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Effects of air on the segregation of particles in a shaken granular bed. PHYSICAL REVIEW LETTERS 2003; 91:014302. [PMID: 12906541 DOI: 10.1103/physrevlett.91.014302] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2002] [Indexed: 05/24/2023]
Abstract
Effects of interstitial air on the motions of a large intruder in a shaken granular bed are studied experimentally as a function of ambient air pressure, particle size of the bed, and the density of the intruder. It is found that the intruder always rises from the granular bed in the absence of air. However, the intruder can acquire both positive and negative buoyancy in the presence of air. Negative buoyancy can be observed only when both the density of the intruder and the particle size of the bed are small enough. This negative buoyancy can be explained by the unusual air pressure distribution found in the bed.
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Abstract
The microstructure in the surface layer of a pure iron plate was refined at the nanometer scale by means of a surface mechanical attrition treatment that generates repetitive severe plastic deformation of the surface layer. The subsequent nitriding kinetics of the treated iron with the nanostructured surface layer were greatly enhanced, so that the nitriding temperature could be as low as 300 degrees C, which is much lower than conventional nitriding temperatures (above 500 degrees C). This enhanced processing method demonstrates the technological significance of nanomaterials in improving traditional processing techniques and provides a new approach for selective surface reactions in solids.
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Combined dorsal root entry zone lesions and neural reconstruction for early rehabilitation of brachial plexus avulsion injury. ACTA NEUROCHIRURGICA. SUPPLEMENT 2003; 87:95-7. [PMID: 14518532 DOI: 10.1007/978-3-7091-6081-7_20] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Brachial plexus avulsion injury is one of the major complications after traffic, especially motorcycle accidents. During the past 12 years, we have encountered more than 40 brachial plexus avulsion injuries. The neurological deficits included pain and paralysis of the damaged limb. Dorsal root entry zone lesions made by thermocoagulation were performed for intractable pain in 34 cases. The pain relief rate was good in about 75%. Combined neural reconstruction was performed in 15 cases. The reconstruction included neurolysis, nerve graft, nerve transfer, and functioning muscle/tendon transfer etc. There were 13 male and 2 female patients. Age distribution was from 21 to 61 years with a mean age of 41.8 years. Eleven patients were found to have whole brachial plexus injury and 4 with upper brachial plexus injury. Twelve patients had good pain relief. Six patients showed good functional result after reconstruction. Three had no improvement. Combined pain control and reconstruction offer an early rehabilitation for brachial plexus avulsion injury.
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Malignant mixed mesodermal tumor of the ovary treated with a cisplatin-irinotecan combination: case report. EUR J GYNAECOL ONCOL 2002; 22:319-21. [PMID: 11766729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Amorphous-to-crystalline transformation induced by thermal annealing of a metastable Al90Fe10composite. ACTA ACUST UNITED AC 2002. [DOI: 10.1080/01418610208240014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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208
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The early stages of fatigue and evolution of persistent slip bands in a copper single crystal. ACTA ACUST UNITED AC 2002. [DOI: 10.1080/01418610208240007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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209
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Abstract
Previous models combining the human cardiovascular and pulmonary systems have not addressed their strong dynamic interaction. They are primarily cardiovascular or pulmonary in their orientation and do not permit a full exploration of how the combined cardiopulmonary system responds to large amplitude forcing (e.g., by the Valsalva maneuver). To address this issue, we developed a new model that represents the important components of the cardiopulmonary system and their coupled interaction. Included in the model are descriptions of atrial and ventricular mechanics, hemodynamics of the systemic and pulmonic circulations, baroreflex control of arterial pressure, airway and lung mechanics, and gas transport at the alveolar-capillary membrane. Parameters of this combined model were adjusted to fit nominal data, yielding accurate and realistic pressure, volume, and flow waveforms. With the same set of parameters, the nominal model predicted the hemodynamic responses to the markedly increased intrathoracic (pleural) pressures during the Valsalva maneuver. In summary, this model accurately represents the cardiopulmonary system and can explain how the heart, lung, and autonomic tone interact during the Valsalva maneuver. It is likely that with further refinement it could describe various physiological states and help investigators to better understand the biophysics of cardiopulmonary disease.
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Multiple imputation methods for estimating regression coefficients in the competing risks model with missing cause of failure. Biometrics 2001; 57:1191-7. [PMID: 11764260 DOI: 10.1111/j.0006-341x.2001.01191.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We propose a method to estimate the regression coefficients in a competing risks model where the cause-specific hazard for the cause of interest is related to covariates through a proportional hazards relationship and when cause of failure is missing for some individuals. We use multiple imputation procedures to impute missing cause of failure, where the probability that a missing cause is the cause of interest may depend on auxiliary covariates, and combine the maximum partial likelihood estimators computed from several imputed data sets into an estimator that is consistent and asymptotically normal. A consistent estimator for the asymptotic variance is also derived. Simulation results suggest the relevance of the theory in finite samples. Results are also illustrated with data from a breast cancer study.
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Granular flows through vertical pipes controlled by an electric field. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:061305. [PMID: 11736178 DOI: 10.1103/physreve.64.061305] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2001] [Indexed: 05/23/2023]
Abstract
The flow of granular nickel particles moving down vertical pipes from a hopper in the presence of a local, horizontal ac electric field is studied experimentally. The flow is initiated by opening the bottom outlet of the pipe after the pipe is fully filled with particles from the hopper. The mass of particles flowing out of the pipe is measured as a function of time by an electronic balance. The time dependence of the steady-state flow rate Q, under each fixed voltage V, is obtained. Depending on the magnitude of V, two types of flow behaviors are observed. For low V (<V(c)=2.0 kV), a downward-moving interface-separating a dense particle region below it from a low-density region above-exists between the hopper and the electrodes. Two prominent peaks exist in the Q(t) curve for V in the range of 1.4 kV< or =V<V(c), resulting in two clearly defined flow rates Q(A2) and, later in time, Q(B). The particles measured by Q(A2) originate from the pipe above the electrodes, and those by Q(B) coming initially from the hopper. For high V (> or =V(c)), no interface exists and the whole region between the hopper and the electrodes are densely filled; only one constant flow rate Q(A2) is observed. (The precise meaning of Q(A2) and Q(B) are defined in the text.) The steady-state flow rates Q(A2) and Q(B) measured for each V, are plotted as a function of V. The flow rate Q(A2) is a monotonically decreasing function of V, which can be approximately fitted by a power law, with an exponent of -0.8, while Q(B) is found to be voltage independent. These features result from a competition between the blocking effect of the electric-field region and the gravity-driven pushing effect from the hopper outlet. The local electric field is able to retard the downward movement of a dense column existing above it, but is ineffective in doing so when the column above is dilute in density.
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[The biological effect of verapamil on hypertrophic scar fibroblast]. ZHONGHUA ZHENG XING WAI KE ZA ZHI = ZHONGHUA ZHENGXING WAIKE ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY 2001; 17:328-31. [PMID: 11838051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To study the mechanism of calcium channel antagonist Verapamil on the treatment of hypertrophic scar and explore the possibility of further clinical application. METHODS After six strains of HSFB were cultured in vitro, we investigated HSFB proliferation by MTT method, investigated HSFB collagen synthesis by 3H-proline uptaken and Hydroxyproline colorimetric analysis, and investigated collagen gene expression by Northern Blot. RESULTS Verapamil can inhibit HSFB proliferation, collagen synthesis and gene expression by a dose-depended manner, especially treated with 100 mumol/L Verapamil. CONCLUSION By inhibiting I, III procollagen gene expression, Verapamil can inhibit the formation of hypertrophic scar.
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[Investigation on skin retrograde degeneration after tissue expansion]. ZHONGHUA ZHENG XING WAI KE ZA ZHI = ZHONGHUA ZHENGXING WAIKE ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY 2001; 17:347-9. [PMID: 11838058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To study the effects of tissue expansion on tissue damage and retrograde degeneration. METHODS 9 cases of conventional intermittent tissue expansion (CITE) and 9 cases of continuous pressure-controlled tissue expansion (CPTE) were chosen for the study. In creating of the expanded flaps, tissue samples were taken for histopathology, molecular biology and transmission electron microscope (TEM) examinations. RESULTS Capillary bleeding, elastic and reticular fiber proliferation, arteriole thrombosis, fibroblast apoptosis and collagenolysis were observed after expansion. Retrograde degeneration was obvious in CITE group and acute lesion was obvious in CPTE group. CONCLUSION Expansion stimulation induces tissue damage and retrograde degeneration, which indicates that the time for conventional intermittent expansion should be shortened and too fast continuous expansion is harmful.
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Abstract
Twenty-five patients (20 men and 5 women) with the chief complaint of facial hyperhidrosis were treated by transthoracic endoscopic T-2, 3 sympathectomy. All patients were essentially in good health except the embarrassment of facial sweating. Fifteen of them also suffered from distressing palmar hyperhidrosis. The ages ranged from 18 to 40 years (mean age 25 years). All of them except two obtained a satisfactory improvement of facial hyperhidrosis after 3 months to 2 years of follow-up. One man demonstrated very mild ptosis in the right eye. Pre- and postoperative sympathetic skin response (SSR) revealed the absence rate from 20% to 72% with electrical stimulation (p < 0.05). This study shows that T-2, 3 sympathectomy is a choice of treatment for facial hyperhidrosis and sympathetic supply to the face may at least partly be from T-2, 3 level.
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Abstract
Absorption of dietary cholesterol from the intestine is an important part of cholesterol homeostasis and represents the first step that allows dietary cholesterol to exert its metabolic effects. Although the role of bile salts in the initial absorption of dietary cholesterol, by the formation of emulsions, is readily appreciated, the recognition that other molecular mechanisms might govern this process is only recently gaining momentum. Not only does the intestine regulate the amount of dietary cholesterol that enters the body; it is very selective with regard to the sterols that are allowed in. The human intestine is responsible for absorbing a significant amount of cholesterol each day. In addition to approximately 0.5 g d(-1) of dietary cholesterol, many other sterols are also present in almost equal abundance in the normal diet. Approximately 0.4 g of plant sterols, such as sitosterol, brassicasterol and avanesterol, are also present. However, the human body seems to allow only cholesterol to enter and remain in the body, with almost negligible amounts of plant sterols being retained. That specific molecular mechanisms are responsible for this behavior is supported by the identification of the genetic defect(s) in a rare disorder, beta-sitosterolemia (MIM 210250), where this process is disrupted. Such studies are now beginning to throw light on sterol absorption and excretion and elucidate the molecular mechanisms that govern these processes.
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[Harmful effect of ultraviolet radiation and sunscreening cosmetics]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 2001; 30:319-20. [PMID: 12561606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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217
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Genetic analysis of early- versus late-stage ovarian tumors. Cancer Res 2001; 61:5895-904. [PMID: 11479231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
In the United States, ovarian cancer is the fourth most common cause of cancer-related deaths among women. The most important prognostic factor for this cancer is tumor stage, or extent of disease at diagnosis. Although women with low-stage tumors have a relatively good prognosis, most women diagnosed with late-stage disease eventually succumb to their cancer. In an attempt to understand early events in ovarian carcinogenesis, and to explore steps in its progression, we have applied multiple molecular genetic techniques to the analysis of 21 early-stage (stage I/II) and 17 advanced-stage (stage III/IV) ovarian tumors. These techniques included expression profiling with cDNA microarrays containing approximately 18,000 expressed sequences, and comparative genomic hybridization to address the chromosomal locations of copy number gains as well as losses. Results from the analysis indicate that early-stage ovarian cancers exhibit profound alterations in gene expression, many of which are similar to those identified in late-stage tumors. However, differences observed at the genomic level suggest differences between the early- and late-stage tumors and provide support for a progression model for ovarian cancer development.
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218
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Melting mechanisms at the limit of superheating. PHYSICAL REVIEW LETTERS 2001; 87:055703. [PMID: 11497785 DOI: 10.1103/physrevlett.87.055703] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2000] [Indexed: 05/23/2023]
Abstract
The atomic-scale details during melting of a surface-free Lennard-Jones crystal were monitored using molecular dynamics simulations. Melting occurs when the superheated crystal spontaneously generates a sufficiently large number of spatially correlated destabilized particles that simultaneously satisfy the Lindemann and Born instability criteria. The accumulation and coalescence of these internal local lattice instabilities constitute the primary mechanism for homogeneous melt nucleation inside the crystal, in lieu of surface nucleation for equilibrium melting. The vibrational and elastic lattice instability criteria as well as the homogeneous nucleation theory all coincide in determining the superheating limit.
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Associated change in plantar temperature and sweating after transthoracic endoscopic T2-3 sympathectomy for palmar hyperhidrosis. J Neurosurg 2001; 95:58-63. [PMID: 11453433 DOI: 10.3171/spi.2001.95.1.0058] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Transthoracic endoscopic T2-3 sympathectomy is currently the treatment of choice for palmar hyperhidrosis. Compensatory sweating of the face, trunk, thigh, and sole of the foot was found in more than 50% of patients who underwent this procedure. The authors conducted this study to investigate the associated intraoperative changes in plantar skin temperature and postoperative plantar sweating. METHODS One hundred patients with palmar hyperhidrosis underwent bilateral transthoracic endoscopic T2-3 sympathectomy. There were 60 female and 40 male patients who ranged in age from 13 to 40 years (mean age 21.6 years). Characteristics studied included changes in palmar and plantar skin temperature measured intraoperatively, as well as pre- and postoperative changes in plantar sweating and sympathetic skin responses (SSRs). In 59 patients (59%) elevation of plantar temperature was demonstrated at the end of the surgical procedure. In this group, plantar sweating was found to be exacerbated in three patients (5%); plantar sweating was improved in 52 patients (88.1%); and no change was demonstrated in four patients (6.8%). In the other group of patients in whom no temperature change occurred, increased plantar sweating was demonstrated in three patients (7.3%); plantar sweating was improved in 20 patients (48.8%); and no change was shown in 18 patients (43.9%). The difference between temperature and sweating change was significant (p = 0.001). Compared with the presympathectomy rate, the rate of absent SSR also significantly increased after sympathectomy: from 20 to 76% after electrical stimulation and 36 to 64% after deep inspiration stimulation, respectively (p < 0.05). CONCLUSIONS In contrast to compensatory sweating in other parts of the body after T2-3 sympathetomy, improvement: in plantar sweating was shown in 72% and worsened symptoms in 6% of patients. The intraoperative plantar skin temperature change and perioperative SSR demonstrated a correlation between these changes.
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Abstract
The authors describe a patient with ossiculum terminale. Thin-section three-dimensional computerized tomography reconstructions, magnetic resonance images, and radiographs of the cervical spine were obtained to evaluate the atlantoaxial stability and structures of the ossiculum terminale. Bone had formed between the ossicles and the body of the odontoid process, and good atlantoaxial stability was clearly demonstrated.
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Non-traumatic cerebrospinal fluid rhinorrhea indirectly caused by remote brain tumor: a case report and review of the literature. Clin Neurol Neurosurg 2001; 103:83-6. [PMID: 11516549 DOI: 10.1016/s0303-8467(01)00118-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Non-traumatic cerebrospinal fluid rhinorrhea indirectly caused by a remote brain tumor has rarely been reported. Here we describe a case of non-traumatic cerebrospinal fluid rhinorrhea that occurred as the initial symptom of a posterior falx meningioma. In addition, based on the period of occurrence of cerebrospinal fluid rhinorrhea before or after the tumor operation, we introduced a novel classification for these cases into pre-treatment and post-treatment types. The findings of the present case and the results of our literature research suggest that different treatments should be used for patients with these two types of non-traumatic cerebrospinal fluid rhinorrhea resulting from remote brain tumor. After tumor excision, patients of the pre-treatment type may receive conservative management or cerebrospinal fluid shunting, while patients of the post-treatment type need direct repair of the fistula.
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MESH Headings
- Adult
- Hematoma, Subdural, Acute/diagnostic imaging
- Hematoma, Subdural, Acute/etiology
- Hematoma, Subdural, Acute/surgery
- Hematoma, Subdural, Chronic/diagnostic imaging
- Hematoma, Subdural, Chronic/surgery
- Humans
- Male
- Neurosurgical Procedures/adverse effects
- Tomography, X-Ray Computed/methods
- Treatment Outcome
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Differential telomerase expression and telomere length in primary intracranial tumors. CHANG GUNG MEDICAL JOURNAL 2001; 24:352-60. [PMID: 11512366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
BACKGROUND Telomerase activity and telomere length have been shown to be involved in controlling cell proliferation and regulating cell senescence. The authors examined telomerase activity and telomere length in intracranial tumors to determine the clinicopathological behavior of primary intracranial tumors with respect to telomerase expression and alteration of telomere length. METHODS Telomerase activity was examined in 139 brain tumor samples. Telomere length was examined in 138 of the 139 samples. These tumors included 61 meningiomas, 27 schwannomas, 19 high-grade neuroepithelial tumors, and 32 low-grade neuroepithelial tumors. Telomerase activity was measured with a telomerase polymerase chain reaction, enzyme-linked immunosolvent assay kit. Telomere length was examined by Southern blot analysis for the terminal restriction fragment length. RESULTS Telomerase activity was detected in 39.2% (20/51) of the neuroepithelial tumors. Detection rates were 47.4% (9/19) for anaplastic astrocytomas and glioblastomas and 34.4% (11/32) for low-grade neuroepithelial tumors. However, detectable telomerase activity was found in 30.8% (4/13) of atypical or malignant meningiomas, but was not detected in any schwannomas. There was a highly significant difference in the telomerase detection rate in neuroepithelial or non-neuroepithelial tumors (p = 0.001). Telomere elongation was found in 11.7% (7/60) of all meningiomas, 46.1% (6/13) of atypical or malignant meningiomas, and 14.8% (4/27) of schwannomas. Elongation of telomere length was detected in 12.6% (11/87) of the cases and 23.5% (12/51) in neuroepithelial tumors. This difference was also significant (p < 0.05). Telomere length was reduced in the majority, (75%, 3/4) of malignant or atypical meningiomas with detectable telomerase activity, but only 45% (9/20) of the neuroepithelial tumors. CONCLUSION These results indicate that telomerase activation may be a critical step in the pathogenesis of intracranial tumors. Telomere length elongation also indicates a high potential for malignant behavior in these tumors.
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Cryptophycin-induced hyperphosphorylation of Bcl-2, cell cycle arrest and growth inhibition in human H460 NSCLC cells. Cancer Chemother Pharmacol 2001; 47:170-8. [PMID: 11269744 DOI: 10.1007/s002800000210] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Bcl-2 has been described as a factor that can protect from apoptosis. The protective effect of Bcl-2 may be lost if the protein is phosphorylated. Bcl-2 phosphorylation can be induced by agents that affect microtubule depolymerization or prevent microtubule assembly. In 13 human tumor cell lines there was a high degree of heterogeneity in Bcl-2 protein expression. Human H460 non-small-cell lung carcinoma (NSCLC) cells expressed high levels of Bcl-2 and were selected for study. Western blot analysis for Bcl-2 phosphorylation was carried out after 4 h and 24 h of exposure to cryptophycin 52, cryptophycin 55, paclitaxel or vinblastine. Cryptophycin 52 and cryptophycin 55 were very potent inducers of Bcl-2 phosphorylation. After 4 h of exposure, Bcl-2 phosphorylation was evident with 0.05 nM cryptophycin 52, 0.25 nM cryptophycin 55, 5 nM vinblastine and 50 nM paclitaxel. The hyperphosphorylated form of Bcl-2 was evident after 24 h exposure of H460 cells to 0.25 nM cryptophycin 52 or cryptophycin 55 and 50 nM vinblastine or paclitaxel. The effects of the compounds on the cell cycle paralleled those on Bcl-2 phosphorylation. In H460 cells 90% cell killing was obtained with 0.13 nM cryptophycin 52, 0.2 nM cryptophycin 55, 20 nM paclitaxel and > 100 nM vinblastine after 24 h of exposure as determined by colony formation. In Bcl-2-negative Calu-6 NSCLC cells, 90% cell killing was obtained with 0.03 nM cryptophycin 52, 0.1 nM cryptophycin 55, 11 nM paclitaxel and 0.5 nM vinblastine using the same experimental design. Thus, cryptophycins are potent inducers of Bcl-2 phosphorylation. The cryptophycins were more potent cytotoxic agents in Bcl-2-negative Calu-6 cells than in Bcl-2-positive H460 cells indicating that pathways triggered by Bcl-2 phosphorylation are involved in cryptophycin-induced lethality.
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Abstract
OBJECTIVES The independent predictors of aphasia outcome for patients with left basal ganglia hemorrhage were evaluated. PATIENTS AND METHODS We included 140 patients of 1,036 patients with spontaneous intracerebral hemorrhage admitted to our hospital from January 1993 through December 1997. Aphasia was assessed using the aphasia scale of the Scandinavian stroke scale. Univariate and step-wise logistic regression analyses were performed to assess the relationships between the initial aphasia score, age, gender, blood volume, locations of hematoma and aphasia outcome. RESULTS Step-wise logistic regression analysis revealed that the following two factors were independently associated with the final aphasia outcome: initial aphasia score (P < 0.0001) and location of hematoma involving the posterior limb of the internal capsule (P = 0.004). CONCLUSIONS A particularly high likelihood of poor aphasia outcomes of patients with left basal ganglia hemorrhage are predicted in those who have poor initial aphasia score and whose brain computed tomography shows the hematoma involves the posterior limb of the internal capsule.
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Diagnosis and results of treatment with radiation therapy in gliomatosis cerebri patient: case report. CHANG GUNG MEDICAL JOURNAL 2001; 24:196-201. [PMID: 11355088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Gliomatosis cerebri (GC) is a rare disease loosely defined as a diffusely infiltrating glioma involving extensive areas of the brain. The prognosis is poor and no definite treatment has proven effective for GC. Little information exists regarding the role of radiation therapy (RT) for GC, but some researchers have suggested that it is a good choice of treatment from their limited experience. In this report, we present a case with imaging and histological diagnosis of GC and demonstrate the treatment results of RT. The patient was a 39-year-old woman with progressive symptoms of dizziness, unsteady gait, headache, vomiting, and consciousness disturbance for 6 months. She received a series of radiographic examinations and surgical interventions for diagnosis. The definite diagnosis of GC was made by a combination of magnetic resonance imaging (MRI) findings and histological examinations. Forty Gray (Gy) of whole brain irradiation followed by 14 Gy reduced-field boosts were given to her. The MRI, following treatment, showed regressive changes, and clinical symptoms were slightly improved. The patient survived 19 months after the diagnosis, which is longer than the average survival time of patients without treatment.
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Local structures of nanocrystalline GaN studied by XAFS. JOURNAL OF SYNCHROTRON RADIATION 2001; 8:830-832. [PMID: 11512947 DOI: 10.1107/s0909049501000103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2000] [Accepted: 12/20/2000] [Indexed: 05/23/2023]
Abstract
X-ray absorption fine structure (XAFS) was used to investigate the local structures around Ga atoms in the hexagonal nanocrystalline and crystalline GaN under 78 and 300 K. For the first nearest neighbor coordination shell of Ga-N. the average bond length R (0.194 nm), coordination number N (4.0), thermal disorder sigma (0.0052 nm) and static disorder sigmaS (0.0007 nm) are neatly independent of the measured temperature and crystalline state. This indicates that the Ga-N covalent bond is much stronger, and the 4 nitrogen atoms in first nearest neighbor around Ga atoms keep the tetrahedral structure (Td). For the second nearest neighbor coordination shell of Ga-Ga, their bond lengths are about 0.318 nm. However, the sigmaS (0.0057 nm) of nanocrystalline GaN is 0.0047 nm larger than that of crystalline GaN (0.001 nm), and the sigmaT of nanocrystalline is 0.0053 nm and 0.0085 nm at the temperature of 78 and 300 K, respectively. The result indicates that the difference of local structure around Ga atoms between nanocrystalline and crystalline GaN occurs mainly at the Ga-Ga second nearest-neighbor coordination shell. The reason is explained as the local lattice distortion and unsaturated surface atoms existing in nanocrystalline GaN.
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Expression of pRB, cyclin/cyclin-dependent kinases and E2F1/DP-1 in human tumor lines in cell culture and in xenograft tissues and response to cell cycle agents. Cancer Chemother Pharmacol 2001; 46:293-304. [PMID: 11052627 DOI: 10.1007/s002800000136] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE Cell cycle regulatory components are interesting targets for cancer therapy. Expression of pRb, cyclin D1, cdk4, cyclin E, cdk2, E2F1 and DP-1 was determined in MCF-7 and MDA-MB-468 breast carcinoma cells, H460 and Calu-6 non-small cell lung carcinoma cells, H82 and SW2 small cell lung carcinoma cells, HCT116 and HT29 colon carcinoma cells and LNCaP and DU-145 prostate carcinoma cells. METHODS For Western blotting, the ratio with actin expression was used to normalize the data; all lines were run on the same gels. RESULTS In cell culture, pRb was not detected in MB-468 and H82 was low in SW2 and DU-145 and highest in HCT116; in tumors, pRb was not detected in MB-468, H82, SW2, and DU-145 and was highest in LNCaP and Calu-6. Cyclin D1 was not detected in SW2 cells in culture, was low in MB-468 and H82, and was highest in LNCaP and H460; in tumors, cyclin D1 was low in MB-468, H460, SW2 and DU 145, and was highest in LNCaP. In cell culture, cdk4 was lowest in Calu-6, HCT116, HT29 and DU-145 and highest in H82 and SW2; in tumors, cdk4 was low in MCF-7, MB-468, H460, Calu-6 and HCT116 and was very high in the SW2. Expression of cyclin E was very low in MCF-7 and HT29 and high in H460 in culture and was very low in MCF-7, H460, Calu-6, H82, HT29 and DU-145 in tumors and high in HCT116 and LNCaP. In cell culture, E2F1 was lowest in MB-468, Calu-6, HT29 and DU-145 cells and highest in LNCaP cells; in tumors, E2F1 was lowest in MCF-7, MB-468 and Calu-6 and highest in LNCaP. In cell culture, DP-1 was lowest in MB-468, HCT116 and HT29 and highest in SW2. The MCF-7 and MB-468 lines were most resistant to flavopiridol and olmoucine and the H460 and Calu-6 lines were most resistant to genistein. The SW2 tumor was most responsive to flavopiridol and olomoucine. CONCLUSIONS There is a high degree of variability in the expression of cell cycle components in human tumor cell lines, resulting in complexity in predicting response to cell cycle directed agents.
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Fabrication of large-aperture lightweight diffractive lenses for use in space. APPLIED OPTICS 2001; 40:447-451. [PMID: 18357017 DOI: 10.1364/ao.40.000447] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We describe the advantages of using diffractive (Fresnel) lenses on thin membranes over conventional optics for, among others, future space telescope projects. Fabrication methods are presented for lenses on two types of freestanding membrane up to 50 cm in size. The first is a Fresnel lens etched into a thin (380-microm) glass sheet, and the second is an approximately 50-microm-thick polymer membrane containing a Fresnel lens made by replication process from a specially made fused-silica master. We show optical performance analysis of all the lenses that are fabricated, including a diffraction-limited Airy spot from a 20-m- focal-length membrane lens in a diffractive telescope system.
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Abstract
PURPOSE Internuclear ophthalmoplegia is a syndrome produced by a lesion in the medial longitudinal fasciculus. Head trauma is a rare cause. We describe an unusual case of bilateral internuclear ophthalmoplegia as an isolated sequela following a minor head injury that resolved completely 3 months later. METHODS Case report. Magnetic resonance images. RESULTS A 34-year-old male developed typical bilateral internuclear ophthalmoplegia after closed head injury. Attempted convergence was normal. Magnetic resonance imaging clearly delineated the focal hemorrhage in the medial longitudinal fasciculus region by showing a small bright lesion in the pontomesencephalic junction in the midline on both T2-weighted and T1-weighted images. The diplopia resolved 4 weeks later. Three months after the accident, his versions were completely normal. CONCLUSION Isolated internuclear ophthalmoplegia should be considered in the differential diagnosis when one encounters an adduction deficit in a recently traumatized patient. Magnetic resonance images enhance the ability to correlate the clinical findings with the anatomic lesion.
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Protein kinase C isoform-dependent myocardial protection by ischemic preconditioning and potassium cardioplegia. J Thorac Cardiovasc Surg 2001; 121:137-48. [PMID: 11135170 DOI: 10.1067/mtc.2001.111210] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Ischemic preconditioning combined with potassium cardioplegia does not always confer additive myocardial protection. This study tested the hypothesis that the efficacy of ischemic preconditioning under potassium cardioplegia is dependent on protein kinase C isoform. METHODS Isolated and crystalloid-perfused rat hearts underwent 5 cycles of 1 minute of ischemia and 5 minutes of reperfusion (low-grade ischemic preconditioning) or 3 cycles of 5 minutes of ischemia and 5 minutes of reperfusion (high-grade ischemic preconditioning) or time-matched continuous perfusion. These hearts received a further 5 minutes of infusion of normal buffer or oxygenated potassium cardioplegic solution. The isoform nonselective protein kinase C inhibitor chelerythrine (5 micromol/L) was administered throughout the preischemic period. All hearts underwent 35 minutes of normothermic global ischemia followed by 30 minutes of reperfusion. Isovolumic left ventricular function and creatine kinase release were measured as the end points of myocardial protection. Distribution of protein kinase C alpha, delta, and epsilon in the cytosol and the membrane fractions were analyzed by Western blotting and quantified by a densitometric assay. RESULTS Low-grade ischemic preconditioning was almost as beneficial as potassium cardioplegia in improving functional recovery; left ventricular developed pressure 30 minutes after reperfusion was 70 +/- 15 mm Hg (P <.01) in low-grade ischemic preconditioning and 77 +/- 14 mm Hg (P <.001) in potassium cardioplegia compared with values found in unprotected control hearts (39 +/- 12 mm Hg). Creatine kinase release during reperfusion was also equally inhibited by low-grade ischemic preconditioning (18.2 +/- 10.6 IU/g dry weight, P <.05) and potassium cardioplegia (17.6 +/- 6.7 IU/g, P <.01) compared with control values. However, low-grade ischemic preconditioning in combination with potassium cardioplegia conferred no significant additional myocardial protection; left ventricular developed pressure was 80 +/- 17 mm Hg, and creatine kinase release was 14.8 +/- 11.0 IU/g. In contrast, high-grade ischemic preconditioning with potassium cardioplegia conferred better myocardial protection than potassium cardioplegia alone; left ventricular developed pressure was 121 +/- 16 mm Hg (P <.001), and creatine kinase release was 8.3 +/- 5.8 IU/g (P <.05). Chelerythrine itself had no significant effect on functional recovery and creatine kinase release in the control hearts, but it did inhibit the salutary effects not only of low-grade and high-grade ischemic preconditioning but also those of potassium cardioplegia. Low-grade ischemic preconditioning and potassium cardioplegia enhanced translocation of protein kinase C alpha to the membrane, whereas high-grade ischemic preconditioning also enhanced translocation of protein kinase C delta and epsilon. Chelerythrine inhibited translocation of all 3 protein kinase C isoforms. CONCLUSIONS These results suggest that myocardial protection by low-grade ischemic preconditioning and potassium cardioplegia are mediated through enhanced translocation of protein kinase C alpha to the membrane. It is therefore suggested that activation of the novel protein kinase C isoforms is necessary to potentiate myocardial protection under potassium cardioplegia.
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Effect of isoflurane versus nicardipine on blood flow of lumbar paraspinal muscles during controlled hypotension for spinal surgery. Spine (Phila Pa 1976) 2001; 26:105-9; discussion 109. [PMID: 11148653 DOI: 10.1097/00007632-200101010-00018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN This study compared the effects of isoflurane and nicardipine on regional blood flow of the lumbar paraspinal muscles. OBJECTIVES The purpose of this study was to determine whether treatment with hypotensive agents result in ischemia of the lumbar paraspinal muscles, thereby facilitating surgical procedures. SUMMARY OF BACKGROUND DATA Despite the general acceptance of controlled hypotension as effective in reducing blood loss during spinal surgery, the changes of blood flow that occur at the lumbar paraspinal muscles when this technique is applied remain unclear. The use of laser Doppler flowmetry allows changes of muscle blood flow to be easily detected in real time with minimal invasion, thereby allowing differences among distinct pharmacological approaches for induction and maintenance of controlled hypotension to be evaluated. METHODS The prehypotensive and hypotensive (reduction of mean arterial pressure by 20 mm Hg) blood flow of the lumbar paraspinal muscles were assessed with a laser Doppler flowmeter in 40 patients undergoing lumbar spinal surgery. The first half of the patients (n = 20) received isoflurane, whereas the second half received nicardipine to achieve arterial hypotension. RESULTS Compared with the prehypotensive state, during the hypotensive state, patients in the isoflurane group exhibited a 17% to 46% (mean, 33.7%) decrease in lumbar paraspinal muscle blood flow, whereas patients in the nicardipine group exhibited a 24% to 177% (mean, 82.5%) increase in lumbar paraspinal muscle blood flow. Statistical analysis showed a significant difference in the changes of flux after induced hypotension between the isoflurane and nicardipine group (P < 0.001). CONCLUSIONS Depending on the pharmacological treatment used to achieve arterial hypotension in spine surgery, there will be either a reduction in paraspinal muscle blood flow (ischemia) or an enhancement of this blood flow (hyperemia).
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Patterns of palmar skin temperature alterations during transthoracic endoscopic T2 sympathectomy for palmar hyperhidrosis. Auton Neurosci 2000; 86:99-106. [PMID: 11269931 DOI: 10.1016/s1566-0702(00)00202-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transthoracic endoscopic T2 sympathectomy has been widely applied to the treatment of a variety of sympathetically mediated disorders. Palmar hyperhidrosis is probably the most common indication for thoracic sympathectomy, especially in certain subtropical areas. Which sympathetic ganglion is to be ablated and how extensive such ablation is enough to eliminate palm sweating are two important issues. Intraoperative monitoring of palmar skin temperature (PST) is the most frequently used method for assessing the accuracy as well as adequacy of ablation of the target sympathetic ganglia. With continuous monitoring of bilateral PST during the operative course of T2 sympathectomy, it was possible to depict the alterations of bilateral PST in response to specific surgical procedures in a real-time manner. For each case, a PST graph was obtained, which represented the graphical expression of intraoperatively recorded bilateral PST data plotted against time. The PST graphs of 93 consecutive cases were analysed. Three types of PST graphs existed, reflecting different responses of bilateral PST to different surgical procedures during the operation. In Type I PST graph pattern, found in 58 cases, skin incision and intercostal muscle dissection caused dramatic bilateral PST drop; and unilateral T2 sympathectomy induced synchronous bilateral PST elevation. Twenty-four cases demonstrated Type II PST graph pattern, in which unilateral T2 sympathectomy caused only ipsilateral PST elevation, although the PST-depressing effect of skin incision and muscle dissection was as significant as in Type I graph pattern. In the 11 cases who showed Type III PST graph pattern, neither skin incision nor T2 sympathectomy induced any apparent changes of PST on either side, giving rise to two rather flat PST curves on the PST graphs. These findings implicate that reciprocal interactions between bilateral sympathetic activities exist in the majority of cases, and that crossover sympathetic modulation may play a role in the neural control of the sudomotor and vasomotor activities of the palms. This study also provides information regarding how PST would possibly change following specific surgical procedures during transthoracic endoscopic T2 sympathectomy, which may be of importance to those who use intraoperative PST monitoring as a guide in determining whether or not the correct sympathetic ganglia are ablated for adequate sympathetic denervation of the palms.
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Conjugate addition reactions of alpha-aminoalkylcuprates with alpha, beta-alkenyl-, alpha,beta-alkynyl-, alpha,beta-beta,gamma-allenyl-, and alpha,beta-gamma,delta-dienyl carboxylic acid derivatives, nitriles, and sulfoxides. J Org Chem 2000; 65:8715-24. [PMID: 11112594 DOI: 10.1021/jo0056038] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
alpha-Aminoalkylcuprates prepared from alpha-lithio carbamates and CuCN.2LiCl participate in 1,4-addition reactions with alpha, beta-unsaturated esters, thiol esters, imides, and nitriles in poor to excellent yields depending upon the electron-withdrawing substituent and the substitution pattern of the unsaturated substrate. These reagents also undergo conjugate addition reactions with alpha,beta-alkynyl esters, sulfoxides, and nitriles and with alpha,beta-beta,gamma-unsaturated allenyl esters. Excellent stereocontrol is achieved in the conjugate additions of alpha-aminoalkylcuprates to the allenyl esters, while poor stereoselectivity results in the conjugate additions to the alkynyl derivatives. Deprotection and cyclization of the alkynyl adducts affords pyrrolin-2-ones, while similar treatment of the allenyl adducts affords 4-alkylidine- pyrrolidin-2-ones and pyrrolizidinones.
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Abstract
BACKGROUND Telomerase activity and telomere length have been shown to be involved in the control of cell proliferation and regulation of cell senescence. The expression of telomerase activity may endow cells with the capacity of unlimited proliferation and immortality. The authors examined the telomerase activity and telomere length of intracranial meningiomas to determine the relation between the results and the clinicopathologic behavior of these tumors. METHODS Sixty-two specimens of meningiomas including 13 atypical and malignant tumors were used in this study. Telomerase activity was measured with polymerase chain reaction and enzyme-linked immunosolvent assay. Telomere length was measured by detecting the terminal restriction fragments using Southern blots. RESULTS Detectable telomerase activity was found in 4 of 13 (30.8%) malignant or atypical meningiomas and only 1 in 49 benign meningiomas (P = 0.006). Elongated telomere length was measured in 6 of 13 (46.1%) patients with malignant or atypical meningiomas and only 1 of 48 (2.1%) in those with benign tumors (P = 0.0002). Three of 4 (75%) of malignant or atypical meningiomas with detectable telomerase activity revealed shortened telomere length, and all tumors with elongated telomere length displayed undetectable telomerase activity. The percentage of malignant or atypical meningiomas with detectable telomerase activity or elongated telomere were significantly higher (76.9%) than that of benign tumors (4.0%). The proliferative index was calculated as the percentage of tumor cell nuclei immunoreactive for Ki-67 to total tumor nuclei. The mean values of proliferative index in benign, atypical, and malignant meningiomas were 1.2, 11.0, and 30.0, respectively. CONCLUSIONS The results indicate that telomerase activation may be a critical step in the pathogenesis of malignant or atypical meningioma. Elongation of the telomere length also implicates the high potential for malignant behavior in these tumors.
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Abstract
The doppel protein (Dpl) is a newly recognized prion protein (PrP)-like molecule encoded by a novel gene locus, prnd, located on the same chromosome as the PrP gene. To study the structural features of Dpl, we have expressed recombinant human Dpl corresponding to the putative mature protein domain (residues 24-152) in Escherichia coli. The primary structure of the recombinant Dpl 24-152 was characterized using gel electrophoresis, N-terminal Edman sequencing, matrix-assisted laser desorption ionization mass spectrometry, and electrospray ionization mass spectrometry. Dpl 24-152 was shown to contain two disulfide bonds (Cys94-Cys145 and Cys108-Cys140). The secondary structure of Dpl was analyzed using far-UV circular dichroism spectroscopy. Dpl 24-152 was found to be an alpha-helical protein having a high helical content (40%). Dpl 24-152 exhibited characteristics of a thermodynamically stable protein that undergoes reversible and cooperative thermal denaturation. In addition, Dpl was found to be soluble and sensitive to proteinase K digestion. Therefore, Dpl 24-152 possesses biochemical properties similar to those of recombinant PrP. This study provides knowledge about the molecular features of human Dpl that will be useful in further investigation into its normal function and the role it may play in neurodegenerative diseases.
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An approach to analysis of large-scale correlations between genome changes and clinical endpoints in ovarian cancer. Cancer Res 2000; 60:5382-5. [PMID: 11034075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
This report describes analyses of associations of genome copy number abnormalities in ovarian cancers with clinical features using genome-wide graphical and analytical procedures. These studies show that tumor grade is a better indicator of the extent of genomic progression than stage, that loss of chromosome 4 occurs preferentially in high-grade tumors, and that gains of 3q26-qter, 8q24-qter, and 20q13-qter occur frequently in low-grade and low-stage tumors and thus may be early events in ovarian cancer development. In addition, loss of chromosome 16q24 and a total number of independent genome copy number aberrations >7 are associated with reduced survival duration. The association of loss of 16q24 (D16S3026) with decreased survival duration was confirmed by quantitative PCR. Regions that frequently are abnormal and associated with altered survival duration are strong candidates for higher resolution analysis and gene discovery and may be useful markers for prediction of clinical outcome.
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[Study on the biology feature and pathogenicities to silkworm of a microsporidium isolated from Barathra brassicae L]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2000; 40:540-4. [PMID: 12548768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
A microsporidium (called as Bab-M) was isolated from Barathra brassicae L. captured from suburban vegetable plot of Guang Zhou. The spores were long-ovoid in shape and 4.02 +/- 0.36 microns x 1.99 +/- 0.36 microns in size. Immunologically the microsporidium shared spore surface specific antigen(s) with N. bombycis. The ultrastructure and life cycle of Bab-M were similar to that of N. b.. The rate of transovarian transmission was high. The initial conclusion was that Bab-M should be referred to as Nosema bombycis, but there was variation between them.
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Superiority of mitral valve replacement with preservation of subvalvular structure to conventional replacement in severe rheumatic mitral valve disease: a modified technique and results of one-year follow up. THE JOURNAL OF HEART VALVE DISEASE 2000; 9:616-22. [PMID: 11041173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND AND AIM OF THE STUDY Mitral valve replacement with preservation of the subvalvular apparatus (MRVP) has been proven superior to conventional mitral valve replacement (MVR). We devised a simple modified MVRP method in this prospective, randomized study to investigate the clinical effects and one-year follow up echocardiographic results of MVRP compared with MVR in patients with severe rheumatic mitral insufficiency (MI). METHODS Sixty-eight patients with severe rheumatic MI with or without stenosis were randomized to MVRP (n = 35) and MVR (n = 33) groups. In MVRP patients, the preserved tissue was pulled back posteriorly to the posterior wall of the left ventricle, then plicated and reaffixed to one-fourth of the annular circumference in the posterior annulus, in order to prevent left ventricular outflow tract (LVOT) obstruction. Clinical data including cumulative ventricular arrhythmias and use of inotropes were collected. Echocardiography examination was performed before surgery, and at five days, three months and one year thereafter. RESULTS There were no preoperative differences patient data. The cross-clamp time was 2.2 min longer in MVRP patients. The one-month mortality rate after surgery was lower in MVRP patients (2.9% versus 15.2%, p = 0.074). Mechanical ventilation and ICU times were shorter in the MVRP group (17.6 versus 24.8 and 52.5 versus 70.6 h, p = 0.001 and 0.1, respectively). There were fewer ventricular arrhythmias and less need for inotropic support in this group. One year follow up echocardiography data showed better preserved left ventricular ejection fraction (LVEF) and better recovery of heart size after MRVP. There was no indication that preserved valvular tissue interfered with mechanical valve function, or caused LVOT obstruction. CONCLUSION This modified MVRP technique is simple, effective and without risk of LVOT obstruction. In severe rheumatic MI patients the outcome of MVRP is superior to that of conventional MVR in term's of mortality, postoperative care needs, left ventricular function and heart dimensions.
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Superheating of confined Pb thin films. PHYSICAL REVIEW LETTERS 2000; 85:1484-1487. [PMID: 10970535 DOI: 10.1103/physrevlett.85.1484] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2000] [Indexed: 05/23/2023]
Abstract
In this work we report, for the first time, an experimental observation of a superheating phenomenon in metal thin films. By means of cold rolling, Pb thin films of about 20 nm thick were sandwiched by Al layers, and between them semicoherent epitaxial Pb/Al interfaces were formed. In situ x-ray diffraction analysis indicated that the confined Pb thin films could be superheated for at least 6 degrees C. Thermodynamic analysis indicated that such a substantial superheating in the confined two-dimensional thin films may originate from suppression of growth of the molten droplets by the epitaxial Al/Pb/Al confinement, instead of suppression of melt nucleation for the confined particle superheating.
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Abstract
STUDY DESIGN A retrospective study of 36 patients with mid- to lower cervical spinal cord injury (CSCI) divided into two groups based on whether delayed apnea developed. OBJECTIVES To determine nonpulmonary risk factors associated with the development of delayed apnea in mid- to lower cervical spinal cord injury. SUMMARY OF BACKGROUND DATA Patients with mid- to lower cervical spinal cord injury are generally at lower risk of developing respiratory failure than those with high cervical spinal cord injury. Respiratory failure manifesting as sudden apnea may occur days or even weeks after injury without any pulmonary complications in such patients. METHODS An index group of eight patients with complete mid- to lower cervical spinal cord injury in whom delayed catastrophic apnea occurred were reviewed. Another group of 28 patients with cervical spinal cord injury of identical magnitude and presentation but without respiratory failure served as the control group. Six parameters presumed to be related to the delayed apnea were analyzed. RESULTS The extent of cord lesions was significantly different, being diffuse in most of the index patients, but focal in the majority of the control patients (P<0.001). Involvement of the C4 segment of cord appeared to be more frequent in the index group; however, the difference was not statistically significant (P = 0.091). The incidence of transient bradycardia (P<0.01) and dyspnea (P<0.001) in the index group was significantly higher than in the control group. Paralytic ileus was a much rarer event and found to be unrelated to the occurrence of apnea. In five of the eight index patients, the apnea occurred during sleep. Six of the eight index patients died of it. CONCLUSIONS Delayed but devastating apnea may develop in patients with mid- to lower cervical cervical spinal cord injury, even when they are clinically stable and free from any pulmonary complications. The presence of diffuse, extensive cord lesions, respiratory distress, or bradycardia with or without associated hypotension, however transient and self-limited, should be regarded as warning signs. Sleep was found to be a risky period of time.
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Transforming growth factor-beta and response to anticancer therapies in human liver and gastric tumors in vitro and in vivo. Int J Oncol 2000; 16:599-610. [PMID: 10675495 DOI: 10.3892/ijo.16.3.599] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Liver cancer and gastric cancer are the most common solid tumors worldwide. Transforming growth factor-beta (TGF-beta) production and lack of response to TGF-beta growth inhibitory effects have been associated with tumor progression and therapeutic resistance. HepG2, Hep3B, and SK-HEP-1 human liver cancer lines produce 3, 5.7, and 2.5 ng TGF-beta1; 1.4, 2, and 4 ng TGF-beta2 and 0.15, 0.2 and 0.22 ng TGF-beta3 per 107 cells (24 h). Expression of the TGF-beta type I receptor is 20x, 1x, and 0.6x the level in mink lung MvLu1 cells in the HepG2, Hep3B, and SK-HEP-1 cells, respectively. HepG2 and Hep3B cells do not express the TGF-beta type II receptor while SK-HEP-1 cells express 7x the level found in mink lung MvLu1 cells. Hs 746T, KATO III, RF-1, and RF-48 human gastric cancer cell lines produce 12. 5, 0.35, 0.4, and 0.4 ng TGF-beta1; 2.6, 0.95, 0.5, and 0.52 ng TGF-beta2 and 0.42, 0.17, 0.12, and 0.14 ng TGF-beta3 per 107 cells (24 h). Expression of TGF-beta type I receptor is 0.7x, 0.7x, 0.8x, 0.6x the level in mink lung MvLu1 cells in the Hs 746T, KATO III, RF-1 and RF-48 cells, respectively. KATO III cells are lacking in the TGF-beta type II receptor while Hs 746T, RF-1 and RF-48 cells express 10x, 0.8x, and 1x the levels in mink lung MvLu1 cells. The IC50 for TGF-beta1 is >>10 ng/ml in all of these lines except RF-48 where TGF-beta1 is mitogenic. The response of the cell lines to radiation, doxorubicin, mitomycin C, cisplatin, 5-fluorouracil, methotrexate, and gemcitabine showed that SK-HEP-1 was the most drug resistant liver cancer cell line and KATO III was the most drug resistant gastric cancer cell line. Overall, there was no correlation between TGF-beta secretion in cell culture and sensitivity of the cells to anticancer agents. Increased TGF-beta1 levels were detectable in the plasma of nude mice bearing Hep3B and Hs 746T xenografts. Those tumors which secreted greater amounts of TGF-beta were more therapeutically resistant in vivo.
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Abstract
A bulk nanocrystalline (nc) pure copper with high purity and high density was synthesized by electrodeposition. An extreme extensibility (elongation exceeds 5000%) without a strain hardening effect was observed when the nc copper specimen was rolled at room temperature. Microstructure analysis suggests that the superplastic extensibility of the nc copper originates from a deformation mechanism dominated by grain boundary activities rather than lattice dislocation, which is also supported by tensile creep studies at room temperature. This behavior demonstrates new possibilities for scientific and technological advancements with nc materials.
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[Transposition of the pedicled latissimus dorsi myocutaneous flap for the treatment of lymphedema of the upper limb after radical mastectomy]. ZHONGHUA ZHENG XING WAI KE ZA ZHI = ZHONGHUA ZHENGXING WAIKE ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY 2000; 16:7-9. [PMID: 11501034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
OBJECTIVE The clinical study was to improve the surgical treatment to upper limb lymphedema. METHODS The author treated 12 cases of severe lymphedenia of the upper limb using the pedicled latissimus dorsi myocutaneous flap. The treatment was completed in one stage. RESULTS The results were satisfactory in all the cases during the follow-up period of one to three years. No recurrence occurred. CONCLUSIONS The method is a good treatment to secondary lymphedema of the upper limb after radical mastectomy as it possesses the advantages of casiness to perform, short operation time, reliable effects, very safety and accordance to physiology.
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Abstract
OBJECT Transthoracic endoscopic T-2 sympathectomy is currently the treatment of choice for palmar hyperhidrosis (PH). Intraoperative monitoring of palmar skin temperature (PST) is often used to assess the adequacy of sympathetic ablation. The aim of this study was to investigate the time course of PST changes during the operation and to determine factors involved in the sympathetic modulation of the palmar skin blood flow. METHODS Eighty-one patients with PH underwent bilateral transthoracic endoscopic sympathectomy of T-2 in which continuous intraoperative PST monitoring was used. Palmar skin temperature data, recorded every 30 seconds throughout the operation, were plotted against time, and a graph of two PST curves was obtained in each case. A multiphasic curve pattern of great similarity was observed in nearly 70% of cases. Specific PST readings at different operative stages were collected and averaged for all cases. The trend of PST changes in response to different procedures during the operation was analyzed. It was found that unilateral procedures caused simultaneous bilateral PST alterations. In almost all cases, bilateral PST was dramatically lowered when unilateral skin incision and intercostal muscle dissection were performed. The temperature remained low until the T-2 sympathectomy was finished on one side. In addition, unilateral T-2 sympathectomy induced synchronous elevation of bilateral PST. However, the ipsilateral response was significantly stronger than that on the contralateral side. CONCLUSIONS Although intraoperative monitoring of PST is a reliable guide for surgeons performing endoscopic transthoracic sympathectomy, it is important to realize that PST fluctuates at different stages during the operation and that surgical procedures themselves can significantly influence PST readings. The PST data recorded at specific time points, therefore, can be misleading in terms of accuracy and the completeness of ablation of the target sympathetic ganglia, especially when the sympathetic trunk or ganglia are anatomically aberrant.
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[Viability and dynamic observation of stretchback of the continuously expanded skin flap in the pig model]. ZHONGHUA ZHENG XING WAI KE ZA ZHI = ZHONGHUA ZHENGXING WAIKE ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY 2000; 16:24-6. [PMID: 11501023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
OBJECTIVE To investigate the viability of the continuously expanded skin flap and the dynamic change of flap stretchback in the pig model. METHODS White piglets and a constant pressure-infusing pump were employed to establish a continuous tissue expansion model. The animals were divided into two groups. The short rectangular expander of 180 ml was used in group A and the long rectangular expander of 210 ml was used in group B. Three days after completion of the continuous expansion, normal random and expanded skin flaps were created to assess flap viability and stretchback. RESULTS Flap survival length in group A and B increased by 92.60% and 91.96% respectively versus normal random flap. But there was no significant difference in survival length between group A and B. Obvious flap stretchback was observed in the early stage. Eight weeks after flap operation the flap width of group A and B restored to that of the random skin flaps (P > 0.05). CONCLUSION Continuously fast-expanded skin flaps are reliable in viability for soft tissue reconstruction. Larger expanders cannot further enhance the viability of the expanded flap.
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The relationship between interleukin-8 and airway hyperresponsiveness in guinea pigs. Chin Med J (Engl) 1999; 112:985-7. [PMID: 11721480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
OBJECTIVE To explore the relationship between interleukin-8 (IL-8) and airway hyper-responsiveness (AHR) of asthma in guinea pigs. METHODS IL-8 at a dose of 0.5 microgram/kg or 5.0 micrograms/kg was administered intranasally to guinea pigs twice a week for 3 weeks. 24 hours after the last administration, airway responsiveness was measured as an overall index of airway response to the increasing concentrations of histamine inhaled (25, 50, 100 and 200 micrograms/ml), and the numbers of different inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted. RESULTS The IL-8 treatment significantly enhanced airway responsiveness to histamine in a dose-dependent manner (P < 0.05 or P < 0.01) and induced a significant influx of neutrophils in BALF (P < 0.01), and a great number of neutrophils were seen within the airway wall, but not within the control animals treated with phosphate buffered saline (PBS). CONCLUSION The IL-8 could produce neutrophil inflammation of the airways and induce AHR, which suggested that IL-8 may play an important role in asthma, especially in the development of AHR.
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Abstract
The mast cell is one of the immune cells, and can be triggered behaviorally to increase in the CNS of the sexually active dove. In the present study, we used ICR mice to investigate the number of brain mast cells in mated (one male with three female mice), non-mated (housed with female mice, but no mating) and control (four male mice housed together in one cage) male mice. We found that at least 40% of mated male mice had significant more mast cells than the maximum value seen in the controls, and that a significant correlation existed between the distribution index of mast cells and the postcoitum date. These mast cells were especially numerous in the thalamus and velum interpositum (VIP). Morphological observations showed that the increased mast cells were ultrastructurally similar to those in the controls, and displayed gonadotropin-releasing hormone (GnRH)-like immunoreactivity. Based on the facts that the number of brain mast cells in the male mice increased significantly after mating and that the change in the distribution of mast cells in the VIP and the thalamic parenchyma correlated well with time postcoitum, we speculate that, after mating, mast cells may migrate from the VIP to the thalamic parenchyma along the vascular tree of the brain. These results strongly suggest that mast cells are involved in the interaction among the immune, endocrine, and nervous systems in the mated male mouse brain.
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