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Biomedical subjects

D Wyss

Publications and source records attributed to D Wyss.

At least 19 recordsLinked to original sources
PubMed2006

Is restricted femoral navigation sufficient for accuracy of total knee arthroplasty?

A total knee arthroplasty performed with navigation results in more accurate component positioning with fewer outliers. It is not known whether image-based or image-free-systems are preferable and if navigation for only one component leads to equal accuracy in leg alignment than navigation of both components. We evaluated the results of total knee arthroplasties performed with femoral navigation. We studied 90 knees in 88 patients who had conventional total knee arthroplasties, image-based total knee arthroplasties, or total knee arthroplasties with image-free navigation. We compared patients' perioperative times, component alignment accuracy, and short-term outcomes. The total surgical time was longer in the image-based total knee arthroplasty group (109 +/- 7 minutes) compared with the image-free (101 +/- 17 minutes) and conventional total knee arthroplasty groups (87 +/- 20 minutes). The mechanical axis of the leg was within 3 degrees of neutral alignment, although the conventional total knee arthroplasty group showed more (10.6 degrees ) variance than the navigated groups (5.8 degrees and 6.4 degrees , respectively). We found a positive correlation between femoral component malalignment and the total mechanical axis in the conventional group. Our results suggest image-based navigation is not necessary, and image-free femoral navigation may be sufficient for accurate component alignment.

Aged↗
PubMed2004

Effect of a novel NK1 receptor selective antagonist (NKP608) on citric acid induced cough and airway obstruction.

The effects of an orally administered novel and selective NK1 antagonist, NKP608, on cough and airway obstruction, induced by citric acid in guinea pigs, were investigated. Guinea pigs were pre-treated with 0.03, 0.3 and 1 mg kg(-1) of NKP608, the NK2 antagonist, SR48968 or both 2 h prior to challenge with citric acid (0.6 M) for a 10 min period. Guinea pigs pre-treated with 0.03, 0.3 and 1mgkg(-1) of NKP608 exhibited a significant reduction of 77, 74 and 79%, respectively, in the numbers of cough compared to vehicle pre-treated animals (P<0.05). SR48968, 10 mg kg(-1), alone did not significantly affect the citric acid-induced cough but when co-administered with 1 mg kg(-1) of NKP608, there was a significant 90% reduction in cough. NKP608 did not significantly reduce the citric acid-induced increase in Penh at any of the doses used. SR48968 significantly reduced the citric acid induced airway obstruction by about 50%. However, when SR48968 was co-administered with NKP608, there was a greater (73%) decrease in the airway obstruction compared with SR48968 alone. These data show that NKP608, a selective NK1 receptor antagonist, is a potent inhibitor of citric acid induced cough in guinea pigs and may therefore have value in the therapy of clinical cough.

Airway Obstruction↗
PubMed2002

Kinetics of airway hyperresponsiveness and airway eosinophilia in BALB/c mice and their modulation by different dexamethasone treatment regimens.

The mechanisms of airway hyperresponsiveness (AHR) are still poorly understood. In this study we have established a model of persistent AHR and eosinophilia and evaluated the prophylactic vs. therapeutic effects of dexamethasone on these parameters. Mice were immunised with ovalbumin (OVA) on day 0 and challenged intranasally on days 10, 11, 12 and 13 with OVA or phosphate buffer saline (PBS). Airway responsiveness to methacholine, measured 24-h post multiple intranasal OVA challenges, was significantly increased compared to time matched PBS-controls (P<0.05). AHR could be detected for up to 14 days after the last OVA challenge although the magnitude of the AHR had diminished by day 14 compared to day 1. OVA challenge of mice induced a significant airway eosinophilia at 24h (P<0.05); this persisted for 2 weeks after the challenge. Prophylactic treatment with dexamethasone (1mg x kg (-1)) reduced the OVA induced AHR, eosinophilia and mucus cell hyperplasia/metaplasia measured 24h post challenge. Therapeutic treatment, with dexamethasone (2 mg x kg(-1)), significantly inhibited established airway eosinophilia, measured at 72 h post OVA challenge, only when treatment was initiated at 24h but not 48 h after challenge. In contrast, AHR measured at 72 h post OVA challenge was significantly reduced when treatment was started at either 24 or 48 h post challenge. Our data shows that the immunization and challenge procedures employed resulted in a persistent type of AHR. Prophylactic intervention with steroids almost completely inhibited its development; however therapeutic intervention only partially resolved AHR.

Animals↗
PubMed2000

Farm and slaughter survey of bovine tuberculosis in captive deer in Switzerland.

In 1998, a survey was conducted by postal questionnaire to gather basic knowledge about the management, health and productivity of captive deer in Switzerland. In addition, lymph nodes were collected from slaughtered deer from 124 of the 262 holdings surveyed, and tested for Mycobacterium bovis and Mycobacterium tuberculosis. The total farmed deer population was 8389 animals kept on 485 holdings; 87 per cent were fallow deer, 8 per cent red deer, 4 per cent sika deer, and there were small numbers of other species. The median herd sizes were 12 for fallow deer and eight for red deer. Few owners had handling facilities or crushes. In none of the lymph nodes examined were lesions typical of bovine tuberculosis observed, and neither M bovis nor M tuberculosis was cultivated from any of the samples.

Animal Husbandry↗
PubMed2000

[Sexual counseling during medical consultation with adolescents].

Family planning has been included in the activities of the Multidisciplinary Unit for Adolescent Health, from its opening. The patients can meet the counsellor for pure information; more often, they discuss many issues related to their personal and sexual life, to contraception or pregnancy, to fertility or sexually transmitted diseases, including HIV. All discussions take into account the developmental tasks of the adolescent as well as his cultural/ethnic background. The originality of this approach is that it is widely integrated in the activities of the Unit. For instance, specific situations and issues are regularly discussed during weekly multidisciplinary meetings bringing all the members of the staff together.

Adolescent↗
PubMed1998

New aza-dipeptide analogues as potent and orally absorbed HIV-1 protease inhibitors: candidates for clinical development.

On the basis of previously described X-ray studies of an enzyme/aza-dipeptide complex,8 aza-dipeptide analogues carrying N-(bis-aryl-methyl) substituents on the (hydroxethyl)hydrazine moiety have been designed and synthesized as HIV-1 protease inhibitors. By using either equally (12) or orthogonally (13) protected dipeptide isosteres, symmetrically and asymmetrically acylated aza-dipeptides can be synthesized. This approach led to the discovery of very potent inhibitors with antiviral activities (ED50) in the subnanomolar range. Acylation of the (hydroxethyl)hydrazine dipeptide isostere with the L-tert-leucine derivative 29 increased the oral bioavailability significantly when compared to the corresponding L-valine or L-isoleucine derivatives. The bis(L-tert-leucine) derivatives CGP 75355, CGP 73547, CGP 75136, and CGP 75176 combine excellent antiviral activity with high blood concentration after oral administration. Furthermore, they show no cross-resistance with saquinavir-resistant strains and maintain activity against indinavir-resistant ones. Consequently they qualify for further profiling as potential clinical candidates.

Administration, Oral↗
PubMed1998

Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure.

Obesity is associated with blunted GH secretion, unfavorable body composition, and increased cardiovascular mortality. The objective of this study was to investigate the effects of oral treatment with the GH secretagogue MK-677 on GH secretion and body composition in otherwise healthy obese males. The study was randomized, double blind, parallel, and placebo controlled. Twenty-four obese males, aged 18-50 yr, with body mass indexes greater than 30 kg/m2 and waist/hip ratios greater than 0.95, were treated with MK-677 25 mg (n = 12) or placebo (n = 12) daily for 8 weeks. Serum insulin-like growth factor I (IGF-I) increased approximately 40% with MK-677 treatment (P < 0.001 vs. placebo). Serum IGF-binding protein-3 was also significantly increased (P < or = 0.001 vs. placebo). GH and PRL (peak and area under the curve values) were significantly increased after the initial dose of MK-677. Significant increases, with the exception of peak PRL, persisted at 2 and 8 weeks of treatment. The increases in GH and PRL after the initial dose were significantly greater than the increase seen after multiple doses. Serum and urinary concentrations of cortisol were not increased at 2 and 8 weeks (P = NS, vs. placebo). Fat-free mass increased significantly in the MK-677 treatment group when determined with dual energy x-ray absorptiometry (P < 0.01) or using a four-compartment model (P < 0.05). Total and visceral fat were not significantly changed with active therapy. The basal metabolic rate was significantly increased at 2 weeks of MK-677 treatment (P = 0.01) but not at 8 weeks (P = 0.1). Fasting concentrations of glucose and insulin were unchanged, whereas an oral glucose tolerance test showed impairment of glucose homeostasis at 2 and 8 weeks. We conclude that 2-month treatment with MK-677 in healthy obese males caused a sustained increase in serum levels of GH, IGF-I, and IGF-binding protein-3. The effects on cortisol secretion were transient. Changes in body composition and energy expenditure were of an anabolic nature, with a sustained increase in fat-free mass and a transient increase in basal metabolic rate. Further studies are needed to evaluate whether a higher dose of MK-677 or a more prolonged treatment period can promote a reduction in body fat.

Adult↗
PubMed1998

Treatment with the oral growth hormone secretagogue MK-677 increases markers of bone formation and bone resorption in obese young males.

The effect of 2 months of treatment with the oral growth hormone (GH) secretagogue MK-677 on markers of bone metabolism was determined in healthy obese male subjects. This was a randomized, double-blind, parallel, placebo-controlled study. Twenty-four healthy obese males, 19-49 years of age, with body mass index > 30 kg/m2 were treated with MK-677 (25 mg/day; n = 12) or placebo (n = 12) for 8 weeks. MK-677 increased markers of bone formation; a 23% increase in the carboxy-terminal propeptide of type I procollagen levels and a 28% increase in procollagen III peptide levels were seen with as little as 2 weeks of MK-677 treatment (p < 0.01 and p = 0.001 vs. placebo, respectively) while a 15% increase in serum levels of osteocalcin was not detected until 8 weeks of treatment (p < 0.01 vs. placebo). Markers of bone resorption were induced within 2 weeks of treatment with MK-677; serum levels of the carboxy-terminal cross-linked telopeptide of type I collagen were increased 26% at 8 weeks (p = 0.001 vs. placebo), and urine hydroxyproline/creatinine and calcium/creatinine ratios at 8 weeks were increased by 23% (p < 0.05 vs. placebo) and 46% (p < 0.05 vs placebo), respectively, MK-677 increased serum insulin-like growth factor binding protein-5 (IGFBP-5) by 43-44% after 2-8 weeks of treatment (p < 0.01 vs. placebo). Serum IGFBP-4 was increased by 25% after 2 weeks of treatment (p < 0.001 vs. placebo) but no significant change from baseline was observed after 8 weeks of treatment. Plasma interleukin-6 was not significantly changed by active treatment. In conclusion, short-term treatment of healthy obese male volunteers with the GH secretagogue MK-677 increases markers of both bone resorption and formation. Large increases in serum levels of IGF-1 and IGFBP-5 and a transient increase in serum IGFBP-4 were found. Future long-term studies are needed to investigate if prolonged treatment with MK-677 increases bone mass.

Administration, Oral↗
PubMed1993

[Changes in indications for obstetric peridural anesthesia in our clinic].

In relation to the Swiss average our hospital has had a constant high rate of spontaneous deliveries and a low rate of cesarean sections. On the other hand the rate of obstetrical peridural anesthesia has been increasing significantly since 1986. This is above all related to its more frequent usage in cases of cervical dystocia and intolerable birth pain. Exactly in these indications peridural anesthesia has been very successful. In almost three quarters of the above-mentioned cases a cesarean section can be avoided due to peridural anesthesia.

Adult↗
PubMed1993

[Importance of chaos research for psychosomatic medicine].

After a critical review of the many unsettled questions in psychosomatic medicine the author emphasizes the importance of the results of the so-called-research in mathematics, physics, biology and internal medicine. He developed various models for a deeper understanding not only of health and sickness but specially of the body/soul-problem and demonstrates the importance and fertility of the chaos-investigation for the psychosomatic medicine.

Humans↗
PubMed1992

Detrimental effect of alcohol intoxication on severity of injuries in male traffic accident victims: a cross-sectional study.

A cross-sectional emergency room study was performed among traffic accident victims aged 16 to 75 years in order to investigate the prevalence of alcohol intoxication (blood alcohol concentration (BAC greater than or equal to 0.8 g/kg) and its potential detrimental effect on injury severity. A BAC greater than or equal to 0.8 g/kg was present in 29% of the male patients. Intoxicated patients had a similar propensity to require inpatient hospital care (65 versus 60%) but had significantly longer hospital stays than the non-intoxicated patients (36 versus 20 days; p less than 0.05), observations which may be explained by the higher prevalence of serious injuries (head and internal injuries) among the intoxicated cohort. This study supports and emphasizes the detrimental effect of alcohol intoxication on the severity of injuries in traffic accident victims, and reinforces the need for further legal and public health measures in preventing alcohol-related traffic accidents.

Accidents, Traffic↗
PubMed1990

Characteristics of 167 consecutive traffic accident victims with special reference to alcohol intoxication: a prospective emergency room study.

This prospective study examined the characteristics of 167 consecutive traffic accident victims admitted to the emergency room of a major Swiss hospital with particular attention to the presence of a detectable blood alcohol concentration (BAC). The majority of the study population were male (71%), 16-29 years of age (56%) and occupants of an automobile or motorcycle (70%). Most patients were injured during the daytime, with nighttime accidents increasing towards the end of the week. Seventy-five percent of the injured were drivers of the crash vehicle and the majority (56%) were involved in multi-vehicle accidents. Fifty-three percent of all injuries consisted of internal lesions and/or fractures with motorcyclists and pedestrians being the most severely injured. There was a 21% incidence of alcohol intoxication (BAC greater than = 0.8 g/kg); 97% of intoxicated patients were male, of which 38% were 16-29 years of age. There was a distinct age-related alcohol intoxication pattern among males, with an intoxication rate of 20% in the 16-29 age range and 40% in the 30-75 age range. Alcohol-related accidents occurred predominantly in the nighttime and towards the end of the week, and victims of single-vehicle crashes were more likely to be intoxicated (28%) than those injured in multi-vehicle crashes (17%). Moped drivers exhibited the highest rate of intoxication (45%) followed by pedestrians (42%). Our study confirms the high prevalence of acute alcohol intoxication among traffic accident victims in Switzerland, a fact which needs to be considered by the treating medical care providers for the early detection and referral of alcohol-related problems, and which should be limited by effective preventive measures.

Accidents, Traffic↗
PubMed1988

Parents' reactions to sex education in the primary school.

This study presents the reactions of parents to a sex education course offered in the Geneva public schools to children aged approximately 10 years. The following points are discussed: (1) parents' reactions to the meeting at which they are informed of the course's content; (2) parents' attitudes concerning the sex education of their children, and (3) parents' viewpoints of the children's reactions following the course. Based on the 100 first replies, the analysis shows that for a very large proportion of parents, the course, considered as a complement to their more or less frequent familial discussions on this subject, corresponds well to the developmental and psychological levels of their children and that it makes further discussion easier.

Attitude↗
PubMed1985

[Significance of speech hermeneutics of E. Biser for medical and psychological anthropology].

The author investigates the significance of E. Bisers linguistic hermeneutics in their relevance for a medical and psychological anthropology. A short review on modern trends in linguistic research reveals E. Bisers outstanding importance for linguistics as he emphasizes language beyond any objective-subjective discrepancy, constituting human relations, and establishing as well as discovering the relationship between language, truth and reality. By this procedure the existencial basis of language is become manifest in its fundamental importance for any anthropological research.

Anthropology, Cultural↗