Long-term results of three randomized trials (58831, 58832, 58881) in childhood acute lymphoblastic leukemia: a CLCG-EORTC report. Children Leukemia Cooperative Group

We present here the long-term results of three randomized clinical trials conducted on children with newly diagnosed acute lymphoblastic leukemia (ALL) between 1983 and 1998 by the Children Leukemia Cooperative Group (CLCG) from EORTC. In study 58831/32, the overall event-free survival (EFS) rates (+/- s.e.) at 6 and 10 years were 66% +/- 1.8% and 65% +/- 1.8%, respectively, and the risk of isolated central nervous system (CNS) relapse was 6% +/- 1% and 7% +/- 1%, respectively. In patients with a standard risk of relapse the omission of cyclophosphamide had no adverse effect on disease-free survival rates at 10 years (trial 58831). In medium- and high-risk patients the omission of radiotherapy did not increase the risk of CNS or systemic relapse (trial 58832). In study 58881 (1989-1998) the overall EFS rate at 8 years was 68.4% +/- 1.2% and the risk of isolated CNS relapse was 4.2%+/-0.5%. In this trial which adressed three randomized questions, the following results were obtained: the combination of cytarabine at high doses with methotrexate at high doses during interval therapy did not improve prognosis. The addition of 6-mercaptopurine iv during maintenance increased the risk of late relapse. E. coli asparaginase was more toxic and has a higher efficacy than Erwinia asparaginase. Leukocyte counts >100 x 10(9)/l, specific genetic abnormalities, a poor initial response to steroids or a high level of minimal residual disease at early time points were consistently associated with an adverse prognosis in the 58881 trial.

Flow limitation and dynamic hyperinflation during exercise in COPD patients after single lung transplantation

STUDY OBJECTIVE

Using the negative expiratory pressure (NEP) method, we have previously shown that patients receiving single lung transplantation (SLT) for COPD do not exhibit expiratory flow limitation and have little dyspnea at rest. In the present study, we assessed whether SLT patients exhibit flow limitation, overall hyperinflation, and dyspnea during exercise.

METHODS

Expiratory flow limitation assessed by the NEP method and inspiratory capacity maneuvers used to determine end-expiratory lung volume (EELV) and end-inspiratory lung volume (EILV) were performed at rest and during symptom-limited incremental cycle exercise in eight SLT patients.

RESULTS

At the time of the study, the mean (+/- SD) FEV(1), FVC, functional residual capacity, and total lung capacity (TLC) amounted to 55 +/- 14%, 67 +/- 12%, 137 +/- 16%, and 110 +/- 11% of predicted, respectively. At rest, all patients did not experience expiratory flow limitation and were without dyspnea. At peak exercise, the maximal mechanical power output and maximal oxygen consumption amounted to 72 +/- 20% and 65 +/- 8% of predicted, respectively, with a maximal dyspnea Borg score of 6 +/- 3. All but one patient exhibited flow limitation and dynamic hyperinflation; the EELV and EILV amounted to 74 +/- 5% and 95 +/- 9% TLC, respectively. The patient who did not exhibit flow limitation during exercise had the lowest dyspnea score.

CONCLUSION

Most SLT patients for COPD exhibit expiratory flow limitation and dynamic hyperinflation during exercise, whereas maximal dyspnea is variable.

[Esophageal-pulmonary fistula in a patient with squamous cell carcinoma of the esophagus]

Acquired eso-respiratory fistulae are usually consecutive to an eso-tracheal or an eso-bronchial fistula. Esophago-pulmonary fistulae have been rarely described. We report a case of esophago-pulmonary fistula in a patient with esophageal carcinoma. Our patient presented progressive necrotizing pneumonia. CT scan of the thorax demonstrated necrosis of the esophagal wall and communication between the esophagus and the lung parenchyma. Furthermore, the biochemical analysis of the lung abcess fluid revealed a high level of amylase. Outcome was poor despite drainage of the lung abcess and insertion of an esophageal stent. Based on this case, we reviewed the cases of esophago-pulmonary fistulae described in the literature.

Purification of functional T lymphocytes from splenocytes of the beluga whales (Delphinapterus leucas)

In an effort to gain knowledge on immune functions in beluga whales, Delphinapterus leucas, we have used two physical methods for the purification of T lymphocytes of spleen cells. Isolation by sheep red blood cells (SRBC) rosetting and by adherence on nylon wool columns were tested. SRBC-rosetting gave unreliable results in obtaining purified T cells. Therefore, the purification of T cells was done using nylon wool columns. Less than 3% of the IgM(+) B cells remained in effluent populations. In the later population, 45% gave positive staining with mouse anti-human CD4 allowing us to verify functionality of the cells. The study of calcium mobilization and tyrosine kinase activation, mediated by CD4 cross-linking permitted verification of the functionality of cells. We also showed that upon activation with mitogens, beluga T cells upregulate the density of MHC class II molecules on their surfaces. CD4 cross-linking with a specific antibody inhibited the proliferation response. Overall, the activation of beluga whales lymphocytes did not differ markedly from what is known in other species. This study can help in the groundwork for functional investigation of the beluga whale's immune system.

Adult Colorado potato beetles, Leptinotarsa decemlineata compensate for nutritional stress on oryzacystatin I-transgenic potato plants by hypertrophic behavior and over-production of insensitive proteases

Protease inhibitors have been proposed as potential control molecules that could be engineered into potato plants for developing crops resistant to the Colorado potato beetle, Leptinotarsa decemlineata, a major pest of potato and other Solanaceae. In this study, we examined the effects of feeding young female beetles with foliage from a cultivar of the "Kennebec" potato line (K52) transformed with a gene encoding oryzacystatin I (OCI), a specific cysteine proteinase inhibitor with proven activity against cathepsin H-like enzymes of larvae and adults of the potato beetle. To evaluate the insect's performance, we collected data over a 16-d postemergence period on survival, diapause incidence, foliage consumption, weight gain, and oviposition of females. Tested individuals were fed untransformed (control) and OCI-transformed foliage at two stages of potato leaf differentiation, corresponding to "low" and "high" levels of OCI expression in leaves of K52. The OCI-expressing foliage did not affect female survival (close to 100%), incidence of diapause (15-30%), relative growth rate (RGR) during postemergence growth (5-9% d(-1)) or maximum weight reached (140-160 mg). Neither did it affect female reproductive fitness as measured by preoviposition time (8-9 d), 16-d fecundity (220-290 eggs), or egg eclosion incidence (86-91%). However, nutritional stress to females feeding on OCI foliage was evident, as reflected in their lower efficiency of conversion of ingested foliage (ECI) during postemergence growth, increased foliage consumed per egg laid (up to 119% more), and adaptation of their digestive proteolytic system to the inhibitory effect of OCI. Interestingly, beetles fed foliage expressing the highest level of OCI reacted rapidly to the presence of OCI by producing OCI-insensitive proteases, and exhibiting strong hypertrophic behavior by ingestion of 2.4-2.5 times more OCI rich foliage apparently as a compensatory response for nutritional stress due to the protease inhibitor in their diet.

Functional, cellular, and biochemical adaptations to elastase-induced emphysema in hamster medial scalene

The scalene has been reported to be an accessory inspiratory muscle in the hamster. We hypothesize that with the chronic loads and/or dynamic hyperinflation associated with emphysema (Emp), the scalene will be actively recruited, resulting in functional, cellular, and biochemical adaptations. Emp was induced in adult hamsters. Inspiratory electromyogram (EMG) activity was recorded from the medial scalene and costal diaphragm. Isometric contractile and fatigue properties were evaluated in vitro. Muscle fibers were classified histochemically and immunohistochemically. Individual fiber cross-sectional areas (CSA) and succinate dehydrogenase (SDH) activities were determined quantitatively. Myosin heavy chain (MHC) isoforms were identified by SDS-PAGE, and their proportions were determined by scanning densitometry. All Emp animals exhibited spontaneous scalene inspiratory EMG activity during quiet breathing, whereas the scalene muscles of controls (Ctl) were silent. There were no differences in contractile and fatigue properties of the scalene between Ctl and Emp. In Emp, the relative amount of MHC(2A) was 15% higher whereas that of MHC(2X) was 14% lower compared with Ctl. Similarly, the proportion of type IIa fibers increased significantly in Emp animals with a concomitant decrease in IIx fibers. CSA of type IIx fibers were significantly smaller in Emp compared with Ctl. SDH activities of all fiber types were significantly increased by 53 to 63% in Emp. We conclude that with Emp the actively recruited scalene exhibits primary-like inspiratory activity in the hamster. Adaptations of the scalene with Emp likely relate both to increased loads and to factors intrinsic to muscle architecture and chest mechanics.

Influences of IGF-I gene disruption on the cellular profile of the diaphragm

The impact of a targeted disruption of the Igf1 gene, encoding the insulin-like growth factor I (IGF-I), on diaphragm (DIA) cellularity was studied in 2-mo-old homozygous mutant [IGF-I(-/-)] mice and their wild-type [WT; i.e., IGF-I(+/+)] littermates. DIA fiber types were classified histochemically. DIA fiber cross-sectional areas (CSA) were determined from digitized muscle sections, and fiber succinate dehydrogenase (SDH) activity was determined histochemically using a microdensitometric procedure. An acidic ATPase reaction was used to visualize capillaries. Myosin heavy chain (MyHC) isoforms were identified by SDS-PAGE, and their proportions were determined by scanning densitometry. The body weight of IGF-I(-/-) animals was 32% that of WT littermates. DIA fiber type proportions were unchanged between the groups. The CSAs of types I, IIa, and IIx DIA fibers of IGF-I(-/-) mutants were 63, 68, and 65%, respectively, those of WT animals (P < 0.001). The DIA thickness and the number of fibers spanning its entire thickness were reduced by 36 and 25%, respectively, in IGF-I(-/-) mice (P < 0. 001). SDH activity was significantly increased in all three types of DIA fibers of IGF-I(-/-) mutants (P < 0.05). The number of capillaries per fiber was reduced approximately 30% in IGF-I(-/-) animals, whereas the capillary density was preserved. The proportions of MyHC isoforms were similar between the groups. Muscle hypoplasia likely reflects the importance of IGF-I on cell proliferation, differentiation, and apoptosis (alone or in combination) during development, although reduced cell size highlights the importance of IGF-I on rate and/or maintenance of DIA fiber growth in the postnatal state. Reduced capillarity may result from both direct and indirect influences on angiogenesis. Improved oxidative capacity likely reflects DIA compensatory mechanisms in IGF-I(-/-) mutants.

Immunosuppression in mice fed on diets containing beluga whale blubber from the St Lawrence estuary and the Arctic populations

In order to assess the immunotoxic potential of naturally relevant mixtures of PCBs and other organohalogens, C57Bl/6 mice were fed on diets in which lipids were replaced by blubber of beluga whales from the highly contaminated population of the Saint-Lawrence River, and the less contaminated population from the Arctic. Different ratios of blubber from both sources were mixed in order to allow a dose-response study. Mice were fed for a period of 90 days at the end of which their immunological status was monitored. For general parameters such as body weight, weight of the spleen and the thymus no significant effect of diets were observed. The immunological endpoints such as the blastic transformation of splenocytes and the spleen NK cell activity were not significantly affected by any of the diets compared to control diets. While the different cell subpopulations of peripheral blood and thymus were not affected by the diets, a significant decrease was noted in the CD8+ T cell population in the spleen of mice fed with most of the diets containing beluga blubber. Moreover, the ability of splenic cells to elicit humoral response against sheep red blood cells as well as the potential of peritoneal macrophages to perform phagocytosis were suppressed by all diets containing beluga blubbers. In summary, there was no differences between the groups fed with a blubber diet with low and high organochlorine contamination. However, a clear immunosuppression was demonstrated when these groups were compared to the group fed with beef oil. Despite the fact that we cannot exclude a possible contribution of the fatty acid composition of the beluga blubber to the immunosupression, these results suggest the sensitivity of mouse immune system towards organohalogens, and point out the toxic potential of contaminant mixtures as found in the less contaminated Arctic population.

Immune function of bovine leukocytes after in vitro exposure to selected heavy metals

OBJECTIVE

To study effects of in vitro exposure of bovine leukocytes to mercury, cadmium, and lead on phagocytosis, natural killer cell activity, and lymphocyte proliferation.

SAMPLE POPULATION

Leukocytes from 6 nonpregnant Holstein heifers.

PROCEDURE

Leukocytes were exposed in vitro to the aforementioned metals, and leukocyte functions were assessed.

RESULTS

Phagocytosis was suppressed by 10(-5) to 10(-7) M CdCl2 and by 10(-5) and 10(-6) M HgCl2, but not 10(-7) M HgCl2 nor 10(-4) to 10(-6) M PbCl2. Spontaneous and concanavalin A- or phytohemagglutinin-stimulated proliferation of metal-treated bovine blood mononuclear cells was not significantly different from that of nontreated control cells, except for enhanced spontaneous proliferation in response to 10(-5) M HgCl2. When proliferation was expressed as a stimulation index, a dose-dependent increase of spontaneous proliferation was observed in response to exposure to HgCl2 and PbCl2. Compared with response to 10(-6) or 10(-7) M CdCl2, reduction of mitogen-induced and spontaneous proliferation was observed on exposure to 10(-5) M CdCl2. Natural killer cell activity against YAC-1 target cells, evaluated by flow cytometry, was decreased only in cells exposed to 10 M HgCl2.

CONCLUSION AND CLINICAL RELEVANCE

Bovine leukocytes are susceptible to the immunomodulatory effects of in vitro exposure to heavy metals at concentrations equal to or higher than those at which similar effects are seen for leukocytes from most other animal species for which data are available for comparison. Exception is phagocytosis, which is severely affected by low concentrations of CdCl2 and HgCl2 in cattle. Reduction of defense mechanisms on exposure to metals could lead to increased susceptibility to potential pathogens.

Morbidity and mortality related to the native lung in single lung transplantation for emphysema

It has been advocated that a major drawback of single lung transplantation (SLT) is the risk of serious complications arising from the native lung. The morbidity and mortality related to the native lung in 46 patients who underwent SLT for pulmonary emphysema in Clichy from 1988 to 1997 were reviewed retrospectively. In particular, infectious complications and native lung hyperinflation were searched. Complications arising from the native lung are not unusual after SLT for subjects with emphysema, and it was concluded they are not responsible for a substantial mortality.

Suppression of rat and mouse lymphocyte function by urban air particulates (Ottawa dust) is reversed by N-acetylcysteine

Epidemiology studies have demonstrated increased pulmonary morbidity such as allergy and infection with episodes of high particulate air pollution (size range 0.1-10 microm diameter, PM10), but the mechanism(s) for this association is not yet well defined. The present study was undertaken to evaluate the effects of EHC-93 urban particles (Ottawa dust) on immune functions of peripheral blood mononuclear cells (PBMCs) and splenocytes from male Fischer 344 rats and C57Bl/6 mice. Immune function endpoints evaluated included cell viability, lymphocyte blastogenesis stimulated by T-cell mitogen (concanavalin A, Con A) or B-cell mitogens [lipopolysaccharide (LPS) or LPS/dextran sulfate], intracellular Ca2+ concentration, interleukin 2 (IL-2) production, and expression of receptors for transferrin (TfR) and IL-2 (IL-2R). In addition, the effect of N-acetylcysteine (NAC), an antioxidant, on the toxicity of EHC-93 particles was evaluated. Total EHC-93 particles, water leachate of EHC-93, and washed EHC-93 suppressed proliferation of PBMCs and splenocytes to T- and B-cell mitogens. Treatment of splenocytes with EHC-93 particles did not alter intracellular Ca2+ concentration or mitogen-induced expression of TfR and IL-2R expression, but increased IL-2 production assayed by enzyme-linked immunosorbent assay (ELISA). In spite of an increase in IL-2 production, exogenous IL-2 when added to cultures was able to reverse the suppression of Con A-induced lymphocyte proliferation by EHC-93 particles. Furthermore, the suppressive effect of EHC-93 particles on mitogen-induced lymphocyte proliferation was completely abolished by addition of the antioxidant NAC to cultures, suggesting a possible role of oxidative factors for the toxicity of EHC-93 particles.

Flow cytometry as a tool to monitor the disturbance of phagocytosis in the clam Mya arenaria hemocytes following in vitro exposure to heavy metals

The effectiveness of toxicology biomonitoring programs could be improved by the addition of sensitive biomarkers. In this study the cell viability and sensitivity of phagocytic function of phagocytes from bivalves (Mya arenaria) to selected heavy metals were measured by flow cytometry, a novel approach. Hemocytes (phagocytes) collected from bivalves by puncture of the posterior adductor muscle were incubated in vitro for 18 h in hemolymph containing 10(-9)-10(-3)M of cadmium chloride, zinc chloride, mercuric chloride, methylmercury chloride or silver nitrate, before determining their capacity to phagocytose fluorescent latex beads by flow cytometry. Heterogeneity of the hemocyte cell population was determined by forward scatter (FSC) and side scatter (SSC) cytometric profile which showed two distinct cell populations. At low doses (10(-9), 10(-8) M), all the metal compounds studied stimulated phagocytic activity except silver nitrate. At higher levels of exposure (10(-6), 10(7) M), all metals caused a significant concentration-related decrease in hemocyte phagocytosis activity. From the concentration of each metal inducing 50% suppression (IC50) of the phagocytic activity, the immunotoxic potential of metals with respect to phagocytic function can be ranked in the following increasing order: ZnCl2 < CdCl2 < AgNO3 < HgCl2 < CH3HgCl. Parallel analysis of hemocyte viability showed that suppression of phagocytosis by heavy metals was not solely related to a decreased cell viability. These results reveal the high but different degree of sensitivity of the phagocytosis activity of bivalves with respect to heavy metals, as measured by flow cytometry, and demonstrate that flow cytometry is a potentially useful tool in ecotoxicological monitoring.

Severe tracheobronchial stenosis in a patient with Crohn's disease

Tracheobronchial involvement in Crohn's disease is rare, usually associated with symptoms of tracheobronchitis, and typically responds well to steroids. The authors report a case of a 29-yr old patient with Crohn's disease, who presented with dyspnoea, fever, and a productive cough. Computed tomography of the chest revealed extensive nodular tracheobronchial stenosis, that was accompanied by severe mucosal inflammation at bronchoscopy. High-dose oral steroids diminished the mucosal inflammation, but had limited efficacy on the underlying tracheobronchial stenosis. It is speculated that this relative ineffectiveness of steroids may be due to the persistence of the untreated inflammatory process.

Blockade of T cell costimulation by CTLA4-Ig inhibits lung inflammation in murine hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is characterized by an influx of activated T cells in the lungs. The CD28/B7 system provides costimulatory signals essential for complete T cell activation and differentiation. We have previously demonstrated that alveolar macrophages from patients with HP have an up-regulated expression of B7 molecules. In the present study, we investigated the effect of i. p. administration of CTLA4-Ig, a CD28/B7 antagonist, on the lung inflammation of mice inoculated with Saccharoplyspora rectivirgula (SR), a major causative agent of HP. Five groups of C57BL/6 mice were intranasally instilled with SR or saline for 3 consecutive days per wk during 3 wk. CTLA4-Ig was administered starting either after 1 wk of SR challenge or 6 h before the first antigenic exposure and continued during the whole period of sensitization. A control-IgG was given similarly during the 3 wk of SR exposure. The groups included: 1, saline; 2, SR; 3, SR + control-Ig; 4, SR + CTLA4-Ig for the last 2 wk; and 5, SR + CTLA4-Ig for 3 wk. CTLA4-Ig treatment markedly decreased lung inflammation as shown by significantly fewer inflammatory cells in the bronchoalveolar lavage and in lung tissue and reduced SR-specific serum and bronchoalveolar lavage Ig levels. Production of IL-4, IL-10, and IFN-gamma by IL-2-stimulated pulmonary T cells was also decreased by CTLA4-Ig. Administration of CTLA4-Ig did not affect the SR-induced up-regulation of B7-2 expression. These results show that blockade of CD28/B7 interactions by CTLA4-Ig inhibits SR-induced lung inflammation and immune response to SR Ag in mice and may provide a novel approach in the treatment of HP.

Effect of weight loss on muscle fiber type, fiber size, capillarity, and succinate dehydrogenase activity in humans

To examine the effects of weight loss on muscle oxidative properties, nine obese subjects (body mass index, 34 +/- 1.5) had muscle biopsies before and after weight loss and weight stabilization. Weight loss ranged from 13-32 kg and represented 20.8 +/- 2.1% of initial weight. After weight loss, there was no change in the proportions of oxidative (type I and type IIa) fibers and also no change in mean fiber cross-sectional area, whereas there was a small, but significant, decrease in the relative interstitial space (P < 0.05). However, weight loss resulted in a 32 +/- 6% (mean +/- SEM) increase in capillary/fiber ratio and a 54% increase in capillary density (P < 0.05). In addition, there was a 41 +/- 13% increase in succinate dehydrogenase (SDH) activity (P < 0.05). This increase in muscle capillarization and SDH activity was seen in all fiber types, even the relatively lower oxidative type IIx fibers. There was a strong correlation between the change in capillary/fiber ratio and the change in SDH activity (r = 0.82; P < 0.02). Thus, weight loss resulted in no change in muscle fiber type or cross-sectional area, but produced increases in capillary/fiber ratio, capillary density, and SDH activity, suggesting an increase in muscle oxidative capacity.

Loss of cyclin D1 in necrotic and apoptotic models of cortical neuronal degeneration

Recent evidence suggests that apoptosis in post-mitotic neurons involves an aborted attempt of cells to re-enter the cell cycle and it is characterized by increased expression of cyclins, such as cyclin D1, prior to death. Cyclin D1 increases to permit transition from growth phase (G0/G1) to synthesis phase (S) during normal development but there is controversy as to which of the cyclins are activated prior to apoptotic cell death. We looked at the expression of cyclin D1 in cortical neuronal cultures treated with either staurosporine to produce apoptotic death, or with glutamate, to produce a non-apoptotic death. Cyclin D1 immunoreactivity was observed in the cytoplasm and nucleus of virtually all neurons under control conditions. Following the addition of either staurosporine or glutamate, cyclin D1 immunoreactivity did not change within 4 h. The cyclin D1 immunoreactivity was lost by 6 h with the appearance of either staurosporine-induced fragmented nuclei or glutamate-induced pyknotic nuclei. These immunocytochemical observations were confirmed with immunoblot analysis. Therefore, cyclin D1 is not a reliable indicator of apoptosis in cortical neuronal cultures and should not be used as an indicator of apoptotic cell death.

Toxicological characterization of sediments from Baie des Anglais on the St. Lawrence Estuary

The sediments of Baie des Anglais on the St. Lawrence Estuary have a history of environmental contamination, but no information exists relating to their toxicity. The purpose of the present study was to characterize three sites in and near Baie des Anglais, in terms of sediment toxicity and contaminants. Sites 1 and 2 within the Baie des Anglais are relatively close to local industry and municipal sewage discharge points, while Site 3 is outside the bay. Three microscale bioassays, Microtox, echinoderm fertilization and Toxi-ChromoPad, showed that sediments from Site 1 were the most toxic, followed by Site 2. Site 3 was non-toxic. While the solid phase Microtox test did indicate that Site 1 was most toxic, the absolute response was weak. Liver cytochrome P450 1A1 mRNA in American plaice (Hippoglossoides platessoides), captured at Site 1 in the bay was significantly induced compared to the P450 system of plaice captured at Sites 2 and 3. Hepatic metallothionein mRNA levels were not significantly different between plaice captured at all three sites. Sediment chemical analyses revealed a gradient in polycyclic aromatic hydrocarbons, polychlorinated biphenyls and dibenzofurans (PCDF) with the highest levels recorded at Site 1, about 10-fold less at Site 2 and 100-fold less at Site 3. Amongst the organochlorines the PCDF group were deemed the most important due to their prevalence and known toxicity. Heavy metal concentrations were low and representative of background levels for the St. Lawrence Estuary.

Optimism and adaptation to multiple sclerosis: what does optimism mean?

The aim of the present study was to determine the meaning of optimism by explicating the dimensions underlying the notion and their links to adjusting to MS. Seventy-three patients responded to optimism questionnaires (i.e., the LOT, Generalized Self-Efficacy Scale) and outcome questionnaires. In confirmatory factor analyses, the underlying dimensions of optimism were specified. Explanatory structural equation modeling was used to examine the relation of the dimensions of optimism to coping (CISS), depression (BDI), and impaired mobility range (SIP). Optimism was found to consist of three dimensions, namely, outcome expectancies, efficacy expectancies, and unrealistic thinking. Outcome and efficacy expectancies explained depression via emotion-oriented coping but did not explain impaired mobility range either directly or indirectly. Unrealistic thinking directly explained impaired mobility range. The present study can be seen as a first step in explicating the role of optimism in the management of chronic disease.

Pulmonary hypertension following hepatopulmonary syndrome in a patient with cirrhosis

We report the case of a patient with liver cirrhosis who successively developed hepatopulmonary syndrome and portopulmonary hypertension. Initially, the patient presented with severe dyspnea and hypoxemia at rest. Technetium-99 macroaggregated albumin lung perfusion scan demonstrated right-to-left shunt, and hemodynamic study revealed a hyperdynamic state with low pulmonary vascular resistance, thus confirming the diagnosis of hepatopulmonary syndrome. More than 2 years after the onset of pulmonary symptoms, a marked improvement in dyspnea and gas exchange was observed. Lung perfusion scan did not disclose any right-to-left shunt and right-sided heart catheterization showed evidence of severe pulmonary hypertension. We conclude that hepatopulmonary syndrome and portopulmonary hypertension are not mutually exclusive. We hypothesize that, by reversing the phenomenon of intrapulmonary vasodilatation, the development of portopulmonary hypertension interfered with each of the potential causes of hypoxemia in hepatopulmonary syndrome (ventilation-perfusion inequalities, intrapulmonary shunting, oxygen diffusion limitation) and, as a result, led to a correction of hypoxemia.

High affinity interaction of HIV-1 integrase with specific and non-specific single-stranded short oligonucleotides

Retroviral integrase (IN) catalyzes the integration of double-stranded viral DNA into the host cell genome. The reaction can be divided in two steps: 3'-end processing and DNA strand transfer. Here we studied the effect of short oligonucleotides (ODNs) on human immunodeficiency virus type 1 (HIV-1) IN. ODNs were either specific, with sequences representing the extreme termini of the viral long terminal repeats, or nonspecific. All ODNs were found to competitively inhibit the processing reaction with Ki values in the nM range for the best inhibitors. Our studies on the interaction of IN with ODNs also showed that: (i) besides the 3'-terminal GT, the interaction of IN with the remaining nucleotides of the 21-mer specific sequence was also important for an effective interaction of the enzyme with the substrate; (ii) in the presence of specific ODNs the activity of the enzyme was enhanced, a result which suggests an ODN-induced conformational change of HIV-1 IN.

Blockade of cannabinoid receptors by SR141716 selectively increases Fos expression in rat mesocorticolimbic areas via reduced dopamine D2 function

The present study investigated, in rats, whether blockade of cannabinoid CB1 receptors may alter Fos protein expression in a manner comparable to that observed with antipsychotic drugs. Intraperitoneal administration of the selective CB1 receptor antagonist, SR141716, dose-dependently (1.0, 3.0 and 10 mg/kg) increased Fos-like immunoreactivity in mesocorticolimbic areas (prefrontal cortex, ventrolateral septum, shell of the nucleus accumbens and dorsomedial caudate-putamen), while motor-related structures such as the core of the nucleus accumbens and the dorsolateral caudate-putamen were unaffected. In the ventrolateral septum, taken as a representative structure, the Fos-inducing effect of SR141716 (10 mg/kg) was maximal 2 h after injection and returned to near control levels by 4 h. Within the prefrontal cortex, SR141716 increased the number of Fos-positive cells predominantly in the infralimbic and prelimbic cortices, presumptive pyramidal cells being the major cell types in which Fos was induced. The D1-like receptor antagonist, SCH23390 (0.1 mg/kg), did not prevent the Fos-inducing effect of SR141716 in any brain region examined (prefrontal cortex, nucleus accumbens, ventrolateral septum and dorsomedial caudate-putamen), although SCH23390 significantly reduced Fos expression induced by cocaine (20 mg/kg) in all these regions. By contrast, the dopamine D2-like agonist, quinpirole (0.25 mg/ kg), counteracted SR141716-induced Fos-like immunoreactivity in the ventrolateral septum, the nucleus accumbens and the dorsomedial caudate-putamen, while no antagonism was observed in the prefrontal cortex. Microdialysis experiments in awake rats indicated that SR141716, at doses which increased Fos expression (3 and 10 mg/kg), did not alter dopamine release in the shell of the nucleus accumbens. Finally, SR141716 increased the levels of neurotensin-like immunoreactivity in the nucleus accumbens, but not in the caudate-putamen. Collectively, the present results show that blockade of cannabinoid receptors increases Fos- and neurotensin-like immunoreactivity with characteristics comparable to those reported for atypical neuroleptic drugs.

Effect of chlorpyrifos on immune function in rats

A commercial formulation of chlorpyrifos was evaluated for effects on selected immune system functions in male Fisher 344 rats. Chlorpyrifos in an olive oil vehicle was administered by oral gavage twice weekly for 28 d at a dose of 5.0 mg/kg for each treatment. Body weight and organ/body weight ratios were unaffected by the chlorpyrifos. In contrast, chlorpyrifos impaired T-lymphocyte blastogenesis induced by concanavalin A (P = 0.03) and phytohemagglutinin (P = 0.023), but did not alter B-lymphocyte blastogenesis induced by lipopolysaccharide/dextran (P = 0.082. Humoral immunity (anti-sheep red blood cell), a T-lymphocyte macrophage-dependent response, was also reduced (P = 0.019) when the antibody response was expressed/10(6) spleen cells, although the response expressed/spleen was unaffected (P = 0.32), reflecting increased lymphocyte production. The total splenic lymphocyte counts in the chlorpyrifos-treated rats increased by 91% (P < 0.0001), therefore reducing the antibody response when expressed/10(6) spleen cells. Chlorpyrifos had no effect on macrophage phagocytosis (P = 0.27), but increased the relative percentage expression of CD5+ (P = 0.028) and CD8+ (P = 0.003). The presence of normal antibody and phagocytic responses in association with reduced T-lymphocyte blastogenesis and enhanced expression of specific cell surface antigens indicated that chlorpyrifos induced immune alterations associated with lymphocyte subpopulations.