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Biomedical subjects

C L Lin

Publications and source records attributed to C L Lin.

At least 19 recordsLinked to original sources

The effect of an adenosine A1 receptor agonist in the treatment of experimental subarachnoid hemorrhage-induced cerebrovasospasm.

BACKGROUND: Adenosine is a potent vasodilator and an important modulator of cardiovascular function. It has been postulated that nitric oxide (NO) is involved in adenosine-induced vasodilation. This study was designed to examine the effect of an adenosine A1 agonist, N6-cyclopentyladenosine (CPA), in the prevention of subarachnoid haemorrhage (SAH)-induced vasospasm. Method. Experimental SAH was induced in Sprague-Dawley rats by injecting 0.3 mL autogenous blood into the cisterna magna. Intraperitoneal injections of CPA (0.003 mg/kg), or vehicle were administered 5 min and 24 hours after induction of SAH. The degree of vasospasm was determined by averaging the cross sectional areas of the basilar artery 2 days after SAH. Expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in basilar artery were evaluated. Findings. There were no significant differences among the control and treated groups in physiological parameters recorded before sacrifice. When compared with animals in the control group, cross-sectional area of basilar arteries areas in the SAH only, SAH plus vehicle and SAH plus CPA groups were reduced by 19% (p < 0.01), 22% (p < 0.01), and 9% (p = 0.133), respectively. The cross-sectional areas of the CPA-treated group differed significantly from those of the SAH only and SAH plus vehicle group (p < 0.05). Induction of iNOS-mRNA and protein in basilar artery by SAH was not significantly diminished by CPA. The SAH-induced suppression of eNOS-mRNA and protein were relieved by CPA treatment. Conclusions. This is the first evidence to show an adenosine A1 receptor agonist is effective in partially preventing SAH-induced vasospasm without significant cardiovascular complications. The mechanisms of adenosine A1 receptor agonists in attenuating SAH-induced vasospasm may be, in part, related to preserve the normal eNOS expression after SAH. Inability in reversing the increased iNOS expression after SAH may lead to the incomplete anti-spastic effect of CPA.

Adenosine↗

Infusion of human umbilical cord blood cells protect against cerebral ischemia and damage during heatstroke in the rat.

Intravenously delivered human umbilical cord blood cells (HUCBC) have been previously shown to improve both morphologic and functional recovery of heat-stroked rats. To extend these findings, we examined both the morphologic and functional alterations in the presence of HUCBC or human peripheral mononuclear cells (PBMC) 24 h before initiation of heatstroke. Anesthetized rats, 1 day before the initiation of heatstroke, were divided into three major groups and given the following: (a) serum-free lymphocyte medium (0.3 ml) intravenously; (b) PBMC (5 x 10(6) in 0.3 ml serum-free lymphocyte medium); or (c) HUCBC (5 x 10(6) in 0.3 ml serum-free lymphocyte medium). Another group of rats were exposed to room temperature (26 degrees C) and used as normothermic controls. In vehicle-treated heatstroke rats, their mean arterial pressure, cerebral blood flow, and brain PO(2) were all lower than in normothermic controls after the onset of heatstroke. However, their body temperatures and striatal levels of inducible nitric oxide synthase (iNOS)-dependent NO, ischemia and damage markers (e.g., glycerol, glutamate, and lactate/pyruvate ratio), and neuronal damage in the striatum were all greater. The heatstroke-induced arterial hypotension, cerebral ischemia and hypoxia, and increased levels of iNOS-dependent NO in the striatum were all significantly reduced by pretreatment with HUCBC, but not with PBMC. Moreover, HUCBC were localized by immunohistochemistry and PCR analysis in the injured brain structures and spleen. These findings indicate that HUCBC transplantation, in addition to having therapeutic values, can be a good choice for preventing heatstroke occurrence.

Analysis of Variance↗

Candidate gene markers for sperm quality and fertility of boar.

Candidate genes gonadotropin releasing hormone receptor (GNRHR), prolactin (PRL), prolactin receptor (PRLR), follicle-stimulating hormone beta (FSHB), luteinizing hormone beta (LHB), follistatin (FST), inhibin alpha (INHA), inhibin beta A (INHBA) and inhibin beta B (INHBB) were investigated for their association with sperm quality traits of sperm concentration (SCON), motility (MOT), semen volume per ejaculate (VOL), plasma droplets rate (PDR), abnormal sperm rate (ASR) and fertility traits of non return rate (NRR) and number of piglets born alive (NBA). The experimental material included 356 boars of Pietrain (PI) and Pietrain x Hampshire (PI x HA). Analysis of variance revealed significant association of GNRHR with MOT (P = 0.0161), PDR (P = 0.0048) and ASR (P = 0.0201), INHBA was found to have significant effects on PDR (P = 0.0318) and ASR (P = 0.0067), INHBB was significant (P = 0.0360) for SCON trait. FSHB, FST, INHA, PRL, PRLR and LHB had no significant effects on any trait in this experiment.

Analysis of Variance↗

A three-dimensional coordination polymer featuring effective ferrimagnetic hydroxide-bridged manganese(II) chains.

A three-dimensional coordination polymer, [Mn3(OH)2Na2(3-cnba)6]n (1) (3-Hcnba = 3-cyanobenzoic acid), has been synthesized by the reaction of MnCl2, NaN3, and 3-Hcnba in water. Its crystal structure was determined by single-crystal X-ray diffraction. Magnetic studies show that the complex behaves as a three-dimensional metamagnet built from effective ferrimagnetic Mn(II) chains in which spin moments are linked by interactions in an AF-F-AF (F = ferromagnetic and AF = antiferromagnetic) sequence in the triangular magnetic repeating unit.

Journal Article↗

Role of hydrodynamic drag on microsphere deposition and re-entrainment in porous media under unfavorable conditions.

Deposition and re-entrainment of 1.1 microm microspheres were examined in packed glass beads and quartz sand under both favorable and unfavorable conditions for deposition. Experiments were performed at environmentally relevant ionic strengths and flow rates in the absence of solution chemistry and flow perturbations. Numerical simulations of experimental data were performed using kinetic rate coefficients to represent deposition and re-entrainment dynamics. Deposition rate coefficients increased with increasing flow rate under favorable deposition conditions (in the absence of colloid-grain surface electrostatic repulsion), consistent with expected trends from filtration theory. In contrast, under unfavorable deposition conditions (where significant colloid-grain surface electrostatic repulsion exists), the deposition rate coefficients decreased with increasing flow rate, suggesting a mitigating effect of hydrodynamic drag on deposition. Furthermore, the re-entrainment rate was negligible under favorable conditions but was significant under unfavorable conditions and increased with increasing flow rate, demonstrating that hydrodynamic drag drove re-entrainment under unfavorable conditions. The drag torque resulting from hydrodynamic drag was found to be 1 order of magnitude or more lower than the adhesive torque based on pull-off forces from atomic force microscopy measurements. This result indicates that hydrodynamic drag was insufficient to drive re-entrainment of microspheres that were associated with the grain surface via the primary energy minimum and suggests that hydrodynamic drag drove re-entrainment of secondary-minimum-associated microspheres.

Biomechanical Phenomena↗

Cell-mediated immunity and head and neck cancer: with special emphasis on betel quid chewing habit.

Betel quid (BQ) chewing is popular in Taiwan, India, and many southeast-Asian countries. BQ chewing has strong association with the risk of oral leukoplakia (OL), oral submucous fibrosis (OSF), and oral cancer (OC). BQ components exhibit genotoxicity and may alter the structure of DNA, proteins and lipids, resulting in production of antigenicity. BQ ingredients are also shown to induce keratinocyte inflammation by stimulating the production of prostaglandins, TNF-alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) in keratinocytes. These events may provoke tissue inflammation, early cell-mediated immunity (CMI), and immune surveillance in BQ chewers. However, BQ components also directly affect the functional activities of immunocompotent cells, and moreover tumor cells may hypo-respond to the CMI via diverse mechanisms such as induction of apoptosis of lymphocytes, induction of production of suppressor T cells, downregulation of MHC molecules in tumor cells, etc. Clinically, an alteration in lymphocyte subsets, a decrease in total number of lymphocytes, and a reduction in functional activities of CMI have been observed in isolated peripheral blood mononuclear cells (PBMC) and tumor infiltrated lymphocytes (TIL) in patients with OSF, OL or OC. Adaptation of tumor cells to immune system may promote clonal selection of resistant tumor cells, leading to immune tolerance. Future studies on effects of BQ components on CMI and humoral immunity in vitro and in vivo can be helpful for chemoprevention of BQ-related oral mucosal diseases. To elucidate how virus infection, tobacco, alcohol and BQ consumption, and other environmental exposure affect the immune status of patients with oral premalignant lesions or OC will help us to understand the immunopathogenesis of OC and to develop immunotherapeutic strategies for OC.

Areca↗

Simultaneous multiple hypertensive intracerebral haemorrhages.

BACKGROUND: Simultaneous occurrence of multiple intracerebral haemorrhages (ICHs) in different arterial territories is a rare clinical event which has been reported to be associated with cerebral amyloid angiopathy, venous sinus thrombosis, coagulopathy, vasculitis, haemorrhagic transformation of cerebral infarcts and multiple intracranial pathologies such as vascular anomalies or tumours. Although hypertension is the most common etiological factor for the development of spontaneous single intracerebral bleeding, its role in simultaneous multiple ICHs is not clear. METHODS: The authors have reviewed all patients with non-traumatic ICH admitted to Kaohsiung Medical University Hospital from 1993 to 2002. Ten hypertensive patients with simultaneous multiple ICHs were found. For the purpose of comparison, another 600 cases with solitary hypertensive ICH were also reviewed as a control group. Computerized tomographic scans and medical records concerning patients' histories, clinical presentations, locations of haematomas, associated risk factors, and outcome were analyzed. FINDINGS: The mean age and sex distribution were similar in both patient groups. Bilateral putaminal or thalamic haemorrhages were the most common combinations of simultaneous bleedings. As for the individual location of haematoma, there was a strong preponderance for the supratentorial space with the thalamus being the most preferable site. The duration of hypertension was longer and the percentage of previous stroke was higher in patients with multiple ICHs. Other associated risk factors were similar in both groups except for higher incidence of hypercholesterolemia in multiple ICHs group. Patients with simultaneous multiple ICHs had a much worse outcome compared to those with solitary ICH. CONCLUSIONS: As with solitary ICH, hypertension is still the most important etiological factor for simultaneous multiple ICHs. The widespread and prolonged degeneration of intracerebral arterioles predispose patients to the development of multiple ICHs, which could be justified by the longer history of hypertension and higher incidence of former strokes. Only hypercholesterolemia was identified to be significantly associated with this unusual brain event in our study. The mechanism underlying the development of simultaneous multiple ICHs is not clear although structural and haemodynamic changes of first haemorrhage may be responsible for the second one. Poorer outcome in patients with multiple ICHs can be explained by the concomitant destruction of crossing and non-crossing fiber tracts and bilateral diaschisis phenomenon.

Aged↗

Polymorphisms in candidate genes as markers for sperm quality and boar fertility.

Alpha-actinins (ACTN1 and ACTN4) and gamma-actin (ACTG2), were investigated as candidate genes on the basis of their known functions, for their possible association with sperm concentration, motility, semen volume per ejaculate, plasma droplets rate, abnormal sperm rate and the fertility traits, non-return rate and number of piglets born alive. Polymorphisms were identified in intron 18 (G>A) of the porcine ACTN1 gene and in exon 22 (A>C) of the porcine ACTN4 gene by comparative sequencing of animals from the Pietrain (PI) and Hampshire (HA) breeds. Pietrain (n = 244) and crossbreed PI x HA (n = 112) boars from an artificial insemination boar station were genotyped for the single nucleotide polymorphisms (SNPs) within ACTN1 and ACTN4 as well as for a previously described microsatellite within ACTG2. The study provides evidence for effects of ACTN1 on fertility and of ACTG2 on sperm quality traits, while no indication of impact of ACTN4 on any of these traits was found.

Actinin↗

Up-regulation of macrophage migration inhibitory factor in infants with acute neonatal necrotizing enterocolitis.

AIMS: To investigate the role of macrophage migration inhibitory factor (MIF) and its downstream cytokine cascade in necrotizing enterocolitis (NEC). METHODS AND RESULTS: The expression of MIF mRNA and protein in NEC guts was assayed by in situ hybridization and immunohistochemistry, respectively. Concentrations of MIF, interleukin (IL)-6 and IL-8 in the serum and in the supernatant of macrophage cultures were examined by ELISA. Increased expression of MIF mRNA and protein was observed in the NEC guts, mainly in the infiltrating macrophages in the mucosa and submucosal layers. Up-regulation of MIF was associated with the accumulation of macrophages and T cells. In addition, serum levels of MIF, IL-6 and IL-8 in NEC patients during the acute stage of the disease were significantly increased. The expression of MIF decreased both locally and systemically after the disease was resolved. MIF was also found to increase the secretion of IL-6 and IL-8 by macrophages isolated from healthy individuals in vitro in NEC. CONCLUSIONS: MIF acts by stimulating macrophage production of IL-6 and IL-8. This further aggravates the inflammatory process by increasing the infiltration of neutrophils and activating inflammatory cells. The results of this study suggest that MIF plays an important role in the pathogenesis of NEC and may serve as a target for therapeutic intervention in NEC.

Acute Disease↗

Low-molecular-weight heparin successfully treating a nephrotic patient complicated by renal and ovarian vein thrombosis and pulmonary embolism.

Thromboembolic complications, frequently associated with idiopathic membranous glomerulonephritis, are frequent and serious problems associated with nephrotic syndrome. However, ovarian vein thrombosis associated with nephrotic syndrome has never been reported. This study describes the case of a 35-year-old woman with idiopathic membranous glomerulonephritis who developed left renal vein thrombosis with ovarian vein thrombosis and pulmonary embolism. The thromboembolic complications were successfully treated with low-molecular-weight heparin. Low-molecular-weight heparin thus appears safe and effective for treating thromboembolism in nephrotic patients.

Adult↗

Tuberculous peritonitis in a haemodialysis patient with elevated serum CA 125 and hypercalcaemia.

CA 125, a glycoprotein derived from coelomic epithelium, is used primarily as a marker of epithelial ovarian cancer. However, elevated levels of serum CA 125 have also been detected in other benign and malignant disorders. This study describes a haemodialysis patient who contracted tuberculous peritonitis associated with hypercalcaemia, erythropoietin-resistant anaemia and elevated CA 125, which normalised gradually following antituberculosis treatment. Tuberculous peritonitis should be considered in the differential diagnosis of ascites with elevated serum CA 125. Additionally, CA 125 is a useful marker for monitoring response to tuberculous peritonitis treatment.

Biomarkers↗

Towards dilute magnetic semiconductors: Fe and Co substituted inorganic-organic hybrid materials based on ZnSe.

Inorganic-organic hybrid nanostructures doped with magnetic ions have been synthesized via substitution of Zn by Co or Fe in the ZnSe(L)0.5 systems under solvothermal conditions. These dilute magnetic semiconductors (DMS), Zn(1-x)MxSe(L)0.5 (M = Co, Fe; L = ethylenediamine or en, 1,3-propanediamine or pda; 0 < x < 1), are composed of perfectly ordered Zn(1-x)MxSe semiconductor monolayers interconnected by organic diamine molecules. The large blue shifts in their optical absorption edges (approximately 1.1-1.5 eV) compared to the bulk ZnSe are a direct result of a very strong quantum confinement effect (QCE). Magnetic studies show that there exist antiferromagnetic interactions between the Co or Fe centers in the structures and the interaction is enhanced as the doping concentration increases. The introduction of Fe or Co to hybrid inorganic-organic semiconductors provides a promising route to generate materials that combine the advantageous features of inorganic, organic, and magnetic functionalities in a single structure.

Cobalt↗

Rac1 gene mutations in human brain tumours.

AIMS: Rac1 is a member of the Ras superfamily of small GTPase and plays a fundamental role in cytoskeleton reorganization, regulation of gene expression and cell proliferation, and cellular transformation. Though recent studies point to an involvement of rac1 in tumorigenesis, little is known about the alteration of rac1 gene in human brain tumours. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR), TA cloning, and DNA sequencing were performed to detect rac1 gene mutations in the surgical specimens of 45 human brain tumours. RESULTS: Twelve of 45 cases had base changes in the rac1 gene. The frequency of rac1 alterations was seven of 18 meningiomas, three of 14 astrocytomas, one of seven pituitary adenomas, and one of four metastatic brain tumours. No mutation was detected in acoustic neurilemomas. The subtypes of seven meningiomas include three meningotheliomatous, two atypical, one transitional and one angioblastic meningioma. Three astrocytomas had rac1 gene mutation, including one grade II, one grade III, and one grade IV astrocytoma. All of single base changes were transitions, five of them being T to C transitions. Sites of rac1 mutation were found in codons 34, 41 (two cases), 42 (two cases), 43, 44, 46 and 58. These mutations are mainly localized in the putative effector-domain of rac1 gene and may enhance the activity of rac1, which increases the survival of brain tumours. CONCLUSION: Our results suggest that rac1 gene may play a role in some brain tumours of divergent histogenesis and that the alterations of rac1 gene may contribute to tumorigenesis and/or metastasis.

Adolescent↗

Massive intracerebral air embolism associated with meningitis and lumbar spondylitis: case report.

BACKGROUND: Massive intracerebral air embolism is a rare pathologic state and never in association with meningitis and lumbar spondylitis. To the best of our knowledge, our presented case is the first of a massive intracerebral air embolism associated with meningitis and lumbar spondylitis of Klebsiella pneumonia. CASE DESCRIPTION: A 55-year-old man presented with a high fever and low back pain. Blood culture showed Klebsiella pneumonia. Lumbar computed tomography (CT) revealed discitis at L1-2 and L2-3 levels and paraspinal abscess in which air was found. Despite management with antibiotics, patient's consciousness deteriorated, and brain CT revealed diffuse intravenous air embolism and severe brain swelling. Cerebrospinal fluid (CSF) examination demonstrated bacterial meningitis, and the CSF culture showed Klebsiella pneumonia. Later, septic shock occurred and patient expired. CONCLUSION: Intracerebral air embolism can occur in the Klebsiella pneumonia meningitis that resulted from lumbar spondylitis and sepsis.

Cerebral Veins↗

Earlier appearance and higher incidence of the rectoanal relaxation reflex in patients with imperforate anus repaired with laparoscopically assisted anorectoplasty.

BACKGROUND: This study aimed to evaluate clinically and manometrically the anorectal function of patients with imperforate anus after repair with laparoscopically assisted anorectoplasty (LAR), as compared with the function of patients after undergoing the conventional method, posterior sagittal anorectoplasty (PSARP). METHODS: The defecation status and anorectal manometry of patients with high or intermediate type imperforate anus repaired with LAR ( n = 9) and age-matched patients repaired with PSARP ( n = 13) were assessed and compared during the first year of postoperative follow-up evaluation. The defecation status was classified by the frequency of bowel openings (<1, 1-4, and >5 times per day). Manometric assessment was performed by an open-tip hydraulic capillary infusion system. The presence of the rectoanal relaxation reflex was determined, and the resting sphincteric pressure and resting rectal pressure were measured. RESULTS: Seven of nine LAR patients had an "acceptable" frequency of one to four bowel openings per day, in contrast to 7 of 13 PSARP patients. The difference in the presentation of daily stooling is not significant ( p > 0.05). A positive RAR was detected in 88.9% (8/9) of the LAR patients, and in only 30.8% (4/13) of the PSARP patients ( p < 0.01). The presence of a rectoanal relaxation reflex also significantly correlated with an acceptable frequency of bowel opening (1-4 times per day) in both LAR and PSARP patients ( p < 0.05). Moreover, a rectoanal relaxation reflex was detected significantly earlier in LAR than in PSARP patients (4.9 +/- 1.2 vs 10.1 +/- 2.5 months; postoperatively p < 0.0001). Both the LAR and PSARP patients had a similar resting sphincteric pressure (21.5 +/- 4.7 vs 25.4 +/- 6.2 cm H2O; p > 0.05). By contrast, the resting rectal pressure was significantly lower in LAR than in PSARP patients (7.7 +/- 1.5 vs 11.5 +/- 1.3 cmH(2)O; p < 0.05). CONCLUSIONS: In the early postoperative stage, patients repaired with LAR had more favorable findings in anorectal manometry than patients repaired with PSARP. Long-term follow-up studies to confirm a superior defecation continence achieved with LAR are warranted.

Abnormalities, Multiple↗

The conditional probabilities of survival in patients with anaplastic astrocytoma or glioblastoma multiforme.

BACKGROUND: By the use of conditional probabilities of survival, we studied the yearly survival rates for individual tumor survivors. METHODS: Conditional survival rate was estimated in 114 consecutive patients with anaplastic astrocytoma or glioblastoma multiforme. Conditional probabilities of surviving some years given survival to a specific period of time after craniotomy and 95% confidence intervals were calculated in the individual tumor survivors. RESULTS: The estimated median survival was 30 months for 45 patients with anaplastic astrocytoma and 12 months for 69 patients with glioblastoma multiforme. The conditional probabilities of surviving next one year given survival to 1 year, 2 years, 3 years, 4 years, or 5 years after craniotomy for anaplastic astrocytoma were 86.2%, 75.0%, 85.9%, 77.8%, or 85.7%, respectively; for glioblastoma multiforme 64.8%, 58.7%, 85.7%, 80.0%, or 75.0%, respectively. The conditional probability of surviving to 5 years given survival to 2 years after craniotomy for anaplastic astrocytoma, i.e., surviving an additional 3 years, was 50.1%, which was better than observed 5-year survival rate (28.6%); for glioblastoma multiforme it was 40.2%, which also was better than observed 5-year survival rate (12.4%). CONCLUSIONS: The conditional probability of survival was a good method to clinically predict yearly survival rate for individual tumor survivors. In addition, the method can estimate the probabilities of surviving next some years given survival to a specific period of time after craniotomy. It also showed a more encouraging result than observed survival rate in patients with supratentorial malignant astrocytomas.

Adult↗

Gene frequencies of the HPA-1 to HPA-8w platelet antigen alleles in Taiwanese, Indonesian, and Thai.

Human platelet antigen (HPA) systems consist of more than eight biallelic antigen polymorphisms in which a base pair substitution leads to change in an amino acid of a glycoprotein expressed on the platelet. HPA typing is essential in the diagnosis and treatment for a variety of diseases. We developed a polymerase chain reaction (PCR)-based method to detect HPA-1 through HPA-8w. In this method, the amplified PCR products were used to recognize the polymorphism after restriction enzyme digestions. Among 295 Taiwanese, 107 Indonesian, and 137 Thai subjects studied, HPA-1a, 2a, 4a, 5a, 6a, 7aw, and 8aw genes were present in every sample tested. HPA-1b, 2b, 4b, 5b, and 6b were rarely found among subjects. Only monomorphic HPA-7aw and 8aw alleles were noted in the samples. HPA-3a and 3b alleles showed frequencies of 0.595/0.405, 0.504/0.496, and 0.507/0.493 in Taiwanese, Indonesian, and Thai subjects, respectively. Our report is the first PCR-based method to detect most of the HPA antigen variants in Taiwanese, Indonesian, and Thai. The genomic typing results were also confirmed by direct sequencing for uncertain and some representative cases. The prevalence rates of HPA-1, 2, 3, 4, and 5 in this study were also consistent with other previous reports using different methods.

Alleles↗