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Biomedical subjects

A Ferro

Publications and source records attributed to A Ferro.

At least 73 records · Page 4Linked to original sources
PubMed1996

Permanence of skeletal changes after function regulator (FR-2) treatment of patients with retrusive Class II malocclusions.

The purpose of this study was to examine the skeletal changes produced by the Fränkel function regulator (FR-2) appliance during the treatment of patients with mandibular retrusive Class II malocclusions and to characterize the permanence of these changes in the years after treatment (5 years, on average). Data from the pretreatment, posttreatment, and long-term serial cephalograms of 14 patients who received FR-2 treatment were compared with data obtained from untreated controls and from published standards. Relative to controls, FR-2 therapy produced a statistically significant decrease in the ANB angle and an increase in the rate of mandibular growth. At the same time, no maxillary effect was noted. During the post-FR-2 period, the rate of mandibular growth showed no compensatory decline or "rebound." Instead, it was remarkably similar to that inferred from age-matched and sex-matched normative standards. The present study thus supports the conclusion that FR-2 therapy, in conjunction with a period of postfunctional fixed- or removable-appliance therapy designed to perfect the occlusion, can produce a statistically and perhaps clinically significant relative increase in mandibular length.

Case-Control Studies↗
PubMed1996

[AIDS--TB complex in Guinea Bissau: an epidemiological updating].

In Guinea Bissau, West Africa's little country, since 1989 to 1995 June the first 3091 patients with tuberculosis have been tested for HIV-1, and HIV-2 infections. During the first two years of epidemic surveillance the HIV-2 seroprevalence among tuberculotics was respectively 14.89% and 17.26%. Since 1991 it has been noticed besides an increase of seroprevalence for HIV-2 up to 20,27% in 1992, a constant increase for HIV-1 infection, associated or not with HIV-2. The Authors conclude that the epidemiologic pattern of Guinea Bissau is particularly interesting because in this country two epidemics (for HIV-1 and for HIV-2) have been followed since the beginning among tuberculotics allowing to study the natural history and epidemiologic evolution with particular accuracy.

English Abstract↗
PubMed1996

Carla's panic attacks: insight and transformation. What comes out of the 'cracks'--monsters or nascent thoughts?

The author gives an account of the analysis of a young woman suffering from severe panic attacks. He describes the initial problems of the setting and how they are progressively overcome, the emergence of highly structured psychotic nuclei and the gradual approach to the patient's splits. Whereas the panic attacks were originally attributed to the shattering of the symbiotic link, the author shows how they increasingly prove to be bound up with the activation of uncontainable emotions of hate, jealousy and anger, by which the patient feels flooded and overwhelmed, and which are evacuated in the panic attacks until it becomes possible to metabolise them, transform them and make them thinkable, at first in the here and now of the sessions and later through the discovery of the infantile roots both of their virulence and of the deficiency of the parental capacity for containment. These primitive emotions often appear in the form of 'characters' that represent split-off parts of the patient. The author shows how a significant dream about monsters emerging from cracks actually ushers in the ability to think. The paper concludes with a description of the theoretical model underlying the clinical work, which is based on Bion's idea of the transformation of protoemotions into thoughts and on Baranger & Baranger's concept of the field.

Adult↗
PubMed1995

Beta-adrenoceptor subtypes in human coronary artery: desensitization of beta 2-adrenergic vasorelaxation by chronic beta 1-adrenergic stimulation in vitro.

We previously demonstrated that right atrial strips from patients treated with beta 1-selective antagonists exhibit sensitization of beta 2-adrenergic responses in vitro. We also showed that cardiac beta 2-adrenergic sensitization can be induced in normal subjects prospectively by beta 1-blocker treatment. To determine whether such cross-talk could be induced in vitro, we studied beta-adrenoceptor-mediated vasorelaxation in deendothelialized rings of human coronary artery from patients undergoing cardiac transplantation. After incubation with 10 microM phenoxybenzamine for 1 h, concentration-effect curves were determined to norepinephrine (NE) and epinephrine (EPI), with or without 300 nM CGP 20712A (a beta 1-selective antagonist), 50 nM ICI 118551 (a beta 2-selective antagonist), or both antagonists. Both beta 1- and beta 2-adrenergic components to vasorelaxation were detected. Other rings were incubated for 16 h with either 1 microM NE (a selective beta 1-adrenoceptor agonist) or 300 nM CGP 20712A, or both. After washout, concentration-effect curves were determined to EPI in the presence of 300 nM CGP 20712A (beta 2-adrenergic responses). No differences in beta 2-adrenergic vasorelaxation were noted after prolonged incubation with either CGP 20712A or the combination of CGP 20712A and NE.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1995

A comparison of the contractile effects of 5-hydroxytryptamine, sumatriptan and MK-462 on human coronary artery in vitro.

1. MK-462 (N,N-dimethyl-2-[5-(1,2,4-triazol-1-ylmethyl)-1H- indol-3-yl]ethylamine) is a novel selective 5-HT1D-receptor agonist which in clinical trials has been shown to be an effective antimigraine agent. As angiographic studies have shown that sumatriptan (an established 5-HT1D-receptor agonist) can cause coronary artery vasoconstriction in patients, we compared the effects of MK-462 with those of 5-HT and those of sumatriptan, on isolated segments of human coronary artery in vitro. 2. Coronary arteries were obtained from explanted hearts from patients (n = 22, 2 females, 20 males, aged 21-60 years) undergoing cardiac transplantation. Endothelium-denuded ring segments of coronary artery, 2mm long were mounted in organbaths for isometric tension recording. For each arterial ring segment, a cumulative concentration-effect curve to either 5-HT, sumatriptan or MK-462 was determined. After maximal response to each agonist had been obtained, ketanserin (a 5-HT2 receptor antagonist) 0.6 microM was added to the tissue bath, followed by methiotepin (0.6 microM) and the reduction in tension produced by the addition of each antagonist was determined. 3. Out of 22 coronary arteries studied, only 10 showed any response (contraction) to 5-HT. Not all arteries which responded to 5-HT contracted in response to both sumatriptan and MK-462 (one ring from each artery being exposed to a single agonist in each case).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Vessels↗
PubMed1995

On the use of antibiotics to reduce rhizoplane microbial populations in root physiology and ecology investigations.

No straightforward method exists for separating the proportion of ion exchange and respiration due to rhizoplane microbial organisms from that of root ion exchange and respiration. We examined several antibiotics that might be used for the temporary elimination of rhizoplane bacteria from hydroponically grown wheat roots (Triticum aestivum cv. Veery 10). Each antibiotic was tested for herbicidal activity and plate counts were used to enumerate bacteria and evaluate antibiotic kinetics. Only lactam antibiotics (penicillins and cephalosporins) did not reduce wheat growth rates. Aminoglycosides, the pyrimidine trimethoprim, colistin and rifampicin reduced growth rates substantially. Antibiotics acted slowly, with maximum reductions in rhizoplane bacteria occurring after more than 48 h of exposure. Combinations of nonphytotoxic antibiotics reduced platable rhizoplane bacteria by as much as 98%; however, this was generally a reduction from about 10(9) to 10(6) colony forming units per gram of dry root mass, so that many viable bacteria remained on root surfaces. We present evidence which suggests that insufficient bacterial biomass exists on root surfaces of nonstressed plants grown under well-aerated conditions to quantitatively interfere with root nitrogen absorption measurements.

Aminoglycosides↗
PubMed1995

[Not Available].

The authors briefly report the epidemiological status of HIV-1 and HIV-2 infections among patients affected by tuberculosis in Guinea Bissau and evaluate the therapeutic follow up in 177 patients contemporarily affected by TBC and HIV-2 infection. The evaluation of the surviving times has been done according to the Kaplan-Meier curve by considering the following determinants: 1) sex; 2) sputum positive for acid-fast bacilli; 3) age range: A) 10-30 years - B) 31-45 years - C) more than 45 years. The total number days/person was 1417. The drop out was moderate. The serum prevalence for HIV-2 in patients affected by tuberculosis in Guinea Bissau is about 20% but in the last two years HIV-1 infection is increasing. There is no significant difference in the surviving curves due to the sex. Tbc-HIV-2+ patients have a longer survival than tbc-HIV-1+ patients reported by European and North America epidemiological data. The present epidemiological data were obtained in an African environment and, due to the low financial support, it was not possible to correlate them with the immunological and microbiological ones.

English Abstract↗
PubMed1994

Perinatal transmission of HIV-2 infection in malnourished children in Guinea Bissau.

Since there have been a few reports of pediatric HIV-2 infection. We therefore investigated the perinatal transmission of HIV-2 in 147 malnourished and 164 well-nourished children attending a health center in the northern part of Guinea Bissau. Specific HIV-2 antibodies were detected in 17 mothers and in 2 malnourished children, one of them with pediatric AIDS. This study demonstrates that mother to child transmission of HIV-2 infection occurs in Guinea Bissau and suggests that there is an increased likelihood of detecting HIV-2 infection in malnourished children. The high seroprevalence of HIV-2 in a rural population without known risk factors may represent a hidden threat to mother/child health.

Acquired Immunodeficiency Syndrome↗
PubMed1993

[Inguinal hernioplasty by a modified Shouldice technic. Our experience with 350 treated cases].

A statistical analysis of 340 patients operated between 1986 and 1991 for inguinal hernia using the Shouldice procedure are reported by the authors. The majority of patients (60%) treated was between 45 and 65 years old. Two-hundred-eighty-one (82%) were controlled with a mean follow-up of 30 months (range 1-6 years) and was executed with physical examination and a medical questionnaire looking for recurring factors of risk. Hundred-twenty-eight patients (45% of controls) were at the high risk, nevertheless hernia recurrences were not noticed. Postoperative course was uncomplicated in 93% of patients. Early or late loco-regional complications had an incidence of 7%. Local infections and edema were reported in 10 of 22 patients. Acute urinary retention, cephalalgia and hypotension correlated with an anesthesiologic method had an incidence of 5% (17 cases). There were no deaths was pulmonary embolisms. A review of literature was performed and compared with our work. From experience in our Division, Shouldice's hospital technique had a high reliability compared to methods utilized in the previous ten years (Bassini, McNealy, Postemskj, Mugnai-Ferrari), in terms of recurrences.

Adolescent↗
PubMed1993

[Palliative biliary-digestive bypass with a Kehr tube for neoplastic surgical cholestatic jaundice].

The authors, in some rare cases of surgical neoplastic icterus operation, had to adopt a technique of biliary-digestive bypass with prosthesis on account of the technical-anatomical and general conditions of the patients. That prosthesis has been made out of the typical Keher's duct which can be generally found in every general surgery. The above mentioned authors describe the operations they have carried out, their directions and the results of six cases which have been treated with a technique similar to Kron's.

Aged↗
PubMed1993

[Morphologic and endocrine changes in the male reproductive system after porta-caval anastomosis in rats. Experimental research].

Quantitative alterations of the sexual hormones are present in cirrhotic patients whose testicular volumes are decreased with tubular atrophy in more than 50% of cases. The authors performed an experimental study utilizing end-to-side portacaval anastomosis in the rat in order to evaluate the consequences of the complete interruption of the portal blood to the liver in the male genital system, i.e. testicular alterations, due to the missing hepatic inactivation. Forty male Sprague-Dawley rats were used for this study. Twenty rats were subjected to end-to-side porta-caval anastomosis according to Lee, 10 rats underwent sham-operation while the remaining 10 rats were utilized as negative controls. The rats were weighed and necropsied three and six months after surgery and the liver and genital organs were weighed. In rats subjected to porta-caval anastomosis loss of weight was shown, about 20 g three months after surgery and 30 g six months after surgery, while other rats (sham-operated and negative controls) showed an increase of its weight, about 60 g after three months and 80 g after six months. In rats subjected to porta-caval anastomosis the liver was hypotrophic and its weight was decreased in comparison with the control group. In the same rats testicular volumes were decreased and hypotrophic in comparison with the control groups with average length 0.5 to 1 cm, while control groups showed values of 1.7 to 2.5 cm. Testosterone levels were 0.50 ng/ml in rats subjected to porta-caval anastomosis while in control groups the levels were 2.20 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Is receptor cross-regulation in human heart caused by alterations in cardiac guanine nucleotide-binding proteins?

1. Guanine nucleotide-binding proteins (G-proteins) play a central role in signal transduction between a wide variety of cell-surface receptors and intracellular second messenger systems. Recently, we and others have demonstrated that cross-regulation can occur between a variety of G-protein-linked receptors in human heart. Chronic beta 1-adrenoceptor blockade gives rise to sensitization of beta 2-adrenoceptor and of 5HT 4-receptor responses, both of which are mediated via stimulation of adenylate cyclase through stimulatory G-proteins (Gs), and also gives rise to desensitization of muscarinic M2-receptor responses, which inhibit adenylate cyclase through inhibitory G-proteins (Gi). 2. In order to investigate whether these effects are due to quantitative changes in cardiac G-protein isoforms, we measured their abundance in right atrial appendage from patients taking or not taking beta 1-adrenoceptor antagonists, by immunoblotting. 3. Samples of right atrial appendage homogenate were subjected to SDS/PAGE, and proteins were electroblotted on to nitrocellulose membranes. These were then probed with specific anti-G protein anti-sera, and binding was revealed by means of a secondary antibody labelled with alkaline phosphatase and using a chromogenic substrate. The resulting bands were quantified by laser densitometry. 4. No quantitative differences were detected, between these two groups of patients, in the amounts of alpha-subunit of 'long' or 'short' Gs isoforms (Gs alpha L and Gs alpha S), or in the amounts of Gi 1 + 2 alpha-subunit (Gi alpha 1 + 2). Nor was any difference found in the abundance of the beta-subunit of G-proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1993

Human endothelin receptors characterized using reverse transcriptase-polymerase chain reaction, in situ hybridization, and subtype-selective ligands BQ123 and BQ3020: evidence for expression of ETB receptors in human vascular smooth muscle.

Our aim was to characterize and determine the function of endothelin (ET) receptor subtypes in human vascular tissue. Reverse transcriptase-polymerase chain reaction with nested oligonucleotide primers detected the presence of mRNA encoding both ETA and ETB receptors in the media from aorta and pulmonary and coronary arteries. In situ hybridization confirmed the presence of mRNA for both subtypes in the media of coronary arteries. Saturation binding assays using 125I-ET-1 found a single population of high-affinity ET receptors (n = three patients, +/- SEM) in aorta (Kd = 0.507 +/- 0.020 nM; Bmax = 9 +/- 4 fmol/mg protein) and pulmonary (Kd = 0.845 +/- 0.245 nM; Bmax = 15 +/- 10 fmol/mg protein) and coronary arteries (Kd = 0.141 +/- 0.020 nM; Bmax = 71 +/- 21 fmol/mg protein). Using media from coronary arteries, the ETA-selective ligand BQ123 (cyclo[D-Asp-L-Pro-D-Val-L-Leu-D-Trp]) and the ETB-selective ligand BQ3020 (Ala11,15-Ac-ET-1[6-21]) both produced biphasic competition binding curves against 125I-ET-1, confirming the presence of high- and low-affinity sites corresponding to the two subtypes: BQ123 (KdETA = 0.85 +/- 0.03 nM; KdETB = 7.58 +/- 2.27 microM; ETA/ETB, 87%:13%) and BQ3020 (KdETA = 0.22 +/- 0.04 microM; KdETB = 0.77 +/- 0.34 nM; ETA/ETB, 62%:38%). BQ123 (0.1 microM) caused a significant parallel rightward shift of ET-1-induced vasoconstriction of coronary arteries in vitro, but BQ3020 and Ala1,3,11,15-ET-1 failed to show any agonist activity when tested at concentrations of < or = 3 microM in three vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Beta 1- and beta 2-adrenoceptor-mediated relaxation in human internal mammary artery and saphenous vein: unchanged beta- and alpha-adrenoceptor responsiveness after chronic beta 1-adrenoceptor blockade.

1. We have recently reported that patients taking beta 1-adrenoceptor-selective antagonists exhibit marked sensitization of beta 2-adrenoceptor responses but unaltered beta 1-adrenoceptor responses in the heart, both in vitro and in vivo. We therefore investigated beta 1- and beta 2-adrenoceptor-mediated relaxant responses in rings of human internal mammary artery and saphenous vein without endothelium, taken from beta 1-blocked and non-beta-blocked patients undergoing coronary artery bypass graft surgery, for comparison. We also examined alpha 1-adrenoceptor-mediated contraction in these vessels, to determine whether beta 1-blockade had any cross-regulatory effect. 2. Following alpha-blockade with 10 microM phenoxybenzamine, both noradrenaline adrenaline produced concentration-dependent relaxations in both blood vessels, their effects being mediated predominantly through beta 2-adrenoceptors; a lesser beta 1-adrenoceptor component to relaxation was also found in internal mammary artery and a minor beta 1-adrenoceptor component was present in saphenous vein. No differences were found in beta 1- or in beta 2-adrenoceptor-mediated vasorelaxation between beta 1-blocked and non-beta-blocked patients. 3. Methoxamine produced concentration-dependent contractions in both blood vessels, and the potency and efficacy were not significantly different between vessels from beta 1-blocked and from non-beta-blocked patients. 4. These findings indicate that, in these tissues, which possess a relatively minor beta 1-adrenoceptor component in contrast to myocardial tissue, chronic beta 1-blocker treatment does not alter either beta 1- or beta 2-adrenoceptor responses. Likewise, in such tissues, alpha 1-adrenoceptor responses are unaffected by prior beta 1-blockade.

Adrenergic beta-Antagonists↗
PubMed1993

Beta adrenoreceptor subtype cross regulation in the human heart.

OBJECTIVES: To find out in a prospective study whether beta 1 blocker treatment causes selective beta 2 adrenoreceptor sensitisation, and to find whether such sensitisation is confined to the heart. DESIGN: A placebo controlled cross over study of two weeks of selective beta 1 blocker treatment with 10 mg of bisoprolol daily. SUBJECTS: Six healthy volunteers. OUTCOME MEASURES: Three days after stopping the 10 mg of bisoprolol or placebo, subjects underwent treadmill exercise (to measure cardiac beta 1 receptor responsiveness) and were given salbutamol injections (to measure cardiac beta 2 receptor responsiveness). Secondary end points were the responses of serum potassium, glucose, and insulin to beta 2 stimulation. RESULTS: There was no difference in exercise induced increases in heart rate, but after treatment with bisoprolol the dose of salbutamol required to increase heart rate by 40 beats/min was 1.9 micrograms/kg compared with 2.9 micrograms/kg after placebo (p < 0.005). The fall in diastolic blood pressure was not significantly different on the two occasions. Hypokalaemia induced by salbutamol, but not hyperglycaemia or hyperinsulinaemia, was enhanced after bisoprolol. CONCLUSION: This study shows that treatment with a beta 1 blocker in vivo leads to sensitisation of cardiac beta 2 adrenoreceptors but not cardiac beta 1 adrenoreceptors or vascular beta 2 receptors. This previously unrecognised form of receptor cross sensitisation in the heart may noticeably diminish the efficacy of selective beta 1 blockade in preventing arrhythmias in patients with ischaemic heart disease. These findings reopen the question of which type of beta blocker is more appropriate for such patients.

Adrenergic beta-Antagonists↗