically reconsider their personal operative environment and its functional design with reference to modernity of practice as currently defined. Historical trends and their analysis offer predictive guides for development of such settings with an eye toward the future. Examination of technical developments in decade timeframes defines the progress in capability and need. Progressive minimalism of manipulation and the presence of operative definition with increasing precision are evident, with concurrent miniaturization of attendant computerized support systems, sensors, robotic interfaces, and imaging devices. These trends and developments offer the opportunity for simplificity of setting design with higher functionality as the desired endpoint.

Equipment Design↗