[Oxygen consumption during cardiovascular surgery conducted under extra-corporeal circulation]

Whole-body oxygen consumption (VO2) is universally considered both a measure of the metabolic activity of the body and an indicator of the adequacy of tissue perfusion during cardiopulmonary bypass as well. There is little agreement in the literature about the main determinants of oxygen consumption during CPB, except for the role of temperature in reducing the metabolic activity of the body. Many studies, which have been performed both on animals and in humans, have reached some contradictory conclusions about the role of delivery and perfusion flow rates, of haemodynamic variables, of the acid-base status, and of drugs influencing the variations of oxygen consumption during CPB. Aim of this paper is to review the evidences in literature about the determinants of whole-body oxygen consumption during cardiopulmonary bypass in man.

Microarrays: biotechnology's discovery platform for functional genomics

Advances in microarray technology enable massive parallel mining of biological data, with biological chips providing hybridization-based expression monitoring, polymorphism detection and genotyping on a genomic scale. Microarrays containing sequences representative of all human genes may soon permit the expression analysis of the entire human genome in a single reaction. These 'genome chips' will provide unprecedented access to key areas of human health, including disease prognosis and diagnosis, drug discovery, toxicology, aging, and mental illness. Microarray technology is rapidly becoming a central platform for functional genomics.

Dopamine D3 receptor in peripheral mononuclear cells of essential hypertensives

Dopamine D3 receptor was studied in peripheral mononuclear cells of high-normal, stage 1, stage 2, and stage 3 essential hypertensives using a radioligand binding assay technique with [3H]-7-hydroxy-N,N-di-n-propyl-2-aminotetraline (7-OH-DPAT) as a radioligand. A group of de novo Parkinsonian patients was also examined as a reference group of impaired dopaminergic function. [3H]-7-OH-DPAT was bound specifically to human peripheral mononuclear cells in a manner consistent with the labeling of a dopamine D3 receptor. No changes in free dopamine, norepinephrine, epinephrine and aldosterone levels, renin activity, dissociation constant of [3H]-7-OH-DPAT binding, or the pharmacological profile of [3H]-7-OH-DPAT binding were found between normotensive control subjects and essential hypertensives or Parkinsonians. The density of peripheral mononuclear cell [3H]-7-OH-DPAT binding sites increased in essential hypertensives parallel to blood pressure value augmentation. A higher density of [3H]-7-OH-DPAT binding sites was found in Parkinsonians. In these patients, the density of [3H]-7-OH-DPAT binding sites was similar to that observed in high-normal subjects and in stage 1 essential hypertensives. The increased density of peripheral mononuclear cell dopamine D3 receptor in hypertension as well as in Parkinson's disease may represent an upregulation mechanism consequent to impaired dopaminergic function. In view of the difficulty in identifying markers of peripheral dopamine function, analysis of dopamine D3 receptor in peripheral mononuclear cells may help evaluate whether the dopaminergic system is involved in hypertension.

Discovery and analysis of inflammatory disease-related genes using cDNA microarrays

cDNA microarray technology is used to profile complex diseases and discover novel disease-related genes. In inflammatory disease such as rheumatoid arthritis, expression patterns of diverse cell types contribute to the pathology. We have monitored gene expression in this disease state with a microarray of selected human genes of probable significance in inflammation as well as with genes expressed in peripheral human blood cells. Messenger RNA from cultured macrophages, chondrocyte cell lines, primary chondrocytes, and synoviocytes provided expression profiles for the selected cytokines, chemokines, DNA binding proteins, and matrix-degrading metalloproteinases. Comparisons between tissue samples of rheumatoid arthritis and inflammatory bowel disease verified the involvement of many genes and revealed novel participation of the cytokine interleukin 3, chemokine Gro alpha and the metalloproteinase matrix metallo-elastase in both diseases. From the peripheral blood library, tissue inhibitor of metalloproteinase 1, ferritin light chain, and manganese superoxide dismutase genes were identified as expressed differentially in rheumatoid arthritis compared with inflammatory bowel disease. These results successfully demonstrate the use of the cDNA microarray system as a general approach for dissecting human diseases.

Non-invasive haemodynamic effects of two nasal positive pressure ventilation modalities in stable chronic obstructive lung disease patients

The aim of this study was to compare the haemodynamic effects of a 45-min session of two modalities of non-invasive positive pressure ventilation (nPPV), by means of cardiac echo-Doppler and right heart catheterization, in chronic obstructive lung disease (COPD) patients with chronic respiratory insufficiency. Fourteen patients with stable COPD (11 males, mean age 62.9 +/- 9.8 years) underwent right heart catheterization using a floating Grandjean catheter and simultaneous echo-Doppler measurements before and during two randomly applied 45-min ventilatory sessions, consisting of nasal intermittent positive pressure ventilation in assist/control mode (nIPPV) and nasal pressure support ventilation (nPSV). Blood gases improved significantly during both modalities of ventilation. A significant increase during ventilatory sessions was found in invasive pulmonary right atrial pressure and cardiac output. A statistically significant decrease was found in the flow velocity peak of the superior vena cava and hepatic vein, and in systodiastolic flow velocity integral of the superior vena cava and hepatic vein. The inferior vena cava collapsibility index also decreased significantly during both ventilations. Right atrium diameter and area significantly decreased while right ventricular diameter significantly increased. The echo-Doppler cardiac output decreased significantly while systolic pulmonary artery pressure increased. A short session of both nIPPV and nPSV even without PEEP can induce significant haemodynamic changes in patients with stable COPD. Two-dimensional Doppler echocardiography is a non-invasive device with sufficient reliability to monitor the haemodynamic effects of nPPV. Further studies are needed to assess the effects of nPPV on vascular peripheral flows.

Parallel human genome analysis: microarray-based expression monitoring of 1000 genes

Microarrays containing 1046 human cDNAs of unknown sequence were printed on glass with high-speed robotics. These 1.0-cm2 DNA "chips" were used to quantitatively monitor differential expression of the cognate human genes using a highly sensitive two-color hybridization assay. Array elements that displayed differential expression patterns under given experimental conditions were characterized by sequencing. The identification of known and novel heat shock and phorbol ester-regulated genes in human T cells demonstrates the sensitivity of the assay. Parallel gene analysis with microarrays provides a rapid and efficient method for large-scale human gene discovery.

Echo-Doppler evaluation of left ventricular impairment in chronic cor pulmonale

The effects of acute right ventricular (RV) pressure and volume overloads on left ventricular (LV) filling are well known, while the significance of chronic RV pressure overload on LV function has been less studied. To evaluate the LV impairment, 30 patients with chronic cor pulmonale and pulmonary arterial hypertension secondary to chronic obstructive lung diseases (COLDs) were studied. All patients underwent respiratory tests and arterial blood gas assessment. An echo-Doppler examination was made to measure LV ejection fraction (EF), RV and LV end-diastolic and end-systolic diameters and areas, RV/LV area indexes, LV diastolic and systolic eccentricity indexes, mitral and tricuspid flow patterns, and mitral flow velocity in late and early diastole (A/E) indexes. A right heart catheterization was carried out to determine the resting mean pulmonary arterial pressure (mPAP). The data showed a marked enlargement of RV, compressing the left through a leftward shift of interventricular septum. A linear regression analysis detected a significant correlation between mPAP and the following parameters: RV/LV diastolic and systolic area indexes (r=0.75, p<0.0001; r=0.84, p<0.000, respectively), mitral A/E index (r=0.61, p<0.0005), and LV diastolic and systolic eccentricity indexes (r=0.93, p<0.0001; and r=0.83, p<0.0001). No correlations were found between echo-Doppler data and functional respiratory parameters. From these results, we conclude that chronic RV pressure overload induces LV filling impairment despite a normal systolic phase, due to septal leftward shift. In fact, chronic RV pressure overload distorts early diastolic LV geometry delaying LV filling phase, and the functional diastolic impairment of the LV is closely correlated to pulmonary hypertension levels.

Genome analysis with gene expression microarrays

Advances in biochemistry, chemistry and engineering have enabled the development of a new gene expression assay. This 'chip-based' approach utilizes microscopic arrays of cDNAs printed on glass as high-density hybridization targets. Fluorescent probe mixtures derived from total cellular messenger RNA (mRNA) hybridize to cognate elements on the array, allowing accurate measurement of the expression of the corresponding genes. Array densities of > 1,000 cDNAs per cm2 enable quantitative expression monitoring of a large number of genes in a single hybridization. A two-color fluorescence detection scheme allows rapid and simultaneous differential expression analysis of independent biological samples. Mass-produced microarrays provide a new tool for genome expression analysis that may revolutionize genetic dissection, drug discovery and human disease diagnostics.

Dopamine D5 receptor expression is unchanged in peripheral blood lymphocytes in essential hypertension

The present study was designed to investigate possible changes in the expression of lymphocyte dopamine receptor in essential hypertension. The expression of dopamine D5 receptor was evaluated by radioligand binding techniques using [3H]-SCH 23390 as ligand. Plasma catecholamines, aldosterone levels and plasma renin activity were also measured. Eleven borderline hypertensive patients, 15 patient with the mild essential hypertension, 7 patients with moderate essential hypertension and 5 patients with severe essential hypertension were examined. Plasma catecholamine levels were assayed by high pressure liquid chromatography with electrochemical detection. Dopamine D5 receptor was measured by radioligand binding techniques. Plasma aldosterone levels and renin activity were determined by radio immunoassay. [3H]-SCH 23390 was specifically bound to human peripheral blood lymphocytes. The binding was time-, temperature- and concentration-dependent with a dissociation constant (Kd) value of 0.59 nM and a maximum density of binding sites (Bmax) of 223 pmol/10(6) cells. Dopamine competed with [3H]-SCH 23390 binding in the submicromolar range suggesting the labelling of a dopamine D5 receptor. No changes in the density of [3H]-SCH 23390 binding sites were observed in human peripheral blood lymphocytes between essential hypertensive patients and normotensive subjects. Also catecholamines, plasma renin activity and aldosterone levels were unchanged. In spite of the availability of a sensitive technique for measuring dopamine receptors in human peripheral lymphocytes, no change in their expression was noticeable in essential hypertension. This suggests that dopamine receptor analysis in essential hypertension is not a useful marker for investigating hypertension-dependent changes of the peripheral dopaminergic system.

Quantitative monitoring of gene expression patterns with a complementary DNA microarray

A high-capacity system was developed to monitor the expression of many genes in parallel. Microarrays prepared by high-speed robotic printing of complementary DNAs on glass were used for quantitative expression measurements of the corresponding genes. Because of the small format and high density of the arrays, hybridization volumes of 2 microliters could be used that enabled detection of rare transcripts in probe mixtures derived from 2 micrograms of total cellular messenger RNA. Differential expression measurements of 45 Arabidopsis genes were made by means of simultaneous, two-color fluorescence hybridization.

Failure of B cells of chronic lymphocytic leukemia in presenting soluble and alloantigens

B-cell-type chronic lymphocytic leukemia (B-CLL) patients have immunological abnormalities of both B and T lymphocytes. Since T cell defects might depend upon a defective accessory function of neoplastic B lymphocytes, we analyzed the ability of peripheral blood B cells of seven B-CLL patients to stimulate allogenic normal T cells in mixed lymphocyte reaction (MLR) and to present tetanus toxoid (TT) to autologous T cells. In both systems, neoplastic B lymphocytes show a defective antigen-presenting function, which is more evident with disease progression. Such a defect cannot be ascribed to a decreased MHC class II molecule expression nor to an abnormal IL-1 beta production, but it can be partially accounted for by a low B7 expression. Pretreatment of neoplastic B cells with interleukin-4 (IL-4) restores primary MLR, but has little effect on the response to TT. The effect of IL-4 is not mediated by quantitative modifications of class II and B7 molecule expression or of IL-1 beta production.

Professional figures in intermediate intensive units

In Italy, respiratory intermediate intensive care units (IICUs) are not yet considered as autonomous hospital departments. The IICU of the Rehabilitation Department of the Medical Centre of Gussago (12 monitored beds) provides care for respiratory and cardiac patients. Ventilatory assistance and noninvasive modalities both in treatment and monitoring suggest a multidisciplinary approach to the patient. Highly professional figures should, therefore, be singled out to provide care in a respiratory IICU. The medical staff is composed of one anaesthesiologist, one cardiologist and one pulmonologist, who can integrate care when respiratory complications occur in a cardiological patient, or when cardiac events affect a respiratory patient. Nurses are capable of specific activities, especially when ventilatory assistance is required. The presence of a physiotherapist reduces the nursing workload, especially for ventilated individuals. The psychological aspect is undertaken by a specialist. Finally, an expert in nutrition provides an individualized dietary regimen. Our 4 year experience encourages such a multidisciplinary approach. An ideal integration of the professional activities should provide adequate and individual care for patients admitted to an IICU.

Epidermal cell fate determination in Arabidopsis: patterns defined by a steroid-inducible regulator

The Arabidopsis mutant ttg lacks both trichomes (epidermal hairs) and anthocyanin pigments. Trichomes and anthocyanins are restored by the constitutive expression of the maize transcriptional regulator (R). The expression of an R-glucocorticoid receptor chimeric protein results in a steroid hormone-dependent, conditional allele of R that functions in whole Arabidopsis plants. The response of the chimeric protein to pulses of hormone was used to define the pattern and timing of trichome formation on the developing leaf epidermis. Each adaxial epidermal leaf cell appears to have an equal probability of differentiating into a trichome; there is a temporal zone of decision for trichome cell fate that proceeds as a wave from the tip to the base of developing leaves.

Structure of homeobox-leucine zipper genes suggests a model for the evolution of gene families

Homeobox genes are present in both plants and animals. Homeobox-leucine zipper genes, however, have been identified thus far only in the small mustard plant Arabidopsis thaliana. This observation suggests that homeobox-leucine zipper genes evolved after the divergence of plants and animals, perhaps to mediate specific regulatory events. To better understand this gene family, we isolated several sequences containing the homeobox-leucine zipper motif and carried out a comparative analysis of nine homeobox-leucine zipper genes (HAT1, HAT2, HAT3, HAT4, HAT5, HAT7, HAT9, HAT14, and HAT22). Gene structures, sequence comparisons, and chromosomal locations suggest a simple model for the evolution of these genes. The model postulates that a primordial homeobox gene acquired a leucine zipper by exon capture. The nascent homeobox-leucine zipper gene then appears to have undergone a series of gene duplication and chromosomal translocation events, leading to the formation of the HAT gene family. This work has general implications for the evolution of regulatory genes.

Pharmacological characterization and autoradiographic localization of dopamine receptors in the human adrenal cortex

The pharmacological characteristics and the anatomical localization of dopamine D1-like and D2-like receptors were studied in sections of the human adrenal cortex using radioligand binding and autoradiographic techniques. [3H]SCH 23390 was used as a ligand of D1-like receptors, whereas [3H]spiroperidol was used to label D2-like receptors. No specific [3H]SCH 23390 binding was detectable in sections of the human adrenal cortex. On the other hand, [3H]spiroperidol was bound to sections of the adrenal gland in a manner consistent with the labelling of dopamine D2-like receptor sites. The binding was time, temperature and concentration dependent, belonging in the range of concentrations of the radioligand used for a single class of high-affinity sites. The dissociation constant (Kd) averaged 2.7 nmol/l, whereas the maximum density of binding sites (Bmax) was 160 nmol/mg tissue. Experiments on the pharmacological specificity of [3H]spiroperidol binding to sections of the human adrenal cortex revealed that clozapine was the most powerful displacer of [3H]spiroperidol from sections of the human adrenal cortex. This suggests the presence in the human adrenal cortex of dopamine receptors of the D4 subtype. Light microscope autoradiography showed the highest density of specific [3H]spiroperidol binding sites in the zona glomerulosa and to a lesser extent in the zona reticularis. Only sparse [3H]spiroperidol binding sites were localized in the zona fasciculata. The possible functional consequences of this localization of dopamine D2-like receptor sites in the human adrenal cortex are discussed.

The role of Bcl-2 in the pathogenesis of B chronic lymphocytic leukemia

At least three categories of genes are envisaged to be involved in the natural history of B-CLL. First, the genes that are responsible for the transforming event(s) in the (presently unknown) target cell; second, the gene(s) that help the progressive accumulation of malignant cells and finally the gene(s) that cause the progression toward a more aggressive lymphoma. The possibility that the clonal expansion of B-CLL is due to a prolonged life-span of monoclonal B cells rather than to an acceleration of their proliferative activity may now be reinterpreted by taking into account some recent findings on the expression of Bcl-2 gene in B-CLL cells. The Bcl-2 gene product regulates programmed cell death and a number of experiments suggest that Bcl-2 is involved in the selection and maintenance of long-lived memory B cells rescuing them from apoptotic death and leading to their accumulation in the GO phase of the cell cycle. Variant chromosomal translocations have been detected in a small fraction (5-10%) of B-CLL, involving Bcl-2 and the Ig light chain gene. Despite the low percentage of Bcl-2 rearrangements the expression of mRNA and protein is appreciable in most samples of fresh B-CLL cells in an amount comparable to that observed in Karpas 422 cells, which contain a t(14;18).(ABSTRACT TRUNCATED AT 250 WORDS)

The HAT4 gene of Arabidopsis encodes a developmental regulator

The HAT4 gene from the plant Arabidopsis thaliana encodes a homeo domain protein that contains a leucine zipper motif. Homeo domain-leucine zipper (HD-Zip) proteins have not been found in animal systems, suggesting that HAT4 may define a new family of transcription factors that regulate higher plant development. To explore this possibility, functional studies of HAT4 were carried out in yeast and in transgenic plants. Point mutants of HAT4 isolated in yeast define functionally critical residues within the HD-Zip domain, many of which correspond to highly conserved positions in known homeo domains and leucine zippers. Transgenic plants bearing constructs that alter HAT4 expression exhibit a series of interesting developmental phenotypes, including changes in morphology and developmental rate. Thus, the HAT4 gene of Arabidopsis encodes an HD-Zip protein that functions as a novel developmental regulator.

Interleukin-2 enhances the production of tumor necrosis factor-alpha in activated B-type chronic lymphocytic leukemia (B-CLL) cells

Tumor necrosis factor-alpha (TNF-alpha) has recently been implicated as a regulator growth and differentiation of normal and malignant B cells. We utilized a selected clone (I-83) of primary resting B-type chronic lymphocytic leukemia (B-CLL) cells, inducible to activation, growth and differentiation in vitro, as a model system to study the possible role of TNF-alpha as an autocrine growth factor for such cells. Our results show that unstimulated I-83 B-CLL cells produced a low level of TNF-alpha mRNA, as shown by Northern blot analysis, and cytoplasmic TNF-alpha, determined in individual cells by immunocytochemistry. Secreted TNF-alpha could, however, not be detected in the medium by ELISA. TNF-alpha synthesis and secretion was, however, induced to high levels by stimulation of the B-CLL cells with interleukin-2 (IL-2) after activation by 12-O-tetradecanoylphorbol-13-acetate (TPA) or Staphylococcus aureus Cowan strain I (SAC) and B-cell stimulatory factor-MP6 (thioredoxin). A moderate increase in TNF-alpha secretion was also induced by TPA or IL-2 alone. IL-4 did not have any major effects on the production of TNF-alpha in activated cells, but inhibited the IL-2-induced production of TNF-alpha in SAC-activated cells. The cell surface expression of TNF-alpha receptors (TNF-R), as determined by binding assay using 125I-labelled recombinant TNF-alpha (rTNF-alpha), was also induced after SAC or TPA activation, but shed receptors (TNF-binding proteins) were only observed after TPA activation. Exogenously added rTNF-alpha in combination with TPA or SAC induced a high level of DNA synthesis in I-83 B-CLL cells. The increased endogenous production and secretion of TNF-alpha during induced growth stimulation, the induced expression of TNF-R, and the mitogenic effect of TNF-alpha on activated B-CLL cells raise the question whether TNF-alpha may function as an autocrine co-stimulator of B-CLL cell growth as recently suggested. anti-TNF-alpha and anti-TNF-R antibodies, however, failed to inhibit the IL-2- and IL-4-induced proliferation of activated I-83 B-CLL cells.

Growth- and differentiation-associated expression of bcl-2 in B-chronic lymphocytic leukemia cells

The bcl-2 gene is translocated into the Ig loci in about 80% of human follicular lymphomas and in 10% of B-type chronic lymphocytic leukemias (B-CLL), resulting in a high level of expression. We have compared the expression of bcl-2 transcripts and protein in B-CLL cells in their normal equivalent CD5+ B cells and in normal B-cell populations representative of different in vivo and in vitro stages of activation and proliferation. We report here that bcl-2 was expressed in 11 of 11 cases of CD5+ B-CLL clones, contrasting with the absent expression in normal CD5+ B cells. Activation of 173 and 183 B-CLL cells by phorbol esters (12-O-tetradecanoylphorbol-13-acetate [TPA]) to IgM secretion without concomitant DNA synthesis resulted in a rapid but transient downregulation of bcl-2 expression. In contrast, the reduction of bcl-2 at both the messenger RNA and protein levels was sustained after mitogenic stimulation, suggesting that bcl-2 expression and proliferation are inversely related in these cells. This notion was further supported by immunocytochemical analysis showing that bcl-2 was primarily expressed in small resting lymphocytes and in cells differentiating to the plasma cell stage, but less expressed in Ki67-positive proliferating B blasts. Moreover, it was also supported by the low level of bcl-2 in exponentially growing Epstein-Barr virus-carrying lymphoblastoid and B-CLL cell lines. The regulation of bcl-2 expression in B-CLL resembled that of normal tonsillar follicular B cells, in which a high level of expression was found in resting mantle zone B cells but not in the proliferating germinal center B cells. Based on these findings and the role of bcl-2 in maintaining B-cell memory, we propose that the phenotype of B-CLL cells corresponds to a mantle zone memory-type B cell.

HD-Zip proteins: members of an Arabidopsis homeodomain protein superfamily

Homeobox genes encode a large family of homeodomain proteins in animal systems. To test whether such genes are also abundant in higher plants, degenerate oligonucleotides complementary to sequences encoding the recognition helix (helix three) of the homeodomain were used to screen genomic and cDNA libraries from the plant Arabidopsis thaliana. Analysis of 8 of the 41 cDNAs isolated revealed that each encodes a presumptive homeodomain; interestingly, most of these clones also contain a leucine zipper motif tightly linked to the homeodomain. It is concluded that Arabidopsis encodes a large family of homeodomain proteins, including members that contain a homeodomain/leucine-zipper (HD-Zip) motif.

HD-Zip proteins: members of an Arabidopsis homeodomain protein superfamily

Homeobox genes encode a large family of homeodomain proteins in animal systems. To test whether such genes are also abundant in higher plants, degenerate oligonucleotides complementary to sequences encoding the recognition helix (helix three) of the homeodomain were used to screen genomic and cDNA libraries from the plant Arabidopsis thaliana. Analysis of 8 of the 41 cDNAs isolated revealed that each encodes a presumptive homeodomain; interestingly, most of these clones also contain a leucine zipper motif tightly linked to the homeodomain. It is concluded that Arabidopsis encodes a large family of homeodomain proteins, including members that contain a homeodomain/leucine-zipper (HD-Zip) motif.

Right ventricular diastolic function in chronic obstructive lung disease

Early detection of diastolic dysfunction in chronic obstructive lung disease (COLD) patients could have great prognostic value. Echocardiography has been shown to be a useful technique in studying left ventricular diastolic function. A noninvasive method of studying right ventricular diastolic function has not yet been reported. Pulsed Doppler echocardiography was used to assess right ventricular diastolic function in three groups of subjects: Group I: 35 COLD patients with pulmonary hypertension; Group II: 32 COLD patients without pulmonary hypertension; and Group III: 18 control subjects. Ratios between peak atrial filling velocity (A) and peak early filling velocity (E) (A/E), deceleration half times of the right ventricular rapid filling wave (DHT), and the interval between pulmonary valve closure and tricuspid valve opening (isovolumic relaxation times) (Pc-To) were significantly different in Group I in comparison to Groups II and III. Sensitivity of A/E ratio and Pc-To were 82 and 77%, respectively, and specificity 90 and 72%, respectively; positive predictive values were 90 and 75%, respectively, and negative predictive value 82 and 74% respectively. The multiple correlation coefficient between A/E, acceleration time (ACT), DHT, Pc-To and mean pulmonary artery pressure was 0.75 for Groups I and II together. In conclusion 2D echo-Doppler proved to be useful in evaluating right ventricular diastolic function in all hypertensive COLD patients, revealing a high correlation between diastolic parameters and mean pulmonary artery pressure in both normotensive and hypertensive COLD patients.

Right ventricular diastolic function in chronic obstructive lung disease

Early detection of diastolic dysfunction in chronic obstructive lung disease (COLD) patients could have great prognostic value. Echocardiography has been shown to be a useful technique in studying left ventricular diastolic function. A noninvasive method of studying right ventricular diastolic function has not yet been reported. Pulsed Doppler echocardiography was used to assess right ventricular diastolic function in three groups of subjects: Group I: 35 COLD patients with pulmonary hypertension; Group II: 32 COLD patients without pulmonary hypertension; and Group III: 18 control subjects. Ratios between peak atrial filling velocity (A) and peak early filling velocity (E) (A/E), deceleration half times of the right ventricular rapid filling wave (DHT), and the interval between pulmonary valve closure and tricuspid valve opening (isovolumic relaxation times) (Pc-To) were significantly different in Group I in comparison to Groups II and III. Sensitivity of A/E ratio and Pc-To were 82 and 77%, respectively, and specificity 90 and 72%, respectively; positive predictive values were 90 and 75%, respectively, and negative predictive value 82 and 74% respectively. The multiple correlation coefficient between A/E, acceleration time (ACT), DHT, Pc-To and mean pulmonary artery pressure was 0.75 for Groups I and II together. In conclusion 2D echo-Doppler proved to be useful in evaluating right ventricular diastolic function in all hypertensive COLD patients, revealing a high correlation between diastolic parameters and mean pulmonary artery pressure in both normotensive and hypertensive COLD patients.

Molecular investigation of the cytokines produced by normal and malignant B lymphocytes

Different normal and malignant human B-cell populations were studied with a twofold aim: to define which cytokines are produced in vivo, and to assess the relationship between cytokine production and kinetic state. To analyse normal B-cells representative of different stages of activation and proliferation in vivo, we purified germinal centre (GC)-B blasts and mantle B (M-B) cells from tonsils. To compare malignant B lymphocytes with their closest normal equivalent cells, we separated malignant CD5+B lymphocytes from the peripheral blood of patients with B-chronic lymphocytic leukemia (B-CLL) and normal CD5+B lymphocytes from cord blood. The expression of interleukins (IL) IL-1 alpha, IL-1 beta, tumour necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta), IL-2, IL-4, and IL-6 genes was analysed using Northern and Western blotting techniques. TNF-alpha mRNA is produced by resting (M-B) and actively proliferating (GC-B) normal B lymphocytes. TGF-beta mRNA is present at high levels in resting normal M-B cells, while the transcript levels are lower in proliferating GC-B and in activated CD5+B lymphocytes. IL-2 production is limited to the actively proliferating GC-B blasts, IL-1 beta and IL-6 to resting M-B cells. The cytokine production profile of CD5+ malignant B-CLL cells differs from that of their putative normal counterparts and is more like the profile of M-B cells, since B-CLL cells produce IL-1 beta, TNF-alpha, TGF-beta, and IL-6. These observations lead to the following conclusions: among normal B lymphocyte populations, resting M-B lymphocytes are the most active cytokine producers, and B-CLL malignant B cells reflect the production pattern of normal resting B lymphocytes.

Physical rehabilitation in coronary patients who have suffered from episodes of cardiac failure

The effects of bicycle training for 5 weeks were evaluated in 12 patients after myocardial infarction with left ventricular dysfunction (left ventricular ejection fraction < 40%) and at least one episode of cardiac failure in the past. The patients were divided into two groups of six according to the Weber classification: Group B (VO2/kg/min: 16-20) and Group C (VO2/kg/min: 10-15). Cardiopulmonary and hemodynamic parameters were evaluated during a maximal exercise test and a simultaneous catheterization of the right side of the heart before and after the training. An increase in the capacity for work was recorded in Group B (p < 0.02), while Group C remained unchanged. A statistically significant increase in minute ventilation (p < 0.05) and VO2/kg/min (p < 0.0006) was recorded in Group B. Group C showed an increase in the mean pulmonary arterial pressure (p < 0.03). All of the other parameters remained unchanged after training. We conclude that physical rehabilitation improves the tolerance to exercise in patients with a mildly depressed cardiac function (Group B) but not in patients with a very depressed cardiac function (Group C).