[Insulin resistance and alteration of cardiac vagal activity in obese patients]. / Insulinorésistance et altération de l'activité vagale cardiaque chez les obèses.

We have previously shown that alterations of vagal control of heart rate variations are found in more than half of non diabetic obese subjects (Int J Obes 1995) and are associated with a more severe insulin resistance in noninsulin dependent diabetic patients (Metabolism 1998). The aim of this study was to examine whether parasympathetic alterations are also associated with a more severe insulin resistance in non diabetic obese subjects. 245 obese subjects (BMI = 34.2 +/- 0.4 kg/m2) aged 38.6 +/- 0.8 years, with a normal oral glucose tolerance test were included. Parasympathetic activity was evaluated by heart rate variations during three standardised tests: Valsalva, deep-breathing and active lying-to-standing, with age being taken into account. The Valsalva maneuver was abnormal in 17.5%, the deep-breathing test in 18% and the lying-to-standing test in 30.3% of the cases. One hundred and thirty subjects (52.1%) had at least one abnormal test. Compared with those with three normal tests, the obese subjects with parasympathetic alterations had very similar BMI and blood pressure, but significantly higher values of heart rate (75.5 +/- 1.4 vs 71.3 +/- 1.1 beats/min, p = 0.02), fasting blood glucose (5.0 +/- 0.1 vs 4.8 +/- 0.1 mmol/L, p = 0.03) and plasma insulin (98 +/- 6 vs 82 +/- 4 pmol/L, p = 0.03). In the whole series of obese subjects, heart rate variations during the deep-breathing and lying-to-standing tests correlated negatively with blood glucose (p = 0.001 and p = 0.03 respectively), and during the deep-breathing test they correlated negatively with the waist/hip ratio (p = 0.004). This data suggests that cardiac parasympathetic alterations should take part in the insulin-resistance syndrome and might account for the poor cardiovascular prognosis linked to this syndrome.

Angiotensinase A gene expression and enzyme activity in isolated glomeruli of diabetic rats.

One of the characteristics of early diabetic nephropathy is glomerular hyperfiltration and hyperperfusion. Many factors have been suggested to induce glomerular hyperperfusion among which are an increased production of vasodilatory prostanoids, an increased synthesis of nitric oxide, a reduced responsiveness of afferent glomerular arterioles to vasoconstrictor stimuli due to diabetic metabolic disturbances and a decreased receptor density for angiotensin II. It has been known for years that angiotensin II is formed locally due to the local activation of the renin angiotensin system. The local angiotensin II concentration, however, is not only regulated by the synthesis rate but also by the local degradation through activation of an aminopeptidase. The main finding of the present study was that the mRNA expression and activity of the angiotensin II degrading enzyme, angiotensinase A, was increased twofold in diabetic rats at 5 weeks and that the increase in mRNA expression was suppressed by insulin therapy and short-term treatment with the angiotensin II antagonist saralasin, whereas angiotensinase A enzyme activity was only reduced by saralasin and not by insulin. These results demonstrate that the angiotensin II degrading exopeptidase angiotensinase A is activated in diabetic glomeruli. This increased activity may be an additional mechanism to explain glomerular hyperfiltration and hyperperfusion in early diabetic nephropathy.

Expression of one of the members of the Arabidopsis chaperonin 60 beta gene family is developmentally regulated and wound-repressible.

To study the pattern of gene regulation of the plastid chaperonin 60 beta gene family a chimaeric gene was constructed fusing the 5'-flanking region of the chaperonin 60 beta B3 gene to the beta-glucuronidase reporter gene. Histochemical and fluorometric analysis of the GUS activity present in transgenic plants harbouring this gene construct showed that the B3 promoter is expressed in leaves, stem, petioles and several flower tissues. The pattern of cell type-specific expression in stems and flowers was found to be developmentally regulated. Expression of the B3 promoter was found not to be heat-inducible, but highly repressed by wounding. The rapid decay in GUS activity upon wounding indicates that, at least under some physiological conditions, the gene product of this reporter gene is not as stable as has been previously thought.

[Comparison of isobaric effects of hypertension and diabetes mellitus on geometric and elastic properties of human arteries]. / Comparaison des effets isobariques de l'hypertension artérielle et du diabète sur les propriétés géométriques et élastiques des artères humaines.

Hypertensive and diabetic mellitus diseases are known to increase stiffness of the arterial wall. However these alterations probably involve different mechanisms. To this end, we compared the effect of hypertension and diabetes on large artery caliber and elasticity at real pressure conditions and at the same level of pressure. Nine poorly controlled non insulino-dependent diabetic men without hypertension and 9 non-diabetic essential hypertensive men underwent measures of lumen diameter (pulsed Doppler) and segmental compliance (Bramwell and Hill formula; pulse wave velocity) at the brachial artery. Isobaric diameter and compliance were deduced from a non linear model, comparing diameter and pressure on one part, and compliance and pressure on the other. Pulse wave velocity was similarly increased in both diseases (11.5 +/- 1 vs 12.8 +/- 1 m/s; NS; respectively in diabetes and hypertension). Both measured and isobaric diameters were smaller in diabetic patients (4.05 +/- 0.2 vs 5.03 +/- 0.2 mm, p less than 0.1% for the measured diameters respectively in diabetes and hypertension and 4.06 +/- 0.2 vs 5.01 +/- 0.2 mm, p less than 1% for isobaric diameters). The measured and isobaric compliances were not significantly different (2.38 +/- 0.4 vs 2.08 +/- 0.2 cm/mmHg10(-4), NS, for the measured compliance respectively in diabetes and hypertension; 2.28 +/- 0.4 vs 2.4 +/- 0.2, NS for the isobaric compliance). After correction of the effect of mechanical arterial stretch induced by the different blood pressure level of the two groups, significant reduction of diameter in diabetic subjects persisted and isobaric and measured compliances remained unchanged between groups.

[Beliefs in diabetics about the etiology of their disease. Influence of ethnicity]. / Croyances des diabétiques sur l'étiologie de leur maladie. Influence de l'ethnie.

The education of diabetics often affects the patient's life-style and habits, and the beliefs of his socio-professional and socio-cultural environment. The patient's knowledge is often satisfactory, while his behavior is inadequate. In this study, a sociologist conducted a semi-structured interview for 40 non-obese diabetic patients: 35 IDD and 5 NIDD, who had a knowledge/behavior gap. Emphasis was placed on the study of their subjective etiological beliefs. Four categories beliefs were found: stress, heredity, food and drink transgression, and fatality. Stress, which can lead to deresponsabilization, was the most frequently mentioned etiology (24 patients). Europeans cited several etiological beliefs. North-Africans, in contrast, cited only one, either stress or fatality, but never heredity or food and drink transgression, probably because genetics and genealogy are not superimposable realities and because of their belief in the symbolic benefits of sugar. In conclusion, the patient's etiological beliefs may contribute to the knowledge/behavior gap. Correct information about a more rational etiology for diabetes could improve patient compliance.

Serological survey of toxoplasmosis in the northern part of Iran, using indirect fluorescent antibody technique.

A total of 1,779 persons from the Caspian Sea area, Iran, were serologically examined by the indirect fluorescent antibody technique for Toxoplasma antibodies. 55.7% were positive with titres of 1:20 or higher. No significant difference was demonstrated between the sexes. The highest antibody level as well as a high geometric mean of reciprocal titres were observed in the population between the ages of two and 19 years.