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Biomedical subjects

P Ferrari

Publications and source records attributed to P Ferrari.

At least 271 records · Page 15Linked to original sources

Abnormalities of insulin and lipid metabolism in Milan hypertensive rats.

Plasma glucose, insulin, triglyceride, and cholesterol concentrations were measured in male rats of the Milan hypertensive strain (MHS) and compared to the Milan normotensive strain (MNS) of the same body weight. Both blood pressure (P less than .001) and left ventricular weight (P less than .005) were higher in rats of the MHS. Although plasma glucose concentrations were similar in both groups, mean (+/- SEM) plasma insulin concentration were significantly higher (P less than .01) in MHS as compared to MNS rats (30 +/- 4 v. 13 +/- 5 microU/mL). In addition mean (+/- SEM) plasma triglyceride concentrations were higher (P less than .01) in MHS rats (112 +/- 9 mg/dL) than in MNS rats (81 +/- 6 mg/dL), as were plasma cholesterol concentrations (114 +/- 3 v 100 +/- 2 mg/dL, P less than .001). These data demonstrate the presence of hyperinsulinemia and hypertriglyceridemia in another genetic model of rat hypertension.

Animals↗

Toxicity and activity of purified trichosanthin.

Trichosanthin was purified from fresh Chinese root tubers of Trichosanthes kirilowii and evaluated for anti-HIV activity. Trichosanthin inhibited syncytium formation between infected H9 cells and uninfected Sup-T1 cells from 0.5 to 4 micrograms/ml. Trichosanthin also inhibited HIV replication in H9 and CEM-SS cells at 1 microgram/ml, but was toxic for MT-4 cells (HTLV-I-positive), at doses greater than 0.25 microgram/ml. This new purification procedure confirms the anti-HIV activity of trichosanthin on some cell lines in different biological assays.

Amino Acids↗

Atrial natriuretic factor after cardiac surgery with cardiopulmonary bypass in children.

OBJECTIVE: To determine circulating atrial natriuretic factor (ANF) concentrations in the postoperative state and to define potential hemodynamic determinants of regional plasma ANF concentrations. DESIGN: Cohort study. SETTING: Pediatric ICU in a university hospital. PATIENTS: Twenty-two children, mean age 4.2 yrs (range 0.9 to 13.5), were studied 18 hrs after corrective surgery on cardiopulmonary bypass. The underlying cardiac malformations were ventricular septum defect (n = 5), transposition of great arteries (n = 5), tetralogy of Fallot (n = 4), pulmonary stenosis (n = 3), and miscellaneous (n = 5). INTERVENTIONS: In addition to the commonly monitored variables in postoperative cardiac patients, blood volume was estimated by the 125I albumin method, and plasma samples for radioimmunoassay determination of ANF concentrations were taken simultaneously from indwelling catheters. MEASUREMENTS AND MAIN RESULTS: Compared with normal age-matched values, plasma ANF concentrations were increased in all patients, with values tending to be highest in the left atrium, followed by systemic artery, superior vena cava, and pulmonary artery (345 +/- 158, 333 +/- 169, 311 +/- 154, and 272 +/- 160 pg/mL, respectively [mean +/- SD; NS]). Simple regression analysis demonstrated a moderate correlation between blood volume and the concentration of ANF in the superior vena cava (p less than .05). Stepwise multivariate analysis showed no significant independent predictor of plasma ANF concentrations. CONCLUSIONS: Plasma ANF concentrations are increased after open-heart surgery in children, with moderate direct correlation to blood volume. The wide scatter of increased hormone concentrations may be explained by the many factors known to influence circulating ANF concentrations, such as age, underlying disease, cardiovascular state, and drugs.

Adolescent↗

Sodium transport kinetics in erythrocytes and inside-out vesicles from Milan rats.

This paper describes the kinetics of the Na(+)-K+ pump and the Na(+)-K(+)-Cl- cotransport in sodium-loaded erythrocytes and of the Na(+)-K(+)-Cl- cotransport in erythrocyte inside-out vesicles (IOV) from Milan hypertensive (MHS) and normotensive (MNS) rats in order to evaluate the possible role of intracellular factor(s). In intact erythrocytes, no difference was detectable in the Na(+)-K+ pump kinetics between the two strains while the apparent affinity (Km) of Na(+)-K(+)-Cl- cotransport for internal sodium was significantly greater and the maximal rate of sodium transport lower in MHS when compared with MNS rats. IOV, which are depleted of cytoskeleton, showed a bumetanide-sensitive potassium- and chloride-dependent sodium uptake. However, the erythrocyte differences in Na(+)-K(+)-Cl- cotransport activity and the Km between strains disappeared in IOV, suggesting tha the altered sodium transport of MHS erythrocyte might be due to some intracellular factor or a membrane skeleton protein abnormality.

Animals↗

Postsynaptic alpha 1-blockade with terazosin does not modify insulin sensitivity in nonobese normotensive subjects.

Plasma insulin levels and the sensitivity of peripheral tissue to insulin (SI) have pathophysiological, therapeutic, and possibly also prognostic relevance. To investigate the effects of short-term selective alpha 1-adrenergic receptor blockade in nonobese normotensive humans on glucose and lipoprotein homeostasis, we assessed SI (determined by the minimal model method of Bergman), before and after glucose load plasma, glucose, and insulin levels, serum total triglycerides and lipoprotein cholesterol fractions, and some other variables in 20 healthy young men (26 +/- 1 years old, mean +/- SEM) during placebo and after 5 weeks of terazosin administration at a dose up to 10 mg once daily. Measurements were made after 3 days of standard diet (2,500 kcal/day, 45% carbohydrates, 40% fat, and 15% proteins) and after an overnight fast. Compared to placebo, terazosin decreased the upright systolic blood pressure (placebo vs. terazosin: 125 +/- 2 vs. 117 +/- 2 mm Hg, p less than 0.05) and increased supine (63 +/- 2 vs. 70 +/- 1 beats/min, p less than 0.05) and upright (77 +/- 2 vs. 88 +/- 2 beats/min, p less than 0.01) heart rates, while the body weight was unaltered. Terazosin did not significantly modify fasting plasma glucose (5.08 +/- 0.09 vs. 5.23 +/- 0.08 mmol/L, respectively), or insulin (8.9 +/- 0.5 vs. 8.6 +/- 0.6 microU/ml), SI (14.3 +/- 1.8 vs 11.8 +/- 1.5 x 10(-4)/min/microU/ml), the areas under the insulin or glucose curves, serum total triglycerides, and cholesterol or lipoprotein cholesterol fractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗

Developing essential hypertension: a syndrome involving ANF deficiency?

The pathogenesis of essential hypertension may possibly involve a deficiency in, or a decreased response to, endogenous vasodilator and natriuretic factor(s). Searching for hereditary or familial defects, it is plausible to evaluate blood pressure (BP) regulating factors in (yet) normotensive offspring of hypertensive parents (OHyp), some of whom are in fact in a stage of prehypertension. Studies by our group demonstrated that compared with healthy offspring of normotensive parents, OHyp have plasma atrial natriuretic (ANF) factor levels that are unaltered on a low salt intake but often fail to increase normally in response to a high salt intake. Plasma levels of cyclic GMP, the presumed second messenger of ANF, also may tend to be decreased in certain OHyp. On the other hand, renal excretory responses of cyclic GMP and electrolytes to ANF infused in "physiological" dose were unchanged in some OHyp tested so far. In borderline to moderate, uncomplicated essential hypertension, plasma ANF levels are often "normal." This may be inappropriately low relative to the existing BP, although the relationship of circulating ANF to atrial pressures in essential hypertension remains to be clarified. A conversion to higher plasma ANF values may occur with cardiac complications such as left ventricular hypertrophy, enlargement, dysfunction, or overt heart failure. Acute or short-term elevation of circulating ANF within the physiological and pathophysiological range by ANF infusion produces an exaggerated natriuresis and lowers BP in essential hypertensive patients. We postulate a syndrome of ANF deficiency, characterized by an impaired response of circulating ANF to high salt intake and by low cyclic GMP levels in certain yet normotensive offspring of essential hypertensive parents and by inappropriately "normal" plasma ANF in some patients with uncomplicated essential hypertension. At the stage of prehypertension, a disturbance in the ANF - cyclic GMP pathway may be expressed primarily at the circulatory rather than at the renal level. Hypertension-prone humans also tend to have an exaggerated vascular reactivity to norepinephrine. Whether the two disturbances may be interrelated is presently unknown. Both defects may potentially predispose to the development of essential hypertension. Relative ANF deficiency, an enhanced natriuretic response to ANF, and a sustained antihypertensive effect of infused ANF may represent a rational basis for treatment of essential hypertension with agents that activate the ANF system.

Animals↗

Endocrine response determines the clinical outcome of pulsatile gonadotropin-releasing hormone ovulation induction in different ovulatory disorders.

To accrue systematic information in different ovulatory disorders on the precise relationship among endocrine response, clinical outcome, and the occurrence of complications, we treated 114 patients with pulsatile GnRH (2.5-5.0 micrograms, iv, every 60 min) for 187 cycles and compared them to 20 normal menstrual cycles. Thirty of these patients had primary hypogonadotropic amenorrhea (PHA; 40 cycles), 33 had other forms of hypogonadotropic hypogonadism (HH; 55 cycles), and 51 had polycystic ovary syndrome (PCOS; 92 cycles). Daily blood samples were drawn for hormone determinations. In PCOS, 50 cycles were preceded by GnRH analog suppression. PHA treatment cycles were characterized by the reestablishment of a normal endocrine pattern, almost no dose-related endocrine differences, elevated ovulatory (93%) and conception rates (23%), and no multiple pregnancies. In the HH subjects the ovulatory (91%) and pregnancy rates (31%) were high; however, while the lower GnRH dose elicited a normal endocrine pattern, the 5-micrograms dose induced excessive folliculogenesis and high estradiol levels and was associated with most of the multiple pregnancies of this study (three of four). GnRH analog suppression was successfully used to avoid recurrence of ovarian over-stimulation in two HH subjects. Finally, GnRH analog suppression in PCOS permitted normalization of the follicular phase endocrine pattern, achievement of good ovulatory (76%) and pregnancy (28%) rates, and avoidance of multiple pregnancies; however, luteal phase steroid secretion was abnormal, and the abortion rate remained elevated (43%). Obesity was associated with a reduced ovulatory rate in PCOS, but not in hypogonadotropic, subjects. Thus, we can conclude that in pulsatile GnRH ovulation induction: 1) a profound hypogonadotropic condition, whether spontaneous as in PHA or induced with GnRH analogs as in other ovulatory disorders, is associated with optimal menstrual cycle restoration, high ovulatory and conception rates, and virtually absent risks of multiple pregnancy; 2) residual hypothalamic activity in HH may be responsible for supraphysiological pituitary-ovarian stimulation and result in multiple pregnancy unless a low GnRH dose (2.5 micrograms/bolus) or GnRH analog pretreatment is employed; 3) obesity does not affect treatment outcome in hypogonadotropic patients; and 4) the high spontaneous abortion rate in PCOS may be related to corpus luteum dysfunction.

Adult↗

Antihypertensive therapy with Ca2+. Antagonist verapamil and/or ACE inhibitor enalapril in NIDDM patients.

OBJECTIVE: To assess the efficacy and tolerance of a diuretic-free antihypertensive therapy with a Ca2+ antagonist and an angiotensin-converting enzyme (ACE) inhibitor in patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: After a 2-wk washout and a 4-wk placebo phase, 47 hypertensive patients with NIDDM randomly received verapamil or enalapril alone and, if blood pressure remained elevated, both agents combined over 30 wk. RESULTS: Verapamil or enalapril alone normalized blood pressure to less than 90 mmHg diastolic in 30 patients; verapamil decreased mean +/- SE blood pressure from 159/98 +/- 3/1 to 146/87 +/- 3/2 mmHg (n = 18, P less than 0.001) and enalapril from 166/99 +/- 5/2 to 146/86 +/- 3/1 mmHg (n = 12, P less than 0.001). In 17 patients who were still hypertensive after 10 wk of monotherapy, combination of both drugs decreased blood pressure from 170/104 +/- 4/2 to 152/90 +/- 4/2 mmHg (P less than 0.001). Fasting plasma glucose, glycosylated hemoglobin, serum fructosamine, total lipids, high-density and low-density lipoprotein cholesterol, apolipoproteins A-I and B, creatinine, and urinary albumin-creatinine ratio were not significantly modified. CONCLUSIONS: In hypertensive patients with NIDDM, a diuretic-free therapy based on the Ca2+ antagonist verapamil and/or the ACE inhibitor enalapril can effectively decrease blood pressure without adversely affecting carbohydrate and lipid metabolism.

Blood Glucose↗

Central role of sodium in hypertension in diabetic subjects.

The common association between diabetes mellitus and hypertension may be promoted by several mechanisms. Patients with insulin-dependent (type I) diabetes and prone to develop nephropathy often have a familial predisposition for essential hypertension, whereas normotensive healthy offspring of nondiabetic essential hypertensive parents tend to have a reduced insulin sensitivity and increased plasma insulin levels. Na+ retention occurs as a characteristic alteration in type I or non-insulin-dependent (type II) diabetes; exchangeable body Na+ (Naex) is increased by 10% on average. This abnormality develops in the uncomplicated stage of diabetes and differentiates diabetic from nondiabetic essential hypertensive subjects. Possible Na(+)- retaining mechanisms include increased glomerular filtration of glucose leading to enhanced proximal tubular Na(+)-glucose cotransport, hyperinsulinemia (which activates several tubular Na+ transporters), an extravascular shift of fluid with Na+, and, once it occurs, renal failure. The pathogenetic role of Na+ retention in diabetes-associated hypertension is supported by positive correlations between systolic or mean blood pressure and Naex and by normalization of blood pressure after removal of excess Na+ by diuretic treatment in hypertensive diabetic subjects. The latter may also have an enhanced sensitivity of blood pressure to Na+. Plasma levels of active renin, angiotensin II, aldosterone, and catecholamines are usually normal or low in metabolically stable type I or type II diabetes. However, an exaggerated vascular reactivity to norepinephrine and angiotensin II commonly occurs already at uncomplicated stages of type I or type II diabetes. This may be a manifestation of functional (i.e., intracellular electrolytes) and/or morphological (proliferation, narrowing, and stiffening) vasculopathy. Diabetes-associated Na+ retention, vasculopathy, and a presumably inherited predisposition for both diabetes and essential hypertension may represent important complementary factors favoring the frequent occurrence of hypertension in the diabetic population.

Diabetes Mellitus, Type 1↗

Microbial de-mannosylation and mannosylation of teicoplanin derivatives.

The single components of the teicoplanin complex, glycopeptide antibiotics active against Gram-positive bacteria, can be converted in the corresponding de-mannosyl derivatives by cultures of Nocardia orientalis NRRL 2450 or Streptomyces candidus NRRL 3218. Conversely, teicoplanin aglycone and other teicoplanin de-mannosyl derivatives can be converted in the corresponding teicoplanin mannosyl derivatives by cultures of Actinoplanes teichomyceticus ATCC 31121. The biological transformation yields are approximately 40% for de-mannosylation and 90% for mannosylation. The processes allow for the preparation of gram quantities of the de-mannosyl derivatives of teicoplanin and of teicoplanin mannosyl derivatives. De-mannosyl teicoplanin and teicoplanin mannosyl-pseudoaglycone were not amenable to preparation by either acidic or basic chemical hydrolysis.

Actinomycetales↗

Antibiotic GE2270 a: a novel inhibitor of bacterial protein synthesis. I. Isolation and characterization.

A novel antibiotic, GE2270 A, was isolated from the fermentation broth of a strain of Planobispora rosea. The product was found to inhibit bacterial protein synthesis. Structural characteristics showed similarities between GE2270 A and thiazolyl peptides such as micrococcin which is known to inhibit protein synthesis by acting directly on the ribosome. Despite this similarity GE2270 A showed functional analogy to kirromycin-like antibiotics and pulvomycin, as its molecular target was found to be elongation factor Tu (EF-Tu). GE2270 A is active against Gram-positive microorganism and anaerobes and differs from the other EF-Tu inhibitors in its spectrum of antimicrobial activity.

Actinomycetales↗

Antibiotic GE2270 a: a novel inhibitor of bacterial protein synthesis. II. Structure elucidation.

GE2270 A, produced by Planobispora rosea ATCC 53773, inhibits Gram-positive bacteria and anaerobes by acting on the bacterial protein synthesis. The structure has been determined by physico-chemical methods applied to the intact molecule and to the main hydrolysis products. Characterization by UV, IR, NMR (double quantum filter COSY), acid-base ionization, elemental analysis and FAB-MS indicated that GE2270 A is a highly modified peptide having MW 1,289 and formula C56H55N15O10S6, and a weak basic function, and that it belongs to the thiazolyl peptide group of antibiotics. Acid hydrolysis yielded a main product (MW 634), responsible for the chromophoric absorption, and a number of hydrolyzed products of lower MW. 13C NMR inverse techniques and MS studies (EI, positive ion chemical ionization, and collision induced dissociation FAB-MS-MS experiments) on GE2270 A, the chromophoric compound, and the other hydrolysis products led to the complete identification of the various amino acid residues and their sequence. Two out of the six chiral centers have been determined. The structure is thought to originate from modification of a chain of 14 amino acids in a process which creates 6 thiazole rings and one pyridine. The modification process also closes the linear polypeptide to form a cyclic part with an attached side-chain. GE2270 A plausibly has a similar biosynthetic origin to that of other thiazolyl peptide antibiotics such as nosiheptide and micrococcin.

Actinomycetales↗

[Reflections on maternal techniques and the rearing of infants and young children in the Ivory Coast].

The core hypothesis of the authors is that certain particularities of the traditional bringing up of infants and young children in Côte-d'Ivoire modify its affective experiencing and therefore its libidinal organization. Ivorian breast feeding is extremely permissive, subjected to the sole wish of the child, traditionally until the age of 2. It maintains a belated mother-infant fusion in the context of intense oral satisfaction. The end of this idyllic fusion state generally is brought about brutally. When it is contemporary to the ending of carrying the child on the back, this milk weaning constitutes a true traumatic experience. The authors suggest that it functions as an "organizor" in the sense of Spitz: interdiction is concerned with access to the maternal body. The child's renouncing of possession of the mother's body thus leads him through replacement to adhere to the socialized and socializing body of the group (age group, siblings group). The main anxiety would be of abandonment as we constantly see in psychiatric clinical experience. Carrying on the back is not only an easy means of transportation of the infants. The fabric pocket which berths the infant since it is born is a privileged place of comfort, of exchange, of maturing and the authors suggest that it functions as a structuring of the body-ego of the infant. They also suggest that so gratifying a technique of back-carrying could lead to a shifting of the erogeneous zone to the body, thus making it apt to express all the richesses of the affective life. Language education is traditionally not the task of the parents but of the grand-parents and of the child community. The latter contributes to the building of a social-ego and of an identity which is defined along ethnical criteria. The enema technique is equally of interest at it is administered since birth and thereon almost daily, thus focusing the infants' interest on an erogeneous zone which in other cultures is less intensely and less early excited. Finally the authors discuss the first forms of socialization of the child after briefly recalling the importance of the lineage to which is attached the notion of the statute. The authors deal first with the social bypassing of opposition and aggression then with the notion of extended family, the roles of fathers, mothers and of the child community.(ABSTRACT TRUNCATED AT 250 WORDS)

Anxiety, Separation↗

[Epidemiological study of maternal depression as a risk factor in the developing of early childhood psychosis].

After reviewing epidemiological literature on the relationships between depression in parents and onset of a psychiatric disturbance in children as well as investigations of the interactions between a depressed mother and her infant, the authors discuss the psychoanalytical concepts of these interactions and the findings of their research. This epidemiological research is based on the assumption that depression in the mother during pregnancy and the first few months of the post-partum constitutes a risk factor for the onset of an early psychosis in the child. This research is a comparative study between a group of mothers with early onset psychotic children and a group of mothers with non patient children, the age and sex of the children in both groups being equally distributed. The methodology includes two instruments aimed at a retrospective assessment of mothers' depression: the SADS-LA questionnaire and a standardized scoring system for semi-structured interviews investigating the mother's feelings during pregnancy and early development of her baby. Results show that there is a statistically significant relationship between a major depressive condition in the mother during pregnancy and/or during the first year of the infant's life and the onset of an autism in the child. It might be that major depressive conditions starting before delivery could by themselves account for the risk. Depression in the mother therefore constitutes a risk factor for early psychosis, the relative risk being about four. This study also emphasizes particular features of the mother's depressive conditions: difficulties to accept the real child, difficulties in perceiving the infant's psychic evolution, decrease of interactive skills. The statistically significant relationship in no way points to a linear causal relationship, which hypothesis seems to be negated by the statistical findings of this research.

Child Development Disorders, Pervasive↗