Nongastric Marginal‐Zone B‐Cell MALT Lymphoma: Prognostic Value of Disease Dissemination

The aim of this study is to describe the clinical features and define the prognostic significance of disease dissemination in a large series of nongastric marginal-zone B-cell mucosa-associated lymphoid tissue (MALT) lymphomas. We studied 208 patients with nongastric marginal-zone B-cell MALT lymphoma diagnosed and treated from 1991 to 2004. Ninety percent of the patients had a single site of MALT involvement--skin (26%), salivary glands (18%), orbit (14%), Waldeyer's ring (13%)--and 39% and 28% had nodal involvement and bone marrow involvement, respectively. After a median follow-up of 2.7 years, the median event-free survival (EFS) time was 2.4 years, and the median overall survival (OS) time was not reached. On univariate analysis, the features significantly associated with longer EFS and OS times were the following: single MALT site involvement (OS), localized disease (EFS and OS), no nodal disease (EFS and OS), skin and orbit lymphoma (OS), and stage IV disease without bone marrow involvement (OS). On multivariate analysis, both bone marrow and nodal involvement were associated with shorter OS. This study describes the clinical features and the natural history of nongastric marginal-zone lymphomas and highlights that the dissemination to lymph nodes and bone marrow is associated with a poorer outcome.

Multiple lines of chemotherapy are the main risk factor for severe infections in patients with chronic lymphocytic leukemia with febrile episodes

We report on febrile episodes occurring among 379 patients affected by chronic lymphocytic leukemia, observed from 1984 to 2002. One hundred and twenty eight patients (33.7%) developed 341 febrile episodes, of which 251 were documented infections (82 severe and 169 moderate). Among various risk factors, only previous treatment with multiple regimens of chemotherapy was associated with severity of infection (p=0.0005).

Bronchiolitis Obliterans Induced by Intratracheal Papaverine: A Novel Animal Model

Constrictive bronchiolitis obliterans (CBO), a highly fatal syndrome seen following toxicant exposure and lung transplantation, is in need of mechanistic study. This report creates an animal model of toxicant induced CBO, validates its pathology and suggests a physiologic mechanism for its origin. Papaverine, the alkaloid in Sauropus plants and responsible for human toxicant-induced CBO, was used to create the rat model. A mini-osmotic pump delivered papaverine intratracheally for up to 28 days (0.25 microL/hr, totaling 6.4 mg). Bronchoalveolar lavage (BAL) was measured. Lung tissue was evaluated for signs of CBO (H&E and Trichrome staining). Cytokines deregulated in human CBO were also measured (TGF-beta and eNOS). Peribronchial inflammation, extensive denudation and destruction of bronchial mucosa, as well as increased peribronchial collagen (all classic signs of CBO) were observed as early as 7 days in papaverine treated animals, with more extensive damage after 28 days. Significant elevations of TGF-beta and eNOS were seen in lung homogenates. Our toxicant induced model of CBO via a novel delivery method of intratracheal papaverine accurately reproduces pathology and cytokine profiles of human CBO. Papaverine has potential for producing CBO by multiple routes. This model introduces a vehicle for both understanding and development of innovative treatment for CBO.

Reduced IL-4 associated antibody responses to vaccine in early pre-diabetes

AIMS/HYPOTHESIS

The aim of this study was to determine whether beta-cell autoimmunity is associated with immune response bias to exogenous antigens.

METHODS

IgG subclass responses against tetanus toxoid and rubella were measured after vaccination in children with (n=36) and without (n=73) islet autoantibodies participating in the BABYDIAB prospective study of offspring of parents with Type I (insulin-dependent) diabetes mellitus. All children had been vaccinated against tetanus toxoid antigen before 6 months of age and at 18 months of age, and against live attenuated rubella virus at 18 months of age and again before 5 years of age. Tetanus toxoid specific IgG subclasses and cytokine responses were compared in a second cohort of subjects.

RESULTS

Responses to tetanus toxoid in islet-autoantibody-negative children were characterized by early IgG1 antibodies at 9 months of age followed by the appearance of IgG4 and lesser IgG2 antibodies at 2 years of age. Children who had developed islet autoimmunity before one year of age (n=15) did not have the shift to IgG4 and IgG2 anti-TT after booster vaccination (p<0.01), and had undetectable or IgG1 restricted responses. This defect was independent of HLA class II genotype, was restricted to children who had islet autoimmunity before 1 year of age, and was most evident in children who already had multiple islet autoantibodies by 9 months of age. IgG4 and IgG2 anti-TT correlated with IL-4 (p<0.005), but not IFNgamma responses. Antibody responses to the IFNgamma-inducing rubella vaccination were strongly IgG1 dominated and no differences were observed between islet autoantibody positive and negative children.

CONCLUSIONS/INTERPRETATION

These data are consistent with a reduced capacity to make IL-4 promoted antibody responses to exogenous antigen in early pre-diabetes.

Prevention of radiation-induced nephropathy and fibrosis in a model of bone marrow transplant by an angiotensin II receptor blocker

Nephropathy, interstitial pneumopathy, and renal and lung fibrosis are major complications of bone marrow transplantation (BMT). This study evaluated the antifibrotic property of an angiotensin II (A2) type-1 receptor blocker (L-159,809) and compared it with those of Captopril and Enalapril, two angiotensin-converting enzyme (ACE) inhibitors, in a rat model of BMT. Male WAG/Rij/MCW rats received a preparative regimen of 60 mg/kg body wt of cytoxan (i.p., Days 9 and 8) and 18.5 Gy of total body irradiation (TBI) in six twice daily fractions (Days 2, 1, and 0) followed immediately (Day 0) by BMT. Modifiers were given in drinking water from Day 10 until autopsy, 8 weeks after BMT. Rats treated with TBI plus cytoxan alone developed severe nephropathy. Trichrome staining showed marked collagen deposition in glomeruli, renal interstitium, and renal arteries and arterioles (especially in their adventitia). Collagen deposition and renal damage were markedly reduced by the three modifiers. Of the three, L-158,809-treated rats had slightly thinner vessels and slightly less collagen than nonirradiated normal controls. The study shows the effectiveness of these drugs in the protection of the renal parenchyma from the development of radiation-induced fibrosis. It also indicates a role for angiotensin II in the modulation of collagen synthesis.

Estrogen and progesterone receptors in gynecomastia

The etiology of gynecomastia is unknown. There seems to be no increased incidence of malignancies in patients with idiopathic gynecomastia; however, patients with Klinefelter syndrome exhibit an increased incidence of malignancy. The authors reviewed the results of 34 patients with gynecomastia diagnosed in adolescence who, following initial evaluation, had a mastectomy. The estrogen and progesterone receptors were analyzed in these patients. Three of the patients were diagnosed with Klinefelter syndrome. These three patients exhibited elevated amounts of estrogen and progesterone receptors. None of the patients who were not diagnosed with this syndrome demonstrated significant elevation of their estrogen or progesterone receptors. The presence of elevated estrogen and progesterone receptors in patients with Klinefelter syndrome provides a potential mechanism by which these patients may develop breast neoplasms. The absence of elevated estrogen and progesterone receptors in patients with idiopathic gynecomastia may serve to clarify why these patients' disease rarely degenerates into malignancy.

Mucormycosis in hematologic malignancies: an emerging fungal infection

BACKGROUND AND OBJECTIVES

In recent years pulmonary mucormycosis has been reported in patients with leukemia and lymphoma and bone marrow transplant recipients. It carries an extremely poor prognosis. We report our experience of clinical findings, diagnostic procedures, treatment and outcome of mucormycosis diagnosed in neutropenic patients affected by hematologic neoplasms admitted to our Department.

DESIGN AND METHODS

From November 1987 to July 1999 we observed 13 cases of Mucor. Their median age was 61 years (range 20-75), and they were predominantly in the aplastic post-chemotherapy period (12/13), affected by acute myeloid leukemia (11 cases ) or non-Hodgkin's lymphoma (2 cases). Six patients (all with leukemia) were receiving inductionEth consolidation therapy, 7 had progressive hematologic disease. At the onset of infection all patients were neutropenic (N < 0.5x10(9)/L). No patients had diabetes mellitus. Two patients had been receiving steroid therapy for 5 and 7 days.

RESULTS

The lung was involved in all cases (13/13); disseminated disease was present in 8/13 patients. All cultures (blood, sputum, nasal swabs and bronchoalveolar lavage) were negative. In 3 patients a histologic diagnosis was made in vivo: in 1 patient by percutaneous pulmonary biopsy, in 1 patient by pulmonary lobectomy, and in the last patient by percutaneous pulmonary biopsy confirmed by excision of a cerebellar abscess. In the remaining 10 cases diagnosis was made post-mortem. Five patients were not treated, 2 because of poor clinical condition and 3 because fungal infection was not suspected. Amphotericin B (1 mg/kg/day) was given empirically to 6 patients and 2 responded to treatment. The remaining 2 patients with neurologic symptoms at the onset of infection were treated with liposomal amphotericin, Ambisome, one with 3 and one with 5 mg/kg/day; of these two patients the first died in 4 days; the second, with both pulmonary and cerebellar localizations, was treated successfully with 5 mg/kg/day for 4 weeks and then with 3 mg/kg/day, and excision of a brain abscess at neutrophil recovery (total dose of Ambisome: 12,000 mg). The 3 surviving leukemic patients were able to complete subsequent consolidation therapy using amphotericin B or liposomal amphotericin as secondary prophylaxis during aplasia.

INTERPRETATION AND CONCLUSIONS

In neutropenic hematologic patients Mucor is rarely suspected. In our patients infection was often characterized by disseminated disease and a rapidly fatal course; only early aggressive amphotericin B (or Ambisome) treatment together with neutrophil recovery appeared to improve the outcome. Diagnosis is very important for programming antifungal therapy and secondary prophylaxis with amphotericin B, because Mucor is usually resistant to itraconazole.

Vitamin A deficiency injures lung and liver parenchyma and impairs function of rat type II pneumocytes

The purpose of this research was to determine the effects of vitamin A deficiency on liver and lung morphology and type II pneumocyte function. Weanling rats were fed a retinol-adequate (control) or -deficient diet for 6 wk. Average food intakes and body weights were not different between the vitamin A-deficient and -adequate rats. Histologic examination revealed that the lungs of vitamin A-deficient rats had less collagen in the adventitia of small caliber arteries and arterioles and in the alveolar septa, which appeared thinner than that of controls. Many areas of the lungs of the same rats were also emphysematous (increased size of air spaces distal to the terminal bronchiole, with thinning and partial or total destruction of septal wall). Content of elastin also was lower in the lung parenchyma, as well as in the small arteries and arterioles, but not in the larger ones. Peribronchial collagen was not affected by the deficient diet. Scattered inflammation was observed in most of the vitamin A-deficient rats; a mild inflammatory reaction also was seen in one of the controls. Vitamin A-deficient rats also exhibited hepatocyte vacuolization and mild inflammation in the liver, specifically in the periportal tracts. Surfactant synthesis and ornithine decarboxylase activity were significantly lower in type II pneumocytes isolated from vitamin A-deficient rats. In conclusion, our data provide evidence that vitamin A deficiency produces profound morphologic alterations in liver and lung parenchyma and impairs pneumocyte function.

Control of radiation-induced pneumopathy and lung fibrosis by angiotensin-converting enzyme inhibitors and an angiotensin II type 1 receptor blocker

PURPOSE

This report summarizes our experiences on the protective effect of angiotensin-converting enzyme (ACE) inhibitors, especially captopril and an angiotensin II type 1 receptor blocker on radiation-induced pulmonary injury.

METHOD

In the first series of experiments, adult male Sprague Dawley rats were given a single dose of either 20 or 30 Gy of gamma rays to a 35 cm2 right hemithorax port, whilst shielding the left, contralateral, lung. Perfusion scans and autopsies were performed at intervals up to 12 months post-radiation. Three different ACE inhibitors, penicillamine and pentoxifylline were given as radiation protectors and their activity compared. A model of irradiation for total bone marrow transplant (BMT) was used for the second group of experiments. Male WAC/Rij/MCW rats received total-body irradiation and a regimen of cyclophosphamide (CTX) in preparation for bone marrow transplant. The modifiers were two ACE inhibitors, captopril and enalapril, and L-158,809, an angiotensin II (A II) type 1 receptor blocker. All drugs were administered in the rats' drinking water and all were well-tolerated.

RESULTS

In the irradiated rats, pulmonary damage progressed from the presence of blebs and detachment from basement membranes of endothelial cells a few days after injury, to severe arteritis and interstitial collagen deposition at 3 months, and then on to severe pneumonitis and extensive pulmonary fibrosis at 6 months. Marked increase of hydroxyproline was also found in the lungs at 6 months. These morphological changes were associated with significant decrease of ACE and plasminogen activator activity (PLA) and a marked increase of prostaglandins (PG12) and thromboxane (Txa2), substances considered as indicators of endothelial pulmonary damage. ACE inhibitors captopril, CL 24817, enalapril and CGS 13945 prevented the markers of endothelial dysfunction. Captopril and CL 24817, which contain a sulphydryl (-SH) radical in their moiety and the AII type 1 receptor blocker, L-158,809, were the most efficient in protecting the lung parenchyma from the inflammatory response and subsequent fibrosis. Penicillamine, an SH-containing compound with weak ACE inhibitory activity was also a strong antifibrotic agent but showed only modest anti-inflammatory properties. Additionally, in the irradiated rats, captopril also reduced the incidence of squamous cell skin carcinomas and subcutaneous sarcomas consequent to the highest doses of radiation.

CONCLUSION

ACE inhibitors and one AII type 1 receptor blocker were effective in protecting lungs from radiation-induced pneumonitis and the development of lung fibrosis in two models of rat radiation injury. In the first series of experiments (unilateral irradiation), those ACE inhibitors containing a sulphydryl radical were more effective than those without it. This observation led to the question of whether this protective effect is related to inhibition of AII synthesis or rather to some of the collateral pharmacologic properties of these drugs, such as anti-oxidation or protease inhibition. The AII receptor blocker, however, was shown to be equally effective, if not better, in its antifibrotic capacity than any ACE inhibitor with or without an SH radical, reaffirming the role of AII in modulation of collagen synthesis.

Diminished energy metabolism and enhanced apoptosis in livers of B6C3F1 mice treated with the antihepatocarcinogen rotenone

Rotenone decreases the incidence of hepatocellular carcinoma and lowers rates of hepatocellular proliferation. In an effort to delineate mechanisms involved, the in vivo effect of rotenone on liver mitochondrial metabolism, apoptotic machinery as well as elements of the hepatic signal transduction pathways were investigated. Mitochondria from livers of male B6C3F1 mice fed a standard diet containing 600 ppm rotenone for 7 days were uncoupled or inhibited when succinate or glutamate plus malate were used as the substrate, respectively. These livers also showed a significant increase in apoptosis compared with control livers. Furthermore, rotenone increased the expression of c-myc mRNA to 5-fold of control values within 3 days, an effect which was still observed (3-fold) after 7 days. Levels of p53 mRNA were also increased 3-fold after 1 day, but declined to control levels by 7 days. Rotenone also caused a transient, yet marked increase in liver particulate glyceraldehyde phosphate dehydrogenase (GAPDH) protein expression, while it did not alter the expression of the cytosolic form of the enzyme. Conversely, mRNA of the proto-oncogene H-ras showed a decline of 35% after 3 days of rotenone treatment, and remained diminished for the duration of the experiment. These data suggest that rotenone may act as an anticancer agent by diminishing mitochondrial bioenergetics which prevents basal hepatocyte proliferation and lowers the threshold for liver cells with DNA damage to undergo apoptosis.

Dietary beta-carotene protects lung and liver parenchyma of rats treated with monocrotaline

Some studies have indicated that the injury induced by the hepato- and pneumotoxin monocrotaline (MCT) is in part mediated by oxidation. Because beta-carotene is a potent antioxidant, we hypothesized that it would protect the lung and liver parenchyma against MCT-induced injury. Twenty rats were assigned randomly to four groups. All rats were fed a standard AIN93G diet with or without beta-carotene. After 1 week on the purified diets, half of the rats fed the control (standard) diet and half of the rats fed the beta-carotene-supplemented diet were injected subcutaneously with 60 mg MCT/kg body weight or its vehicle (water). All rats were sacrificed at 4 weeks. Histological examination showed that beta-carotene alone did not affect lung or liver structure. On the other hand, lungs of MCT-treated rats had severe focal pneumonia, extensive deposition of collagen in the septa, marked inflammation of the small arteries and arterioles, and arterialization of the small venules. Livers of MCT-treated rats showed some fatty infiltration and diffuse hemorrhages, more prominent sometimes in the centrilobular area and sometimes in the periportal region. Concomitant treatment with beta-carotene protected the lung parenchyma from the inflammatory reaction and the septal fibrosis, but did not prevent cardiac right ventricular hypertrophy and only slightly reduced the thickening of the wall of small arteries and arterioles. Incidence of steatosis and hemorrhages was decreased in the liver. These results indicate that MCT-induced pulmonary vascular remodeling occurs in the absence of inflammatory cell infiltration. Furthermore, beta-carotene prevented inflammation and protected the lung and liver parenchyma of MCT-treated rats.

Mechanism of captopril toxicity to a human mammary ductal carcinoma cell line in the presence of copper

Captopril (D-3-mercapto-2-methylpropanoyl-L-proline) is an angiotensin converting enzyme (ACE) inhibitor, used widely in the treatment of hypertension and congestive heart failure. Captopril also inhibits proliferation of a variety of cell types, including several lacking ACE and renin acitvity. We have previously demonstrated that human mammary ductal carcinoma cells are among the cell types whose mitotic activity is inhibited by captopril. In those cells, captopril also reduces estrogen receptor (ER) and increases progesterone receptor (PR) concentrations. The present study evaluated the mechanism of captopril's antiproliferative action in an ER/PR-negative human mammary ductal carcinoma cell line, Hs578T. Cells grown in a 10% serum medium showed negligible changes in the presence of captopril alone. However, in the presence of subphysiologic concentrations of copper salts or copper-loaded ceruloplasmin, captopril caused a dose-dependent reduction in cell number, thymidine incorporation and mitochondrial dehydrogenase activity. In contrast, iron salts and iron-saturated transferrin had no effect on captopril activity. Catalase and horseradish peroxidase nullified the cytotoxic effects of captopril/Cu++, whereas H2O2 mimicked those effects. These data are consistent with the notion of a copper-catalyzed oxidation of captopril, leading to the generation of H2O2 as the cytotoxin to this clinically important cell type.

Ex vivo manipulation of hematopoietic stem cells for transplantation: the potential role of amifostine

High-dose chemotherapy with autologous stem cell transplantation is an increasingly used procedure in oncohematologic diseases and represents a promising strategy in selected patients with solid tumors. In autologous stem cell transplantation, the risk of reinfusion of clonogenic tumor cells is a remarkable biologic obstacle that can be at least partly overcome by ex vivo graft purging to reduce residual tumor. Mafosfamide and 4-hydroxyperoxycyclophosphamide, active metabolites of cyclophosphamide, are the most widely used pharmacologic agents for ex vivo bone marrow purging. However, in addition to killing tumor cells, they are toxic to normal bone marrow as measured by reduced colony-forming unit granulocyte-macrophage (CFU-GM). Thus, the therapeutic index of these alkylating agents is narrow, and parameters for dose selection must include toxicity to normal bone marrow progenitor cells that can delay bone marrow engraftment and increase risk of infections, bleeding complications, hospitalization, and the need for a costly transplantation procedure. Amifostine (WR-2771, Ethyol; Alza Pharmaceuticals, Palo Alto, CA/US Bioscience, West Conshohocken, PA) selectively protects human CFU-GM progenitor cells from the cytotoxicities of active metabolites of cyclophosphamide without altering its cytotoxic effect on malignant cells. This has been demonstrated both in preclinical and clinical studies in patients with breast cancer, malignant lymphomas, and acute leukemia. Amifostine use during the ex vivo procedure significantly shortened the time to bone marrow engraftment with decreased incidence of infections and need for red blood cell transfusions.

Pleurodesis by autologous blood, doxycycline, and talc in a rabbit model

BACKGROUND

Management of recurrent spontaneous pneumothorax or symptomatic pleural effusion often uses thoracoscopic pleurodesis, about which many questions remain. Both effectiveness and toxicity of agents currently used for pleurodesis were evaluated in a rabbit model.

METHODS

Agents administered were autologous blood 1 mL/kg, talc slurry (70 mg x mL(-1) x kg(-1)), and doxycycline 10 mg/mL, given through a chest tube to 30 rabbits. Controls had only chest tubes inserted. At 30 days surfaces were graded by gross observation and histologic examination. Blood and lung tissue from all animals were analyzed for enzymes and blood chemistries.

RESULTS

Gross observations showed mediastinal thickening and adhesions with doxycycline, and threadlike adhesions with talc. Autologous blood was only slightly more effective than a chest tube alone. Talc significantly increased angiotensin converting enzyme activity in serum, whereas doxycycline changed liver function enzymes and produced tissue toxicity.

CONCLUSIONS

Doxycycline produced effective pleurodesis but yielded remarkably severe local effects. The distant sequelae of talc and doxycycline pleurodesis-histologic changes in the contralateral lung and serum enzyme elevations-suggests undesirable systemic effects for the commonly used agents, and autologous blood exhibited no significant pleurodesis, short-term. The search for the ideal agent for chemical pleurodesis continues.

A subdepressor low dose of ramipril lowers urinary protein excretion without increasing plasma potassium

Angiotensin-converting enzyme (ACE) inhibitors are increasingly administered to patients with chronic renal disease. One issue of concern with the use of ACE inhibitors in patients with impaired renal function is the possible development of hyperkalemia. We reasoned that the impact of ACE inhibitors on plasma potassium could be minimized by administering these agents at very low doses. To examine this issue, we investigated the effect of a low dose of ramipril (1.25 mg orally once daily) and an eight-fold higher dose (10 mg orally once daily) on plasma potassium in 13 patients with proteinuria and mild chronic renal insufficiency. The study was divided into four phases: placebo (4 weeks), low-dose ramipril (8 weeks), high-dose ramipril (8 weeks), and washout phase (4 weeks). With the low dose of ramipril, urinary protein excretion decreased significantly as early as after 1 week of administration (from 4.4 +/- 0.5 to 3.7 +/- 0.4 g/24 h; P < 0.025) and did not decrease any further thereafter even when the dose was increased eight-fold. Mean arterial blood pressure and plasma potassium did not change significantly with the low dose of ramipril, whereas with the higher dose, mean arterial blood pressure decreased significantly (from 107 +/- 2.0 to 100 +/- 2.0 mm Hg, P < 0.005), and plasma potassium increased significantly (from 4.53 to 4.78 mEq/L, P < 0.05). We conclude that a low dose of ramipril can reduce proteinuria to the same extent as an eight-fold higher dose without significantly lowering blood pressure or increasing plasma potassium. This latter feature may be advantageous for the treatment of patients at risk for hyperkalemia who require ACE inhibitors.

Possible stage-specific function of NF-kappaB during pre-B cell differentiation

Lipopolysaccharide (LPS)-induced differentiation of the murine pre-B cell line 70Z/3 is a model for pre-B to B cell differentiation and has been used to show that the transcription factor NF-kappaB is essential to induce the expression of the Ig kappa gene. We have investigated the mechanism involved in late stages of the process when all cells have reached a more mature B phenotype, i.e. beyond 48 up to 96 h of LPS treatment. NF-kappaB binding activity was induced at early times by LPS treatment, but its DNA binding activity disappeared after 84 h of LPS treatment. Accumulation of IkappaB alpha protein in the nucleus correlated with the disappearance of NF-kappaB activity at 72, 84 and 96 h, and treatment of nuclear extracts of 72-96 h LPS-treated cells with Na-deoxycholate restored NF-kappaB binding activity. The data indicate that NF-kappaB, while important to initiate the process of Ig kappa gene transcription in 70Z/3 pre-B cells, is no longer required for its maintenance in differentiated 70Z/3 cells.

Changes of prothrombin fragment 1+2 (F 1+2) as a function of increasing intensity of oral anticoagulation--considerations on the suitability of F 1+2 to monitor oral anticoagulant treatment

Plasma F 1+2 levels, the activation peptide originating from the factor Xa-mediated activation of prothrombin, increase in many clinical conditions associated with hypercoagulability and decrease in patients on oral anticoagulant treatment (OAT). However. the usefulness of F 1+2 measurement to monitor OAT has not yet been investigated in clinical studies. Before those studies are attempted, the plausibility of its implementation in the laboratory control of OAT should be evaluated. In this respect, a thorough investigation of the pattern of changes of F 1+2 as a function of increased intensity of anticoagulation expressed as International Normalized Ratio is essential. One hundred and thirty-two patients on long-term warfarin treatment were recruited to cover 8 ranges of anticoagulation from < 1.5 to 9.0 INR. F 1+2 was measured in batch on frozen plasma and INR was determined on fresh plasma. The relationship of F 1+2 vs. INR showed a hyperbolic pattern with F 1+2 levels decreasing progressively and significantly as a function of increasing INR up to 3.0. A further decrease in F 1+2 levels observed at INR up to 4.0 was not statistically significant. At INR greater than 4.0, F 1+2 reached a plateau, with mean levels not significantly different for patients at increasing INR up to 9.0. Since the risk of bleeding increases at INR greater than 4.5, our results suggest that F 1+2 is of little value to assess the hemorrhagic risk in patients on OAT.

Glutamate-dependent activation of NF-kappaB during mouse cerebellum development

NF-kappaB and activator protein 1 (AP-1) are dimeric transcription factors involved in transcriptional regulation in many cells, including neurons. We have examined their activity during mouse cerebellum development, a postnatal process starting just after birth and completed by the fourth postnatal (PN) week. The activity of these factors was analyzed by binding of nuclear extracts to a synthetic oligonucleotide representing the kappaB site of human immunodeficiency virus or the AP-1 site of the urokinase promoter. NF-kappaB activity was observed from 7 PN, was restricted to the developing cerebellum, and was not observed in the early postnatal neocortex and hippocampus. On the other hand, AP-1 activity was not found in cerebellum but was present in both neocortex and hippocampus. Moreover, a kappaB-driven transgene was found to be increasingly expressed in the cerebellum from 5 PN to 10 PN but not in the adult. The regulation of NF-kappaB activation in mouse cerebellum was analyzed by intraperitoneal injection of glutamate receptor antagonists to 9 PN mice, which abolished NF-kappaB-binding activity, suggesting an endogenous loop of glutamate receptor activation. Glutamate receptor agonists, on the other hand, induced NF-kappaB nuclear translocation in the cerebellum of 5 PN mice, which is a stage in which NF-kappaB is not yet endogenously activated. This effect was specific for NF-kappaB and not observed for AP-1. In adult mice, NF-kappaB activity was absent in the cerebellum and was not induced by intraperitoneal injection of glutamate receptor agonists. These data show that NF-kappaB is specifically activated during cerebellum development and indicate an important role of glutamate receptors in this process.

Annexin I in fibrotic rat lung and cultured lung fibroblasts following irradiation

Radiation-induced lung fibrosis is a result of collagen accumulation in the interstitium, partly due to increased collagen synthesis by fibroblasts. One feature of active collagen synthesis is increased membrane trafficking in the fibroblasts. A group of proteins called annexins is believed to play a regulatory role in membrane fusion and exocytosis. Therefore, increased annexin activity might be expected in the fibrotic lung. We tested this hypothesis by measuring annexin I levels, hydroxyproline content and ultrastructural changes in radiation-induced pulmonary fibrosis in rat. Three months after a single exposure to 30 Gy of X-rays to the right hemithorax, the right lung of the rat was atrophied and fibrotic with a concomitant increase in size of the shielded left lung. Electron micrographs revealed that the irradiated lung was ladened with interstitial collagen fibrils, with increased number of fibroblasts amongst them. Hydroxyproline concentration in the irradiated lung was nearly twice that in the sham-irradiated lung. Annexin I in the irradiated lung, on the other hand, was markedly reduced, and barely detectable on immunoblots. Since increased annexin I might precede enhanced collagen production, we also measured annexin I levels in rat lungs 3 days after 30 Gy irradiation and correlated that with hydroxyproline concentration. We found no appreciable difference in annexin I levels and hydroxyproline content between sham-irradiated and irradiated lungs at 3 days. To determine whether annexin I levels in cultured fibroblasts were altered by irradiation, we assayed annexin I in cultured rat lung fibroblasts 3 days after 0.10 Gy exposure, with concomitant measurement of 14C-proline incorporation. The annexin I level in fibroblasts irradiated with 10 Gy X-rays was 55% higher than in sham-irradiated fibroblasts. However, incorporation of 14C-proline into collagenase-sensitive macromolecules in the culture medium and extracellular matrix was not different between these two groups of cells. These data demonstrate a radiation-induced increase in immunoreactive annexin I in cultured lung fibroblasts, but fail to support the hypothesis of a positive correlation between annexin I concentration and fibrosis in irradiated rat lung.

Captopril modulates hormone receptor concentration and inhibits proliferation of human mammary ductal carcinoma cells in culture

The present study evaluated the effect of the angiotensin converting enzyme (ACE) inhibitor captopril on estrogen (ER) and progesterone (PR) receptor concentration and on proliferation in two lines of human mammary ductal carcinoma cells in culture: T-47D (ER+/PR+) and Hs578T (ER-/PR-). The incorporation of [3H]thymidine, validated by cell count, served as an index of proliferation. Compared to control cells, T-47D cells incubated for 48 hrs in 1, 2, or 5 mM captopril (but not in 0.5 mM) exhibited a reduction in ER from 130 +/- 6 to 32 +/- 32 fmol/mg cytosolic protein, and an increase in PR from 1780 +/- 120 to 2740 +/- 400 fmol/ mg protein (p < 0.05). Western analysis confirmed these drug-induced changes in the concentration of immunoreactive receptor proteins. Captopril also induced the appearance of low but detectable PR in the Hs578T cells at concentrations as low as 50 microM. Captopril inhibited the incorporation of [3H]thymidine by both cell types during a 48 hr incubation, although Hs578T cells were 2-3 times more resistant than were T-47D cells. This cytostatic effect of captopril was not due to cytotoxicity as indicated by 51Cr release, and was not accompanied by significant changes in cell cycle distribution as determined by flow cytometry. The incorporation of [3H]uridine (RNA synthesis) and [14C]alanine (protein synthesis) also were inhibited by captopril, suggesting a general antimetabolic effect of the drug in the ductal carcinoma cells. These are novel actions of a common antihypertensive agent. In contrast, the nonthiol ACE inhibitor lisinopril, and penicillamine, a thiol compound with virtually no ACE inhibitory activity, had no effect on any of these endpoints.

Annexin I concentration and prostacyclin production in rat lung and alveolar macrophages following irradiation

The purpose of this study was to gather additional evidence in irradiated rat lung on the relationship between annexin I and prostaglandin synthesis. The right hemithorax of the animal was exposed to a single dose of 0 or 30 Gy of X-rays, and the animals were killed 3 months postirradiation. Levels of annexin I and synthesis of prostacyclin (PGI2) were determined in lungs, in cell-free bronchoalveolar lavage (BAL) fluid, and in macrophages lavaged from those lungs. In addition, protein concentration, lactate dehydrogenase (LDH) activity and macrophage count in BAL fluid obtained from irradiated lung were compared with that from sham-irradiated (0 Gy) lung. Levels of annexin I, the putative inhibitor of phospholipase A2, in lung and cell-free BAL fluid were decreased in samples from irradiated animals. By contrast, the level of annexin I in macrophages lavaged from irradiated lung was higher than that in macrophages from sham-irradiated lung. The irradiated lung produced nearly 3.5 times more prostacyclin than did the control lung. However, prostacyclin synthesis by macrophages lavaged from irradiated lung was no different than that of macrophages from sham-irradiated lung. Protein, LDH and macrophage number in BAL fluid from irradiated lungs were significantly higher than in corresponding specimens from sham-irradiated lungs. These data demonstrate that reduced levels of annexin I, as well as increased protein concentration, LDH activity and macrophage numbers in irradiated rat lung are reflected in BAL fluid. Therefore, information obtained from BAL fluid, but not from BAL macrophages, reflects lung status, and may serve as a minimally invasive index of radiation pneumonitis in this model. In irradiated lung, increased PGI2 synthesis coupled with a decreased annexin I level are consistent with the hypothesis of an inhibitory role of annexin I in prostaglandin metabolism. However, this hypothesis is not supported by findings in BAL macrophages, where increased annexin I concentration is not accompanied by a decrease in PGI2 production. In view of the latter findings, and a previous study from our laboratory demonstrating that phospholipase activity in irradiated rat lung is in fact decreased, despite the reduction in annexin I concentration and the hyperproduction of prostanoids, it would seem unlikely that annexin I negatively modulates prostaglandin synthesis via inhibition of phospholipase in this model.

Dose-response effects of radiation on the permeability of endothelial cells in culture

Increased permeability is an early and universal response of the vasculature to radiation injury, yet the biological basis of this reaction is poorly understood. The present study determined the time course and the dose-response relationship of radiation-induced hyperpermeability in cultured bovine pulmonary artery endothelial (BPAE) cells. BPAE cells were grown to a confluent monolayer on microcarrier beads, and column chromatography methods were used to evaluate permeability to two low molecular weight compounds: sodium fluorescein (NaFlsc, mol. wt. = 342) and cyanocobalamin (B12, mol. wt. = 1355). This is a novel in vitro model to study mechanisms and modifiers of radiation-induced permeability of endothelial cells under flow conditions using nonradioactive tracers. Cell-covered beads were exposed to a single dose of 10 Gy Of 137Cs gamma rays and placed in the column, and permeability was measured every 30 min for 3 h. There was a time-dependent increase in permeability to both tracers, reaching significance by 2 h. Increased permeability was accompanied by perturbations in F-actin distribution in the BPAE cells as determined by rhodamine-phalloidin fluorescence microscopy. Neither catalase nor captopril ameliorated this hyperpermeability, but dibutyryl cAMP partially prevented it. At 3 h after 0, 1, 2, 5 and 10 Gy irradiation, permeability values of 11.8 +/- 2.1, 13.9 +/- 2.2, 20.9 +/- 3.6, 24.8 +/- 2.8 and 27.2 +/- 3.3 (10(-5) cm/s, +/- SEM), respectively, were observed using NaFlsc. The increase was significant (P < 0.05) at 2 Gy or higher. Permeability to B12 was significantly elevated after 5 or 10 Gy. These results suggest that permeability of endothelial cells to low molecular weight solutes increases within 3 h after therapeutic doses of radiation, and that cAMP ameliorates this response.

Early markers of ventilator-induced lung injury in rats

Positive pressure ventilation with hyperdistention of the lungs (PPVHDL) causes microscopic lung injury in rats and in mice. This study compared lung lavage and serum levels of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatinine phosphokinase (CPK), lung lavage and plasma endothelin-1 (ET-1) concentration, lung tissue ET-1 mRNA expression, angiotensin converting enzyme (ACE) activity of lung homogenates, and histology of the lung structure in control and PPVHDL rats. Rats were anesthetized with pentobarbital. While control rats were breathing spontaneously, the PPVHDL rats were ventilated with a rodent ventilator delivering 30 percent oxygen, a tidal volume of 18.6 +/- 4.5 ml/kg, and a respiratory rate of 55 to 60 per minute. End-tidal CO2 was maintained at 38-40 mm Hg. After seven hours, rats were killed and the lungs were lavaged. Red blood cells were present in the sediment of lavage fluid in PPVHDL rats and their lung structure showed severe congestion, alveolar septa filled with red cells, and extravasation of red blood cells and inflammatory cells into the alveolar space. Lung lavage fluid AST and LDH were significantly higher in the PPVHDL compared with the control group (P < 0.03 and P < 0.001, respectively). Electrophoresis of the lung lavage LDH showed increased peak-5 in the PPVHDL group. Serum LDH, CPK, AST, and potassium concentrations [K]+ were significantly higher in the PPVHDL rats whereas their serum total protein level was significantly lower than the control group (P < 0.001). Electrophoretic patterns of serum and lung lavage protein were similar in both groups indicating a transmural passage of serum protein from the intravascular to the intra-alveolar space. No significant difference was found in lung tissue ET-1 mRNA expression and lung protein concentration between the two groups. Lung ACE activity, in contrast, was significantly lower in PPVHDL rats. This study demonstrated that moderate alveolar hyperdistention caused significant structural lung damage accompanied by decreased ACE activity after seven hours of mechanical ventilation and that elevated lung lavage and serum LDH and AST levels in lung lavage and in serum might be early markers of ventilator-induced lung injury in this rat model.

Captopril preserves function and ultrastructure in experimental radiation nephropathy

Captopril protects rat lung from radiation-induced pneumonitis and fibrosis and preserves function and survival in experimental radiation nephropathy. This study determined the structural benefit of captopril used preventively in radiation nephropathy. Twenty-eight Wag/RijMCW rats, divided in six groups, received 0 to 17 Gray total body irradiation followed by syngeneic bone marrow transplant. Captopril 0, 62.5, 125, 250, or 500 mg/l was given in the drinking water from the time of irradiation, and the rats were killed at 20 weeks. Using light and electron microscopy, kidneys of irradiated no-drug rats showed glomerular tuft capsular adhesions and hyalinization, focal tubular necrosis, severe interstitial fibrosis, and marked thickening and hyaline degeneration of the wall of interlobular arteries and arterioles, with intimal proliferation and periadventitial edema and inflammation. Lumens of the smaller arteries were often occluded. Significant collagen deposition was present in glomeruli, interstitium, and adventitia of interlobular arteries. Marked reduction of glomerular, tubular, vascular, and interstitial damage was seen in irradiated, captopril-treated animals, with only mild focal tubular interstitial injury and fibrosis seen. alpha smooth muscle actin-positive cells, probably myofibroblasts, were enhanced in the irradiated kidneys, and this expression was reduced in a dose-related fashion by captopril. There was also reduction in the arteriolar wall thickening, luminal occlusion, and collagen deposition in captopril-treated animals. The presence of elastin was not affected by radiation or drug treatment. Blood pressure and azotemia were lower and survival was higher in irradiated drug-treated rats compared with irradiated no-drug rats. We conclude that captopril exerts significant functional and structural protection against renal radiation injury. There was notable reduction in radiation-induced fibrosis in captopril-treated animals in this model, as in experimental lung radiation injury.