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Biomedical subjects

Yong Ke

Publications and source records attributed to Yong Ke.

9 recordsLinked to original sources
PubMed2006

Unusual forms of immature sporulating Coccidioides immitis diagnosed by fine-needle aspiration biopsy.

Coccidioidomycosis is an endemic infection acquired by inhalation of the spores (arthroconidia) of the thermally dimorphic fungus, Coccidioides immitis. The arthroconidia transform into spherical cells called mature spherules in the lung. Immature spherules and other atypical forms of immature C immitis have rarely been found in vivo. We report on a case that presented unusual forms of immature sporulating C immitis in a fine-needle aspiration specimen. A 36-year-old Chinese woman, living in New Jersey for the past 10 years, presented with fever, night sweats, hemoptysis, and an abnormal chest radiograph approximately 9 months after a brief vacation trip to the Grand Canyon in Arizona. She was treated with antibiotics for 4 weeks without improvement. Subsequent chest computed tomography showed a 3-cm cavitary lesion in the right lower lobe of the lung. Fine-needle aspiration biopsy revealed diverse morphologic forms of a fungus that was confirmed by culture as immature sporulating C immitis.

Adult↗
PubMed2005

Prefrontal GABA levels in cocaine-dependent subjects increase with pramipexole and venlafaxine treatment.

RATIONALE: There is evidence that prefrontal lobe GABA levels are low in cocaine-dependent (CD) individuals, and treatment with GABA agonists decreases cocaine self-administration. OBJECTIVES: The aim of the study is to measure changes in GABA levels in CD subjects at baseline and after 8 weeks of treatment with pramipexole, venlafaxine, or placebo. METHODS: CD subjects enrolled in a treatment trial for cocaine dependence were recruited for this proton (1H) magnetic resonance spectroscopy (MRS) study. GABA levels in the prefrontal lobe were measured before and after treatment. RESULTS: Mean percentage changes in GABA levels were as follows: pramipexole +17.0+/-28.0%, venlafaxine +13.0+/-11.0%, and placebo -2.1+/-19.5%. Pramipexole-treated subjects had significantly increased brain GABA levels compared to placebo (p=0.031). Venlafaxine treatment was nonsignificantly associated with increased GABA levels compared to placebo (p=0.16). The overall statistical model for the effect of drug treatment vs placebo on brain GABA levels, including adjustment for baseline levels, was highly significant (p=0.002). Despite significant changes in GABA levels, there were no significant differences in the number of urine samples positive for cocaine metabolites. CONCLUSIONS: This study demonstrates that 1H MRS can measure changes in GABA levels following pharmacologic treatment. The increase in GABA levels, although significant, is modest compared to other MRS studies of depression or epilepsy associated with clinical improvements. The failure to see larger increases in GABA levels and an associated reduction in cocaine consumption may reflect the relatively low doses of medication used.

Adult↗
PubMed2005

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Ascitic Fluid↗
PubMed2004

Frontal lobe GABA levels in cocaine dependence: a two-dimensional, J-resolved magnetic resonance spectroscopy study.

Non-invasive measures of brain gamma-aminobutyric acid (GABA) concentrations may be especially useful in the identification of cocaine-related changes in brain chemistry that can be used to guide the development of future treatments for cocaine-dependent persons. This study assessed whether brain GABA levels in cocaine-dependent subjects with and without an alcohol disorder differ from GABA levels in healthy comparison subjects. Two-dimensional, proton magnetic resonance spectroscopy was used to determine GABA levels in the left prefrontal lobe of cocaine-dependent subjects (N=35) recruited from a National Institute on Drug Abuse (NIDA)-sponsored treatment trial of cocaine dependence and a comparison group (N=20). At treatment baseline, mean GABA concentrations were 0.93+/-0.27 mM/kg in cocaine-dependent subjects and 1.32+/-0.44 mM/kg in the comparison sample (t [d.f.=53]=3.65, P<0.001). Cocaine-dependent subjects with a history of a co-morbid alcohol disorder (N=23) had significantly lower baseline GABA levels (0.87 mM/kg) (t [d.f.=41]=4.31, P<0.001) than the comparison group. However, cocaine-dependent subjects without an alcohol disorder (N=12) also had lower GABA levels (1.04 mM/kg) than the comparison subjects (t [d.f.=30]=2.09, P=0.045), suggesting that cocaine dependence alone can decrease GABA levels.

Adult↗
PubMed2004

Oral choline increases choline metabolites in human brain.

Choline, a precursor of acetylcholine and phosphatidylcholine, is largely obtained from the diet. Animal studies demonstrate increased choline metabolites in brain following oral administration. Several proton magnetic resonance spectroscopy ((1)H-MRS) reports differ as to whether similar increases are observable in human subjects. This study was designed to minimize intra-subject variance and thereby maximize the ability to determine if a significant increase in brain choline can be detected after choline ingestion. (1)H-MRS was performed continuously for 2.5 h on 11 healthy young males following choline ingestion. Nine of the original subjects returned for identical scans without choline ingestion. Following oral choline, there was a statistically significant increase in the choline signal (Cho) measured from the left putamen, representing choline-containing compounds, as measured against creatine (Cr) or N-acetylaspartate (NAA). The mean increase in Curve maxima (C(max)) is 6.2% for Cho/Cr and 3.0% for Cho/NAA. The Mean Time to C(max) (T(max)) was approximately 2 h after ingestion. A 3-6% increase in Cho by MRS likely corresponds to a 10-22% increase in phosphocholine, similar to findings in animal studies. In conclusion, a significant increase in choline-containing compounds in human brain can be detected by (1)H-MRS after choline ingestion in young subjects.

Administration, Oral↗
PubMed2003

Secretion of IL-2 and IFN-gamma, but not IL-4, by antigen-specific T cells requires extracellular ATP.

Extracellular ATP and other nucleotides transmit signals to cells via surface-associated molecules whose binding sites face the extracellular milieu. Ecto-nucleoside triphosphate diphosphohydrolase is such an ATP-binding enzyme that is expressed by activated lymphocytes. We have previously shown that nonhydrolyzable ATP analogs block the lytic activity of NK cells and CD8(+) T cells as well as their E-NTPDase activity. These results suggest that the hydrolysis of ATP may play a role in lymphocyte function. Here we report that E-NTPDase activity is up-regulated within 15 min of T cell stimulation and that reversible and irreversible enzyme inhibitors profoundly reduce secretion of IL-2 and IFN-gamma, but not IL-4. TNF-alpha, IL-10, and IL-5 production showed intermediate sensitivity to these ATP analogs. Depletion of extracellular ATP also inhibited secretion of IFN-gamma, but not IL-4, supporting the interpretation that extracellular ATP is required for secretion of some, but not all, cytokines. E-NTPDase antagonists reduced transcription of IL-2 mRNA and inhibited TCR-mediated intracellular calcium flux. These results suggest that extracellular ATP plays an essential role in the TCR-mediated signal transduction cascade for expression of certain cytokine genes.

Adenosine↗
PubMed2003

Inhibition of tumor rejection by gammadelta T cells and IL-10.

Although many tumors express tumor-specific antigens, most fail to stimulate effective immune responses. Tumors generally lack co-stimulatory molecules, which can lead to tolerance of tumor-specific T cells and progressive tumor growth. Here, we demonstrate that the ovalbumin (OVA) transfected EL4 tumor, E.G7-OVA, grows progressively in syngeneic mice even though the tumor can be rejected if the mice are immunized with OVA in adjuvant. E.G7-OVA grew more rapidly in RAG-1 deficient than sufficient mice suggesting that normal mice make an abortive immune response to this tumor. Depletion of gammadelta T cells or IL-10 augmented the ability of B6 mice to reject E.G7-OVA. Spleen cells from normal, but not IL-10 knockout, mice reconstituted rapid tumor growth in gammadelta T cell-deficient mice. Thus, gammadelta T cells play an important role in preventing immune elimination of this tumor by a mechanism that directly or indirectly involves IL-10.

Animals↗
PubMed2002

Detection of pyloric metaplasia may improve the biopsy diagnosis of Crohn's ileitis.

BACKGROUND: Pyloric metaplasia (PYME) is seen frequently in ileal resections from patients with Crohn's disease (CD). It represents a nonspecific reparative reaction in intestinal ulcers. The presence of PYME in terminal ileum biopsies (TIbxs) of CD has not received much attention and has been considered a rare finding. STUDY: We reviewed 45 TIbxs from 45 adult patients with indisputable clinicopathologic diagnosis of CD. Endoscopic biopsies were obtained with an Olympus CIF 140 videoscope. The samples were fixed in 10% buffered formalin and were processed routinely. RESULTS: Pyloric metaplasia was identified in 10 TIbxs from 10 patients. Most of the metaplastic glands formed small aggregates in the mucosal base, and they were frequently noted below regenerating crypts and in the vicinity of granulation tissue and ulceration. CONCLUSIONS: In our material, 22.2% of the TIbxs revealed PYME. The single previous study with similar data showed an incidence of 2.27%. The difference could reflect the stage of the disease or the thoroughness of the endoscopic and pathologic examinations. Pyloric metaplasia, despite its lack of specificity, remains a sensitive indicator of persistent ulceration with inflammation. Because PYME is not as rare as previously thought, it should be carefully looked for in TIbxs to support the diagnosis of CD in the appropriate clinical setting.

Biopsy↗