Alterations in folate-dependent one-carbon metabolism as colon cell transition from normal to cancerous

Folate-dependent one-carbon cycle metabolism (FOCM) plays a critical role in maintaining genomic stability through regulating DNA biosynthesis, repair and methylation. Folate metabolites as well as other metabolites in the FOCM are hypothesized to be altered when cells transition from normal to cancerous state. Using cells at different stages in their development into colorectal cancer, the FOCM metabolites were profiled as an effort to phenotype the cells, and the metabolite levels were compared to the expressions of related genes. Here, we investigate whether there is a correlation between the metabolite levels, DNA methylation levels and the expression of the related genes that drive the levels of these metabolites. Using CRL1459, APC10.1, HCT116 and Caco-2, we show for the first time that FOCM metabolites correlate with the gene expression patterns. These differences follow a trend that may facilitate distinguishing colon cells at the different stages as they transition into cancerous state. The folate distribution and methionine levels were found to be key in determining the staging of the colon cells in CRC development. Also, expression of CBS, MTRR and MAT genes may facilitate distinguishing between untransformed and transformed colon cells.

Abstract 2398: Tumor cell-adipocyte gap junctions activate lipolysis in breast cancer

During mammary tumorigenesis, a cell-cell interface exists between adipocytes and cancer cells. Several studies have demonstrated that breast tumor cells can secrete cytokines that induce lipolysis in adjacent adipocytes. However, evidence of tumor-adjacent lipolysis in clinical samples has been lacking. We therefore assayed for lipolysis in normal tissue adjacent to breast tumors (NAT) using (1) the three-component breast composition measure, a radiographic imaging method derived from dual-energy mammography that allows lipid content of a tissue to be quantified, on breast tumors and NAT from 46 patients, (2) a publically available dataset of gene expression in primary breast tumors and NAT from 9 patients, (3) laser capture microdissection and proteomics on primary breast tumors, stroma and NAT from 75 patients, and (4) immunoblot analysis of NAT from several patient-derived and transgenic mouse models of breast cancer. We found strong evidence in all cases that lipolysis is activated in breast cancer-adjacent adipose tissue. We next set out to model the breast cancer-adipocyte interface and determine the contribution of cell-cell contact to induced lipolysis. Gap junctions are cell-cell junctions formed by proteins called connexins, which are known to transport a variety of small molecules (<1kD) including cAMP, a critical pro-lipolytic signaling molecule. Using established dye transfer assays, we determined that gap junctions form between breast cancer cells, and between breast cancer cells and adipocytes. Using biochemical assays, we demonstrated that cAMP is a substrate of breast cancer cell gap junctions, that transfer of cAMP from breast cancer cells to adipocytes occurs, and that breast cancer cells activate lipolytic signaling, all in a gap junction-dependent manner. Finally, we found that gap junction communication in this context is dependent upon connexin 31 (Cx31), and we establish the importance of Cx31 for breast tumor growth and activation of lipolysis in tumor-adjacent adipose tissue in vivo.

Citation Format: Roman Camarda, Jeremy Williams, Serghei Malkov, Lisa J. Zimmerman, Suzanne Manning, Dvir Aran, Andrew Beardsley, Daniel Van de Mark, Jeffrey van Haren, Yong Chen, Charles Berdan, Sharon Louie, Celine Mahieu, Juliane Winkler, Elizabeth Willey, John D. Gagnon, Kosaku Shinoda, K. Mark Ansel, Zena Werb, Daniel C. Nomura, Shingo Kajimura, Torsten Wittmann, Atul J. Butte, Melinda E. Sanders, Daniel C. Liebler, Gregor Krings, John A. Shepherd, Andrei Goga. Tumor cell-adipocyte gap junctions activate lipolysis in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2398.

Assessment of Tocilizumab (Anti-Interleukin-6 Receptor Monoclonal) as a Potential Treatment for Chronic Antibody-Mediated Rejection and Transplant Glomerulopathy in HLA-Sensitized Renal Allograft Recipients

Extending the functional integrity of renal allografts is the primary goal of transplant medicine. The development of donor-specific antibodies (DSAs) posttransplantation leads to chronic active antibody-mediated rejection (cAMR) and transplant glomerulopathy (TG), resulting in the majority of graft losses that occur in the United States. This reduces the quality and length of life for patients and increases cost. There are no approved treatments for cAMR. Evidence suggests the proinflammatory cytokine interleukin 6 (IL-6) may play an important role in DSA generation and cAMR. We identified 36 renal transplant patients with cAMR plus DSAs and TG who failed standard of care treatment with IVIg plus rituximab with or without plasma exchange. Patients were offered rescue therapy with the anti-IL-6 receptor monoclonal tocilizumab with monthly infusions and monitored for DSAs and long-term outcomes. Tocilizumab-treated patients demonstrated graft survival and patient survival rates of 80% and 91% at 6 years, respectively. Significant reductions in DSAs and stabilization of renal function were seen at 2 years. No significant adverse events or severe adverse events were seen. Tocilizumab provides good long-term outcomes for patients with cAMR and TG, especially compared with historical published treatments. Inhibition of the IL-6-IL-6 receptor pathway may represent a novel approach to stabilize allograft function and extend patient lives.

Pharmacotherapy of critical asthma syndrome: current and emerging therapies

The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.

Economic costs of HIV infection: an employer's perspective

The introduction of highly active antiretroviral therapy has proven highly effective in treating patients with HIV/AIDS. However, the high cost of the advanced antiretroviral therapy has led to increased financial constraints on both patients and payers. From business firms'perspective, especially those with operations in developing countries, it is crucial to determine the long-term economic cost implications of alternative employment and benefit policies for HIV-infected workers or those at high risk for the disease. A simulation model is developed to predict the comprehensive lifetime economic costs of HIV-infected workers to an employer. This model employs age,CD4(+) cell counts,and plasma HIV-1 RNA level as major predictors of the disease progression and patient survival in the determination of various cost functions. Major cost components considered include direct expenses on health insurance premium,life insurance premium, short-term disability benefits, long-term disability benefits, hiring/training expenses, and indirect costs resulting from reduced or lost productivity at work. An individual model and a group model are derived to estimate the costs of an individual and a group of HIV-infected patients, respectively. Over a 10-year period, following the nonadvanced antiretroviral treatment regimen, the group model predicts that the total lifetime cost of an HIV-infected worker can be as high as U.S. 90,000 dollars to his/her employer, of which 60,000 dollars would be various explicit costs and 30,000 dollars lost work productivity. Sensitivity analysis further demonstrated that changes in the initial level of age,CD4(+) cell count, HIV-1 RNA viral load,CD4(+) cell decline rate, and the costs of medical care influence the dynamics of the cost functions. HIV infection can result in sizable economic costs to an employer over the lifetime course of an infected employee if not treated with the advanced antiretroviral therapy. These cost estimates provide a rational economic basis for an employer to optimally assess the longrun costs and benefits of alternative employment and insurance policies in the care of employees with HIV infection.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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)

Circulating immune complexes with pulmonary hemorrhage during pregnancy in idiopathic pulmonary hemosiderosis

Circulating immune complexes occurred during pulmonary hemorrhage in a pregnant patient with idiopathic pulmonary hemosiderosis, an association not previously reported. The patient required mechanical ventilation, but recovered; after a prolonged hospitalization, she was delivered of a healthy infant without further complications.

Oxidation of biologic molecules by ozone: the effect of pH

Ozone (O3) is a powerfully oxidizing pollutant gas. Its toxic effects to animals appear to be worsened by coexposures to acid-generating compounds such as oxides of nitrogen and sulfur. Ozone (16 ppm) oxidizes ascorbic acid and uric acid (two important antioxidants in lung lining fluids) at equal rates at pH 5.0 or pH 7.4. Loss of intrinsic fluorescence and formation of carbonyls in albumin exposed to O3 are similar at both pH values. However, albumin-SH groups are lost much faster on exposure to O3 at pH 7.4 than at acidic pH values. A similar slower rate of -SH group disappearance at acidic pH is seen when cysteine or reduced glutathione are exposed to O3. We suggest that the ability of reduced glutathione, albumin, and other proteins containing -SH groups to scavenge O3 in the respiratory tract is impaired at low pH and that this effect could contribute to the aggravation of O3 toxicity.

Effect of tracheal insufflation of deferoxamine on acute ozone toxicity in rats

To test the hypothesis that deferoxamine (DFO) may protect the lung against the acute toxicity of ozone (O3), male Sprague-Dawley rats (250 to 300 gm) were tracheally insufflated before exposure to O3 (2 ppm for 4 hours) with DFO (25 mg/kg), ferric-DFO, or sterile water. Measurements of bronchoalveolar lavage fluid (BALF) protein, ascorbate, hydrogen peroxide, and lipid hydroperoxides were made immediately after O3 exposure and 12 and 24 hours later. DFO (25 mg/kg) decreased BALF protein concentration (p < 0.05) and was associated with higher BALF ascorbate concentrations (p < 0.01) in O3-exposed animals. Ferric-DFO did not show these protective effects. No peroxides were found in BALF from any control or O3-exposed animals (detection limit: H2O2, 1 pmol; lipid hydroperoxides, 0.3 pmol). Higher DFO doses (50 mg/kg and 100 mg/kg) did not decrease BALF protein concentration immediately after O3 exposure or 12 hours later. Indeed, the highest dose was toxic to O3-exposed animals. Although DFO is able to protect against O3-induced lung damage in rats, apparently by chelating iron, its effect dose range appears to be narrow.

Antioxidant protection against hypochlorous acid in human plasma

Hypochlorous acid (HOCI) is a powerful oxidizing and chlorinating agent produced by the neutrophil enzyme myeloperoxidase. The antioxidant defenses of freshly prepared human plasma against HOCI/OCI- were explored. Addition of HOCI/OCI- to plasma caused rapid oxidation of ascorbic acid and thiol (-SH) groups but not of uric acid. Plasma -SH groups (which are known to be largely located on albumin) were quantitatively the most important scavenger of HOCI/OCI-, but adding extra ascorbate to plasma caused this molecule to have a more important scavenging role against HOCI/OCI-. Added HOCI/OCI- produced no detectable lipid peroxidation in plasma or depletion of lipid-soluble antioxidants (alpha-tocopherol or ubiquinol-10). No evidence of oxidative damage to protein amino acid residues (other than -SH) was detected by the carbonyl assay. It seems that -SH groups are a major target of attack by HOCI/OCI- in vivo, and plasma albumin may be an important protective antioxidant. Ascorbic acid might also play a protective role, especially in individuals supplemented with this vitamin. Ascorbate might also be important in extracellular fluids with low albumin concentrations such as synovial, respiratory tract lining, and cerebrospinal fluids.

Interaction of nitrogen dioxide with human plasma. Antioxidant depletion and oxidative damage

Nitrogen dioxide (NO2.) is often present in inhaled air and may be generated in vivo from nitric oxide. Exposure of human blood plasma to NO2. caused rapid losses of ascorbic acid, uric acid and protein thiol groups, as well as lipid peroxidation and depletions of alpha-tocopherol, bilirubin and ubiquinol-10. No increase in protein carbonyls was detected. Supplementation of plasma with ascorbate decreased the rates of lipid peroxidation, alpha-tocopherol depletion and loss of uric acid. Uric acid supplementation decreased rates of lipid peroxidation but not the loss of alpha-tocopherol. We conclude that ascorbic acid, protein -SH groups, uric acid and alpha-tocopherol may be important agents protecting against NO2. in vivo. If these antioxidants are depleted, peroxidation of lipids occurs and might contribute to the toxicity of NO2..

Oxidative stress and abnormal cholesterol metabolism in patients with adult respiratory distress syndrome

Oxidative stress has been implicated in the adult respiratory distress syndrome (ARDS). In this study, we determined the levels of selected antioxidants in the plasma of 25 patients with ongoing ARDS and 16 healthy control subjects. We also examined these plasmas and pulmonary edema fluid of ARDS patients for lipid hydroperoxides. Both ascorbate and ubiquinol-10 concentrations in ARDS plasma were significantly lower than in normal plasma. alpha-Tocopherol concentrations, when standardized to total plasma cholesterol, were not lower in ARDS patients than in normal subjects. A pattern of antioxidant levels virtually identical to that observed in ARDS plasma was obtained after in vitro incubation of healthy plasma with stimulated polymorphonuclear leukocytes: very low ascorbate, decreased ubiquinol-10, and unchanged alpha-tocopherol concentrations. Nanomolar concentrations of lipid hydroperoxides were found in pulmonary edema fluid of ARDS patients, but not in plasma, nor in the plasma of healthy individuals, when a sensitive and selective chemiluminescence assay for hydroperoxides was used. ARDS patients also showed significant decreases in plasma levels of cholesterol esters in conjunction with discoidal high-density lipoprotein profiles, indicating a decrease in lecithin-cholesterol acyltransferase activity. We conclude that ARDS is associated with oxidative stress, possibly exerted by oxidants released from activated phagocytic leukocytes, and major changes in plasma cholesterol metabolism.

A family outbreak of hemolytic-uremic syndrome associated with verotoxin-producing Escherichia coli serotype O157:H7

All five siblings (three boys and two girls, aged 1.5-9 years) in a family developed hemolytic-uremic syndrome associated with verotoxin-producing Escherichia coli O157:H7 at a lakeside vacation cottage during the fall of 1985. All five were hospitalized and made a full recovery. Both parents remained asymptomatic, and neither had evidence of this infection. In four children who were investigated prospectively, free verotoxin was still detectable in the stools for between 3 and 7 weeks. The prodromal diarrheal illness in the children occurred over a 10-day period. The epidemic curve was consistent with a point-source outbreak, but continuous exposure or person-to-person transmission could not be ruled out. The source of the infection was not identified.

Diadenosine 5',5'''-P1,P4-tetraphosphate, a potential antithrombotic agent

Diadenosine tetraphosphate (AP4A), a competitive inhibitor of ADP-induced platelet aggregation, was tested as an antithrombotic agent in a rabbit intracarotid thrombosis model previously shown to be sensitive to antiplatelet agents. Eighty-four percent of control rabbits formed clots. The infusion of AP4A at a dose of 50 mg/kg over 2 hours reduced the incidence of thrombosis to 56% (p less than 0.05). Blood AP4A increased 125-fold at the end of infusion, but was completely cleared within 10 minutes. Plasma ATP showed bimodal early and late increases. Platelets recovered from AP4A-treated rabbits exhibited a pattern of reduced reactivity to ADP, but not to collagen, similar to platelets exposed to AP4A in vitro. This study shows that AP4A may be a potentially useful antithrombotic agent.

Effects of cycloheximide and puromycin on cytotoxic activity of Escherichia coli verocytotoxin (Shiga-like toxin)

Verocytotoxin (VT)-producing Escherichia coli is closely associated with hemorrhagic colitis and hemolytic uremic syndrome. The diagnosis of this infection requires the demonstration of VT activity in fecal filtrates or the isolation of VT-producing E. coli from stools. To improve the sensitivity of the Vero cell assay for detecting VT, we investigated the interaction between this toxin and cycloheximide and puromycin, agents which, like VT and the related Shiga toxin, are protein synthesis inhibitors. Cycloheximide-treated cells were found to be about eightfold more sensitive to VT, this effect being most pronounced when the drug was added before the toxin. In contrast, puromycin treatment had an antagonistic effect in that it decreased the sensitivity of the cells to VT. In assays of VT in fecal filtrates, the addition of cycloheximide (at 4 to 8 micrograms/ml) increased the sensitivity without affecting the specificity of the assays. Likewise, the use of cycloheximide led to an increase in the sensitivity of the serum VT-neutralizing antibody test by a factor of over eightfold.

Postirradiation malignant fibrous histiocytoma of the trachea

A 77-yr-old woman presented with a malignant fibrous histiocytoma (MFH) of the trachea 11 yr after right subtotal thyroidectomy and delivery of 5,400 rads to the neck for infiltrating papillary thyroid carcinoma. The tumor developed in the irradiated area. Postirradiation MFH tends to occur in subcutaneous tissues, and is rare in lung parenchyma or airways.

Penicillamine associated pulmonary hemorrhage

Penicillamine is the drug of choice in Wilson's disease and a therapeutic alternative in rheumatoid arthritis. Autoimmune complications associated with penicillamine include cases resembling systemic lupus erythematosus and Goodpasture's syndrome. We report a case of diffuse pulmonary hemorrhage associated with prolonged penicillamine use in a patient with Wilson's disease with evidence of circulating immune complexes and complement activation, but without serologic or morphologic evidence of systemic lupus erythematosus, Goodpasture's syndrome or renal disease.

Low dose methotrexate pneumonitis in rheumatoid arthritis

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Pseudo-pseudo-pseudotumor of the lung

Benign lesions may simulate bronchogenic carcinoma by virtue of radiologic appearance or false-positive cytologic studies. A lung opacity initially suspected to be malignant was, on review, considered to be a loculated effusion. Needle biopsy yielded cells which appeared malignant. The resected lesion was a benign infarct.

Pancreatic pleuropericardial effusions. Fistulous tracts demonstrated by computed tomography

Demonstration of the fistulous tract linking pancreatic pseudocysts to the mediastinum and pleural cavity has diagnostic and therapeutic implications. In four cases, pseudocyst drainage through the esophageal and aortic diaphragmatic crus into the mediastinum and pleural cavity was delineated by computed tomography. In two cases, significant pericardial effusions were demonstrated. Computed tomography offers an effective diagnostic method when treatment is dependent on anatomic localization of the disrupted pseudocyst and its intrathoracic drainage tract.

Effects of ergometrine on airway smooth muscle contractile responses

A 26-year-old asthmatic female developed severe asthma within a few hours of receiving three oral doses of 0.4 mg ergometrine maleate for the control of postpartum haemorrhaging. This experience and two previous reports of bronchospasm in asthmatic subjects following ergometrine suggested that ergometrine altered airway smooth muscle tone. In the present investigation the effect of ergometrine was studied on canine tracheal smooth muscle strips. Ergometrine (10(-9) M-10(-4) M) induced contraction of canine tracheal smooth muscle. The concentration causing 50% of maximal contraction (EC50) was 4.73 X 10(-8) M. The acetylcholine EC50 was not altered by ergometrine (10(-9) M or 10(-8) M); however, acetylcholine (10(-4) M and 10(-3) M) induced contractions were enhanced by ergometrine (10(-8) M). The data suggest that ergometrine maleate may cause broncho-constriction in some patients with asthma.

Effective and fibrin-specific clot lysis by a zymogen precursor form of urokinase (pro-urokinase). A study in vitro and in two animal species

A single-chain 55,000-mol wt form of urokinase (UK), similar to that previously isolated from urine, was purified from a transformed kidney cell culture medium and characterized; and its fibrinolytic properties were evaluated. The preparation immunoprecipitated with UK antiserum, had a low intrinsic amidolytic activity that was 0.1% of its active derivative, and resisted diisopropyl fluorophosphate treatment and inactivation by plasma inhibitors. The single-chain UK was therefore designated pro-UK. In the presence of plasmin and during clot lysis, activation by conversion to two-chain, 55,000-mol wt UK (TC-UK) was demonstrated. This did not occur during blood clotting nor on incubation with purified thrombin. Clot lysis in plasma consistently occurred in 2-5 h with 50-100 IU per ml of pro-UK, whereas comparable lysis was inconsistently achieved by 500-1,000 IU of UK. Pro-UK, in sharp contrast to UK, caused no fibrinogen degradation at fibrinolytic concentrations. In the absence of a clot, pro-UK in plasma was stable for more than 2 d. When a clot was added after incubation (37 degrees C) for 50 h, activation to full lytic activity took place. The findings in vivo were comparable but the rapid clearance of pro-UK required that it be given by a constant infusion despite its plasma stability. In rabbits, a UK-resistant species, pro-UK was significantly (P less than 0.001) more efficacious than TC-UK but neither induced significant fibrinogen degradation. In dogs, a more sensitive species, the high specificity of thrombolysis by pro-UK contrasted with the defibrinogenation and uncontrollable bleeding that accompanied thrombolysis by UK. It was concluded that clot lysis by pro-UK is more effective and specific than UK. The advantage of pro-UK is in the limitation of its activation to the site of a clot. This can be explained by an activation mechanism that is dependent, under physiological conditions, on fibrin-stabilized plasmin.

The antithrombotic effect of aspirin and dipyridamole in relation to prostaglandin synthesis

The antithrombotic effect of aspirin (ASA) and dipyridamole (DIP) was evaluated in rabbits in which platelet thromboxane A2 (TXA2) and arterial prostacyclin (PGI2) were measured. An intracarotid cannula thrombosis model previously shown to be sensitive to antiplatelet agents was used. Prostaglandins were determined by radioimmunoassays for thromboxane B2 (TXB2) and 6-keto-prostaglandin PGF1 alpha, the stable metabolites of TXA2 and PGI2. In the aspirin-treated animals, reduction in thrombosis was seen only in rabbits which received a low-dose (1-2 mg/kg), and was related to a selective suppression of platelet TXA2. In contrast, higher doses of ASA (10 or 100 mg/kg), which suppressed both TXA2 and PGI2, were not associated with thrombus inhibition. DIP alone had a lesser antithrombotic effect which was augmented by low-dose ASA but not by high-dose ASA. It is concluded that 1) the antithrombotic effect of ASA in this animal model is dependent on selective TXA2 suppression; 2) ASA has no antithrombotic properties beyond its inhibition of prostaglandin synthesis by platelets; 3) selective suppression of TXA2 in vivo can be achieved in rabbits by a single dose of ASA but only over a narrow dose-range; 4) DIP may have an antithrombotic effect additive to that of low-dose ASA; 5) measurement of serum TXB2 may be used to determine the minimal ASA dose necessary to suppress TXA2 and therefore be most likely to spare PGI2.

Penetration of clindamycin into decubitus ulcers

Forty tissue samples, primarily of skin and bone, were obtained from 29 patients undergoing excision of decubitus ulcers after intravenous injection of 600 mg of clindamycin. Antibiotic concentrations exceeded 2.5 mug/g in 80% of the samples. In 50% of the instances, tissue levels were greater than those simultaneously present in the serum.

Antibodies in human sera to oncorna virus-like proteins from normal or leukemia marrow cell cultures

Some human marrows in culture release particles with oncornavirus-like properties. This study was designed to examine the immunological properties of similar particles in human marrow culture supernates. Leukemic and nonleukemic marrows were cultured for 5-7 days in the presence of [14C]uridine and [3H]leucine or [3H]glucosamine. Labeled supernatant components banding in sucrose gradient densities of 1.20-1.24 g/ml were used as antigen in a double antibody immunoprecipitation assay. The assay was validated by end point titrations and competition with unlabeled antigen; purified myeloma proteins were used as negative controls. Cross-reactivity with mammalian oncornaviruses, as judged by competitive inhibition of precipitation by these viruses, was slight and at the border of the sensitivity of the method. Precipitated antigens analyzed by SDS polyacrylamide gel electrophoresis contained three distinct polypeptides of about 70,000, 45,000 and 30,000 mol wt; these comigrated with the gp 70, pg 45, and p 30 of a murine leukemia virus. Similar polypeptides were obtained from both leukemic and nonleukemic marrow culture supernates. As determined by the radioimmunoprecipitation assay, 32 of 45 leukemic sera (71%), 36 of 45 normal sera (80%), 15 of 19 sera from family contacts of leukemic patients (79%), 14 of 21 cord blood specimens (67%), and 21 of 23 sera (91%) from patients with systemic lupus erythematosus had detectable antibody activity.