Nail-fold capillaroscopy in the study of microcirculation in elderly hypertensive patients

Hypertension represents one of the most important atherosclerotic risk factors, since it causes vascular damage both to macro- and microcirculation. Capillaroscopy is very useful to examine "in vivo" the small vessels of nail-fold and conjunctival layer of the bulb which are the most suitable areas for a morphological study of microcirculation. Capillaroscopy gives remarkable information from a clinical and diagnostic point of view, both in the diseases involving microcirculation (connective tissue disorders, diabetes) and in the evaluation of microvascular impairments in systemic diseases such as arterial hypertension. Aim of the present study was at evaluating capillaroscopic characteristics in a consecutive and non-selected series of elderly hypertensive patients and comparing the results to those observed on fundus oculi. Our study revealed the decrease of the number of capillary loops which appear thin and lengthened, in the hypertensive persons, as compared to the control group. Dilated and tortuous capillaries, arteriovenous sludge and "flea bite" juxtacapillary microhemorrhages were found more frequently in the patients with isolated systolic hypertension; they are linked to the atherosclerotic nature of that disease.

Tests of General Relativity from Timing the Double Pulsar

The double pulsar system PSR J0737-3039A/B is unique in that both neutron stars are detectable as radio pulsars. They are also known to have much higher mean orbital velocities and accelerations than those of other binary pulsars. The system is therefore a good candidate for testing Einstein's theory of general relativity and alternative theories of gravity in the strong-field regime. We report on precision timing observations taken over the 2.5 years since its discovery and present four independent strong-field tests of general relativity. These tests use the theory-independent mass ratio of the two stars. By measuring relativistic corrections to the Keplerian description of the orbital motion, we find that the "post-Keplerian" parameter s agrees with the value predicted by general relativity within an uncertainty of 0.05%, the most precise test yet obtained. We also show that the transverse velocity of the system's center of mass is extremely small. Combined with the system's location near the Sun, this result suggests that future tests of gravitational theories with the double pulsar will supersede the best current solar system tests. It also implies that the second-born pulsar may not have formed through the core collapse of a helium star, as is usually assumed.

Transient radio bursts from rotating neutron stars

The radio sky is relatively unexplored for transient signals, although the potential of radio-transient searches is high. This was demonstrated recently by the discovery of a previously unknown type of source, varying on timescales of minutes to hours. Here we report a search for radio sources that vary on much shorter timescales. We found eleven objects characterized by single, dispersed bursts having durations between 2 and 30 ms. The average time intervals between bursts range from 4 min to 3 h with radio emission typically detectable for <1 s per day. From an analysis of the burst arrival times, we have identified periodicities in the range 0.4-7 s for ten of the eleven sources, suggesting origins in rotating neutron stars. Despite the small number of sources detected at present, their ephemeral nature implies a total Galactic population significantly exceeding that of the regularly pulsing radio pulsars. Five of the ten sources have periods >4 s, and the rate of change of the pulse period has been measured for three of them; for one source, we have inferred a high magnetic field strength of 5 x 10(13) G. This suggests that the new population is related to other classes of isolated neutron stars observed at X-ray and gamma-ray wavelengths.

A Double-Pulsar System: A Rare Laboratory for Relativistic Gravity and Plasma Physics

The clocklike properties of pulsars moving in the gravitational fields of their unseen neutron-star companions have allowed unique tests of general relativity and provided evidence for gravitational radiation. We report here the detection of the 2.8-second pulsar J0737-3039B as the companion to the 23-millisecond pulsar J0737-3039A in a highly relativistic double neutron star system, allowing unprecedented tests of fundamental gravitational physics. We observed a short eclipse of J0737-3039A by J0737-3039B and orbital modulation of the flux density and the pulse shape of J0737-3039B, probably because of the influence of J0737-3039A's energy flux on its magnetosphere. These effects will allow us to probe magneto-ionic properties of a pulsar magnetosphere.

An increased estimate of the merger rate of double neutron stars from observations of a highly relativistic system

The merger of close binary systems containing two neutron stars should produce a burst of gravitational waves, as predicted by the theory of general relativity. A reliable estimate of the double-neutron-star merger rate in the Galaxy is crucial in order to predict whether current gravity wave detectors will be successful in detecting such bursts. Present estimates of this rate are rather low, because we know of only a few double-neutron-star binaries with merger times less than the age of the Universe. Here we report the discovery of a 22-ms pulsar, PSR J0737-3039, which is a member of a highly relativistic double-neutron-star binary with an orbital period of 2.4 hours. This system will merge in about 85 Myr, a time much shorter than for any other known neutron-star binary. Together with the relatively low radio luminosity of PSR J0737-3039, this timescale implies an order-of-magnitude increase in the predicted merger rate for double-neutron-star systems in our Galaxy (and in the rest of the Universe).

Heterologous expression and characterization of the exopolysaccharide from Streptococcus thermophilus Sfi39

The genes responsible for exopolysaccharide (EPS) synthesis in Streptococcus thermophilus Sfi39 were identified on a 20-kb genomic fragment. The two genes, epsE and epsG, were shown to be involved in EPS synthesis as their disruption lead to the loss of the ropy phenotype. Several naturally selected nonropy mutants were isolated, one acquired an insertion sequence (IS)-element (IS905) in the middle of the eps gene cluster. The eps gene cluster was cloned and transferred into a nonEPS-producing heterologous host, Lactococcus lactis MG1363. The EPS produced was shown by chemical analysis and NMR spectroscopy to be identical to the EPS produced by S. thermophilus Sfi39. This demonstrated first that all genes needed for EPS production and export were present in the S. thermophilus Sfi39 eps gene cluster, and second that the heterologous production of an EPS was possible by transfer of the complete eps gene cluster alone, provided that the heterologous host possessed all necessary genetic information for precursor synthesis.

[Polydistrectual atherosclerosis in the elderly. Ischemic cardiopathy and obliterative peripheral arteriopathy of the lower limbs]

BACKGROUND

Numerous epidemiological studies have recently drawn attention to the polydistrict nature of atherosclerotic disease. In particular, it has been made clear the frequent association between coronary heart disease and peripheral arterial disease of the lower limbs. We have therefore evaluated the frequency of peripheral arterial disease in a consecutive unselected series of patients affected by coronary heart disease, over 65 and under 65. We have besides evaluated the frequency of some factors of risk for atherosclerotic disease on the subjects affected by coronary heart disease alone and in those with associated peripheral arterial disease.

METHODS

We have studied 502 patients (280 males and 222 females) with coronary heart disease admitted to the II Division of General Medicine of Pugliese-Ciaccio Hospital of Catanzaro. Of the 502 patients examined, 367 (72.7%) over 65 and 137 (27.3%) under 65. Factors of risk considered were familiarity, cigarette smoking, diabetes mellitus, dyslipidosis, arterial hypertension.

RESULTS AND CONCLUSIONS

Peripheral arterial disease was present in 37% of the subjects examined. In the elderly group there was a frequency of 87.6%, while in subjects under 65 the frequency was 12.4%. Symptoms of claudicatio were present in 100% of the subjects under 65 and 58.6% of the elderly subjects. Risk factors that apply with greater frequency were diabetes mellitus, arterial hypertension and smoking. The results of our study show the importance of searching for stenosis even if asymptomatic in patients with coronary heart disease, above all if elderly.

[Nailfold capillaroscopy in the study of microcirculation in childhood]

The nailfold capillaroscopy allows to study the microcirculation: for its simple and rapid execution it can be used also in children. We examined the nailfold capillaroscopy features in childhood and valued the maturation of microcirculation in connection to age and presented some pathologic patterns. We studied nailfold capillaroscopy patterns in sixty-six children without chronic cutaneous diseases. Our results showed that development of microcirculation during childhood is incomplete. In connection to age we observed the capillaries are arranged as arches in children younger than six months, there are disposed as saddles between 12 and 24 months and they became similar to those of the adult at about 10-11 years. We observed immature capillaries in one child with hypothyroidism and one's delay growth. The cutaneous hemorrhages were rarely found in children who bit the in nails. The capillaroscopy is helpful to value the maturation of the capillaries from the birth to the adolescence. Moreover we would like to underline how our children took part to this exam almost like as if it were a game.

Aging and sex influence the permeability of the blood-brain barrier in the rat

The aim of the present study was to investigate the existence of aging- and sex-related alterations in the permeability of the blood-brain barrier (BBB) in the rat, by calculating a unidirectional blood-to-brain transfer constant (Ki) for the circulating tracer [14C]-alpha-aminoisobutyric acid. We observed that: a) the permeability of the BBB significantly increased within the frontal and temporo-parietal cortex, hypothalamus and cerebellum in 28-30 week old rats, in comparison with younger animals; b) in several brain areas of female intact rats higher Ki values (even though not significantly different) were calculated at oestrus than at proestrus; c) in 1-week ovariectomized rats there was a marked increase of Ki values at the level of the frontal, temporo-parietal and occipital cortex, cerebellum and brain-stem. One can speculate that aging- and sex-related alterations in the permeability of the BBB reflect respectively changes in brain neurochemical system activity and in plasma steroid hormone levels.

[Liver pathology caused by drugs. Pathogenetic, histopathological and clinical notes and case reports]

After a brief review of drug metabolic pathways in the liver, the various mechanisms leading to liver damage are described. The different histological lesions and the clinical situations that can arise are discussed. A case survey is reported.

[Antisalmonellal agglutination in liver cirrhosis and chronic hepatitis]

A positive serum diagnosis for Salmonellae was obtained in 7 patients with cirrhosis of the liver and 18 with chronic hepatitis (22 males and 3 females), even though their history was negative and they had not even been vaccinated against thyphus and paratyphus. The results are seen as a warning that laboratory data that might lead to a mistaken diagnosis and incorrect treatment should be interpreted with particular care.