Can insulin action induce myocardial texture alterations in essential hypertension?

The prevalence of hyperinsulinemia/insulin resistance in hypertensive individuals, as well as the effects of insulin on myocytic and fibroblastic growth, are well known in both epidemiologic and animal models. To check whether there are any links between ultrasonic myocardial texture parameters and insulin level in essential hypertensives, we compared 18 essential hypertensive men (Group 1, H) with 18 age- and gender-matched healthy controls (Group 2, C) (age, 57 +/- 10 years). For all study subjects we performed ambulatory blood pressure monitoring (ABPM); conventional 2-D Doppler echocardiography for the assessment of the left ventricular mass index (LVMi) and function; quantitative analysis of digitized echocardiographic images for evaluation of cyclic variation (CVI) of mean gray level (MGL) at the septum and posterior wall levels; and 75-g 3-h oral glucose tolerance test (OGTT) for analysis of area under glycemic curve (AUGC, g/min/dL) and insulinemic curve (AUIC, mU/min/mL), as well as serum glucose and insulin peaks. Both the daily mean blood pressure (H: 109 +/- 4.6 v C: 94.6 +/- 4.6, P < .0001) and LVMi (adjusted for body surface) (H: 133 +/- 24 v C: 97 +/- 21 g/m2, P < .0001) were significantly higher in hypertensives. Values for AUIC were significantly higher in hypertensives (10.37 +/- 5.53 v 6.33 +/- 5.28), P < .032); CVI was also significantly higher in group C, for both septum (C: 40.2 +/- 16.9 v H: 15.9 +/- 18.1, P < .0001) and posterior wall (C: 44.5 +/- 19.6 v H: 20 +/- 17.5; P < .0001). There was a significant inverse correlation between AUIC and CVI for both septum (r: -0.57, P < .001) and posterior wall (r: -0.50, P < .002). The significantly higher impairment of myocardial ultrasonic texture and the higher level of the AUIC insulinemia in hypertensives, as well as the significant inverse relationship between CVI and hyperinsulinemia, are our major findings. Hyperinsulinemia/insulin resistance could cause an altered collagen/muscular ratio, which could potentially explain, at least in part, the CVI alterations detected in hypertensive patients.

A genomic region encompassing a cluster of olfactory receptor genes and a myosin light chain kinase (MYLK) gene is duplicated on human chromosome regions 3q13-q21 and 3p13

The olfactory receptor (OR) multigene family is widely distributed in the human genome. We characterize here a new cluster of four OR genes (HGMW-approved symbols OR7E20P, OR7E6P, OR7E21P, and OR7E22P) on human chromosome 3p13 that is contained in an approximately 250-kb region. This region has been physically mapped, and a 106-kb portion containing the OR genes has been sequenced. All the OR sequences are disrupted by frameshifts and stop codons and appear to have arisen through local duplications. A myosin light chain kinase pseudogene (HGMW-approved symbol MYLKP) lies at one end of the OR gene cluster. Sequences spanning the entire region are also present at 3q13-q21, the site of the functional MYLK gene. This region duplicated locally before the divergence of primates, and the two paralogous copies were later separated to sites on either side of the centromere. This study increases our understanding of the evolution of the human genome. The 3p13 cluster is the first example of a tandem array of OR pseudogenes, and duplications of such clusters may account for the accumulation of a large number of pseudogenes in the human genome.

Dissociation between albuminuria and insulinaemia in hypertensive and atherosclerotic men

To better understand the links between circulating insulin and albuminuria in essential hypertension, the plasma insulin response t alpha a 75 gram glucose load and albuminuria were evaluated in 53 glucose-tolerant essential hypertensives and 12 controls. To allow any direct pressure-independent albuminuric effect of insulin to emerge more clearly, those same parameters were also evaluated in 20 glucose-tolerant normotensive patients with stable atherosclerotic peripheral vascular disease, a condition in which hyperinsulinaemia could be anticipated on the basis of previous reports. In response to glucose ingestion, hyperinsulinaemia was evident in both hypertensive and normotensive atherosclerotic patients, while, on average, urine albumin was elevated only in the former. When plasma insulin, systolic and diastolic blood pressure (BP) (by 24-h ambulatory BP monitoring), plasma glucose, triglycerides and body mass index were entered into a multiple regression analysis, only systolic BP appeared to exert an independent effect on urine albumin. Post-glucose load plasma insulin did not differ between hypertensive patients with (n = 14) and without (n = 39) microalbuminuria (albuminuria > 20 micrograms/min). In further analyses, insulin and systolic BP values were divided in quartiles: albuminuria did not differ across insulin quartiles, while it was significantly higher in the top (n = 21) vs the bottom (n = 21) systolic BP quartile. Thus, hyperinsulinaemia and microalbuminuria were unrelated variables in these hypertensive and atherosclerotic patients. Blood pressure, particularly systolic, emerged as a primary predictor of urinary albumin excretion, although the importance of this parameter needs to be proved prospectively.

Ultrasonic myocardial texture versus Doppler analysis in hypertensive heart: a preliminary study

-Doppler-derived parameters of transmitral flow are useful indices of diastolic dysfunction in the hypertensive heart. Different degrees of myocardial involvement in hypertensive heart can be detected by videodensitometric myocardial textural analysis. The aim of this study was to compare Doppler-derived and ultrasonic videodensitometric parameters in the differentiation of healthy hearts from hypertensive hearts. We compared a group of age-matched (59+/-9 years) male essential hypertensive patients (n=53) with normotensive healthy subjects as controls (n=32). All subjects provided ambulatory blood pressure measurements for the evaluation of 24-hour mean systolic and diastolic blood pressure. A transmitral flow Doppler analysis was performed on all subjects. A quantitative analysis of the echocardiographic digitized imaging was performed with the help of a calibrated digitization system to calculate the septum and the posterior wall textural parameters. The myocardial mean gray level (MGL) was calculated to derive the cyclic variation index (CVI): (MGLend-diastolic-MGLend-systolic)/MGLend-diastolic x100. When compared with controls, the hypertensive patients showed a significantly lower CVI for both septum (-11.1+/-26.8% versus 34. 7+/-16.3%; P<0.001) and posterior wall (-11.2+/-27.6% versus 38. 2+/-15.4%; P<0.001). Individual analyses for the ratio of peak transmitral flow velocity in early diastole to the peak transmitral flow velocity in late diastole showed that only 24% of the patients (13/53) were discriminated from normal subjects by this parameter. Individual analyses for CVI, however, at both septum and posterior wall levels, showed that 74% of the patients (39/53) were discriminated from normal subjects by this second parameter. In comparison with Doppler-derived indices of diastolic filling, the videodensitometric parameters showed a significantly higher ability to discriminate between hypertensive subjects and normal controls.

Large multi-chromosomal duplications encompass many members of the olfactory receptor gene family in the human genome

The human genome contains thousands of genes that encode a diverse repertoire of odorant receptors (ORs). We report here on the identification and chromosomal localization of 74 OR-containing genomic clones. Using fluorescence in situ hybridization (FISH), we demonstrate a striking homology among a set of approximately 20 OR locations, illustrating a history of duplications that have distributed OR sequences across the genome. Half of the OR-containing BACs cloned from total genomic DNA and 86% of cosmids derived from chromosome 3 cross-hybridize to a subset of these locations, many to 17 of them. These paralogous regions are distributed on 13 chromosomes, and eight lie in terminal bands. By analyzing clones from an approximately 250 kb clone-walk across one of these sites (3p13), we show that the homology among these sites is extensive (>150 kb) and encompasses both OR genes and intergenic genomic sequences. The FISH signals appear significantly larger at some sites than at the native location, indicating that portions of some duplicons have undergone local amplification/attrition. More restricted duplications involving pairs of other genomic locations are detected with 12% of the OR-BACs. Only a small subset of OR locations is sufficiently diverged from the others that clones derived from them behave as single-copy FISH probes. We estimate that duplications encompassing members of the OR gene family account for >0.1% of the human genome. A comparison of FISH signals at orthologous locations in other primates indicates that a portion of this OR 'subgenome' has been in flux during the divergence of primates, possibly as a mechanism for evolving the repertoire of olfactory receptors.

The clinico-ophthalmological spectrum of antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a hypercoagulable disorder with highly variable symptomatology including ocular manifestations. Antiphospholipid antibodies (aPL) are the serologic markers of this clinical entity. Our aim was to note the main associated ocular features of APS and elucidate which pathogenic mechanisms may participate. Retinal vascular thrombosis and different neuro-ophthalmologic manifestations, such as optic neuropathy and amaurosis fugax, may be considered as the ocular hallmarks of this syndrome. Ocular features due to aPL-induced thrombosis should be treated with anticoagulant drugs. Conversely, for the treatment of ocular features due to immunological mechanisms such as vasculitis, immunosuppressive regimes seem to be more appropriate.

[Ultrasonic tissue characterization analysis in type 1 diabetes: a very early index of diabetic cardiomyopathy?]

BACKGROUND

Based on various epidemiological observations, it has been hypothesized that there is a "diabetic cardiomyopathy" strictly related to diabetes per se and probably due to an increase in the collagen content at the myocardial level, to microangiopathy or to complex alteration of myocardial metabolic pattern. Ultrasonic tissue characterization has recently been applied with different methodological approaches in order to identify early structural alterations of the myocardium.

METHODS

We used two different methods of myocardial tissue characterization, i.e. integrated backscatter and videodensitometry, to analyze 26 type I diabetics without clinical symptoms, without hypertension or coronary artery disease, which were excluded on the basis of a negative exercise ECG, and in whom conventional echocardiographic parameters were normal. Seventeen healthy age- and sex-matched subjects were evaluated as the control group.

RESULTS

Of the common left ventricular functional indexes, only E/A ratio (expression of global diastolic function) was lower in diabetics compared with controls (p < 0.01). The integrated backscatter index (IBI%) at the septum and posterior wall was significantly higher in diabetics as compared to controls, expressing an increased collagen content on a myocardial level. The cyclic variation index (%) of the mean gray level (videodensitometry) was significantly lower in diabetics in comparison with controls, both for the septum (p < 0.0001) and posterior wall (p < 0.002). This probably expresses an altered intrinsic myocardial contractility, due to an increase in myocardial collagen content and/or impairment of micro-circulatory function.

CONCLUSION

In agreement with previous studies, we found an altered behavior in myocardial tissue reflectivity in type I diabetics. The real significance of this finding in the "normal" heart is the subject of intense debate. One hypothesis is that these findings could be considered a very early index of a "diabetic cardiomyopathy".

A gene recently inactivated in human defines a new olfactory receptor family in mammals

The olfactory receptor (OR) gene family constitutes one of the largest multigene families and is distributed among many chromosomal sites in the human genome. Four OR families have been defined in mammals. We previously demonstrated that a high fraction of human OR sequences have incurred deleterious mutations, thus reducing the repertoire of functional OR genes. In this study, we have characterized a new OR gene, 912-93, in primates. This gene is unique and it defines a new OR family. It localizes to human chromosome 11q11-12 and at syntenical sites in other hominoids. The sequence marks a previously unrecognized rearrangement of pericentromeric material from chromosome 11 to the centromeric region of gibbon chromosome 5. The human gene contains a nonsense point mutation in the region corresponding to the extracellular N-terminus of the receptor. This mutation is present in humans of various ethnic groups, but is absent in apes, suggesting that it probably appeared during the divergence of humans from other apes, <4 000 000-5 000 000 years ago. A second mutation, a frameshift at a different location, has occurred in the gorilla copy of this gene. These observations suggest that OR 912-93 has been recently silenced in human and gorilla, adding to a pool of OR pseudogenes whose growth may parallel a reduction in the sense of smell in primates.

Transvascular and urinary leakage of albumin in atherosclerotic and hypertensive men

Increased urine albumin is associated with atherosclerotic disease and predicts cardiovascular morbidity and mortality in nondiabetic populations. This finding is frequently postulated to reflect the impact of atherosclerotic damage on glomerular and systemic capillary permeability, an interesting but as yet untested hypothesis. The transcapillary escape rate of albumin (TERalb, the 1-hour decline rate of intravenous 125I-albumin, a measure of capillary macromolecular permeability), albuminuria, lipid levels, echocardiographic wall thickness, and insulin responses to oral glucose were measured in 30 untreated dipstick-negative lean men and clinically stable atherosclerotic peripheral vascular disease; tolerance to oral glucose was a requirement for inclusion in the study. Because hypertension per se might influence TERalb, the sample included either normotensive (n=18, 118+/-6/72+/-7 mm Hg) or hypertensive (n=12, 141+/-7/84+/-6 mmHg by 24-hour blood pressure monitoring) arteriopathic patients; 11 normal age- and gender-matched subjects (121+/-7/76+/-5 mmHg) were used as control subjects. TERalb was higher in patients (10.7+/-3.2 versus 7.4+/-1.7%/h, P<0.013), a difference that persisted after postload glucose, insulin, and lipid levels were accounted for by covariance analysis; atherosclerosis and hypertension together did not further impair vascular permeation to albumin. In contrast with TERalb, albuminuria was elevated only in the hypertensive subgroup; the 2 variables showed no relationship, even when the data were analyzed separately in normotensive and hypertensive subgroups. Urine albumin correlated positively with 24-hour blood pressure and wall thickness. Thus, systemic capillary permeability is altered in nondiabetic atherosclerotic patients independently from blood pressure levels, but this abnormality is not reflected by proportionate changes in albuminuria.

Heart involvement in systemic sclerosis: an ultrasonic tissue characterisation study

BACKGROUND

Clinicoepidemiological findings indicate that symptomatic heart involvement in patients with systemic sclerosis (SSc) predicts a very poor prognosis. At necropsy studies, SSc heart involvement without significant coronary lesions is characterised by patchy myocyte necrosis and contraction band necrosis with collagen replacement leading to myocardial fibrosis. There is a discrepancy between the frequency of clinically evident myocardial disease (25%) and autoptical myocardial fibrosis (81%).

OBJECTIVE

The aim of this study was to detect preclinical myocardial alterations in SSc patients by ultrasonic videodensitometric analysis.

METHODS

Thirty five SSc patients (three male, aged 48.6 (11) SD years, range 22-65) with normal ventricular function and 25 age and sex matched healthy controls were studied. All patients had a negative maximal exercise stress; in all cases arterial hypertension, renal involvement, and diabetes were excluded. Echocardiographic images were digitised by a real time videodigitiser (Tomtec Imaging Systems). Quantitative texture analysis was performed on data from the septum and the posterior wall, obtaining mean gray level histogram (MGL) at both end-diastole (d) and end-systole (s). The cyclic variation index (CVI), was calculated according to the formula ((MGLd-MGLs)/MGLd) x 100. Left ventricular mass (LVM), body surface corrected, was calculated according to Penn convention.

RESULTS

Comparable systolic and diastolic blood pressure, LVM, diastolic and systolic function were recorded in both SSc patients and controls. In contrast, in SSc patients the CVI, which is the expression of the intrinsic myocardial structural function, was significantly lower than in controls (septum: -18 (28)% v 35 (10)%, p < 0.0001; and posterior wall: -13 (32)% v 50 (20)%, p < 0.0001). Changes in cyclic echo amplitude, probably related to myocardial fibrosis, were detected in the large majority of SSc patients (88%).

CONCLUSIONS

Ultrasonic videodensitometric analysis represents a non-invasive, feasible method that can detect early myocardial changes in SSc patients, which could be related to both fibrosis and microcirculatory abnormalities. Their potential evolution towards ventricular dysfunction and their link with cardiac sudden death, because of severe conduction system or rhythm disturbances, should be further investigated.

Distribution of olfactory receptor genes in the human genome

We demonstrate that members of the olfactory receptor (OR) gene family are distributed on all but a few human chromosomes. Through FISH analysis, we show that OR sequences reside at more than 25 locations in the human genome. Their distribution is biased for terminal bands. Flow-sorted chromosomes were used to isolate 87 OR sequences derived from 16 chromosomes. Their sequence-relationships are indicative of the inter- and intrachromosomal duplications responsible for OR family expansion. The human genome has accumulated a striking number of dysfunctional copies: 72% of the sequences are pseudogenes. ORF-containing sequences predominate on chromosomes 7, 16 and 17.

Ultrasonic myocardial texture in hypertensive mild-to-moderate left ventricular hypertrophy: a videodensitometric study

Myocardial texture analysis of two-dimensional echocardiographic gray level distribution is abnormal in hypertensive patients with severe increase of left ventricular mass. The aim of this study was to investigate the behavior of this parameter in hypertensive patients with absent-to-moderate left ventricular hypertrophy, more representative of the overall hypertensive population. We compared male essential hypertensive patients, with absent or mild-to-moderate left ventricular hypertrophy, with normotensive sedentary healthy subjects as controls. The groups (n = 18 each) were age- (+/- 2 years) and sex-matched. All subjects performed ambulatory blood pressure measurements for the evaluation of 24 h mean systolic and diastolic blood pressure. Quantitative analysis of echocardiographic digitized imaging was performed through a calibrated 256 gray level digitization system to calculate midseptum and midposterior end-diastolic and end-systolic first and second order textural analysis. In particular were observed the mean gray level cyclic variations to deriving the cyclic variation index (CVI). The hypertensives showed a significantly lower CVI compared with controls both for septum (P < .001) and for posterior wall (P < .0001). No significant relationships were found between CVI and relative diastolic thickness both of septum and posterior wall. Conversely, a significant inverse relationship was found between systolic arterial pressure values and CVI both of septum and posterior wall. Abnormalities of two dimensional echocardiographic gray level distribution are present also in hypertensive patients with absent or with mild-to-moderate levels of left ventricular hypertrophy, but seem unrelated to the degree of echocardiographic hypertrophy as such. Changes in collagen network distribution or microcirculatory alterations, secondary to pressure-volume overload per se or to other complex humoral factors, could explain these abnormalities. Further work is needed to establish the clinical, therapeutic, and prognostic implications of these findings.

Members of the olfactory receptor gene family are contained in large blocks of DNA duplicated polymorphically near the ends of human chromosomes

We have identified three new members of the olfactory receptor (OR) gene family within a large segment of DNA that is duplicated with high similarity near many human telomeres. This segment is present at 3q, 15q, and 19p in each of 45 unrelated humans sampled from various populations. Additional copies are present polymorphically at 11 other subtelomeric locations. The frequency with which the block is present at some locations varies among populations. While humans carry seven to 11 copies of the OR-containing block, it is located in chimpanzee and gorilla predominantly at a single site, which is not orthologous to any of the locations in the human genome. The observation that sequences flanking the OR-containing segment are duplicated on larger and different sets of chromosomes than the OR block itself demonstrates that the segment is part of a much larger, complex patchwork of subtelomeric duplications. The population analyses and structural results suggest the types of processes that have shaped these regions during evolution. From its sequence, one of the OR genes in this duplicated block appears to be potentially functional. Our findings raise the possibility that functional diversity in the OR family is generated in part through duplications and inter-chromosomal rearrangements of the DNA near human telomeres.

Effect of faecal occult blood testing on colorectal mortality: results of a population-based case-control study in the district of Florence, Italy

The aim of our case-control study was to estimate the effect on mortality from colorectal cancer (CRC) of a population-based screening with a faecal occult blood test started in 1982 in a rural area of the district of Florence. We examined the relationship between mortality and the interval since the most recent screening. The cases in the study were 206 individuals who had died from CRC after the age of 41 years. Five controls were selected randomly from the list of individuals alive at the time of diagnosis of the corresponding case and were matched by sex, age and place and length of residence. After adjustment for potentially confounding factors, the odds ratio (OR) for death from CRC for screened persons vs. those not screened was 0.60 [95% confidence interval (CI), 0.4-0.9]. The OR was lowest in the first 3 years after the most recent test (OR = 0.54; 95% CI, 0.3-0.9) and increased towards unity subsequently. Our results suggest that screening for CRC by biennial faecal occult blood testing can reduce mortality from the disease.

Erythrocyte Na+/H+ exchange and preclinical abnormalities of the left ventricular diastolic function in normotensive type 1 (insulin-dependent) diabetic patients

We assessed the relationship between erythrocyte Na+/H+ antiport activity and myocardial anatomical-functional parameters (by Doppler echocardiography) in normotensive IDDM patients, with and without microalbuminuria. We studied 33 normotensive IDDM subjects and 14 matched healthy controls (group 4). Based on urinary albumin excretion rate (UAER), 23 diabetics were normoalbuminuric, 10 microalbuminuric (group 3). Normoalbuminurics were divided up for normal (group 1, n = 13) or high (group 2, n = 10) antiport activity. We evaluated fasting glycaemia and 24-h urine glucose output, HbA1c, plasma lipids, urea, creatinine and electrolyte clearances, UAER, erythrocyte Na+/H+ countertransport, M-Mode and 2D echocardiograms with Doppler analysis. Antiport, which was higher in diabetics than controls, was significantly overactive in groups 2 and 3 vs group 4, independently from UAER. Diabetics showed left ventricular volume, cardiac mass and systolic function within the control range. In left ventricular diastolic filling, while peak E was similar in diabetic and healthy people, the late peak transmitral flow velocity (peak A) was significantly higher in diabetics than controls, and this was also true in groups 2 and 3 vs group 4. Antiport activity was positively related to peak A (p < 0.03). These observations suggest that (a) the Na+/H+ antiport may be overactive in diabetes, apart from microalbuminuria; (b) increased Na+/H+ antiport activity, in normotensive IDDM people, may be associated with preclinical diastolic myocardial dysfunction ("incipient diabetic cardiomyopathy"?).

[Nonsteroidal anti-inflammatory agents: their topical use in the treatment of xerophthalmia secondary to Sjögren's syndrome]

The authors, in a case-control study, analyzed the topical application of nonsteroidal anti-inflammatory drug (flurbiprofene drops) in patients affected by keratoconjunctivitis sicca in Sjögren's syndrome. The variation of break-up-time values, and xerophthalmia grade were analyzed. A mild increase of mean values of break-up-time (two seconds in the treated group), and a mild decrease of xerophthalmia grade were found.

Ischemic optic neuritis in Churg-Strauss syndrome

There are few reports of neuro-ophthalmologic involvement in Churg-Strauss syndrome (CSs). We described a case of unilateral optic atrophy in a 46-year-old-white man with CSs. The patient had severe bronchial asthma, allergic rhinitis, hypereosinophilia (8%) and peripheral neuropathy. The visual acuity in his right eye was light perception. At the biomicroscopy there were no corneal and conjunctival lesions. Ophthalmoscopy showed a pale right optic disc and fluorangiography revealed a marked hypofluorescence of the disc at early phase of angiogram. We suggested that the optic atrophy was most probably due to vasculitis of the ciliary arteries.

Increased myocardial echo density in left ventricular pressure and volume overload in human aortic valvular disease: an ultrasonic tissue characterization study

Quantitatively assessed ultrasonic backscatter is an index of ultrasonic tissue characterization directly related to morphometrically evaluated collagen in human beings. Our objective was to assess myocardial reflectivity pattern of patients with severe left ventricular hypertrophy caused by either aortic stenosis (AS) or aortic regurgitation (AR). Ten patients with AS, 10 patients with AR, and 10 closely age- and gender-matched healthy controls were studied by two-dimensional Doppler echocardiography. By using an echocardiographic prototype, we performed a radiofrequency analysis to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and the posterior wall (integrated backscatter index: IBI, expressed in percentage). All patients with stenosis or aortic insufficiency showed a normal regional and global resting systolic function (fractional shortening: AS = 36.0 +/- 6.6 versus AR = 40.3 +/- 6.2 versus control = 40.2 +/- 8.7; p = not significant [NS]) Left ventricular mass index (Devereux's formula) was markedly increased in patients with stenosis or aortic insufficiency (AS = 199.3 +/- 18 versus AR = 208.8 +/- 60 versus control = 97.3 +/- 11 g/m2; p < 0.0001). Myocardial echo density was increased in patients with stenosis or aortic insufficiency in comparison with controls, both in the septum (IBI%: AR = 40.7 +/- 7.9 versus AS = 33.4 +/- 4.2 versus control = 23.0 +/- 6.2; p < 0.0001) and in the posterior wall (IBI%: AR = 27.1 +/- 4.3 versus AS = 23.0 +/- 2.6 versus control = 15.0 +/- 4.2; p < 0.0001). No significant correlations were found between septal and posterior wall IBI and their thickness. Abnormally increased myocardial echo density--possibly related to disproportionate collagen deposition--can be detected in patients with pressure or volume overload caused by aortic valve disease and without overt systolic dysfunction.