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Biomedical subjects

James Li

Publications and source records attributed to James Li.

11 recordsLinked to original sources

IMA clipping for a type ii endoleak: combined laparoscopic and endovascular approach.

We describe herein a combined laparoscopic and endovascular approach to treat a type II endoleak due to retrograde flow in the patent inferior mesenteric artery (IMA). A 61-year-old gentleman presented with enlarging aneurysm sac confirmed on computed tomography scan evaluation after elective endovascular repair of an infrarenal abdominal aortic aneurysm. A combined laparoscopic and endovascular approach was used. After distal IMA was identified and marked with a clip laparoscopically, on-table angiography showed a proximal left colic branch and persistent flow in the IMA. Therefore, further laparoscopic exploration was performed by dissection along the distal branch. The origin of IMA was then located and subsequently sealed with 2 surgical clips. The completion angiography confirmed the proper position of the surgical clips and absence of endoleak. Our case demonstrated useful role of endovascular techniques in identifying the origin of IMA during laparoscopic approach for treating type II endoleak.

Aortic Aneurysm, Abdominal↗

Attaining asthma control.

PURPOSE OF REVIEW: Despite our knowledge of asthma pathophysiology and several guidelines, studies have indicated growing morbidity. This review highlights the rationale for the trend in asthma care of separating asthma control from asthma severity. RECENT FINDINGS: Recent research has highlighted why asthma morbidity continues to be such a conundrum. This includes the variability of asthma control over time, inability to achieve total asthma control in some patients, disagreement between various measures of asthma control and the lack of an agreed tool for determining asthma control. SUMMARY: By dissociating asthma control and severity, the clinician may focus on the level of control during each encounter, independent of asthma medication. One can still build upon the step-up and step-down algorithm, while reinforcing control of asthma as the ultimate goal. Asthma control connotes the status of the disease, highlighting the dynamic nature of this illness both as the response to a trigger as well as therapy. Although more aggressive intervention may be required to achieve adequate control in severe persistent asthma versus mild persistent disease, the goal of appropriate asthma control remains constant in the spectrum of asthma severity.

Asthma↗

Characterization of agonist-induced motilin receptor trafficking and its implications for tachyphylaxis.

The motilin receptor (MR) is a member of the seven-transmembrane receptor family and is expressed throughout the gastrointestinal tract of humans and other species. Motilin, the natural MR peptide ligand, has profound stimulatory effects on gastrointestinal contractility, indicating a therapeutic potential for MR modulators. However, long-term clinical use of certain MR agonists is limited by tachyphylaxis, a reduced responsiveness to repeated compound exposure. This study was meant to characterize the ligand-induced endocytosis of MR and to test whether receptor trafficking contributes to tachyphylaxis. A cell-based assay was developed by fusing a green fluorescent protein (GFP) moiety to the motilin receptor, and high-content biology instrumentation was used to quantify time and dose dependence of MR-GFP endocytosis. Maximal internalization of MR-GFP was induced after 45 min of constant exposure to 80 nM motilin. This process was disrupted by nocodazole, suggesting an essential role for microtubules. Internalized MR-GFP vesicles disappeared within 15 to 45 min of motilin withdrawal but did not overlap with the lysosomal compartment, indicating that MR-GFP escaped degradation and was recycled back to the plasma membrane. It is noteworthy that the kinetics of MR-GFP redistribution varied substantially when stimulated with motilin, erythromycin, 6,9-hemiacetal 8,9-anhydro-4''-deoxy-3'-N-desmethyl-3'-N-ethylerythromycin B (ABT-229), or N-[(1S)-1-[[[(1S)-1-(aminocarbonyl)-3-phenylpropyl]amino]carbonyl]-3-phenylpropyl]-2'-(1,3-benzodioxol-5-ylmethyl)tetrahydro-1',3'-dioxo-spiro[piperidine-4,5'(6'H)-[1H][1,2,4]triazolo[1,2-a]pyridazine]-8'-carboxamide (BMS-591348) at equipotent doses for Ca(2+)-mobilization. Retardation of the intracellular MR-GFP sorting cycle seemed to correlate with the tachyphylaxis-inducing properties of each compound, but not its EC(50). These results indicate that MR internalization, desensitization, and resensitization are ligand-dependent and that appropriate screening strategies may enable the development of small molecule agonists with ideal combinations of these distinct properties.

Base Sequence↗

Discovery of potent, nonsystemic apical sodium-codependent bile acid transporter inhibitors (Part 1).

Elevated plasma levels of low-density lipoprotein (LDL) cholesterol are a major risk factor for atherosclerosis leading to coronary artery disease (CAD), which remains the main cause of mortality in Western society. We believe that by preventing the reabsorption of bile acids, a minimally absorbed apical sodium-codependent bile acid transporter (ASBT) inhibitor would lower the serum cholesterol without the potential systemic side effects of an absorbed drug. A series of novel benzothiepines (3R,3R'-2,3,4,5-tetrahydro-5-aryl-1-benzothiepin-4-ol 1,1-dioxides) were synthesized and tested for their ability to inhibit the apical sodium dependent bile acid transport (ASBT)-mediated uptake of [(14)C]taurocholate (TC) in H14 cells. A 3R,4R,5R/3S,4S,5S racemate was found to have greater potency than the other three possible racemates. Addition of electron-donating groups such as a dimethylamino substituent at the 7 position greatly enhanced potency, and incorporation of a long-chain quaternary ammonium substituent on the 5-phenyl ring was useful in minimizing systemic exposure of this locally active ASBT inhibitor while also increasing water solubility and maintaining potency. The reported results describe the synthesis and SAR development of this benzothiepine class of ASBT inhibitors resulting in an 6000-fold improvement in ASBT inhibition with desired minimal systemic exposure of this locally acting drug candidate.

Animals↗

Discovery of potent, nonsystemic apical sodium-codependent bile acid transporter inhibitors (Part 2).

In the preceding paper several compounds were reported as potent apical sodium-codependent bile acid transporter (ASBT) inhibitors. Since the primary site for active bile acid reabsorption is via ASBT, which is localized on the luminal surface of the distal ileum, we reasoned that a nonsystemic inhibitor would be desirable to minimize or eliminate potential systemic side effects of an absorbed drug. To ensure bioequivalency and product stability, it was also essential that we identify a nonhygroscopic inhibitor in its most stable crystalline form. A series of benzothiepines were prepared to refine the structure-activity relationship of the substituted phenyl ring at the 5-position of benzothiepine ring and to identify potent, crystalline, nonhygroscopic, and efficacious ASBT inhibitors with low systemic exposure.

Absorption↗

The "prudent layperson" definition of an emergency medical condition.

The study objectives, based on federal and state legislative language, were to objectively define symptoms and signs commonly agreed on by "prudent laypersons" as "emergency medical conditions." After comprehensive tabulation of symptom classifications from the International Classification of Diseases (ICD-9), we performed a survey of nonmedical laypersons. Data analysis included descriptive statistics, proportional calculations, and 95% confidence intervals. A minority of symptoms and signs (25/87, 29%) were considered emergency medical conditions by more than half of nonmedical survey respondents who were self-defined as prudent laypersons. The leading conditions deemed emergencies were loss of consciousness, seizure, no recognition of one side of the body, paralysis, shock, gangrene, coughing blood, trouble breathing, chest pain, and choking. Pain, except for renal colic or chest pain, was not considered an emergency. No symptoms or signs specifically related to gynecologic disorders were considered emergencies. Most symptoms and signs tabulated in the diagnostic coding manual, ICD-9, are not considered emergency medical conditions by self-designated prudent laypersons. These include many conditions that are commonly investigated and treated in the emergency department setting. Use of the prudent layperson standard for reimbursable emergency health services may not reflect the actual scope of symptoms necessitating emergency care.

Adult↗

Aortic calcification on plain chest radiography increases risk for coronary artery disease.

STUDY OBJECTIVES: To determine whether an association exists between aortic calcification viewed on plain chest radiography and coronary artery disease. METHODS: Retrospective review of all chest radiographs obtained from consecutive patients undergoing coronary angiography at a primary cardiac center during 1999. Plain chest radiographs were reviewed by blinded radiologists, and interobserver consistency was measured. The presence or absence of aortic arch calcification was abstracted and compared with the results of coronary angiography. RESULTS: Of 654 cases, 329 of 360 patients with aortic arch calcification vs. 241 of 294 patients without aortic arch calcification had coronary artery disease demonstrated on angiography. The 9% absolute difference in proportions was significant (p = 0.0003). The relative risk (measured by risk ratio) was 1.11 (95% confidence interval, 1.05 to 1.19). CONCLUSION: Several objective signs (e.g., hypertension, hyperlipidemia, and ECG changes) have been associated previously with the presence of coronary artery disease. This study further suggests an association between coronary disease and aortic arch calcification on plain chest radiography. These results may assist primary-care providers performing routine health assessments as well as emergency practitioners evaluating patients with potential angina.

Adult↗

A comparison of coping factors in Western and non-Western cultures.

This study presents convergent support for the use of three empirically constructed factors, across four samples, from the Ways of Coping Questionnaire. Planning, Positive Reappraisal, and Distancing factors were congruent for comparisons made between U.S. healthcare workers, Chinese healthcare workers, Chinese teachers, and Taiwanese teachers. Additional evidence of congruency was provided on specific factors between specific pairs of groups. The results support the usage of common factors across languages, cultures, and occupational groups but also highlight the importance of not administering a test in a different cultural setting without assessing its dimensionality.

Adaptation, Psychological↗

Successful surgical management of pelvic congestion and lower extremity swelling owing to absence of infrarenal inferior vena cava.

Absence of isolated infrarenal inferior vena cava (IVC) is a rare condition documented in only a few published cases and typically treated with anticoagulation. We herein describe successful surgical management of the isolated infrarenal IVC absence in a healthy 35-year-old woman who presented with disabling pelvic congestion. An ascending venogram showed the absence of infrarenal IVC with a large left ovarian vein draining pelvic collateral vessels to the normal left renal vein and suprarenal IVC. The patient was successfully treated with a common femoral vein to the suprarenal IVC bypass using a bifurcated polytetrafluoroethylene graft, with rapid symptom resolution, and remained symptom free 6 months later. This is the first reported case describing a surgical strategy for isolated infrarenal IVC absence in a symptomatic patient.

Adult↗