Biomedical subjects

J Lin

Publications and source records attributed to J Lin.

At least 19 recordsLinked to original sources

PubMed2007

Subinsular vascular lesions: an analysis of 119 consecutive autopsied brains.

The insula of Reil constitutes a functionally intriguing complex of the brain related to multifunctional activities. We examined the subinsular region in 119 consecutively autopsied patients, as T2 hyperintense lesions are frequently observed in magnetic resonance diagnosis of this region. The patients were admitted in neurology wards and were diagnosed as having cerebrovascular disease in 55 patients (46%), other neurological diseases in 57 patients (48%) and non-neurological diseases in seven patients (6%). Demyelination of the white matter was semi-quantified as a fiber density score (percent stained area/total area) with computer-assisted image analysis on Klüver-Barrera-stained sections. Astrogliosis was assessed by immunohistochemistry for glial fibrillary acidic protein. The lesion analysis showed a dilated perivascular space in 29 patients (24%), demyelination (fiber density score less than the mean - 1 SD) in 27 patients (23%), slit-shaped lesion in six patients (5%), lacunar infarction in one patient (1%) and cerebral hemorrhage in one patient (1%). A histologic-radiologic comparison in two patients with subcortical ischemic vascular dementia showed correspondence between subinsular hyperintensities, and demyelination, gliosis and a dilated perivascular space. These results indicate that subinsular lesions rarely signifies focal vascular lesions, and are consisted of demyelination, gliosis and a dilated perivascular space.

Aged↗

PubMed2007

Anomalous intracranial venous drainage associated with basal ganglia calcification.

We describe the neuroradiologic findings in a 7-year-old boy with anomalous intracranial venous drainage and cerebral calcification. CT scans demonstrated that his scalp mass was a plexus of scalp veins filled through the emissary foramen, and there were cerebral calcifications. Angiography revealed bilateral sigmoid sinus atresia with most of the intracranial venous drainage via the prominent mastoid emissary veins into dilated scalp vein. The possible relationship between cerebral calcification and anomalous intracranial venous drainage is discussed.

Basal Ganglia Diseases↗

PubMed2006

Interleukin-10 gene promoter polymorphisms and their protein production in peritoneal fluid in patients with endometriosis.

Although associations of interleukin-10 (IL-10) gene promoter polymorphisms and their protein production with endometriosis risk have been reported, the correlations remain controversial. The objective of this study was to determine IL-10 gene promoter polymorphisms at -1082, -819 and -592 sites and their protein production in peritoneal fluid (PF) in patients with and without endometriosis. IL-10 gene promoter polymorphisms at -1082 site were detected by amplification refractory mutation system (ARMS)-PCR and that at -819 and -592 sites was genotyped by restriction fragment length polymorphism (RFLP)-PCR. Protein levels of IL-10 in PF were measured by enzyme-linked immunosorbent assay (ELISA). There were no significant differences in the genotype and allele frequencies of IL-10 gene promoter polymorphisms at position -1082 between the endometriosis and the control groups. However, the frequency of -819 or -592 C alleles was significantly increased in patients with endometriosis compared with controls. The protein levels of IL-10 in PF were statistically higher in the endometriosis group than in the control group. Moreover, the polymorphisms at -1082, -819 and -592 sites were associated with protein levels of IL-10 in PF in the endometriosis group while in the control group only the polymorphisms at position -1082 correlated with protein levels. Increased frequency of -819 or -592 C allele and increased protein production of IL-10 in PF in patients with endometriosis compared with controls and correlations of polymorphisms at -819 and -592 sites with protein levels of IL-10 in PF in patients with endometriosis may suggest that polymorphisms at -819 and -592 sites and their protein production are associated with endometriosis risk.

Ascitic Fluid↗

PubMed2006

Methotrexate for ankylosing spondylitis.

BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown cause, characterised by sacroiliitis and spondylitis. Generally, treatment is limited to the alleviation of symptoms using non-steroidal anti-inflammatory drugs (NSAIDs). Recently, disease-modifying antirheumatic drugs (DMARDs) have been used for patients for whom NSAIDs do not work. Methotrexate (MTX), a widely used DMARD, is effective for rheumatoid arthritis (RA), and so might work for AS too. OBJECTIVES: To evaluate the efficacy and toxicity of MTX for treating AS. SEARCH STRATEGY: We conducted searches in any language in: CENTRAL (The Cochrane Library Issue 4, 2005); MEDLINE (1966 to November 20, 2005); EMBASE (1980 to November 20, 2005); CINAHL (1982 to November 20, 2005), and the reference sections of retrieved articles. SELECTION CRITERIA: Randomised and quasi-randomised trials examining the efficacy of MTX versus placebo, other medication, or no medication, for AS. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed unblinded trial reports for inclusion, assessed methodological quality and entered trial data into RevMan 4.2 using the double-entry facility. Disagreements were resolved by a third reviewer. In the absence of significant heterogeneity, results for continuous data were combined using weighted mean difference or standardised mean difference. Relative risk was used for dichotomous data. MAIN RESULTS: Three trials, involving 116 patients, were included. One 12-month trial compared naproxen plus MTX with naproxen alone. Two 24-week trials compared different doses of MTX with placebo. No statistically significant differences were found for the primary outcome measures of physical function, pain, spinal mobility, peripheral joints/entheses pain, swelling and tenderness, changes in spine radiographs and patient and physician global assessment. Only the response rate in one trial showed a statistically significant benefit of 36% in the MTX group compared to the placebo group (RR 3.18, 95% CI 1.03 to 9.79). This response rate was a composite index that included assessments of morning stiffness, physical well-being, Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), health assessment questionnaire for spondyloarthropathies (HAQ-S), and physician and patient global assessment. However, no single outcome showed a statistically significant difference between the MTX and placebo groups when endpoint results were compared. Therefore, this benefit of MTX is questionable. No serious side effects were reported in these trials. AUTHORS' CONCLUSIONS: There is not enough evidence to support any benefit of MTX in the treatment of AS. High-quality randomised controlled trials of longer durations and with larger sample sizes are needed to clarify the effect(s) of MTX on AS.

Antirheumatic Agents↗

PubMed2006

Hip and non-spine fracture risk reductions differ among antiresorptive agents: Evidence from randomised controlled trials.

A number of antiresorptive agents reduce the risk of vertebral fractures, but few have shown consistent effects on hip and other non-spine fractures. Meta-analysis provides a more precise estimate than individual trials when results are consistent across pooled trials. Earlier meta-analyses summarised the results for vertebral and non-spine fractures. New data have emerged for hormone therapy (HT), alendronate (ALN), risedronate (RIS) and ibandronate (IBN). We surveyed recent reports of randomised, placebo-controlled trials with non-spine and/or hip fracture data, and used meta-analysis where appropriate to test for heterogeneity and derive pooled estimates. The magnitude of effect on hip fracture appears to be similar to that for non-spine fracture for each drug, but differs among drugs. Based on the current data, ALN reduces the risk of hip and non-spine fracture by 49-55%, HT by 25-36% and RIS by 26-27%. There is insufficient and/or inconsistent evidence of an effect on these fractures for IBN, calcitonin and raloxifene.

Aged↗

PubMed2006

Vasopressin administration facilitates fluid removal during hemodialysis.

Inadequate secretion of vasopressin during fluid removal by hemodialysis may contribute to the cardiovascular instability that complicates this therapy and administration of exogenous hormone, by supporting arterial pressure, may facilitate volume removal. To test this, we measured plasma vasopressin in patients with end-stage renal disease (ESRD) during hemodialysis and found that despite significant fluid removal, plasma vasopressin concentration did not increase. We further found that ESRD did not alter the endogenous removal rate of plasma vasopressin and that plasma hormone is not dialyzed. Finally, in a randomized, double-blinded, placebo-controlled trial in 22 hypertensive patients, we examined the effect of a constant infusion of a non-pressor dose of vasopressin on the arterial pressure response during a hemodialysis in which the target fluid loss was increased by 0.5 kg over the baseline prescription. We found that arterial pressure was more stable in the patients receiving vasopressin and that while only one patient (9%) in the vasopressin group had a symptomatic hypotensive episode, 64% of the patients receiving placebo had such an episode (P=0.024). Moreover, increased fluid removal was achieved only in the vasopressin group (520+/-90 ml vs 64+/-130 ml, P=0.01). Thus, administration of non-pressor doses of vasopressin to hypertensive subjects improves cardiovascular stability during hemodialysis and allows increased removal of excess extracellular fluid. Inadequate vasopressin secretion during hemodialysis-induced fluid removal is a likely contributor to the intradialytic hypotension that limits fluid removal.

Antidiuretic Agents↗

PubMed2006

African Americans and participation in clinical trials: differences in beliefs and attitudes by gender.

OBJECTIVES: To explore gender differences in perceptions of 1) barriers and motivators to participation in clinical trials and perceived need of clinical trials and 2) perceptions of risks and benefits of participation in clinical trials in African American men and women. METHODS: Focus groups were conducted among African American participants by gender. A total of 67 African American participated in the focus groups. All focus groups were audio-taped and transcribed verbatim. Data analysis was performed by combining the key elements of grounded theory and content analysis with the assistance of the qualitative software ATLAS.ti 5.0. RESULTS: Different themes emerged for men versus women. The business and economic of research were important to male participants. The researcher-participant relationship emerged as one of the strongest themes related to potential female participation in research. DISCUSSION: Focus group results indicate that African American men and women present different preferences, beliefs and barriers to participation. Men expressed the desire to know information on funding issues, financial benefit and impact of the research. Women expressed the desire to be treated respectfully and as an individual as opposed to just a study subject. Integrating gender preferences into researcher-participant interactions, advertisement, informed consent delivery and advertisement of research studies may lead to increased participation rates. Discussing and presenting relevant information on clinical research funding mechanisms, and the business of clinical research with potential participants may be helpful in building trust with the researcher and the research team. Creating a process for information exchange and methods to minimize the power imbalance between the researcher and participant may also build trust and help participants feel more comfortable to participate in research.

Adult↗

PubMed2006

Thermal decomposition of commercial silicone oil to produce high yield high surface area SiC nanorods.

This article reports on the synthesis of high surface area (563m2/g) beta-SiC nanorods by thermal decomposition of commercial silicone oil at a relatively low reaction temperature (800 degrees C) in a closed Swagelok cell. High yield (75%) of SiC nanorods are obtained in this one-stage, solvent-, catalyst-, and template-free synthesis technique that runs at a relative low temperature and employs cheap single-precursor. The morphological (TEM, HR-SEM), compositional (CHNS, EDX, SAEDX]), structural (XRD, HR-TEM, and ED), thermal (TGA) characterizations and surface area analysis are carried out for the obtained SiC nanorods. The possibility of hydrogen storage in this high surface area nano-SiC rods are also tested and reported for the first time.

Carbon Compounds, Inorganic↗

PubMed2006

Variable-radius focused optical vortex with suppressed sidelobes.

We propose a design for a phase mask for generating an optical vortex with suppressed sidelobes in the focal plane where the radius of the intensity ring is variable. A radial modulation added to conventional phase mask exp(iltheta) projects the light diffracted from different annular zones into a single intensity ring in the focal plane.

Journal Article↗

PubMed2006

High-aspect-ratio aluminum borate nanowire bundles supported by sucrose.

High-aspect-ratio and single-crystal aluminum borate (Al(18)B(4)O(33)) nanowire bundles with an ordered orientation were synthesized by using an innovative sucrose-assisted growth process. The process involves the dehydration and polycondensation of aluminum borate-sucrose solution to form a highly viscous precursor. The sucrose plays a crucial role in the growth of the nanowire bundles by supporting as a polymeric substrate and a type of adhesive template. Electron microscopy was used to characterize the high-aspect-ratio nanowire bundles. A possible growth mechanism for the nanowire bundles is proposed.

Journal Article↗

PubMed2006

Core-shell structured SiO2@YVO4:Dy3+/Sm3+ phosphor particles: sol-gel preparation and characterization.

Spherical SiO(2) particles have been coated with YVO(4):Dy(3+)/Sm(3+) phosphor layers by a Pechini sol-gel process, leading to the formation of core-shell structured SiO(2)@YVO(4):Dy(3+)/Sm(3+) particles. X-ray diffraction (XRD), Fourier-transform IR spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as lifetimes were used to characterize the resulting SiO(2)@YVO(4):Dy(3+)/Sm(3+) core-shell phosphors. The obtained core-shell phosphors have perfect spherical shape with narrow size distribution (average size ca. 300 nm), smooth surface and non-agglomeration. The thickness of shells could be easily controlled by changing the number of deposition cycles (20 nm for one deposition cycle). The core-shell particles show strong characteristic emission from Dy(3+) for SiO(2)@YVO(4):Dy(3+) and from Sm(3+) for SiO(2)@YVO(4):Sm(3+) due to an efficient energy transfer from YVO(4) host to them. The PL intensity of Dy(3+) and Sm(3+) increases with raising the annealing temperature and the number of coating cycles.

Gels↗

PubMed2006

Effect of R-(+)-alpha-lipoic acid on experimental diabetic retinopathy.

AIMS/HYPOTHESIS: Hyperglycaemia-induced mitochondrial overproduction of reactive oxygen species (ROS) is central to the pathogenesis of endothelial damage in diabetes. R-(+)-alpha-lipoic acid has advantages over classic antioxidants, as it distributes to the mitochondria, is regenerated by glycolytic flux, and has a low redox potential. METHODS: To assess the effect of R-(+)-alpha-lipoic acid on experimental diabetic retinopathy, three groups of male Wistar rats were studied: non-diabetic controls, untreated diabetic controls, and diabetic rats treated with 60 mg/kg bodyweight R-(+)-alpha-lipoic acid i.p. for 30 weeks. Quantitative retinal morphometry included acellular occluded capillaries and pericyte numbers. The effects of R-(+)-alpha-lipoic acid on parameters of oxidative and nitrative stress, AGE and its receptor and nuclear factor kappa B (NFkappaB) were assessed by immunoblotting, and NFkappaB activation by electrophoretic mobility shift assay. Angiopoietin-2 and vascular endothelial growth factors were also determined by immunoblotting. RESULTS: After 30 weeks of diabetes, the number of acellular capillaries was significantly elevated in diabetic rats (57.1+/-10.6 acellular capillary segments [ac]/mm(2) of retinal area) compared with non-diabetic (19.8+/-5.1 ac/mm(2); p<0.001). Treatment with 60 mg/kg R-(+)-alpha-lipoic acid reduced the numbers by 88% (p<0.001 vs diabetic). Pericyte loss was also significantly inhibited in diabetic rats treated with R-(+)-alpha-lipoic acid (non-diabetic: 1,940+/-137 pericytes/mm(2)capillary area; untreated diabetic: 1,294+/-94 pericytes/mm(2)capillary area vs treated diabetic: 1,656+/-134 pericytes/mm(2); p<0.01). R-(+)-alpha-lipoic acid treatment reduced oxidative stress, normalised NFkappaB activation and angiopoietin-2 expression, and reduced vascular endothelial growth factor in the diabetic retina by 43% (p<0.0001). CONCLUSIONS/INTERPRETATION: R-(+)-alpha-lipoic acid prevents microvascular damage through normalised pathways downstream of mitochondrial overproduction of ROS, and preserves pericyte coverage of retinal capillaries, which may provide additional endothelial protection.

Animals↗

PubMed2006

High-power efficient multiple optical vortices in a single beam generated by a kinoform-type spiral phase plate.

We propose using a solitary kinoform-type spiral phase plate structure to generate an array of vortices located in a single beam. Kinoform-type spiral surfaces allow each wavelength component of the phase modulation value to be wrapped back to its 2 pi equivalent for optical vortices of high charge. This allows the surface-relief profiles of high-charge vortices to be microfabricated with the same physical height as spiral phase plates of unity-charged optical vortices. The m-charged optical vortex obtained interacts with the inherent coherent background, which changes the propagation dynamics of the optical vortex and splits the initial m charge into /m/ unity-charged optical vortices within the same beam. Compared to a hologram, a multistart spiral phase plate is more efficient in the use of available spatial frequencies and beam energy and also is computationally less demanding. Furthermore, using microfabrication techniques will allow for greater achievable tolerances in terms of smaller feature sizes.

Journal Article↗

PubMed2006

Intramedullary cervical tuberculoma.

STUDY DESIGN: Case report. OBJECTIVE: To report a rare lesion of intramedullary cervical tuberculoma. SETTING: Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, The People's Republic of China. CASE REPORT: A 15-year-old boy presented with pain in the neck and shoulder. Examination showed mild left hemiplegia and pinprink hyperalgesia on the left side up to C3 level. Chest X-ray and CT scan showed patch and dot lesions indicating old tuberculous lesions and MRI showed a ring-enhancing intramedullary lesion at C3/4 level. Tuberculoma resection and antituberculous therapy was given. There was satisfactory recovery clinically. CONCLUSION: Intramedullary cervical tuberculoma is a rare, coexisting systemic tuberculosis and MRI scan helps in obtaining a correct diagnosis; combining surgery with anti-tuberculosis therapy is the treatment of choice.

Adolescent↗

PubMed2006

Photodynamic therapy increases brain edema and intracranial pressure in a rabbit brain tumor model.

The objective of this study was to evaluate the effect of a single photodynamic therapy (PDT) on brain edema and intracranial pressure (ICP) in a rabbit model of brain tumor. A total of 57 adult New Zealand rabbits were assigned to 3 groups: the PDT group, the tumor group, and the tumor plus PDT group. Rabbits in the PDT group (n = 9) received PDT but no tumor implantation; rabbits in the tumor group (n = 18) received VX2 carcinoma implantation but no PDT; rabbits in the tumor plus PDT group (n = 30) received tumor implantation with subsequent PDT 16 days later. Brain edema and ICP levels were then evaluated. We found that ICP in the PDT group was 7.43 +/- 0.50 mmHg. After tumor implantation, ICP increased rapidly (18.43 +/- 1.10 mmHg, 21 days later). PDT alone did not increase ICP, but compared with that in the tumor group, ICP increased significantly in the tumor plus PDT group (9.55 +/- 1.32 vs. 13.31 +/- 1.13 mmHg, p < 0.01) 24 hours after treatment. Brain water content in the tumor group increased rapidly after tumor implantation. PDT again increased perineoplastic brain edema 24 hours after treatment (81.09 +/- 0.97% vs. 78.32 +/- 0.49%, p < 0.01). It should be noted that PDT alone did not induce brain edema. In conclusion, PDT causes transient brain edema and increases ICP in a rabbit brain tumor model.

Animals↗

PubMed2006

Mild hypothermia via selective head cooling as neuroprotective therapy in term neonates with perinatal asphyxia: an experience from a single neonatal intensive care unit.

OBJECTIVE: The objective of this study was to determine the efficacy of mild hypothermia via selective head cooling as a neuroprotective therapy in term infants with perinatal asphyxia. STUDY DESIGN: Full-term newborns who had 5 min Apgar scores <6, first arterial blood gas pH<7.10 or BD>15 mEq/l, and with the clinical signs of encephalopathy were enrolled within 6 h after birth. Patients were randomized to receive mild hypothermia treatment via selective head cooling for a total of 72 h or receive routine treatment as a control. Brain hypoxic-ischemic injury was quantified based on the head computed tomographic scan (CT scan) at postnatal age 5-7 days and a Neonatal Behavioral Neurological Assessment (NBNA) score at 7-10 days of life. RESULTS: A total of 58 patients (30 hypothermia, 28 control) completed the study. Hypothermia was well tolerated in this study and attenuated the hypoxic-ischemic brain injury due to perinatal asphyxia. Head CT scan demonstrated moderate to severe hypoxic-ischemic changes in only 4/30 cases from the hypothermic group. In contrast, 18/28 cases in the control group showed moderate to severe hypoxic-ischemic changes (chi (2)=15.97, P<0.01). Brain hypothermia also significantly improved the NBNA score (32+/-2 in the hypothermic group vs 28+/-3 in the control group, P<0.01). CONCLUSIONS: Our results suggest that selective head cooling may be used as a neuroprotective therapy in term neonates with perinatal asphyxia. A long-term follow-up study is needed to further validate the results of this study.

Apgar Score↗

PubMed2006

The association of serum lipids and inflammatory biomarkers with renal function in men with type II diabetes mellitus.

Dyslipidemia and inflammation may promote renal disease via mechanisms of vascular endothelial cell dysfunction in type II diabetes mellitus (DM). Sparse data, however, are available on the relation of lipids and inflammatory biomarkers and glomerular filtration rate (GFR) in type II DM. We performed a cross-sectional study of 732 men with type II DM enrolled in the Health Professionals' Follow-Up Study. Plasma creatinine was used to estimate GFR by the simplified Modification of Diet in Renal Disease (MDRD) equation. In men with a GFR <60 ml/min/1.73 m(2), triglycerides, non-high-density lipoprotein (HDL), apoprotein B, fibrinogen, soluble tumor necrosis factor receptor (sTNFR-2) and vascular cell adhesion molecule-1 (VCAM) were significantly higher when compared to the referent group (GFR> or =90 ml/min/1.73 m(2)). In multivariable logistic regression, those in the highest quartiles of the following biomarkers had increased odds of having a GFR <60 ml/min/1.73 m(2) when compared to those in the lowest quartiles: triglycerides (odds ratio (OR) 3.11; 95% CI, 1.52-6.36), fibrinogen (OR 5.40; 95% CI 2.14-13.65), sTNFR-2 (OR 8.34; 95% CI 3.50-19.88) and VCAM (OR 4.50; 95% CI 1.98-10.23). An inverse association was observed for HDL (OR 0.48; 95% CI 0.24-0.98). We found no association between C-reactive protein and GFR. The results were similar when creatinine clearance by Cockcroft-Gault was used to estimate kidney function. We conclude that several potentially modifiable lipid and inflammatory biomarkers are elevated in the setting of moderately decreased GFR in men with type II DM and may be the link between renal insufficiency and increased risk for cardiovascular events in this population.

Aged↗

PubMed2006

A novel, model-based insulin and nutrition delivery controller for glycemic regulation in critically ill patients.

BACKGROUND: Critically ill patients are often hyperglycemic and insulin resistant, as well as highly dynamic. Tight glucose control has been shown to significantly reduce mortality in critical care. A physiological model of the glucose-insulin regulatory system is improved and used to develop an adaptive control protocol utilizing both nutritional and insulin inputs to control hyperglycemia. The approach is clinically verified in a critical care patient cohort. METHODS: A simple two-compartment model for glucose rate of appearance in plasma due to stepwise enteral glucose fluxes is developed and incorporated into a previously validated system model. A control protocol modulating intravenous insulin infusion and bolus, with an enteral feed rate, is developed, enabling tight and predictive glycemic regulation to preset targets. The control protocol is adaptive to patient time-variant effective insulin resistance. The model and protocol are verified in seven 10-h and one 24-h proof-of-concept clinical trials. Ethics approval was granted by the Canterbury Ethics Committee. RESULTS: Insulin requirements varied widely following acute changes in patient physiology. The algorithm developed successfully adapted to patient metabolic status and insulin sensitivity, achieving an average target acquisition error of 9.3% with 90.7% of all targets achieved within +/-20%. Prediction errors may not be distinguishable from sensor measurement errors. Large errors (>20%) are attributable to highly dynamic and unpredictable changes in patient condition. CONCLUSIONS: Tight, targeted stepwise regulation was exhibited in all trials. Overall, tight glycemic regulation is achieved in a broad critical care cohort with optimized insulin and nutrition delivery, effectively managing glycemia even with high effective insulin resistance.

Aged↗