Search PubMed⌕ Search

Biomedical subjects

S Louie

Publications and source records attributed to S Louie.

At least 19 recordsLinked to original sources
PubMed2001

Elevated blood pressure in subjects with lipodystrophy.

OBJECTIVES: To assess the prevalence of elevated blood pressure in patients with lipodystrophy. DESIGN: Case-control study. PARTICIPANTS: Forty-two patients with abnormal body fat (100%) and serum lipids (86%) (HIV-positive cohort) were matched by age and sex to 42 HIV-positive controls without previously diagnosed lipodystrophy and to 13 HIV-negative controls. SETTING: Tertiary care, university-based, fully dedicated HIV clinic. MAIN OUTCOME MEASURES: Frequency and magnitude of elevated blood pressure during highly active antiretroviral therapy. RESULTS: There were 23 +/- 16 and 22 +/- 12 blood pressure measurements recorded per subject over 21 +/- 11 and 22 +/- 11 months for the HIV-positive cohort and HIV-positive controls, respectively. Three or more elevated readings occurred in 74% of the cohort and in 48% of the HIV-positive controls (P = 0.01) and accounted for 38 +/- 25% versus 22 +/- 26% (P = 0.01) of the total readings, respectively. The average of the three highest systolic readings (153 +/- 17 versus 144 +/- 15 mmHg; P = 0.01) and diastolic readings (92 +/- 10 versus 87 +/- 9 mmHg; P = 0.01) was greater for the cohort than for the HIV-positive controls. Family history of hypertension was more common in the cohort than in the controls but accounted for only 13% of the log odds ratio value for elevated blood pressure in the cohort. Systolic blood pressure was correlated with waist-to-hip ratios in the cohort (r = 0.45; P = 0.003) but not in the HIV controls (r = 0.06; P = 0.68) and tended to be related to fasting triglycerides (r = 0.34; P = 0.052) in subjects with HIV. CONCLUSIONS: Elevated blood pressure may be linked to the metabolic disorders occurring in patients with HIV, as in the dysmetabolic syndrome.

Adipose Tissue↗
PubMed2001

Mediastinal tumors.

Mediastinal tumors are comprised of various benign and malignant neoplasms that share the same anatomic location within the thorax. The mediastinum is traditionally divided into three compartments: the anterior, middle, and posterior mediastinum. This division, based on lateral chest radiographs, helps clinicians establish appropriate differential diagnoses and plan further imaging, diagnostic, and treatment strategies. With the continued and complex advances in imaging, medical treatment, and surgery, we recommend a multidisciplinary approach to the management of mediastinal tumors. This discussion is intended to guide the pulmonary specialist through this potentially complex approach.

Humans↗
PubMed2001

Pharmacologic treatment of the adult hospitalized asthma patient.

Acute severe asthma calls for aggressive and early therapy of a multifaceted and all-inclusive approach (Fig. 2). Therapy merely begins in the ED and manifold distinct issues need to find consideration during ongoing hospital care. Currently, beta-agonists, anti-cholinergic agents, and corticosteroids remain the mainstay of therapy. Methylxanthines and magnesium may find consideration in carefully selected patients. Multiple new therapeutic avenues, such as the anti-leukotriene drugs, seem promising and future studies will hopefully extend our armamentarium against life threatening complication of a common disease. Asthma education begun in the hospital may provide the platform for preventing severe acute exacerbations and hospitalization.

Acute Disease↗
PubMed2000

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is associated with hyperinsulinemia and insulin resistance.

High exposures of Vietnam veterans to 2,3,7, 8-Tetrachlorodibenzo-p-dioxin, a dioxin contained in the herbicide mixture Agent Orange, have previously been demonstrated to be associated with an increased prevalence of diabetes and hyperinsulinemia in non-diabetic subjects. Sixty-nine persons were identified who were in good health and had normal glucose levels during glucose tolerance testing. These subjects lived within 25 miles of the Vertac/Hercules Superfund site located in Jacksonville, Arkansas. The blood sera lipid concentrations of TCDD for the 69 subjects ranged between 2 and 94 ppt. When subjects with blood sera lipid TCDD levels in the top 10% (TCDD > 15 ppt, n = 7) were compared to subjects with lower levels (2-15 ppt, n = 62), there were no group differences in age, obesity, gender distribution, total lipids, or glucose levels. However, plasma insulin concentrations, at fasting and 30, 60, and 120 min following a 75 g glucose load, were significantly higher in the group with high blood TCDD levels. These finding could not be explained by other known risk factors for hyperinsulinemia. The finding of the TCDD-hyperinsulinemia relationship is consistent with studies of Vietnam veterans and suggests that high blood TCDD levels may cause insulin resistance.

Adult↗
PubMed2000

Approach to pulmonary metastases.

The prognosis and response to therapy of metastases to the lungs are variable and highly dependent on the origin of the primary tumor and on the extent and pattern of spread. Due to the complex pathogenesis underlying the development of pulmonary metastases, specific tumor types often display characteristic clinical and radiographic patterns. Understanding these concepts is of paramount importance when planning a diagnostic work-up for patients with possible pulmonary metastases. This review presents state of the art strategies in imaging, medical therapy, and surgery. It should provide the busy pulmonologist with the information needed to devise safe and efficient diagnostic and treatment strategies for patients with pulmonary metastases of extrathoracic origin.

Bronchoscopy↗
PubMed1999

Determination of low-molecular-mass antioxidant concentrations in human respiratory tract lining fluids.

Antioxidants present within lung epithelial lining fluids (ELFs) constitute an initial line of defense against inhaled environmental oxidants such as ozone, nitrogen oxides, and tobacco smoke, but the antioxidant composition of human ELFs is still incompletely characterized. We analyzed ELF concentrations of the low-molecular-mass antioxidants ascorbate, urate, glutathione (GSH), and alpha-tocopherol by obtaining bronchoalveolar lavage (BAL) and nasal lavage fluids from healthy nonsmoking volunteers and compared two different BAL procedures. ELF dilution by the lavage procedures was estimated by measurement of urea in recovered BAL fluids in comparison with those in blood plasma from the same subjects. The results indicated that a recently developed single-cycle BAL procedure minimizes influx of non-ELF urea into the instilled fluid and thus allows for a more accurate determination of ELF antioxidant concentrations. Using this procedure, we determined that bronchoalveolar ELF contains 40 +/- 18 (SD) microM ascorbate, 207 +/- 167 microM urate, 109 +/- 64 microM GSH, and 0.7 +/- 0.3 microM alpha-tocopherol (n = 12 subjects). Similar analysis of nasal lavage fluid yielded nasal ELF levels of 28 +/- 19 microM ascorbate and 225 +/- 105 microM urate (n = 12 subjects), whereas GSH was undetectable (<0.5 microM). Our results demonstrate that ascorbate and urate are major low-molecular-mass ELF antioxidants in both the upper and lower respiratory tract, whereas GSH is present at significant concentrations only in bronchoalveolar ELF.

Adolescent↗
PubMed1999

Paclitaxel is safe and effective in the treatment of advanced AIDS-related Kaposi's sarcoma.

PURPOSE: Liposomal anthracyclines are the present standard treatment for advanced AIDS-related Kaposi's sarcoma (KS). No effective therapies have been defined for use after treatment failure of these agents. A phase II trial was thus conducted with paclitaxel in patients with advanced KS to assess safety and antitumor activity. MATERIALS AND METHODS: A regimen of paclitaxel at a dose of 100 mg/m(2) was given every 2 weeks to patients with advanced AIDS-related KS. Patients were treated until complete remission, disease progression, or unacceptable toxicity occurred. RESULTS: Fifty-six patients with advanced AIDS-related KS were accrued. Tumor-associated edema was present in 70% of patients and visceral involvement in 45%. Forty patients (71%) had received prior systemic therapy; 31 of these were resistant to an anthracycline. The median entry CD4(+) lymphocyte count was 20 cells/mm(3) (range, 0 to 358). A median of 10 cycles (range, 1 to 54+) of paclitaxel was administered. Fifty-nine percent of patients showed complete (n = 1) or partial response (n = 32) to paclitaxel. The median duration of response was 10.4 months (range, 2.8 to 26.7+ months) and the median survival was 15.4 months. The main side effects of therapy were grade 3 or 4 neutropenia in 61% of patients and mild-to-moderate alopecia in 87%. CONCLUSION: Paclitaxel at 100 mg/m(2) given every 2 weeks is active and well tolerated in the treatment of advanced and previously treated AIDS-related KS. The median duration of response is among the longest observed for any regimen or single agent reported for AIDS-related KS. Paclitaxel at this dosage and schedule is a treatment option for patients with advanced AIDS-related KS, including those who have experienced treatment failure of prior systemic therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Induced preference or conditioned aversion for sodium chloride in rats with chronic bile duct ligation.

We examined whether a learned aversion to saline could account for the reduction in saline intake produced by bile duct ligation (BDL) in rats and whether increased saline intake by BDL rats was associated with hypotension. In three experiments, rats were given continuous access to water in choice with saline after surgery. In Experiment 1, rats were deprived of food and fluid for 24 h and then given 2-h access to either 0.15 or 0.3 M saline. Rats received a BDL or sham-ligation immediately (paired) or 48 h after (nonpaired) the 2-h bout of saline ingestion. The results show that nonpaired BDL rats increased their daily saline intake relative to nonpaired sham-ligated or paired BDL rats approximately 1-4 weeks after surgery. In Experiment 2, when water and either cherry or grape Kool-Aid (0.05% w/v) dissolved in 0.15 M saline to distinguish the flavor of the solution was offered prior to surgery, BDL rats reduced their ingestion of grape-flavored saline after surgery regardless of whether they were exposed to grape- or cherry-flavored saline prior to surgery. In Experiment 3, when rats were offered water and 0.3 M saline 48 h after surgery, BDL rats ligated for 4 weeks increased their saline intake relative to sham-ligated controls and this elevation in saline intake by BDL rats was associated with hypotension. The results suggest that the symptoms associated with the BDL surgery can serve as effective unconditioned stimuli in the acquisition of learned flavor aversions, and that hypotension may play a role in the elevated intake of saline by BDL rats.

Animals↗
PubMed1998

Oxidative stress and antioxidants at biosurfaces: plants, skin, and respiratory tract surfaces.

Atmospheric pollutants represent an important source of oxidative and nitrosative stress to both terrestrial plants and to animals. The exposed biosurfaces of plants and animals are directly exposed to these pollutant stresses. Not surprisingly, living organisms have developed complex integrated extracellular and intracellular defense systems against stresses related to reactive oxygen and nitrogen species (ROS, RNS), including O3 and NO2. Plant and animal epithelial surfaces and respiratory tract surfaces contain antioxidants that would be expected to provide defense against environmental stress caused by ambient ROS and RNS, thus ameliorating their injurious effects on more delicate underlying cellular constituents. Parallelisms among these surfaces with regard to their antioxidant constituents and environmental oxidants are presented. The reactive substances at these biosurfaces not only represent an important protective system against oxidizing environments, but products of their reactions with ROS/RNS may also serve as biomarkers of environmental oxidative stress. Moreover, the reaction products may also induce injury to underlying cells or cause cell activation, resulting in production of proinflammatory substances including cytokines. In this review we discuss antioxidant defense systems against environmental toxins in plant cell wall/apoplastic fluids, dead keratinized cells/interstitial fluids of stratum corneum (the outermost skin layer), and mucus/respiratory tract lining fluids.

Air Pollutants↗
PubMed1998

Perception of fatigue and quality of life in patients with COPD.

INTRODUCTION: Although dyspnea is considered the primary activity-limiting symptom in patients with COPD, other symptoms, such as fatigue, are frequently reported. The purpose of this study was to determine the relationship between fatigue and pulmonary function, exercise tolerance, depression, and quality of life in patients with COPD. METHODS: Forty-one patients (age = 62+/-8 years; FEV1 = 1.08+/-0.55 L; FEV1 percent predicted = 35.8+/-17%) from two sites participated in the study. Spirometric measures of pulmonary function were carried out in each patient. The Multidimensional Fatigue Inventory was used to measure five subscales of fatigue: general, physical and mental fatigue, reduction in activity, and reduction in motivation. The St. George Respiratory Questionnaire, used to measure quality of life, has three subscale dimensions (symptom, activity, and impact), as well as an overall or total quality of life score. Depression was measured with the Centers of Epidemiological Studies Depression Scale. In 19 patients, exercise tolerance was determined with the 6-min walking distance. RESULTS: General fatigue correlated with FEV1, percent predicted (r = -0.32, p < 0.05), exercise tolerance (r = -0.55, p < 0.05), depression (r = 0.44, p < 0.01), and overall quality of life (r = 0.75, p < 0.01). Among the dimensions of fatigue, depression correlated with general and mental fatigue only. Physical dimensions of fatigue correlated with an increase in the severity of pulmonary impairment and reduction in exercise tolerance. The cognitive components of fatigue, such as reduction in motivation and mental fatigue, were not found to be highly correlated with physical dimensions of quality of life. All five subscales of fatigue showed relationship to the functional impact dimension and total impairment score in quality of life. CONCLUSIONS: These data show a relationship between dimensions of fatigue and pulmonary function, exercise tolerance, and quality of life in COPD. Based on these results, fatigue is an important symptom requiring evaluation and management in patients with COPD. These data clarified also the relationship between depression and fatigue in this patient population.

Exercise Tolerance↗
PubMed1997

Phase I study of human chorionic gonadotropin given subcutaneously to patients with acquired immunodeficiency syndrome-related mucocutaneous Kaposi's sarcoma.

BACKGROUND: In vitro and in vivo clinical studies have shown that certain preparations of human chorionic gonadotropin have antitumor activity against Kaposi's sarcoma, the most common tumor in patients infected with human immunodeficiency virus type 1 (HIV-1). METHODS: A phase I trial was conducted in 18 male patients with acquired immunodeficiency syndrome-related Kaposi's sarcoma. Successive cohorts of six patients each received human chorionic gonadotropin (A.P.L.; Wyeth-Ayerst, Radnor, PA) subcutaneously at doses of 5000 IU daily (level I), 10,000 IU three times a week (level II), or 10,000 IU daily (level III). Toxic effects, changes in reproductive hormone levels, HIV-1 RNA plasma levels, and response to therapy were evaluated. RESULTS: A.P.L. treatment was well tolerated at all dose levels, and no maximum-tolerated, dose-defined toxic effects were observed at the highest dose tested. The most common side effects were weight gain, increased libido, and increased energy. A persistent increase in testosterone level and a persistent decline in luteinizing hormone and follicle-stimulating hormone levels were seen over time. Major responses were observed in six patients. Partial remissions (> or =50% decrease in lesion numbers, volume, or surface area) were observed at dose level I and dose level II (two patients each); biopsy-confirmed complete remissions (resolution of all lesions) were observed at dose level III (two patients). All but one major response have persisted from 207 to more than 515 days. Nine patients had stable disease lasting 10 weeks or longer. CONCLUSIONS: A.P.L. given at daily doses ranging from 5000 to 10,000 IU has antitumor activity in patients with acquired immunodeficiency syndrome-related Kaposi's sarcoma. A.P.L. can be given for more than 1 year with minimal side effects. Larger efficacy studies are warranted.

Acquired Immunodeficiency Syndrome↗
PubMed1996

The effects of preparations of human chorionic gonadotropin on AIDS-related Kaposi's sarcoma.

BACKGROUND: Kaposi's sarcoma is the most common cancer in patients with the acquired immunodeficiency syndrome (AIDS). Recently, certain preparations of human chorionic gonadotropin (hCG) have been shown to inhibit the growth of Kaposi's sarcoma cell lines in vitro and in immunodeficient mice. METHODS: After in vitro evaluation of four commercially available hCG preparations, the most active product was evaluated in 36 patients with AIDS-related Kaposi's sarcoma. In a phase 1-2 trial, 24 patients received intralesional injections of hCG three times a week for two weeks at doses of 250, 500, 1000, or 2000 IU (6 patients each). In each patient three nodular lesions were injected, two with the drug and one with diluent alone. In a double-blind trial, 12 additional patients were randomly assigned to receive intralesional injections of 2000 IU of hCG or diluent alone (6 patients each; two lesions per patient). At the conclusion of therapy, the lesions were measured, their gross appearance assessed, and biopsy specimens evaluated. RESULTS: A.P.L. (Wyeth-Ayerst), which had the most in vitro activity against Kaposi's sarcoma cell lines, was selected for the clinical investigation. Treatment with A.P.L. was well tolerated at all doses. In the cohorts given 250, 500, 1000, and 2000 IU, 1, 5, 5, and 10 of the 12 injected lesions responded, respectively (P=0.03 for trend). Complete tumor regression was observed in one lesion each at the 250-IU and 500-IU doses, in two lesions given the 1000-IU dose, and in five lesions given the 2000-IU dose. In the double-blind study, none of the 12 lesions in the six patients injected with diluent had responses, as compared with 10 of the 12 lesions in the six patients injected with hCG (P=0.015). Microscopical evidence of apoptosis was observed only in hCG-treated lesions. The percentage of cells that died increased in a dose-dependent manner (P<0.001). Serum levels of follicle-stimulating hormone (P=0.002) and luteinizing hormone (P=0.001) declined after the last injection of hCG, but there was no effect on these hormones in the diluent-treated patients. CONCLUSIONS: The intralesional injection of hCG induces the regression of AIDS-related Kaposi's sarcoma lesions in a dose-dependent manner. The response of these tumors appears to be mediated by the induction of apoptosis.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Effects of interleukin-1 and interleukin-1 receptor antagonist in AIDS-Kaposi's sarcoma.

Kaposi's sarcoma (KS) is the most common tumor seen in patients with HIV-1 infection. HIV-1 may induce KS directly through viral protein(s) or indirectly through regulation of cytokines such as IL-1 and IL-6. We have shown that AIDS-KS spindle cells express IL-1 beta and that IL-1ra inhibits KS-spindle cell growth. IL-1ra had little effect on human umbilical vein endothelial cells (HUVEC), human aortic smooth muscle cells (HASM), and human foreskin fibroblast (NN41). These findings support an autocrine activity for IL-1. Furthermore, exogenous IL-1 can enhance AIDS-KS cell growth, and this effect is completely blocked by IL-1ra. As expected, IL-1ra also blocks IL-1 mediated upregulation of IL-6 and bFGF, both of which are autocrine growth factors for KS. IL-1ra is thus a potential candidate for the treatment of AIDS-associated KS.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Induction of ornithine decarboxylase activity in mouse B lymphocytes.

We have examined the role in B cell activation of ornithine decarboxylase (ODC), the labile rate-limiting enzyme in the synthesis of polyamines thought to be required for S phase entry in all cells. When small resting mouse splenic B cells were stimulated with the mitogenic agents phorbol myristate acetate (PMA) plus ionomycin (lo), LPS or the B cell specific agent F(ab')2 anti-lg, ODC activity was greatly increased. ODC activity in small dense B cells remained near baseline levels for the first 6 h after treatment with LPS, but then increased approximately 150-fold in the next 18 h. When purified B cells were not separated by cell density, ODC activity was 30-fold greater at baseline and rose earlier after LPS stimulation, reaching a level about three times that of LPS-stimulated small, dense B cells at 24 h, implying that large (preactivated) B cells have much greater ODC responses than small, dense B cells. ODC activity, like S phase entry, could also be induced in small, dense B cells by PMA and lo but failed to respond to either agent alone. ODC levels rose transiently by approximately 40-fold between 2 and 6 h following stimulation of small B cells with F(ab')2 anti-lg, then declined to baseline. Whole anti-lg did not stimulate ODC activity and also blocked the F(ab')2 anti-lg mediated increase in ODC activity, just as it produced the expected inhibition of thymidine incorporation and cellular progression into S phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Oxidants, antioxidants, and respiratory tract lining fluids.

Respiratory tract lining fluids (RTLFs) are a heterogeneous group of substances covering the respiratory tract epithelial cells (RTECs) from nasal mucosa to alveoli. Antioxidant contained in the RTLFs can be expected to provide an initial defense against inhaled environmental toxins. The major antioxidants in RTLF include mucin, uric acid, protein (largely albumin), ascorbic acid, and reduced glutathione (GSH). RTLF antioxidants can be augmented by such processes as transudation/exudation of plasma constituents; RTEC secretory processes, including glandular mucus secretion; and cellular antioxidants derived from lysis of RTECs and of inflammatory cells. The antioxidant composition of RTLFs and their role in modulating normal and pathophysiologic RTEC functions under conditions of oxidative stress are yet to be fully characterized.

Animals↗