Differential expression of chemokine receptors and chemotactic responsiveness of type 1 T helper cells (Th1s) and Th2s

T helper cells type 1 (Th1s) that produce interferon-gamma predominantly mediate cellular immune responses and are involved in the development of chronic inflammatory conditions, whereas Th2s which produce large amounts of IL-4 and IL-5 upregulate IgE production and are prominent in the pathogenesis of allergic diseases. The precise factors determining whether Th1- or Th2-mediated immune responses preferentially occur at a peripheral site of antigen exposure are largely unknown. Chemokines, a superfamily of polypeptide mediators, are a key component of the leukocyte recruitment process. Here we report that among four CXC (CXCR1-4) and five CC (CCR1-5) chemokine receptors analyzed, CXCR3 and CCR5 are preferentially expressed in human Th1s. In contrast, Th2s preferentially express CCR4 and, to a lesser extent, CCR3. In agreement with the differential chemokine receptor expression, Th1s and Th2s selectively migrate in response to the corresponding chemokines. The differential expression of chemokine receptors may dictate, to a large extent, the migration and tissue homing of Th1s and Th2s. It may also determine different susceptibility of Th1s and Th2s to human immunodeficiency virus strains using different fusion coreceptors.

Role of metalloproteases in the release of the IL-1 type II decoy receptor

The IL-1 type II receptor (decoy RII) is a nonsignaling molecule the only established function of which is to capture IL-1 and prevent it from interacting with signaling receptor. The decoy RII is released in a regulated way from the cell surface. Here, we reported that hydroxamic acid inhibitors of matrix metalloproteases inhibit different pathways of decoy RII release, including the following: (a) the slow (18 h) gene expression-dependent release from monocytes and polymorphonuclear cells exposed to dexamethasone; (b) rapid release (minutes) from myelomonocytic cells exposed to tumor necrosis factor, chemoattractants, or phorbol myristate acetate; (c) phorbol myristate acetate-induced release from decoy RII-transfected fibroblasts and B cells. Inhibition of release was associated with increased surface expression of decoy RII. Inhibitors of other protease classes did not substantially affect release. However, serine protease inhibitors increased the molecular mass of the decoy RII released from polymorphonuclear cells from 45 to 60 kDa. Thus, irrespective of the pathway responsible for release and of the cellular context, matrix metalloproteases, rather than differential splicing, play a key role in production of soluble decoy RII.

Genetics of renal mechanisms of primary hypertension: the role of adducin

PURPOSE

To summarize data concerning the identification of adducin as a 'candidate' gene in the Milan hypertensive strain of rats (MHS), a genetic model of essential hypertension, and in human essential hypertension.

RESULTS

The sequence of events from renal function to cell membrane ion transports and finally to the molecular defect has been established in MHS rats. This led to the identification of polymorphisms in the cytoskeletal protein adducin. These polymorphisms are involved in blood pressure regulation in these rats. A linkage and an association study on Caucasian populations support the involvement of adducin in human hypertension also. A polymorphism of alpha-adducin gene is significantly associated with human hypertension. In particular, both in humans and in rats, adducin polymorphisms affect kidney function by modulating the overall capacity of tubular epithelial cells to transport ions.

CONCLUSIONS

Adducin polymorphisms account for only a portion of hypertension both in humans and rats. Therefore additive or epistatic interactions with other genes involved in renal sodium handling need to be studied.

Renal artery stenosis: evaluation with breath-hold, three-dimensional, dynamic, gadolinium-enhanced versus three-dimensional, phase-contrast MR angiography

PURPOSE

To compare breath-hold, three-dimensional, gadolinium-enhanced magnetic resonance (MR) angiography with three-dimensional, phase-contrast MR angiography in the evaluation of renal artery stenosis.

MATERIALS AND METHODS

Fifty-five consecutive adult patients with clinical suspicion of renovascular disease were prospectively examined with three-dimensional, phase-contrast MR angiography and breath-hold, three-dimensional MR angiography with injection of a standard dose of gadopentetate dimeglumine to evaluate the number of renal arteries and the presence and degree of stenosis. The standard of reference was intraarterial digital subtraction angiography.

RESULTS

Gadolinium-enhanced MR angiography depicted all 105 main renal arteries, whereas phase-contrast MR angiography depicted 104. The number of accessory renal arteries depicted was significantly higher with gadolinium-enhanced (17 of 18) than with phase-contrast (11 of 18) studies (P = .04). Both techniques depicted 27 of the 29 stenoses (sensitivity, 93%; P > .05). Sensitivities, specificities, and accuracies in the diagnosis of hemodynamically significant stenosis (> 50% narrowing) were, respectively, 94%, 96%, and 96% for phase-contrast and 100%, 97%, and 98% for gadolinium-enhanced MR angiography (P > .05).

CONCLUSION

Gadolinium-enhanced MR angiography is superior to phase-contrast MR angiography in accessory renal artery depiction. No statistically significant difference in the assessment of stenosis has been found between the two techniques.

Erythrocyte calpain activity and left ventricular mass in essential hypertension

BACKGROUND

Calpains are cytoplasmic proteases widely distributed among eucaryotic cells. Low levels of calpain activity were found in hypertrophic hearts from hypertensive rats, but its role in hypertrophic hearts from human hypertensives is unknown. Therefore, calpain activity was investigated in erythrocytes from essential hypertensive patients in relation to their left ventricular mass.

OBJECTIVE

To study the role of calpain activity in the development of left ventricular hypertrophy (LVH) in human essential hypertension.

METHODS

A total of 115 hypertensives (72 untreated and 43 with treatment interrupted for at least 4 months) were included in the study. Calpain I activity was measured in human erythrocytes and LVH was measured as left ventricular mass index (LVMI) by M-mode echocardiography.

RESULTS

Values are given as mean+/-SEM. The hypertensives (97 men and 18 women) were 43.5+/-0.9 years old with mild to moderate levels of hypertension (systolic/diastolic blood pressure of 147.9+/-1.4/98.7+/-0.9 mmHg) and relatively recent LVH onset (3.5+/-0.5 years). An inverse relation between LVMI and erythrocytic calpain activity was present in all (P = 0.0023, R2 = 7.9%). This relation was still present considering only untreated hypertensives (P = 0.008; R2 = 9.7%), but was lost in the 43 previously treated hypertensives. Moreover, in the untreated hypertensives, after excluding the possible confounding effects of sex, age, body mass index, blood pressure and duration of hypertension, a stepwise regression showed that only two variables remained significantly related to LVMI: calpain (F = 6.23) and mean arterial pressure (F = 4.689). No relations were found between LVMI and calpastatin activity either in the whole population, or in treated or untreated hypertensives.

CONCLUSIONS

If we assume that the level of erythrocyte calpain activity mirrors the level in cardiomyocytes, these data seem to suggest that increased protein degradation by calpain may prevent the development of LVH in hypertensive patients. This effect is independent of the duration and severity of hypertension.

Uncertainty in liver function assessment on the basis of single-point galactose concentration

The uncertainty in liver function assessment based on single-sample galactose levels after galactose injection, in comparison to the standard procedure using the galactose elimination capacity (GEC), was assessed in 905 tests performed in a wide range of liver functions. The 45-min galactose levels significantly correlated with GEC, the correlation being better in subjects with a good liver function. In cirrhosis, the prediction using the 60-min galactose value was better than when the 45-min value was used. In the whole series, the 95% confidence interval of GEC predicted by 45-min galactose was as large as +/- 1.55mg x kg(-1) x min(-1) as absolute value, corresponding to a range from -41 to +47% of measured GEC. In cirrhosis, the 95% confidence interval was +/- 1.42 mg x kg(-1) x min(-1) and between -40 and +46% of measured GEC. The 60-min values were more predictive, but in Child class C patients the average error was 0.42 mg x kg(-1) x min(-1) (95% confidence interval -0.64 to +1.49, corresponding to -39 to +76% of measured GEC). The uncertainty was maintained within +/- 10% of measured values only in 50% of the tests. We conclude that the single-point galactose test introduces a considerable error, mainly in patients with more advanced liver disease, which may bias the decision-making process.

Ouabain-like factor quantification in mammalian tissues and plasma: comparison of two independent assays

The resolution of controversies that concern the detectability of an endogenous ouabain-like factor (OLF) in mammalian tissues and plasma was approached by the application of a standardized method for its extraction and quantification. Two independent assays were used to quantify the OLF: (1) a radioimmunoassay, which used a polyclonal anti-ouabain antiserum, and (2) a radioenzymatic assay based on the inhibition of dog kidney Na+,K+-ATPase. Plasma and tissues were obtained from the Milan hypertensive strain (MHS) and the Milan normotensive strain (MNS) of rats and from healthy human volunteers. Results indicate that (1) a single high-performance liquid chromatography (HPLC) fraction identical to that of ouabain was identified by both assay methods in the rat hypothalamus and hypophysis and in both rat and human plasma; (2) dilution curves of OLF and standard ouabain were parallel and with a similar Kd, both in radioimmunoassay (3 nmol/L) and ATPase assay (14 nmol/L); (3) after HPLC, OLF was similarly quantified by the two methods in the hypothalamus, hypophysis, adrenals, and plasma of rats and in human plasma; (4) OLF was present in larger amounts in the hypothalamus, hypophysis, and plasma of MHS rats than that of MNS rats; (5) the HPLC fraction of human plasma was quantified similarly by both assays (range, 60 to 150 pmol/L); (6) recovery of standard ouabain in pre-HPLC plasma extracts was approximately 90%; and (7) pre-HPLC OLF concentrations in human plasma ranged between 0.05 and 0.75 nmol/L. Rat cerebral tissues and both rat and human plasma contained measurable amounts of OLF, which were quantified similarly by radioimmunoassay and ATPase assay, both before and after HPLC fractionation. The increased MHS tissue and plasma levels of OLF are in keeping with the pathogenetic role of this factor in MHS hypertension.

Serum autoantibodies in chronic hepatitis C: comparison with autoimmune hepatitis and impact on the disease profile

Antibodies to nuclei (ANA), smooth muscle (SMA), and liver/kidney microsomes type 1 (anti-LKM1) may occur in chronic hepatitis C. Distinct subspecificities, including ANA with the homogeneous pattern (ANA-H) and SMA with antiactin specificity (SMA-AA), are found in autoimmune hepatitis (AIH). This study was performed to characterize the hepatitis C virus (HCV)-associated autoantibodies and to evaluate their influence on the profile of the disease. Two hundred ninety consecutive patients with chronic hepatitis C and 35 control cases with AIH were screened for autoantibodies by indirect immunofluorescence (IFL) at 1:40 serum dilution. The ANA pattern was defined by IFL on HEp-2 cells and the SMA-AA identified by the presence of at least two of the following elements: 1) SMA(T) or SMA(G) pattern by IFL on kidney sections; 2) XR1 precipitating system by counterimmunoelectrophoresis; or 3) typical pattern by IFL on liver sections from phalloidin-intoxicated rats. ANA, SMA, and anti-LKM1 occurred in 9%, 20%, and 6% of chronic hepatitis C cases, respectively. The overall prevalence of autoantibodies was 30% (87 of 290). Compared with AIH, HCV-associated ANA and SMA exhibited ANA-H and SMA-AA at a lower prevalence (38% vs. 71%, P = .04 and 8% vs. 87%, P < .000001, respectively) and had a lower median titer (1:80 vs. 1:320, P < .001 and 1:40 vs. 1:320, P < .000001, respectively). The concomitant positivity for ANA-H and SMA-AA was detected in none of the HCV cases, but in 46% of AIH sera (P < .000001). Two parameters were independently associated with the autoantibodies in chronic hepatitis C: high alanine transaminase (ALT) serum levels (F = 14.04) and female gender (F = 5.03). At the univariate analysis, patients with autoantibodies had a more severe portal-periportal necroinflammation (median Scheuer's score: 2.05 vs. 1.64, P = .003). The presence of autoantibodies did not influence the response to interferon (IFN). In chronic hepatitis C, serum autoantibodies are common, but their subspecificities are distinct from those occurring in AIH. Whereas the absence of ANA-H and/or SMA-AA does not exclude AIH, the characterization of ANA and SMA may help to discriminate between the two conditions. As compared with the seronegative counterpart, autoantibody-positive chronic hepatitis C is more common in females and exhibits a more severe biochemical and histological activity. The response to IFN therapy, however, is similar.

Polymorphism of gamma-adducin gene in genetic hypertension and mapping of the gene to rat chromosome 1q55

Adducin (ADD) is a heterodimeric protein involved in cellular signal transduction. A mutation in the alpha subunit affects ion transport and blood pressure in primary hypertension of Milan rats (MHS) and humans. In rats this effect is modulated by another mutation in the beta subunit. The recently described gamma subunit is a new member of the ADD family that should take the place of beta subunit in cells and tissues expressing alpha but not beta-Add. A missense mutation (Q572K) has been found in the gamma subunit of the Milan rats. Nineteen normotensive and five hypertensive inbred rat strains were genotyped for the polymorphisms in alpha, beta and gamma-Add genes. A disequilibrium was evident in the distribution of MHS-like Add genotype, being more frequent between the hypertensive than the normotensive strains (Chi-Square = 13.03, p = 0.0003). In kidney, brain, spleen, liver and heart a cDNA differing from gamma subunit by an in-frame insertion of 96 nucleotides, was found by PCR amplification and confirmed by RNase protection analysis. The rat gamma-Add gene was localized to chromosome 1q55 by fluorescence in situ hybridization.

[Simplifies case record in emergency surgery]

The Authors present an original case record simplified for urgency and emergency, with the aim to allow a quick and exact framing of the "acute" and consequently with a great saving of time. This is possible also thanks to the simple but efficacious graphic representation of the human body and his main districts. Moreover, it is possible to report data in a computerized system.

Characterization of voltage-dependent calcium influx in human erythrocytes by fura-2

Thus far, the methods used to determine erythrocyte Ca2+ influx have not allowed the assessment of the kinetics of ion uptake. To overcome this drawback, we studied a new method, using the fluorescent Ca2+-chelator fura-2, which directly quantifies intracellular Ca2+ changes in human erythrocytes. This method has the advantage over previous techniques that it monitors continuously cellular Ca2+ levels. The Ca2+ influx is modulated by cellular membrane potential in the presence of a transmembrane Ca2+ concentration gradient and exhibits a first slow increase of the intracellular Ca2+ concentration, followed, after the reachment of a threshold value of 125 +/- 13 nM Ca2+, by a faster increase until a plateau is reached. The influx rate is inhibited by dihydropyridines in the micromolar range. These findings support the hypothesis that erythrocyte Ca2+ influx is mediated by a carrier similar to the slow Ca2+ channels and is dependent on membrane depolarization.

Renal genetic mechanisms of essential hypertension

Human essential hypertension is a polygenic disease whose phenotypic expression is modulated by the environment. Though the kidney could play a major role in the initiation and maintainment of hypertension, many questions remain open. Rat models of primary hypertension provided the substantial information with experiments on kidney cross-transplantation showing that at least a portion of hypertension could be transplanted with the kidney in all strains where such experiment has been carried out. Data consistent with those of rats have also been obtained in humans. Many abnormalities in kidney function and cell membrane on transport have been described in hypertensive rats and humans but the logical sequence of events going from a genetic-molecular abnormality to a cellular abnormality which causes hypertension via a modification of kidney function is difficult to prove. We established this sequence in Milan hypertensive rats using a variety of experimental techniques such as the study of isolated kidney and renal cell function, cell membrane ion transport, cross-immunisation with membrane proteins, molecular biology, genetic crosses and manipulation. Such study led to the identification of a polymorphism in the cytoskeletal protein adducin and to the demonstration of its role in blood pressure control. Recently, alpha-adducin variants have been associated to both human primary hypertension and salt sensitive hypertension. Finally, recent findings strongly support the hypothesis that adducin variants may affect kidney function by modulating the overall capacity of the tubular epithelial cells to transport ions through both a modification in the assembly of actin cytoskeleton, and a modulation of sodium pump activity.

[Renal injury in childhood]

The Authors report a case of blunt renal trauma in a nine-year-old boy. Clinical and therapeutic approaches are discussed in the light of a wide review of the literature.

IL-15 is chemotactic for natural killer cells and stimulates their adhesion to vascular endothelium

Interleukin-15 (IL-15) is a recently described cytokine with IL-2-like stimulating activities on T lymphocytes and natural killer (NK) cells. IL-15 mediates its function through the beta- and gamma-chains of the IL-2 receptor. In this work, we have investigated the effect of IL-15 on the directional migration of NK cells in chemotaxis assays and on the ability of NK cells to bind to vascular endothelium. IL-15 (10-20 ng/mL) had chemotactic effects on freshly isolated resting NK cells as well as on long-termed IL-2-cultured NK cells. A checkerboard experiment demonstrated that migration in response to IL-15 was observed only in the presence of a positive gradient (chemotaxis). Overnight treatment of freshly isolated NK cells with IL-15 (10-20 ng/mL) augmented their binding to cultured endothelial cells (EC) in vitro, especially to resting EC. IL-15-activated NK cells bound to resting and tumor necrosis factor-activated EC by use of LFA-1/ICAM-1 and VLA-4/VCAM-1 adhesion pathways, essentially as untreated NK cells do. The fact that IL-15 increased NK cell binding to ICAM-1-transfected NIH-3T3 fibroblasts, together with the finding that IL-15 did not increase binding to extracellular matrix proteins, where the major molecules involved are VLA proteins, indicated that IL-15 primarily stimulates LFA-1-dependent adhesion. By increasing NK cell adhesion to vascular endothelium and migratory response, IL-15 is an important determinant of NK cell recruitment in tissues.

[Aorto-enteric fistula: current information on diagnostic and therapeutic procedures]

The Authors point out how AEFs represent a serious complication of aortic vascular surgery. Special attention is given to the diagnostic and therapeutic approach, also supported by a wide review of the literature.

Clinical implications of GBV-C/HGV infection in patients with "HCV-related" chronic hepatitis

BACKGROUND/AIMS

To evaluate the clinical, biochemical and histological implications of a concomitant HGV infection in "HCV-related" chronic liver disease.

METHODS

Eighty-three HCV-RNA positive patients with chronic liver disease were tested for GBV-C/HGV coinfection by heminested PCR.

RESULTS

Twenty-two (26.5%) patients were found to be positive for GBV-C/HGV RNA. GBV-C/HGV+ patients differed significantly from GBV-C/HGV- ones for younger age, higher frequency of history of drug addiction, which in turn might favor coinfection with interferon-sensitive HCV genotypes (3a), and increased probability of long-term response to interferon. GBV-C/HGV infection appears to have no responsibility for specific aspects of HCV infection such as biochemical or histological cholestatic features, lymphoid follicles, symptomatic cryoglobulinemia or presence of serum autoantibodies, including LKM1. It does not worsen the HCV-related disease (ALT levels and histological activity) and does not significantly interfere with HCV infection, as explored by the number of hepatocytes positive for HCV antigens. The amount of steatosis (mean score) was shown to be higher in GBV-C/HGV+ patients. A virological follow up was performed in 17 interferon-treated GBV-C/HGV+ patients On the whole, GBV-C/HGV seems to be as sensitive to IFN treatment as HCV, but recurrence after withdrawal is more frequent. In spite of this, ALT levels often remain normal after treatment withdrawal.

CONCLUSIONS

The present data suggest that GBV-C/HGV infection, apart from more marked liver steatosis, does not modify the overall picture of chronic hepatitis due to HCV infection.

Polymorphisms of alpha-adducin and salt sensitivity in patients with essential hypertension

BACKGROUND

Abnormalities in renal sodium transport may be involved in hypertension. Adducin, an alpha/beta heterodimeric protein found in the renal tubule is thought to regulate ion transport through changes in the actin cytoskeleton. We investigated whether an alpha-adducin polymorphism (Gly 460 Trp) is involved in essential hypertension in two separate populations.

METHODS

Linkage analysis of three DNA markers at different distances from the alpha-adducin locus (20-2500 kb) was done in 137 hypertensive sibling-pairs. 477 hypertensive and 322 normotensive individuals were genotyped for the alpha-adducin polymorphism. The blood-pressure response to acute and chronic changes in sodium balance was studied in hypertensive individuals with and without the 460 Trp alpha-adducin allele.

FINDINGS

Significant linkage was found for all three markers in the sibling-pair study. The extra shared alleles (9.1%, 6.5%, and 4.7%) and the significance level for linkage (p = 0.0006, p = 0.0119, and p = 0.0211) both decreased with increasing distance from the alpha-adducin locus. There was a significant association between the 460 Trp mutation and hypertension (p = 0.0003). In the salt-sensitivity test, to assess the acute blood-pressure response to changes in body sodium in 86 hypertensive patients, the decrease in mean arterial pressure was greater in 65 patients who were heterozygous for the mutant allele (Gly/Trp) than in 21 wild-type homozygotes (Gly/Gly) (mean decrease 15.9 [SE 2.0] vs 7.4 [1.3] mm Hg; p = 0.001). Similarly, 21 heterozygous hypertensive patients showed a greater fall in mean arterial pressure in response to 2 months' treatment with hydrochlorothiazide than did 37 wild-type homozygous hypertensive patients (mean decrease 14.7 [2.2] vs 6.8 [1.4] mm Hg; p = 0.002).

INTERPRETATION

Our findings of significant linkage of the alpha-adducin locus to essential hypertension and greater sensitivity to changes in sodium balance among patients with the mutant allele suggest that alpha-adducin is associated with a salt-sensitive form of essential hypertension. We suggest the alpha-adducin polymorphism may identify hypertensive patients who will benefit from diuretic treatment or manoeuvres to reduce total body sodium.

[Signet ring cell adenocarcinoma of the colon (signet ring carcinoma): is it really a rare neoplasm?]

The Authors report two cases of primary carcinoma of the colon-rectum largely invasive, characterized signet ring cells. This is an uncommon neoplasm representing only 2% of primary carcinoma of the colon-rectum. The Authors discuss the diagnostic and therapeutic approach through a wide review of the literature.