PubMed Health⌕ Search

Biomedical subjects

T Buller

Publications and source records attributed to T Buller.

8 recordsLinked to original sources
PubMed2003

Percutaneous fetoscopic tracheal balloon occlusion in sheep.

BACKGROUND: In order to minimize maternal trauma from current techniques for temporary fetoscopic tracheal occlusion, we tried to develop a percutaneous fetoscopic technique in sheep. METHODS: In nine ewes between 77 and 128 days of gestation, the amniotic cavity was entered percutaneously. Each fetus was positioned and the feasibility of fetal laryngoscopy and percutaneous fetoscopic tracheal balloon occlusion was assessed. RESULTS: Percutaneous intraamniotic access, fetal positioning, oropharyngeal sheath insertion, and fetoscopic laryngoscopy were achieved in all nine fetal sheep. Following some technical modifications to the working channel of the fetoscope, percutaneous fetoscopic tracheal balloon occlusion was successfully achieved in the last seven sheep. CONCLUSION: Percutaneous fetoscopic balloon occlusion of the fetal trachea can effectively and safely be achieved in sheep. Because intraamniotic spatial relationships, fetal position, and umbilical cord length are technically less favorable in sheep, our operative techniques might be feasible in humans even if difficult intraamniotic conditions are encountered.

Animals↗
PubMed2003

Percutaneous fetoscopic patch coverage of experimental lumbosacral full-thickness skin lesions in sheep.

BACKGROUND: In order to minimize maternal trauma from open fetal surgery for prenatal coverage of fetal myelomeningoceles in humans, we assessed the feasibility of a percutaneous fetoscopic approach in sheep. METHODS: In seven ewes between 90 and 100 days of gestation, the amniotic cavity was entered percutaneously. Each fetus was postured and a full-thickness skin lesion was created in the lumbosacral region. Then, the feasibility of covering this lesion with a patch and fetal skin by standard endoscopic suturing techniques (n = 3) or robot assistance (n = 4) was assessed. RESULTS: Percutaneous fetoscopic patch and skin coverage of the full-thickness skin lesion was achieved in six of the seven fetal sheep. Five fetuses survived gestation and were delivered healthy. CONCLUSIONS: Percutaneous fetoscopic posturing and patch coverage of lumbosacral full-thickness skin lesions can effectively and safely be achieved in sheep. This approach promises to provide a substantial reduction of maternal trauma from fetal surgery for myelomeningoceles.

Animals↗
PubMed2001

Multimodal fetal transesophageal echocardiography for fetal cardiac intervention in sheep.

BACKGROUND: The overall performance of available mechanical intravascular ultrasound catheters for fetal transesophageal echocardiography during fetoscopic fetal cardiac interventions in sheep has been limited by radioelectronic interference, low system frame rates, and low acoustic outputs. Therefore, a more reliable device is desired for human fetoscopic surgical procedures. METHODS AND RESULTS: We assessed the potential of a newly available 10-French phased-array intravascular ultrasound catheter for multimodal fetal transesophageal echocardiography in 5 fetal sheep between 78 and 98 days of gestation (term, 145 to 150 d). The intravascular ultrasound catheter was easily inserted through the mouth into the esophagus in all 5 sheep fetuses (mean weight, 600 g), and it permitted high-quality 2D imaging of the fetal heart in vertical imaging planes that were validated by MRI. Color Doppler and pulsed Doppler imaging permitted clear assessment of fetal cardiovascular flows and recording of velocity-time integral tracings of the fetal heart and great vessels. The vertical imaging planes were particularly useful to demonstrate interventional material inside the fetal heart and great vessels. CONCLUSIONS: Our early experience with the phased-array intravascular ultrasound catheter indicates that multimodal fetal transesophageal echocardiography has now become possible in these smallest of patients.

Animals↗
PubMed2001

Competence and risk-relativity.

In this paper I discuss the view that the appropriate concept of competence is a decision-relative one: that a person may be competent to make one decision but not another. The argument that I present is that neither of the two competing theories supporting the decision-relative approach, internalism and externalism, can provide a coherent explanation of why a person's competence should be thought to be relative to a particular decision. On the one hand, internalism, which regards competence as exhaustively a matter of the person's understanding, fails to identify the specific skills or content that would warrant linking a specific decision with competence, and thus cannot provide an account of decision-relative that parallels task-relative. On the other hand, externalism, which regards competence as a matter of the person's understanding in relation to external elements such as risk, cannot adequately defend why a person's competence to make a decision should 'track' the level of probable harm that results from the decision.

Cognition↗
PubMed1993

[Accident risk in epilepsy].

Patients with seizures without daytime preference are highly jeopardized by accidents. The majority of seizure-related accidents occurred in the household. All household accidents lead to injuries. Therefore, household activities carry the highest risk. Traffic-related accidents were also common but severe injuries occurred less frequently. Car drivers had only property damages. Only one third of all car drivers were seizure-free for two years. Accidents while working or exercising occurred very infrequently, hence indicating no increased risk at work of sports (N = 104 patients).

Accident Prevention↗
PubMed1990

Overt attempts to change hand preference: a study of group and individual characteristics.

Previous work by Porac, Coren, and Searleman (1986) looked at overt attempts to change hand preference from the left to the right side. We extended this research by studying individuals who shifted their handedness from the left to the right side as well as a group who attempted a shift in the opposite direction (right to left). Comparisons of the two shift attempts revealed that the timing, method, and agent of change differed significantly for right versus left shifts. More right than left shifts were successful. Overall, most shift attempts were rated as unsuccessful because they did not result in a handedness classification consistent with the direction of the shift. Individuals classified as successful shifters, whether in the right or left direction, displayed a more ambihanded behavioural pattern than either unsuccessful shifters or the no shift control group. Evidence suggested that left-shift attempts were promoted by original ambihanded tendencies but that ambihandedness in successful right shifts stemmed from the partial success of the switch attempt.

Adult↗
PubMed1990

Comparison of Dolichos biflorus lectin and other lectin-horseradish peroxidase conjugates in staining of cutaneous blood vessels in the hairless mini-pig.

Angiogenesis is necessary for normal growth, wound healing, and plays a key role in many pathologic processes. A variety of endothelial markers have been used to investigate angiogenesis. Unfortunately, excellent markers for vascular endothelium in human tissues exhibit little or no staining of endothelia in tissues of other animal species, including the pig. We are interested in the hairless Yucatan strain of mini-pig as an animal model for studying cutaneous wound healing because its skin is histologically and functionally very similar to that of man. Hoping to find a specific marker to identify vascular endothelium in the mini-pig, we therefore screened a battery of 11 different lectin-horseradish peroxidase conjugates. Based on specificity and staining intensity, Dolichos biflorus agglutinin (DBA) was chosen from this battery to investigate vascular changes in the healing of cutaneous wounds in the mini-pig. When compared with routine histologic sections stained with hematoxylin and eosin, blood vessels were much easier to identify in sections stained histochemically with DBA. Lectin histochemistry was particularly useful in investigations of early events in angiogenesis during wound healing when newly derived capillary buds and minute blood vessels were obscured in normal histologic sections by an inflammatory cell infiltrate associated with the healing wound. Ultrastructural lectin cytochemistry revealed staining along the luminal surface and the basolateral plasmalemma of endothelial cells. Histochemical staining with DBA promises to provide a useful method for further investigation of angiogenesis and other vascular phenomena in a variety of normal and pathologic processes using the hairless Yucatan strain of mini-pig as the animal model.

Animals↗