PubMed Health⌕ Search

Biomedical subjects

M Re

Publications and source records attributed to M Re.

At least 19 recordsLinked to original sources
PubMed1992

The circadian rhythm of atrial natriuretic peptide, vasoactive intestinal peptide, beta-endorphin and cortisol in healthy young and elderly subjects.

Atrial natriuretic peptide, vasoactive intestinal peptide, beta-endorphin and cortisol are humoral variables characterized by a 24-h periodicity. We evaluated the circadian rhythm of these peptides and hormones in healthy subjects who were young (between 20-25 years) or elderly (between 65-75 years). All were on controlled diets. Blood samples were collected six times during a 24-h period (at 06.00, 08.00, 12.00, 18.00, 20.00 and 24.00 h) beginning 8-h after start of recumbency. The time-related data were analysed by the Cosinor method in order to validate the circadian rhythm and to quantify rhythmometric parameters which included the midline estimate of rhythm (mesor). In contrast to the young subjects, Cosinor analysis failed to reveal a significant circadian rhythm in elderly subjects, for plasma cortisol. In elderly subjects oscillation (mesor) of atrial nutriuretic peptide was higher, while that of vasoactive intestinal peptide and beta-endorphins was lower. The results suggest changes in the physiological secretion of these three peptides in healthy elderly subjects.

Adult↗
PubMed1992

Impaired response to hepatitis B vaccine in HIV infected children.

Eighteen human immunodeficiency virus (HIV) vertically infected children (HIV group) and 33 seroreverted children (SR group), who had completed hepatitis B vaccination (Engerix B, 20 micrograms dose) were studied. Four out of 18 (22%) HIV children failed to develop protective antibody levels (anti-HBs titres less than 10 mIU ml-1) compared with 1 out of 33 (3%) SR children (p less than 0.05). Magnitude of response among HIV children was significantly lower than among SR children. In HIV children the probability that anti-HBs titres persist above the protective levels was significantly lower than in the SR group at any time during the 24 month follow-up. These results show that HIV children have a suboptimal response to hepatitis B immunization and the protection is less durable. Further studies are needed to determine the optimal protocol for hepatitis B immunization in HIV children.

Child, Preschool↗
PubMed1992

Effect of aging on circadian rhythm of atrial natriuretic peptide, plasma renin activity, and plasma aldosterone.

Atrial natriuretic peptide (ANP) shows a nychtohemeral fluctuation and an age-related trend. The aim of this study was to explore the circadian rhythm of ANP as a function of age. Circadian rhythms of plasma renin activity (PRA), aldosterone (PA), and cortisol (PC) were explored as well. Twenty clinically healthy subjects, 10 young (20-25 yrs) and 10 elderly (65-75 yrs), were investigated, while recumbent, after synchronization to light-dark regimen and meal timing. Blood samples for RIA tests were collected six times during the 24-hr span. The chronobiologic analysis in young subjects demonstrated a significant circadian rhythm for all the investigated variables with an acrophase-timing located at 16.48 for ANP, 4.44 for PRA, 5.32 for PA, and 7.12 for PC. In elderly subjects we documented an important increase of 24-hr mean plasma levels but not a statistically significant circadian rhythm for ANP, and a decrease in mean value of PRA which maintained, however, a significant periodic 24-hr oscillation in parallel with PA and PC. The results in young subjects reinforce the concept that ANP plays physiologically an inhibitory role on the phasic secretion of renin. The lack of the circadian rhythm for ANP along with the divergent changes in ANP and PRA 24-hr mean concentration of elderly subjects both suggest that ANP exerts with advancing age only a counterregulatory role on the tonic rather than the phasic release of renin.

Aged↗
PubMed1991

Vasoactive intestinal peptide fluctuates in human blood with a circadian rhythm.

The vasoactive intestinal peptide (VIP) may be radioimmunoassayed in systemic venous blood. The plasma concentrations of VIP were investigated in human blood according to a chronobiological design. The study documented a circadian rhythmicity in time-qualified concentrations of VIP. Accordingly, VIP may be ascribed to biological variables characterized by periodicity in their physiological attributes. The rhythmic physiology of VIP is, however, highly disturbed in its tonic and phasic properties during senescence.

Adult↗
PubMed1991

Temporal interrelationships between circadian rhythms of vasoactive intestinal peptide and T lymphocyte subpopulations.

Recent investigations documented an immunosuppressive action of VIP. Previous studies demonstrated that T lymphocytes exhibit a circadian rhythm (CR). This investigation was, thus, performed with the aim of detecting the relationships intercurrent between the 24-h patterns of VIP and T lymphocyte subsets. The hypothesis was formulated that circulating VIP may play a role in controlling the CR of T cells. The research was carried out on 10 clinically healthy subjects, tested six times during the 24-h span by assaying circulating levels of VIP and total T (OKT3), T helper (OKT4), and T suppressor/cytotoxic (OKT8) lymphocytes. Time data series were analyzed by Cosinor method. All investigated variables were seen to be characterized by a statistically significant CR. While the acrophase of VIP CR was found to be located at 18.20, the crest of OKT3, OKT4, OKT8 CR was seen to occur at 03.04, 02.16 and 02.56, respectively. The phase shift was found to be significant, suggesting that VIP and T lymphocytes physiologically fluctuate with a phase angle during their nyctohemeral cyclicity. The finding can be regarded as an indirect evidence of a negative VIPergic chronoregulation of CR of T lymphocytes.

Adult↗
PubMed1991

[The evaluation of urinary NAG activity in patients undergoing urography].

A study has been carried out to verify the nephrotoxic effect of hyperosmotic substances used as a contrast medium in radiology employing the enzymuria technique (NAG). The research was carried out in 202 patients, some of whom diabetic, suffering from various pathologies and subjected to perfusion urography by inoculating an iodate contrast medium (isopaque). The result showed that NAG urinary activity grows significant in the 24-36 hours subsequent to X-ray examination in both diabetics and nondiabetics although the increase is greater in the former. After 5-7 days, enzymuria returns to normal in nondiabetic patients but remains high in the diabetic.

Acetylglucosaminidase↗
PubMed1990

[A comparison between the urinary and serum NAG activity in subjects with chronic nephropathies and essential arterial hypertension].

Various substances can interfere with the urinary activity of N-acetyl-beta-D-glycosaminidase (NAG), particularly certain bacteria that exert inhibitory or enhancing effects on the enzyme. Clearly, all this constitutes a limitation on the use of the technique. For these reasons, in patients suffering from interstitial and glomerular nephropathies and essential arterial hypertension a comparative study was carried out between the activity of urinary and serum NAG to establish if the latter produces more reliable results than the former. The results of urinary NAG activity confirm that there is no significant difference between healthy subjects and those with essential arterial hypertension; on the other hand, nephropathic patients present significantly higher urinary enzyme activity than healthy controls. On the other hand, evaluation of serum NAG does not seem to provide any practical aid as it does not highlight any difference between measurements carried out in healthy subjects and those carried out in hypertensive patients or those suffering from interstitial or glomerular nephropathy.

Acetylglucosaminidase↗
PubMed1989

[Tumor markers in the early diagnosis of thyroid neoplasms].

Radioimmunological techniques were used to assay tumour markers in order to identify neoplasms in patients with thyroid nodules at the earliest possible stage. In the 7 patients with differentiated thyroid tumours, the marker findings were within normal limits. On the basis of these results it is concluded that at the present time these markers are of no value for the early diagnosis of thyroid tumours.

Adolescent↗
PubMed1988

[Isoenzymes of serum N-acetyl-beta-D-glucosaminidase in insulin-dependent diabetic subjects].

N-acetyl-beta-D-glycosaminidase (NAG) isoenzymes were studied in 28 insulin-dependent diabetics. After electrophoretic migration isoenzyme. A levels were higher than in healthy controls. This suggests that the increase in total serum NAG in diabetics is due to a specific increase in this enzyme. A comparison of these results with those of other authors suggests that NAG alterations are specific to various pathologies.

Acetylglucosaminidase↗
PubMed1987

[Urinary NAG activity and diabetic microangiopathy].

The behaviour of urinary NAG was monitored in diabetic patients some of whom presented more or less severe vascular alterations. The results showed a relationship between urinary NAG levels and the severity of the vascular condition (in fact the greatest NAG activity was found in patients with overt kidney damage). NAG may therefore reveal the existence of a vascular nephropathy that is still too slight to be identified by the standard non-invasive clinical examinations.

Acetylglucosaminidase↗
PubMed1987

[Changes in urinary NAG activity in patients with climacteric syndrome treated with estrogens].

The behaviour of urinary NAG activity was studied in patients during menopause, some of whom were given estrogen therapy due to severe vasomotor symptoms (hot flushes etc.). One group of these patients revealed slightly higher than normal blood pressure. A second group had slight arterial hypertension and pancreatic diabetes. The third group consisted of apparently healthy menopausal women. The significant increase in enzymuria in the first two groups suggests that blood pressure should be carefully checked before starting estrogen therapy. Furthermore this treatment should be given very cautiously and under constant surveillance in the presence of slight hypertension. In patients with diabetes or more severe hypertension, estrogens should never be given.

Acetylglucosaminidase↗
PubMed1985

Microcomputer programs for the evaluation of predictable long-term exposure.

Some methods proposed for evaluation of predictable long-term exposure by statistical treatment of workshift exposure values are considered. Predictable long-term exposure is a useful parameter for risk assessment procedures, as it allows the evaluation of workplace hazards by taking into account interday variability of exposure to air contaminants. Statistical calculations required for evaluating predictable long-term exposure may be performed easily by hand-held programmable calculators. The programs reported here are for use with a Texas Instruments TI-59 hand-held programmable calculator equipped with a PC-100 C thermal printer. They are designed for users inexperienced in programming, since an interactive approach has been adopted that helps communication between user and computer.

Environmental Exposure↗
PubMed1979

Cryptorchid human testis after HCG treatment: histological study on Sertoli cells.

Histological studies have been carried out on Sertoli cells in cryptorchid patients after long-term HCG treatment. Morphological studies revealed the absence of differentiation of mature Sertoli cells. This behaviour with the persistence of fibroblast cells in the interstitium after long-term HCG treatment suggests that the morphological action of HCG on the Sertoli cells is closely correlated with the maturation of the Leydig cells, particularly with their androgen production.

Child↗
PubMed1979

Ultrastructural characteristics of idiopathic spermatidic arrest.

Previous studies on some cases of idiopathic spermatidic arrest showed an anomaly in glucose metabolism, in particular decreased utilization of glycogen at stage 3 of spermatogenesis, when condensation of the spermatid head commences. Histological patterns seen on light microscopy confirmed the reduced utilization of glycogen at stage 3 of spermatogenesis. Electron microscopy revealed an arrest at stage 3 of spermiogenesis and, at the cytoplasm level of the Sertoli cell, a modification in the smooth endoplasmic reticulum characterized by the presence of dilated cisternae. From a morphological viewpoint, the equivalent of a biochemical modification which characterizes this maturation disorder in the germinal epithelium is hypothesized.

Humans↗