Pulmonary masses in a patient with blue-gray cutaneous hyperpigmentation.

Authors describe a case of pulmonary masses and estensive skin pigmentation: "blue-gray syndrome" occurred in a patient in amiodarone therapy who presented with progressive dyspnea, cough, and fever. The diagnosis was suspected by detection of a high attenuation of the pulmonary masses on the nonenhanced chest computed tomography (CT) and lots of foamy macrophages in the bronchoalveolar lavage fluid. Relief of respiratory symptoms and radiological improvement was achieved when amiodarone treatment was stopped.

Characterization of the effects induced on DNA in mouse and hamster cells by lithocholic acid.

Lithocholic acid (LCA) is a promoting agent in colon carcinogenesis. In this work we have tried to characterize the DNA alteration induced by LCA in cells grown in vitro and in nuclei. Confirming previous findings, a clear increase in elution rate was observed at both alkaline and neutral pH. The extent of the increase was very similar at the two pHs. However, an increased elution rate could be observed only when lysing the nuclei at high ionic strength and low detergent concentration (2 M NaCl + 0.2% N-lauroylsarcosine sodium salt). No effect could be observed when the nuclei were lysed with a high detergent concentration (2% sodium dodecyl sulfate). In addition, a slight effect could be observed using a method for the evaluation of DNA unwinding in alkali. After termination of the incubation with LCA, the DNA alteration observed with DNA elution disappeared very rapidly both in intact cells and nuclei, even when the incubation buffer was totally unsuitable for the repair of the type of DNA damage induced by typical genotoxic agents. The effect of LCA on DNA was apparently not mediated through an inhibition of topoisomerase II. Only the intact chromatin of nuclei was responsive, not the quasinaked DNA of nuclei lysed at high ionic strength. We advance the hypothesis that the increased alkaline and neutral elution rate observed with LCA could be independent of DNA fragmentation and related to changes in chromatin structure.

Synergistic treatment of enterococcal endocarditis: in vitro and in vivo studies.

Combinations of penicillin G sodium or ampicillin plus streptomycin sulfate do not produce synergism against all strains of enterococci. This lack of synergism was considered the cause of the failure in the treatment of enterococcal endocarditis. The effect of various combinations of antibiotics on 15 enterococcus strains, which had been isolated from patients with enterococcal endocarditis, was examined. The antibiotics included those that interfere with cell-wall synthesis and those that act on cell metabolism. The in vitro results have shown that while penicillin- or ampicillin-streptomycin combination was not synergistic in eight of 15 strains, penicillin- or ampicillin-gentamicin sulfate combination was synergistic in 100% of the cases. We report seven cases of enterococcal endocarditis that were successfully treated with penicillin- or ampicillin-gentamicin combination, thus confirming the effectiveness of this therapeutic regimen.

The beta-core fragment of human chorionic gonadotrophin inhibits growth of Kaposi's sarcoma-derived cells and a new immortalized Kaposi's sarcoma cell line.

OBJECTIVE: Kaposi's sarcoma (KS), a condition often associated with HIV infection, is more common in men than in women; pregnancy and sex hormones could be involved. Urinary human chorionic gonadotrophin (hCG) has been reported to inhibit the growth of KS cell lines, with great variability among preparations. Urinary hCG often contains free forms of the hCG subunits and a fragment of the free beta-subunit, the beta-core, which may have biological activity. We compared the effect of the beta-core fragment, the beta-subunit, recombinant and urinary hCG on KS immortal and spindle cells. DESIGN AND METHODS: A new immortal KS cell line was phenotypically and karyotypically characterized. The effects on growth of this cell line and of primary KS spindle cells by hCG and its purified derivatives were tested. Induction of apoptosis was demonstrated using acridine orange/ethidium bromide staining. RESULTS: The beta-core fragment harboured the most potent growth inhibitory activity on a molar basis. After 72 h of treatment with the beta-core, 60-70% of KS cells show apoptotic nuclei. No effects were observed on endothelial cells. CONCLUSIONS: The beta-core fragment of hCG proved to be the most effective part of the hCG molecule, inducing growth inhibition and apoptosis of KS cells. Thus, the beta-core could be the most appropriate hCG derivative for the therapy of KS.

Isolation of spindle-shaped cell populations from primary cultures of Kaposi's sarcoma of different stage.

Cell lines derived both from sporadic and epidemic KS biopsies show similar characteristics: a mixture of mesenchymal and vascular markers as well as production of factors which recruit endothelial cells in vitro and induce neoangiogenesis in vivo. Most established KS spindle cell strains are derived from patch or plaque stage KS lesions, which are easily collected during routine biopsies. Here we have characterized KS-derived spindle cell lines obtained from the four different stages typical of KS progression: angiomatous macula, patch, plaque and nodular KS to show if the similar features of our KS cell lines are linked to a particular stage of progression or to an in vitro selection/differentiation during KS cell culture. These four KS cell lines have shown the same pattern of characterization as the previous established KS cell lines, apart from an early selection of the spindle cell population we have also observed an easy inducible phenotypic differentiation through a myofibroblastic spindle cell type simply plating cells on gelatin-coated flasks. These data confirm the hypothesis of spindle cell selection in culture and the possible differentiation of these mesenchymal cells.

HIV type 1 Tat protein is a survival factor for Kaposi's sarcoma and endothelial cells.

The HIV-1 Tat protein has been directly implicated in the pathogenesis of AIDS-related Kaposi's sarcoma (KS); however, its effects on KS spindle-shaped and endothelial cell apoptosis are largely unexplored. Since susceptibility to apoptosis is relevant for tumor development and response to therapy, we investigated the effects of Tat on KS and endothelial cell survival from apoptosis. The effect of Tat was evaluated in three KS cell lines (KS-imm, KS-C1, and KS-L3) exposed to the chemotherapy agent vincristine, currently used for the treatment of this tumor, and in human umbilical vein-derived endothelial cells (HUVECs) induced to undergo apoptosis by serum withdrawal. Apoptosis was assessed by enzymatic assays, microscopic examination of chromatin and cytoskeleton, evaluation of plasma membrane integrity and subdiploid DNA content, TUNEL assays, and measurement of caspase-3 activity. Tat, in a dose-dependent manner, protected the three KS cell lines and HUVECs from apoptosis induced by vincristine or serum starvation, respectively. This effect appeared to be independent of modulation of Fas, Bcl-2, or Bax expression. In contrast, Tat upregulated Bcl-X(L) expression and induced a relevant decrease in caspase-3 activity in vincristine-treated KS cells. Taken together, these results suggest that the HIV-1 Tat protein may factor KS development and progression by sustaining endothelial and transformed cell survival.

Characterization of kaposis sarcoma-derived cell-cultures from an epidemic and a classic case.

Cells derived from skin biopsies from two Kaposi's sarcoma patients, an elderly female with a sporadic non-AIDS form, and an AIDS-affected homosexual male, were established in culture. The classic patient had a few small lesions, while the epidemic case presented-large, disseminated, cutaneous and oral mucosa lesions. The cells obtained from both patients, termed IST-KS2 and AIDS-IST-KS3 respectively, had the characteristic spindle shape reported for Kaposi's sarcoma-derived cells. By immunocytochemistry they were both found to express the smooth muscle specific isoform of alpha actin. The KS cells expressed the fibroblastic antigen TE-7, which is not expressed in endothelial cells. Furthermore both KS cultures were negative for the endothelium associated markers Factor VIII, EN4 and PAL-E. They were also negative for the leukocyte antigen CD45, but were positive for vimentin. Immunocytochemistry studies were therefore suggestive of a primitive mesenchymal cell. When the KS-derived cells were grown on a gel of reconstituted basement membrane, both cultures formed large branching colonies characteristic of malignant cells of mesenchymal origin. No differences were observed between HIV-related and the sporadic KS-derived cultures studied. Fibroblasts and smooth muscle cells did not form branching colonies, while endothelial cells on matrigel differentiated forming tube-like structures. Supernatants from both sporadic and AIDS-related KS cell cultures had similar effects on endothelial cell growth in vitro and were also found to stimulate chemotaxis and chemoinvasion of normal vascular endothelial cells in the Boyden chamber assay, showing angiogenic potential in vitro. Our results demonstrate that long term cultures of spindle shaped cells derived from either HIV-associated and classic KS show the same histocytochemical phenotype, have invasiveness in matrigel similar to that of malignant sarcomas, and share in vitro angiogenic properties. Therefore, factors from the host are likely to be responsible for the divergent clinical picture of the classic and epidemic Kaposi's patients studied here.

Effects of fenoterol on oxygen transport in patients with chronic airflow obstruction.

A rise in cardiac output and a fall in arterial oxygen tension are well known side effects of bronchodilator drugs, particularly beta-adrenergic agonists. In recent years, fenoterol (Berotec), an effective beta-adrenergic agonist, has been used at increasing rates in asthmatic subjects, as well as in patients with chronic obstructive pulmonary disease (COPD). The effects of fenoterol on systemic hemodynamics or arterial oxygenation (or both) in patients with COPD have not been investigated; in these individuals, who often have increased sympathetic tone and hypoxemia even at rest, cardiovascular stimulation and a fall in arterial oxygen tension would be particularly undesirable side effects. In 14 patients with COPD (seven without a reversible component of airflow obstruction [group 1]; and seven with a reversible component of airflow obstruction [group 2]), we studied all of the important parameters of oxygen transport before and 60 minutes after administration of fenoterol. Studies were performed at rest and after exercise. At baseline, group 1 showed a faster heart rate, a lower cardiac output, a lower arterial oxygen flow, a wider arteriovenous oxygen content difference (C[a-v]O2), and a higher fraction of oxygen extracted by the tissues from a given arterial oxygen flow. In both groups, all measured parameters, including cardiac output and arterial oxygen pressure (PaO2) remained statistically unchanged one hour after administration of fenoterol; with exercise, the heart rate, blood pressure, minute ventilation, oxygen consumption, C(a-v)O2, and the percentage of oxygen extracted from arterial oxygen flow, as well as cardiac output and PaO2, increased in all instances; the exercise responses were not affected by the drug. These results suggest that at the time of its maximal effect on the airways (60 minutes), fenoterol has no untoward effect on the oxygen transport system, at rest or during exercise, in patients with COPD with or without a reversible component.

Cardiopulmonary exercise testing in the evaluation of patients with ventilatory vs circulatory causes of reduced exercise tolerance.

INTRODUCTION: Cardiopulmonary exercise testing (CPX) is considered a useful procedure in the evaluation of circulatory, ventilatory, or mixed origin of reduced exercise tolerance. Our study was designed to compare CPX and a standard clinical-instrumental approach in the evaluation of patients with cardiopulmonary disorders. METHODS: Fifty-seven patients (31 male, 26 female; mean [+/- SE] age, 60 +/- 2 years) were studied. Each patient was evaluated by two different observers: one used standard clinical criteria, the other used gas exchange indexes, monitored during a maximal incremental CPX, performed on a cycle ergometer. Cardiac output (CO), at rest and at submaximal work level, was also obtained. RESULTS: In 46 patients (80.7 percent), a concordant evaluation was reached by the two observers (24 were found to have a predominant ventilatory disorder, 22 to have a circulatory disorder); among these, in subjects considered to have circulatory impairment, the maximal CO/maximal workload ratio was significantly lower than in the ventilatory group; in those with ventilatory impairment, the reduced exercise tolerance correlated with the resting spirometric values. In the remaining 11 patients (19.3 percent), CPX better defined the underlying pathophysiology of exercise limitation: in 10 of them, clinically classified as having a mixed or predominantly ventilatory disorder, a greater importance of the circulatory component was detected; 4 had evidence of pulmonary vascular impairment (high VE/VCO2 at anaerobic threshold). CONCLUSIONS: Our study confirmed the sensitivity of CPX in the evaluation of a reduced exercise tolerance in dyspneic patients with cardiopulmonary conditions; when compared with a clinical-laboratory approach, in some patients it allowed the detection of an underestimated circulatory component causing exercise limitation.

The effect of oxygen on sodium excretion in hypoxemic patients with chronic obstructive lung disease.

In advanced chronic obstructive lung disease (COLD), sodium retention is common, associated with reduction in renal plasma flow (RPF) and stimulation of the renin-aldosterone (PRA-PA) system, two abnormalities due to or influenced by hypercapnia: the independent role of hypoxemia in perturbing sodium homeostasis is unknown. In five stable patients with COLD (FEV1 = 0.9 +/- 0.21, mean +/- SE) with mild edema, during two weeks of a low sodium diet (one week on room air: pH = 7.39 +/- 0.02; PaO2 = 55 +/- 4 mm Hg; PaCO2 = 49 +/- 4 mm Hg; and one week on O2: pH = 7.38 +/- 0.01; PaO2 = 72 +/- 6 mm Hg; PaCO2 = 52 +/- 4 mm Hg) we monitored sodium balance, systemic and renal hemodynamics, plasma sodium and potassium, PRA, PA, and atrial natriuretic hormone (ANH). During air breathing, patients uniformly showed a depression of RPF despite normal cardiac output; plasma hormone levels did not differ from controls but there was elevation (greater than 2 SD above the normal mean) of PRA in four patients, PA in two patients, and ANH in two of five patients. During O2 breathing, urinary sodium increased significantly from 67 +/- 7 to 102 +/- 10 mEq/24 h. Surprisingly, the patients experienced a small but significant weight gain (0.6 +/- 0.1 kg). None of the other variables was affected by O2 therapy. The following conclusions were reached: in advanced COLD, correction of hypoxemia results in sodium diuresis, indicating that hypoxemia (in the presence of hypercapnia) contributes to sodium retention. The mechanism for this beneficial effect of O2 will require further investigation.

Effect of inorganic phosphate in hypoxemic chronic obstructive lung disease patients during exercise.

We have shown that normal subjects exercise more efficiently with increased plasma phosphate, presumably due to decreased hemoglobin-oxygen affinity and thus enhanced tissue O2 extraction. We subjected nine stable hypoxemic COLD patients to exercise at 0 (control), 24 (experimental) and 48 hrs (recovery) after phosphate infusion. Baseline variables were identical for each time period. Exercise responses at 0 and 48 hours were also indistinguishable. Exercise response at 24 hrs differed from those at 0 and 48 hours as follows: widening of A-V O2 content difference was more pronounced (28 +/- 6 vs 15 +/- 6 ml/L, p less than 0.03) and the increment in tissue O2 extraction was larger (14 +/- 3 vs 8 +/- 3 percent, p less than 0.03). P50 and related variables did not change during the course of the study. Thus, like normal subjects, hypoxemic patients stimulated with phosphate administration can exercise perhaps more efficiently; but, in contrast to normal subjects, this effect cannot be attributed to changes in hemoglobin-oxygen affinity. These data suggest that phosphate administration may be beneficial in hypoxemic states where adequate tissue oxygenation cannot be achieved by other more conventional methods. The mechanism of this effect remains to be elucidated.

Pharmacologic elevation of blood inorganic phosphate in hypoxemic patients with COPD.

We have shown that in patients with COPD, myocardial efficiency during exercise is enhanced following acute elevations of plasma phosphate (Pi). A decrease in Hb-O2 affinity (increase in P50) was not responsible for the improvement. We postulated that the physiologic benefit was due to the acute reversal of a subclinical myocardial Pi depletion. To further test this hypothesis in a chronic state, we studied nine stable hypoxemic (PaO2 = 64 +/- 2 mm Hg [+/- SEM]) patients with COPD over five weeks: two weeks at normal plasma Pi; and three weeks at elevated plasma Pi, induced by etidronate disodium (Didronel; 750 mg orally daily). Administration of etidronate disodium increased (p less than 0.05) plasma level of Pi (4.4 +/- 0.2 to 5.8 +/- 0.1 mg/dl), RBC level of Pi (3.1 +/- 0.2 to 4.1 +/- 0.2 mg/dl), RBC level of 2,3-DPG (16.2 +/- 1.1 to 21.3 g+/- 1.3 mumol/g of Hb) and P50 (23.7 +/- 0.5 to 26.0 +/- 0.8 mm Hg). At the end of the treatment, the widening of the C(a-v)O2 with exercise (7.1 +/- 0.8 to 8.9 +/- 0.6 ml/dl) was less pronounced than under control conditions (6.9 +/- 0.4 to 10.1 +/- 0.6 ml/dl; p less than 0.02); concomitantly, the crossover point (COP; the PaO2 below which a rightward-shifted Hb-O2 curve causes the C(a-v)O2 to become narrower rather than wider) increased (37 +/- 2 to 49 +/- 1 mm Hg). Indicators of myocardial work efficiency were not affected by etidronate disodium at rest or during exercise. We postulate that during exercise the potential beneficial effect of the rightward shift of the Hb-O2 curve upon cardiac function was negated by the fall of PaO2 to or below the COP level, a situation which would limit increases in tissue O2 extraction.

Nutritional state and exercise tolerance in patients with COPD.

We hypothesized that in patients with COPD, poor nutritional status adversely influences exercise tolerance by limiting aerobic capacity of exercising muscles. In 28 patients with stable COPD, we correlated nutritional status with gas exchange indexes obtained during maximal incremental cycle ergometer exercise and with respiratory function parameters. On the basis of percent of ideal body weight (%IBW), patients were divided into three groups (GP): GP1 (n = 8, %IBW < 90); GP2 (n = 13, %IBW > or = 90 < 110); and GP3 (n = 7, %IBW > or = 110). When compared with normally nourished individuals (GPs 2 and 3), malnourished GP1 patients showed greater reduction in maximal workload and in peak O2 uptake (VO2 peak), with earlier onset of metabolic acidosis (anaerobic threshold [AT]); in addition, indexes reflecting O2 cost of ventilation were higher in GP1. Nutritional status could be correlated with exercise tolerance (VO2 peak, r = 0.82, p < 0.0001), with onset of metabolic acidosis (AT, r = 0.69, p < 0.0001) and with dead space/tidal volume ratio (VD/VT, r = -0.59, p < 0.001). Body weight was inversely correlated with indexes that are likely to reflect the increase in O2 cost of ventilation. We conclude that in patients with stable COPD, (1) malnutrition significantly affects muscle aerobic capacity and exercise tolerance, and (2) high wasted ventilation and O2 cost of ventilation may be responsible for the weight loss.

Effect of reduced body weight on muscle aerobic capacity in patients with COPD.

BACKGROUND: Reduced muscle aerobic capacity in COPD patients has been demonstrated in several laboratories by phosphorus magnetic resonance spectroscopy and by analysis of oxygen uptake (VO2) kinetics. COPD patients are usually elderly, hypoxemic, poorly active with muscle atrophy, and often malnourished. Under these conditions there is usually reduction of O2 delivery to the tissues (bulk O2 flow), redistribution of fiber type within the muscle, capillary rarefaction, and decreased mitochondrial function, alterations all capable of reducing muscle aerobic capacity. In COPD, the effect of reduced body mass on muscle aerobic capacity has not been investigated (to our knowledge). METHODS: We studied 24 patients with stable COPD with moderate-to-severe airway obstruction (68+/-5 [SD] years; FEV1, 39+/-12% predicted; PaO2, 66+/-8 mm Hg; PaCO2, 41+/-3 mm Hg) with poor to normal nutritional status, as indicated by a low-normal percent of ideal body weight (IBW). Each subject first underwent 1-min maximal incremental cycle ergometer exercise for determination of VO2 peak and lactate threshold (LT). Subsequently, they performed a 10-min moderate (80% of LT-VO2) constant load exercise for determination of oxygen deficit (O2DEF) and mean response time VO2 (MRT). VO2, CO2 output (VCO2), and minute ventilation were measured breath by breath. RESULTS: Patients displayed low VO2 peak (1,094+/-47 [SE] mL/min), LT-VO2 (35+/-3% predicted O2 max), and higher MRT-VO2 (67+/-4 s). Univariate regression analysis showed that percent of IBW correlated with indexes of maximal and submaximal aerobic capacity: vs VO2 peak, R=0.53 (p<0.01); vs MRT R=-0.77 (p<0.001). Using stepwise regression analysis, MRT correlated (R2=-0.70) with percent of IBW (p<0.01) and with PaO2 (p<0.05). CONCLUSIONS: Reduced body mass has an independent negative effect on muscle aerobic capacity in COPD patients: this effect may explain the variability in exercise tolerance among patients with comparable ventilatory limitation.

Ventilatory and metabolic adaptations to walking and cycling in patients with COPD.

To test the hypothesis that in chronic obstructive pulmonary disease (COPD) patients the ventilatory and metabolic requirements during cycling and walking exercise are different, paralleling the level of breathlessness, we studied nine patients with moderate to severe, stable COPD. Each subject underwent two exercise protocols: a 1-min incremental cycle ergometer exercise (C) and a "shuttle" walking test (W). Oxygen uptake (VO(2)), CO(2) output (VCO(2)), minute ventilation (VE), and heart rate (HR) were measured with a portable telemetric system. Venous blood lactates were monitored. Measurements of arterial blood gases and pH were obtained in seven patients. Physiological dead space-tidal volume ratio (VD/VT) was computed. At peak exercise, W vs. C VO(2), VE, and HR values were similar, whereas VCO(2) (848 +/- 69 vs. 1,225 +/- 45 ml/min; P < 0. 001) and lactate (1.5 +/- 0.2 vs. 4.1 +/- 0.2 meq/l; P < 0.001) were lower, DeltaVE/DeltaVCO(2) (35.7 +/- 1.7 vs. 25.9 +/- 1.3; P < 0. 001) and DeltaHR/DeltaVO(2) values (51 +/- 3 vs. 40 +/- 4; P < 0.05) were significantly higher. Analyses of arterial blood gases at peak exercise revealed higher VD/VT and lower arterial partial pressure of oxygen values for W compared with C. In COPD, reduced walking capacity is associated with an excessively high ventilatory demand. Decreased pulmonary gas exchange efficiency and arterial hypoxemia are likely to be responsible for the observed findings.

Oxygen effect on O2 deficit and VO2 kinetics during exercise in obstructive pulmonary disease.

We evaluated the effect of supplemental O2 on energy metabolism of hypoxemic humans by measuring O2 uptake (VO2) kinetics and other cardiorespiratory parameters in nine male chronic obstructive pulmonary disease (COPD) patients and seven age-matched control subjects (on air and on 30% O2) at rest and during moderate cycle ergometer exercise. Heart rate, ventilation, VO2, CO2 output, respiratory exchange ratio, O2 cost of work, and work efficiency were measured with a computerized metabolic cart; O2 deficit and VO2 time courses were calculated. In COPD patients, 30% O2 breathing resulted in 1) reduction of O2 deficit (from 488 +/- 34 ml in air to 398 +/- 27 ml in O2; P < 0.05) and phase 2 VO2 time constant (from 116 +/- 13 s in air to 74 +/- 12 s in O2; P < 0.05); 2) a smaller steady-state increment in CO2 output than in room air (315 +/- 17 ml/min in O2 vs. 358 +/- 27 ml/min in air; P < 0.02), which resulted in a lower exercise respiratory exchange ratio (0.75 +/- 0.02 in O2 vs. 0.80 +/- 0.02 in air; P < 0.02); and 3) reduced steady-state ventilation (22.6 +/- 1.0 l/min in O2 vs. 25.4 +/- 1.1 l/min in air; P < 0.05). In conclusion, 30% O2 breathing accelerated exercise VO2 kinetics in mildly hypoxemic COPD patients. The observed VO2 kinetics improvement with O2 supplementation is consistent with an enhancement of aerobic metabolism in skeletal muscles during moderate exercise.

Regulation of atrial natriuretic peptide release in normal humans.

Atrial volume, pressure, and heart rate are considered the most important modulators of atrial natriuretic peptide (ANP) release, although their relative role is unknown. Continuous positive-pressure breathing in normal humans may cause atrial pressure and atrial volume to go in opposite directions (increase and decrease, respectively). We utilized this maneuver to differentially manipulate atrial volume and atrial pressure and evaluate the effect on ANP release. Effective filling pressure (atrial pressure minus pericardial pressure) was also monitored, because this variable has been proposed as another modulator of ANP secretion. We measured right atrial (RA) pressure, RA area, esophageal pressure (reflection of pericardial pressure), and RA and peripheral venous ANP in seven healthy adult males at rest and during continuous positive-pressure breathing (19 mmHg for 15 min). Continuous positive-pressure breathing decreased RA area (mean +/- SE, *P less than 0.05) 13.6 +/- 1.1 to 10.5 +/- 0.8* cm2, increased RA pressure 4 +/- 1 to 16 +/- 1* mmHg, increased esophageal pressure 2 +/- 1 to 12 +/- 1* mmHg, and increased effective filling pressure 2 +/- 0 to 4 +/- 1* mmHg. RA ANP increased from 67 +/- 17 to 91 +/- 18* pmol/l and peripheral venous ANP from 43 +/- 4 to 58 +/- 6* pmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Invasiveness and chemotactic activity of oncogene transformed NIH/3T3 cells.

The role of oncogenes in the acquisition of invasive and metastatic capabilities is controversial. Interactions with basement membranes are critical in the process of tumor invasion and metastasis. We compared the ability of 3T3 cells transformed by oncogenes involved in various stages of signal transduction to invade a reconstituted basement membrane in vitro and to grow in a three dimensional basement membrane gel (matrigel). Cell lines transformed by various oncogenes and oncoviruses: v-sis (a growth factor), v-erb-B (a truncated EGF receptor), Moloney sarcoma virus (v-mos: a protein kinase homologue), mutated c-ras oncogenes (G protein homologues), FBJ virus (v-fos: a nuclear protein) were investigated. All transformed cell lines were able to invade in the chemoinvasion assay, where a layer of matrigel is coated onto chemotaxis filters. FBJ/3T3 were the least invasive and SSV/3T3 the most invasive. Control 3T3 cells could not cross the matrigel barrier. All transformed cells grew on matrigel forming invasive, branching colonies, whereas control 3T3 were unable to grow in matrigel. Cells transfected with the v-erb-B gene grew as multilayers inside matrigel. Invasiveness and growth on matrigel were accompanied by a high chemotactic response to laminin (LN) in all transformed lines. These results suggest that invasion and growth on matrigel, together with migration to LN, are induced by a large spectrum of oncogenes. When 3T3 cells were transfected with v-sis oncogene under the transcriptional control of the metallothionein (MMT) promoter and exposed to Zn++, their in vitro invasiveness was specifically increased by around 3 fold. These findings provide further evidence supporting a direct role of the v-sis oncogene in the invasive phenotype.

Red blood cell alkalosis and decreased oxyhemoglobin affinity.

The behavior of the oxyhemoglobin curve was studied in ten patients with respiratory alkalosis (arterial [H+] less than 37 nM, pCO2 less than 32 mmHg and HCO-3 less than 22.0 mEq/L) and ten patients with metabolic alkalosis ([H+] less than 34 nM, pCO2 greater than 37 mmHg and HCO-3 greater than 28.0 mEq/L) to determine whether different alkalotic states similarly affect the red blood cell [H+] and 2,3-diphosphoglycerate interaction and thus the oxygen affinity of hemoglobin. The findings were statistically indistinguishable in respiratory alkalosis and metabolic alkalosis: a) low plasma [H+], normal red blood cell [H+], and high transmembrane [H+] gradient; b) elevated red blood cell 2,3-diphosphoglycerate inversely proportional to low arterial plasma [H+]; c) decrease in oxygen affinity of hemoglobin when normalized for plasma [H+], but less decreased when normalized for red blood cell [H+]. Other factors capable of affecting the oxygen affinity of hemoglobin were: mean corpuscular hemoglobin concentration; red blood cell adenosine triphosphate; carboxyhemoglobin; and methemoglobin were not significantly different between groups. These results: 1) agree with data previously reported from this laboratory on patients with portal-systemic encephalopathy; 2) underscore the importance of RBC [H+] in defining the oxygen affinity of hemoglobin; 3) suggest the decrease in oxygen affinity of hemoglobin is mediated through the 2,3-diphosphoglycerate elevation; and 4) indicate the high transmembrane [H+] gradient is principally due to the cellular accumulation of [H+] (2,3-diphosphoglycerate ionization).

Atrial natriuretic peptide, renin and aldosterone in obstructive lung disease and heart failure.

Elevations of atrial natriuretic peptide (ANP) in congestive heart failure (CHF) and chronic obstructive lung disease (COLD) are presumably due to atrial hypertension, while secondary hyperaldosteronism in these patients is thought to result from diminished renal perfusion. The responsiveness of the ANP and renin (PRA)-aldosterone (PA) systems to acute increases in right atrial pressure has not been studied in these patients, but in normals a reciprocal relationship between ANP with PRA and PA has been shown. The authors monitored venous pressure (VP, reflective of right atrial pressure), ANP, PRA and PA in 15 stable COLD patients, seven stable CHF patients and three normal controls at baseline and after elevation of VP by antishock trousers. Inflation of the trousers resulted in increased VP and ANP (p less than 0.05): control ANP, 84 +/- 17 to 108 +/- 23 pg/ml; COLD ANP, 176 +/- 5 to 200 +/- 7; and CHF ANP, 388 +/- 20 to 499 +/- 37. PRA and PA were not suppressed by increasing ANP levels and the delta ANP/delta VP ratio was similar among groups. No intergroup differences in resting PRA and PA were noted, but PRA was higher (p = 0.007) and PA tended to be higher (p = 0.08) in a sub-group of six edematous patients, as compared with non-edematous patients and controls. These findings: (1) confirm previously reported ANP differences between COLD and CHF; (2) indicate that the ANP system remains responsive to physiologic manipulations in COLD and CHF; and (3) demonstrate that ANP and the PRA-PA axis are not reciprocally related in either group.