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J Lin

Publications and source records attributed to J Lin.

At least 73 records · Page 4Linked to original sources
PubMed2001

The cell specific temporal expression of nitric oxide synthase isoforms during achilles tendon healing.

OBJECTIVE AND DESIGN: We have previously shown that nitric oxide synthase (NOS) activity is upregulated following tendon injury, and that this activity is important to Achilles tendon healing. The aim of this study was to identify the cellular distribution of nitric oxide synthase isoforms during tendon healing. MATERIAL OR SUBJECTS: Surgical division of the right Achilles tendon was performed in eighty-five male Sprague-Dawley rats. Healing Achilles tendons were harvested at 4, 7, 14 and 21 days following the surgery. The un-injured left Achilles tendons were used as controls. Using RNase protection assays, in situ hybridization and immunohistochemistry, mRNA and protein of NOS isoforms were evaluated. RESULTS: Minimal NOS expression was found in un-injured tendon. A cell specific temporal pattern for the mRNA and protein for all three NOS isoforms was found following injury to the Achilles tendon. iNOS was maximal on day 4 in macrophages and fibroblasts. eNOS was maximal on day 4 in endothelial cells and fibroblasts. bNOS expression gradually increased up to day 21 and was found only in fibroblasts. CONCLUSIONS: These results suggest that all three nitric oxide synthase isoforms are expressed by fibroblasts in a coordinated temporal sequence during tendon healing. The sequential pattern of NOS expression in healing fibroblasts suggests that each NOS isoform may play a different role in the healing process and provides opportunities to modify tendon healing in the clinical setting.

Achilles Tendon↗
PubMed2001

Growth suppression of hamster flank organs by topical application of catechins, alizarin, curcumin, and myristoleic acid.

Hamster flank organ growth, as measured by an increase in the area of the pigmented macule, is androgen-dependent. When flank organs of a castrated hamster are treated topically with testosterone, the flank organ becomes larger and darker. Since this growth is known to be dependent on the intracellular active androgen, 5alpha-dihydrotestosterone (DHT), inhibitors of 5alpha-reductase which converts testosterone to DHT can inhibit the growth of the flank organ. Certain unsaturated aliphatic fatty acids, such as gamma-linolenic acid and myristoleic acid, as well as other natural compounds, including alizarin and curcumin, are 5alpha-reductase inhibitors and inhibited flank organ growth. Green tea catechins, including (-)-epicatechin-3-gallate, and (-)-epigallo-catechin-3-gallate (EGCG) are also 5alpha-reductase inhibitors and inhibited flank organ growth. However, (-)-epicatechin and (-)-epigallocatechin, which are not 5alpha-reductase inhibitors, also inhibited flank organ growth. EGCG also inhibited DHT-dependent growth of flank organs. These catechins, therefore, may act by a mechanism other than inhibition of 5alpha-reductase. The effect of EGCG and other compounds was localized at the site of application; they did not affect the growth of the contralateral flank organ in the same animal. Since these compounds do not appear to exhibit systemic effects, they may be potentially useful for treatment of androgen-dependent skin disorders.

Administration, Topical↗
PubMed2001

Quantification of key odorants formed by autoxidation of arachidonic acid using isotope dilution assay.

Six odor-active compounds generated by autoxidation of arachidonic acid (AA) were quantified by isotope dilution assay (IDA), i.e., hexanal (1), 1-octen-3-one (2), (E,Z)-2,4-decadienal (3), (E,E)-2,4-decadienal (4), trans-4,5-epoxy-(E)-2-decenal (5), and (E,Z,Z)-2,4,7-tridecatrienal (6). Compound 1 was the most abundant odorant with about 700 mg/100 g autoxidized AA, which corresponds to 2.2 mol% yield. Based on the odor activity values (ratio of concentration to odor threshold), odorants 3 (fatty) and 5 (metallic) showed the highest sensory contribution followed by 1 (green), 2 (mushroom-like), 6 (egg white-like), and 4 (fatty). For the first time, reliable quantitative results are reported for odorants 1-6 in autoxidized AA, in particular odorant 6, which is a characteristic compound found in autoxidized AA. Synthesis of deuterated 6, required for IDA, is described in detail. The formation of odorants 1-6 by autoxidation of AA is discussed with respect to the quantitative data.

Aldehydes↗
PubMed2001

Treatment of N,N-dimethylacetamide waste gas by a trickle-bed air biofilter.

The system performance of a trickle-bed air biofilter (TBAB) for treating N,N-dimethylacetamide (DMAC) waste gas was investigated under different gas flow rates and influent concentrations. In the pseudo-steady-state conditions, the DMAC elimination capacity increased but the removal efficiency decreased as the influent loading increased. More than 90% and 80% DMAC removal efficiencies are achieved for influent loadings below 20.2 and 34.5 g DMAC/m3/h, respectively. The TBAB appears to be an effective treatment process for controlling DMAC emission with low-to-medium loadings and the effectiveness could be maintained over a long-period operation.

Acetamides↗
PubMed2001

Murine prolactin-like protein E synergizes with human thrombopoietin to stimulate expansion of human megakaryocytes and their precursors.

The aim of this study was to determine the effect of promegakaryocytopoietic murine hormone prolactin-like protein E (PLP-E) on human megakaryocytopoiesis. Human bone marrow CD34+ cells, cultured in serum-free medium with combinations of thrombopoietin (TPO), stem cell factor (SCF), Flt-3 ligand (Flt-3L), and PLP-E, were analyzed via microscopy, flow cytometry, and clonogenic assay. Unlike the situation with mouse cells, PLP-E alone did not promote human megakaryocyte (MK) differentiation, but instead synergizes with TPO to increase colony-forming unit megakaryocyte (CFU-MK), burst-forming unit erythroid (BFU-E), and and colony-forming unit granulocyte erythroid macrophage mixed (CFU-GEMM) expansion, as well as total MK production. These effects can be attributed to an increase in colony frequency, combined with a significantly greater total cell expansion induced by adding PLP-E along with TPO. The number of cells in each CFU-MK colony is an indication of the maturity of the progenitor population, with larger colonies deriving from a more immature progenitor cell. PLP-E significantly expanded immature, intermediate, and mature CFU-MK subsets at 3 days of culture, as well as the intermediate and mature subsets at day 6. PLP-E combined with TPO induced significant expansion of all CFU-MK subsets at all time points. PLP-E further increased the effect of SCF and Flt-3L on TPO-induced total cell and CFU-MK expansion.PLP-E may act as a survival factor for primitive human megakaryocytic and erythroid progenitors. It appears to preserve the highly proliferative immature fraction of the progenitor compartment but by itself does not promote total cell proliferation or human MK production. PLP-E may prove useful in combination with TPO and other cytokines for ex vivo expansion of hematopoietic progenitors to be used in a clinical setting.

Animals↗
PubMed2001

Stress analysis of the distal locking screws for femoral interlocking nailing.

In femoral locked nailing, the distal locking screws are vulnerable to mechanical failure. Biomechanical studies have shown that the stress on these screws is substantially affected by the fit of the nail in the medullary canal. In this study, a "closed form" mathematical model based on elastic beam-column theory was developed to investigate how the nail-cortical contact, which was simulated by a linear elastic foundation, affected the stress on the distal locking screws. Providing data for the model was a construct of a fractured femur with an intramedullary locked nail loaded by an eccentric vertical load. The stress on the locking screw was analyzed as a function of the distance from the fracture to the locking screw in the distal fragment under two situations: with and without nail-cortical contact in the distal fragment. With nail-cortical contact, the screw stress decreased as the length of nail-cortical contact and the distance between the distal locking screw and the fracture site increased, but this stress contrarily increased when the nail reached the femoral region at which the screw length increased. The screw stress was much higher without nail-cortical contact than with contact and continued to increase as the nail was inserted further. The mathematical model developed here can be a convenient means of rapid stress evaluation and parametric analysis for locked femoral nailing. It may be used to improve the design of interlocking nails and surgical technique.

Biomechanical Phenomena↗
PubMed2001

Treatment of methylacetate waste gas using a trickle-bed air biofilter.

The trickle-bed air biofilter (TBAB) performance for methylacetate (MA) removal from waste gases was evaluated under different gas flow rates and influent concentrations. In the pseudo-steady-state conditions, the elimination capacity increased but the removal efficiency decreased with the increase of MA loading. More than 95 and 90% removal efficiencies were achieved for influent MA loadings below 390 and 727 g/m3/h, respectively. The TBAB appears to be a very effective treatment process for controlling MA emission under low to high loading conditions, and the effectiveness could be maintained over 190 days of laboratory operation.

Acetates↗
PubMed2001

Cytokine stimulation of energy expenditure through p38 MAP kinase activation of PPARgamma coactivator-1.

Cachexia is a chronic state of negative energy balance and muscle wasting that is a severe complication of cancer and chronic infection. While cytokines such as IL-1alpha, IL-1beta, and TNFalpha can mediate cachectic states, how these molecules affect energy expenditure is unknown. We show here that many cytokines activate the transcriptional PPAR gamma coactivator-1 (PGC-1) through phosphorylation by p38 kinase, resulting in stabilization and activation of PGC-1 protein. Cytokine or lipopolysaccharide (LPS)-induced activation of PGC-1 in cultured muscle cells or muscle in vivo causes increased respiration and expression of genes linked to mitochondrial uncoupling and energy expenditure. These data illustrate a direct thermogenic action of cytokines and p38 MAP kinase through the transcriptional coactivator PGC-1.

Animals↗
PubMed2001

Identification of potent odorants formed by autoxidation of arachidonic acid: structure elucidation and synthesis of (E,Z,Z)-2,4,7-tridecatrienal.

The aroma composition of autoxidized arachidonic acid was characterized by aroma extract dilution analysis. The most potent odorant was trans-4,5-epoxy-(E)-2-decenal followed by 1-octen-3-one, (E,Z)-2,4-decadienal, (E,Z,Z)-2,4,7-tridecatrienal, (E,E)-2,4-decadienal, and hexanal. (E,Z,Z)-2,4,7-Tridecatrienal was unequivocally identified by mass spectrometry and nuclear magnetic resonance (NMR) data. The stereochemistry of its extended double-bond system was elucidated on the basis of NMR measurements. The target compound was synthesized in four steps starting with bromination of 2-octyn-1-ol, followed by copper-catalyzed coupling of the bromide with ethylmagnesium bromide and (E)-2-penten-4-yn-1-ol. Partial hydrogenation of the resulting C(13)-compound with triple bonds in the positions C-4 and C-7 gave rise to (E,Z,Z)-2,4,7-tridecatrien-1-ol, which was finally oxidized to the target compound. It exhibits a typical egg-white-like, marine-like odor at low concentrations, and an intense orange-citrus, animal-like odor at higher concentrations. Its odor threshold was estimated by gas chromatography-olfactometry to be 0.07 ng/L air, which is of the same order of magnitude as that reported for 1-octen-3-one and (E,E)-2,4-decadienal.

Arachidonic Acid↗
PubMed2001

Coordinated Muc2 and Muc3 mucin gene expression in Trichinella spiralis infection in wild-type and cytokine-deficient mice.

Mucin hypersecretion is an important component of the immune response to gastrointestinal nematode infection. Two discrete types of mucin proteins exist in the mouse intestine, secretory Muc2 and membrane-bound Muc3. We examined Muc2 and Muc3 expression in wild-type mice and mice lacking gamma interferon receptor (IFNgammaR-/-), tumor necrosis factor receptor 1 (TNFR1-/-) and interleukin 4 (IL4-/-) infected with Trichinella spiralis. Infected wild-type mice demonstrated significant goblet cell hyperplasia and increased mucin glycoprotein. In situ hybridization showed this was accompanied by increases in Muc2 and Muc3 mRNA. Total intestinal mucin protein and Muc2 and Muc3 mRNA levels were also significantly increased in cytokine-deficient mice. These data demonstrate the coordinated up-regulation of two types of mucin genes in response to T. spiralis infection and may form the basis of an innate mucosal response independent of IFN-gamma, TNF, and IL-4.

Animals↗
PubMed2001

Isolation of an aerobic denitrifying bacterial strain NS-2 from the activated sludge of piggery wastewater treatment systems in Taiwan possessing denitrification under 92% oxygen atmosphere.

AIMS: To isolate aerobic denitrifying bacteria which will be applied to piggery wastewater treatment facilities for enhanced nitrate and nitrite removal. METHODS AND RESULTS: Nitrate-supplemented basal medium in airtight, crimp-sealed serum bottles containing an atmosphere of 92% oxygen was inoculated with denitrifiers, strains NS-2 and SM-3, and incubated at 30 degrees C. After 20 h, the concentration of nitrate was decreased rapidly by both NS-2 and SM-3. Nitrite production was almost zero during the whole experimental period for both strains. Nitrogen gas production peaked at the 20 h for both NS-2 (8.20 +/- 1.03 mmol l(-1)) and SM-3 (3.93 +/- 0.16 mmol l(-1)). CONCLUSIONS: Strain NS-2, which produced the highest N2 concentration in this work, was identified as Pseudomonas stutzeri. This strain is the most capable of aerobic and anaerobic conversion of nitrate to N2 without forming a nitrite intermediate. SIGNIFICANCE AND IMPACT OF THE STUDY: Strain NS-2 is highly promising for future application in in situ piggery wastewater treatment.

Aerobiosis↗
PubMed2001

Obesity-related glomerulopathy: an emerging epidemic.

BACKGROUND: We report the first large renal biopsy-based clinicopathologic study on obesity-related glomerulopathy. METHODS: Obesity was defined as body mass index (BMI)> 30 kg/m2. Obesity-related glomerulopathy (ORG) was defined morphologically as focal segmental glomerulosclerosis and glomerulomegaly (O-FSGS; N = 57) or glomerulomegaly alone (O-GM; N = 14). RESULTS: Review of 6818 native renal biopsies received from 1986 to 2000 revealed a progressive increase in biopsy incidence of ORG from 0.2% in 1986-1990 to 2.0% in 1996-2000 (P = 0.0001). Mean BMI in ORG was 41.7 (range 30.9 to 62.7). Indications for renal biopsy included proteinuria (N = 40) or proteinuria and renal insufficiency (N = 31). Seventy-one patients with ORG were compared to 50 patients with idiopathic FSGS (I-FSGS). Patients with ORG were older (mean 42.9 vs. 32.6 years, P < 0.001) and more often Caucasian (75% vs. 52%; P = 0.003). ORG patients had a lower incidence of nephrotic range proteinuria (48% vs. 66%; P = 0.007) and nephrotic syndrome (5.6% vs. 54%; P < 0.001), with higher serum albumin (3.9 vs. 2.9 g/dL; P < 0.001), lower serum cholesterol (229 vs. 335 mg/dL; P < 0.001), and less edema (35% vs. 68%; P = 0.003). On renal biopsy, patients with ORG had fewer lesions of segmental sclerosis (10 vs. 39%; P < 0.001), more glomerulomegaly (100% vs. 10%; P < 0.001), and less extensive foot process effacement (40 vs. 75%; P < 0.001). Glomerular diameter in ORG (mean 226 mu) was significantly larger than age- and sex-matched normal controls (mean 168 mu; P < 0.001). Follow-up was available in 56 ORG patients (mean 27 months) and 50 idiopathic FSGS controls (mean 38 months). A total of 75% of ORG patients received angiotensin-converting enzyme (ACE) inhibition or A2 blockade while 78% of the I-FSGS patients received immunosuppressive therapy. ORG patients had less frequent doubling of serum creatinine (14.3% vs. 50%; P < 0.001) and progression to ESRD (3.6% vs. 42%; P < 0.001). On multivariate analysis, presenting serum creatinine and severity of proteinuria were the only predictors of poor outcome in ORG. CONCLUSION: ORG is distinct from idiopathic FSGS, with a lower incidence of nephrotic syndrome, more indolent course, consistent presence of glomerulomegaly, and milder foot process fusion. The ten-fold increase in incidence over 15 years suggests a newly emerging epidemic. Heightened physician awareness of this entity is needed to ensure accurate diagnosis and appropriate therapy.

Adult↗
PubMed2001

Death as a complication of peripherally inserted central catheters in neonates.

We report 2 neonatal deaths caused by cardiac tamponade related to peripherally inserted central catheters (PICCs). A total of 3 deaths were noted for 390 PICCs placed, giving an incidence of 0.76%. To determine the magnitude of neonatal death related to PICCs, directors of neonatal intensive care units in the United States were surveyed by means of a questionnaire. Myocardial perforation and pericardial effusion were reported by 29% and 43%, respectively. Deaths were attributed to PICCs by 24% of the respondents. Uniform guidelines need to be formulated to avoid this complication.

Cardiac Tamponade↗
PubMed2001

Optimal treatment for distal ureteral calculi: extracorporeal shockwave lithotripsy versus ureteroscopy.

BACKGROUND: The optimal treatment for distal ureteral calculi remains controversial. We present data from our institution to compare the efficacy of extracorporeal shockwave lithotripsy (SWL) and ureteroscopy with different lithotripsy modalities (URSL). METHODS: From January 1994 to September 1997, 954 distal ureteral calculi were treated at our institution using in situ SWL (Siemens Lithostar) in 524 patients and ureteroscopy (Wolf 8.0F instrument and Swiss Lithoclast) in 430 patients. Stone sizes and patient ages were similar in these two groups. RESULTS: In the SWL group, the 3-month stone-free rate was 87%, and the effectiveness quotient (EQ) was 68.7%. In the URSL group, there was a 96% stone-free rate with an EQ of 92.1%. The SWL treatment was more expensive than URSL. CONCLUSION: At our institution, ureteroscopy is more efficacious than SWL for the treatment of distal ureteral calculi. In selected patients who had stones >10 mm with evidence of impaction and severe colic pain, we strongly suggest that URSL is the best choice.

Adult↗
PubMed2001

Sacral insufficiency fractures: a report of two cases and a review of the literature.

Sacral insufficiency fractures (SIF) are a type of stress fracture that occur primarily in postmenopausal women. They were first described in 1982 by Lourie and have since been frequently overlooked as a cause of low back, buttock, or groin pain. We present two cases of SIF to demonstrate the clinical presentation, diagnosis, and treatment of patients with SIF. Both patients were elderly women with complaints of pelvic and low back pain in the absence of significant trauma. Physical examination was significant for marked sacral tenderness. Diagnostic imaging supported the diagnosis of SIF. Both patients underwent early rehabilitation, including early ambulation, and had good functional outcomes. These patients serve to illustrate how conservative treatment yields excellent clinical results in the majority of patients, with most reporting improvement within 1-2 weeks after fracture and complete resolution of symptoms after 6-12 months of treatment.

Accidental Falls↗
PubMed2001

Treating premenstrual dysphoric disorder using serotonin agents.

Premenstrual syndrome (PMS) affects 20%-50% of all women. Premenstrual dysphoric disorder (PMDD), which can be conceptualized as a more severe variant of PMS, can affect 3%-9% of all women. Because a significant number of women suffer from premenstrual disorders and afflicted women may spend up to half the month suffering from symptoms, it is important to identify and provide effective treatment for such women. Historically, it has been difficult to distinguish premenstrual disorders from other depressive disorders, given the high comorbidity of the two disorders. Most studies attempt to remove this confounding factor by excluding women with concurrent depressive disorders. Despite the difficulties and limitations inherent in studying treatments for premenstrual disorders, most investigations support the use of serotonin agents in treating PMDD.

Female↗
PubMed2001

Developmental changes in the long form leptin receptor and related neuropeptide gene expression in the pig brain.

The hypothalamus is the key site of central regulation of energy homeostasis, appetite, and reproduction. The long form leptin receptor (Ob-Rl) is localized within the hypothalamus along with several neuropeptides that are involved in regulation of the neuroendocrine axis. In the present study, developmental changes in gene expression of the Ob-Rl, preproorexin, proopiomelanocortin (POMC), corticotropin releasing factor (CRF), somatostatin, and GnRH in the hypothalamus was studied. Expression of Ob-Rl and neuropeptide mRNA was examined by semiquantitative reverse transcription-polymerase chain reaction in hypothalami collected from 106-day-old fetus (n = 3) and 7-day-old (n = 3), 3.5-mo-old (n = 3), and 6-mo-old (n = 2) gilts. In addition, leptin mRNA expression in the first three ages was examined in back fat. Leptin mRNA expression increased (P < 0.05) by 7 days postnatal, but Ob-Rl mRNA expression increased (P < 0.01) by 3.5 mo. Expression of preproorexin (P < 0.05), somatostatin, and GnRH (P < 0.01) mRNA peaked by 3.5 mo of age while POMC mRNA expression increased markedly (P < 0.01) by 6 mo of age. The CRF mRNA expression did not change across ages. These findings suggest a possible relationship among Ob-Rl and a number of hypothalamic and peripheral peptides in the development of the neuroendocrine axis. These peptides may serve as messengers that link mechanisms that regulate reproduction and energy balance.

Animals↗