Biomedical subjects

T Bucher

Publications and source records attributed to T Bucher.

9 recordsLinked to original sources

PubMed2006

[Aging and sexuality].

This contribution describes sexual desire, activity and satisfaction of people aged 45-91 years on the basis of an empirical study conducted in the German-speaking part of Switzerland. Sexual desire and activity diminish with age but there is a great variability. Sexual satisfaction remains stable in elderly people. Physical, hormonal and neuronal changes cause a greater vulnerability for sexual problems but relationship, psychosocial and biographical factors as well as coping strategies have a strong moderating effect. The medicalization of the sexuality of aging people is critically depicted. Recommendations for health care practitioners are given.

Age Distribution↗

PubMed2005

Kinefold web server for RNA/DNA folding path and structure prediction including pseudoknots and knots.

The Kinefold web server provides a web interface for stochastic folding simulations of nucleic acids on second to minute molecular time scales. Renaturation or co-transcriptional folding paths are simulated at the level of helix formation and dissociation in agreement with the seminal experimental results. Pseudoknots and topologically 'entangled' helices (i.e. knots) are efficiently predicted taking into account simple geometrical and topological constraints. To encourage interactivity, simulations launched as immediate jobs are automatically stopped after a few seconds and return adapted recommendations. Users can then choose to continue incomplete simulations using the batch queuing system or go back and modify suggested options in their initial query. Detailed output provide (i) a series of low free energy structures, (ii) an online animated folding path and (iii) a programmable trajectory plot focusing on a few helices of interest to each user. The service can be accessed at http://kinefold.curie.fr/.

Algorithms↗

PubMed2005

[Erectile dysfunction in men in their second half of life].

BACKGROUND: Studies to date on the prevalence of erectile dysfunction (ED) report varying results. The present study investigates the frequency and degree of ED, its determining factors as well as the help-seeking behavior of the patients. PATIENTS AND METHODS: A random sample of 628 Swiss men (mean age: 61.5 years) were examined by questionnaire regarding their sexual functioning, comorbidity, and help-seeking behavior. RESULTS: Of the respondents, 9.6% reported complete, 18.0% moderate, and 41.4% minimal ED. All grades of the disorder increased with age and correlated with somatic and psychiatric comorbidity as well as with drug intake. Only 3.2% reported having used drugs for improvement of erectile functioning. CONCLUSION: Only a small number of men suffering from ED seek the help of a doctor. Considering the efficacy of PDE5 inhibitors, objective information and competent medical counseling of ED patients are indicated.

Adult↗

PubMed2003

Prediction and statistics of pseudoknots in RNA structures using exactly clustered stochastic simulations.

Ab initio RNA secondary structure predictions have long dismissed helices interior to loops, so-called pseudoknots, despite their structural importance. Here we report that many pseudoknots can be predicted through long-time-scale RNA-folding simulations, which follow the stochastic closing and opening of individual RNA helices. The numerical efficacy of these stochastic simulations relies on an O(n2) clustering algorithm that computes time averages over a continuously updated set of n reference structures. Applying this exact stochastic clustering approach, we typically obtain a 5- to 100-fold simulation speed-up for RNA sequences up to 400 bases, while the effective acceleration can be as high as 105-fold for short, multistable molecules (<or=150 bases). We performed extensive folding statistics on random and natural RNA sequences and found that pseudoknots are distributed unevenly among RNA structures and account for up to 30% of base pairs in G+C-rich RNA sequences (online RNA-folding kinetics server including pseudoknots: http://kinefold.u-strasbg.fr).

Algorithms↗

PubMed2001

Sexuality in patients with noninvasive mechanical ventilation due to chronic respiratory failure.

In patients with chronic respiratory failure (CRF) noninvasive mechanical ventilation (NMV) improves quality of life. We studied some basic issues concerning sexuality in patients with NMV. In 383 patients with NMV for CRF (age, > 40 yr) physiologic data (lung function, blood gases, and exercise) were taken from within the 6 mo period before enrollment. The questionnaire was focused on sexuality after initiation of NMV. Of the patients, 54.3% sent back the questionnaire. NMV was used for 41.1 +/- 27.0 mo. A total of 34.1% of patients were sexually active. Compared with patients receiving NMV, control persons had a higher rate of sexual activity (84%, p < 0.0001) and masturbation rate (13 versus 40%). Sexually active patients had greater VC (2.1 versus 1.8 L), higher FEV(1) (1.4 versus 1.1 L), higher Pa(O(2)) at rest (64.0 versus 60.4 mm Hg), a higher maximal work load (72.0 versus 58.8 W), were younger, and most of them were married or had sexual partners. Changes in sexual activity after NMV initiation were reported to be as follows: "Nothing changed," 46.3%; "less active," 35.8%; "more active," 12.6%; and "fantasy increased," 10.5%. Increased sexual fantasy predominated in men. "Sexually active" patients with NMV had sexual intercourse 5.4 +/- 4.8 times per month. Sexuality in patients receiving NMV for CRF is markedly reduced compared with normal subjects. In half of the patients, sexual activity is influenced by initiation of NMV.

Analysis of Variance↗

PubMed1996

Angiographic Results and Late Clinical Outcomes Utilizing a Stent Synergy (Pre-Stent Atheroablation) Approach in Complex Lesion Subsets.

To investigate the strategy of ÒdebulkingÓ in complex lesions before stent implantation (stent synergy) to improve procedural safety and achieve optimal acute and long-term results, we reviewed our experience in 389 patients with 504 lesions undergoing a combined stent procedure (45% rotational atherectomy, 24% laser angioplasty, 20% directional atherectomy, and 11% transluminal extraction atherectomy before stent implantation). Procedural success was achieved in 94.5%, with 4% major ischemic complications (1.1% death, 1.9% Q-wave myocardial infarction, and 2.3% emergency coronary artery bypass surgery). Overall, subacute stent thrombosis occurred in 1.5% of patients. Target-lesion revascularization during follow-up was required in 9.8% of the patients. We conclude that a strategy of selective pre-stent atheroablation in complex lesion subsets results in excellent procedural outcomes with acceptable complications and favorable long-term results.

Journal Article↗

PubMed1996

Safety and efficacy of elective stent implantation following rotational atherectomy in large calcified coronary arteries.

Rotational atherectomy is an effective transcatheter therapy for calcified coronary lesions. In large (> 3-mm) calcified coronary arteries, stent implantation following rotational atherectomy may further improve acute and especially, long-term benefit. To determine the safety and efficacy of this device synergy approach, we studied 24 consecutive patients undergoing this procedure electively in native coronary arteries. Procedural success was achieved in 100% without any major ischemic complications. There was also no incidence of subacute thrombosis or cardiac event during 30-day follow-up period. Thus, we conclude that elective stent implantation following rotational atherectomy in large, calcified coronary arteries is safe and results in excellent clinical benefit up to 30 days.

Aged↗

PubMed1985

Analysis of the cardiovascular effects of co-derocrine (Hydergine).

The antihypertensive effect of co-dergocrine (Hydergine) has previously been thought to be due to alpha-adrenoceptor blockade and/or an action exerted in the CNS. The present experiments do not support this view. The doses necessary to inhibit vasoconstrictor responses to phenylephrine and noradrenaline by 50% in anaesthetized cats and dogs are 10-50 times that which lowers blood pressure in these species by 30 mmHg. Despite the fact that co-dergocrine is a potent alpha-adrenoceptor antagonist in isolated tissues (pA2: 8.4-9.4), its activity in vivo is too weak to contribute significantly to its effect on blood pressure. Slow intravertebral artery infusion of 10 micrograms/kg co-dergocrine produces a smaller blood pressure fall in the dog than intravenous infusion of the same dose. The reverse is true for the centrally-acting alpha 2-adrenoceptor stimulant, guanfacine. In addition, efferent splanchnic nerve activity in the cat is not affected by doses up to 100 micrograms/kg i.v. The dose of co-dergocrine depressing nerve activity by 50% is approximately 900 micrograms/kg; the dose of clonidine producing comparable inhibition is 3.4 micrograms/kg i.v. Since falls in blood pressure and heart rate can be obtained with co-dergocrine at a dose of only 10 micrograms/kg i.v., a central action cannot be considered to play a role in the cardiovascular effects of the drug in response to acute administration. Heart rate increases evoked by stimulating the accelerans nerve of ganglion-blocked cats are inhibited dose-dependently by co-dergocrine from a dose of 1 microgram/kg i.v. The drug also depresses pressor responses to stimulation of the lumbar sympathetic outflow in pithed rats. Both effects are prevented by pretreatment with the dopamine receptor antagonist, sulpiride (300 micrograms/kg). Intravenous administration of 10 micrograms/kg co-dergocrine depresses pressor responses to a psychological stimulus or raising the forequarters in conscious dogs, and produces marked falls in blood pressure and heart rate in anaesthetized, baroreceptor-denervated dogs. These effects are also abolished by sulpiride. It is concluded that the cardiovascular responses to acute administration of low doses of co-dergocrine are due to stimulation of prejunctional dopamine receptors.

Adrenergic alpha-Antagonists↗

PubMed1982

Assignment of phosphoglycerate mutase (PGAMA) to human chromosome 10. Regional mapping of GOT1 and PGAMA to subbands 10q26.1 (or q25.3).

Human phosphoglycerate mutase (PGAM, EC 2.7.5.3) is under the control of two structural loci that code for subunits A and B. By means of gene-dosage studies, Bücher et al. (1980) have assigned the loci for GOT1 and PGAMA to chromosome 19 of Mus musculus. Because of the known homologies between human and murine chromosomes, gene dosage studies were carried out in erythrocytes from one patient trisomic for the entire band 10q26 and from another patient monosomic for 10q26.2 and q26.3. Results were compatible with the assignment of PGAMA and GOT1 to 10q26.1 (or 10q25.3).

Aspartate Aminotransferases↗