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.

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.

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.

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.

An In vitro microbial-caries model used to study the efficacy of antibodies to Streptococcus mutans surface proteins in preventing dental caries.

The first step for a pathogenic bacterium to initiate infection is via attachment (i.e., through surface determinants) to a suitable receptor. An in vitro microbial artificial-mouth model was used to test the efficacy of polyclonal antibodies to Streptococcus mutans cell surface proteins (CsAb) and a cell surface 59-kDa protein (59Ab) in preventing S. mutans colonization and carious lesion formation. In study 1, groups of 12 human teeth specimens were inoculated with S. mutans, which were incubated with different concentrations of CsAb (A1 [positive control], sterile saline, no antibody; A2, 0.007 mg of antibody protein/ml; and A3, 0.7 mg of antibody protein/ml) for 1 h at 37 degrees C. The negative control group (B1) was not infected and was incubated with Trypticase soy broth (TSB) without dextrose supplemented with 5% sucrose (TSBS). In study 2, the same study design was used except that 59Ab was used instead of CsAb, normal rabbit serum was used in the positive control group (A1), and TSB supplemented with 1% glucose was used as the nutrient to control for sucrose-dependent colonization. All groups were exposed for 4 days to circulating cycles of TSBS and TSB (study 1 and study 2, respectively; 30 min each, three times per day) and a mineral washing solution (21 h per day). Prior to each nutrient cycle, 1 ml of the appropriate CsAb or 59Ab solution was administered to each group and allowed to mix for 30 min before cycling was resumed. Data obtained by confocal laser scanning microscopy demonstrated the presence of a significantly smaller (P < 0.05) lesion area and a smaller total lesion fluorescence in group A3 than in group A1 for both studies. In study 1, group A2 had significantly smaller values than A1 for lesion depth and area. There were no significant differences between groups A2 and A3 for lesion area or between groups A1 and A2 for total lesion fluorescence. In study 2, there were no significant differences among groups A1 and A2 for lesion depth or between groups A2 and A3 for all of the parameters studied. In both studies, there were no significant differences between S. mutans plaque CFU numbers among any of the groups. These studies demonstrated the efficacy of CsAb and 59Ab in reducing primary caries development in this model, although the underlying mechanism remains unclear.

Interactions of Streptococcus mutans fimbria-associated surface proteins with salivary components.

Streptococcus mutans has been implicated as the major causative agent of human dental caries. S. mutans binds to saliva-coated tooth surfaces, and previous studies suggested that fimbriae may play a role in the initial bacterial adherence to salivary components. The objectives of this study were to establish the ability of an S. mutans fimbria preparation to bind to saliva-coated surfaces and determine the specific salivary components that facilitate binding with fimbriae. Enzyme-linked immunosorbent assay (ELISA) established that the S. mutans fimbria preparation bound to components of whole saliva. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot techniques were used to separate components of whole saliva and determine fimbria binding. SDS-PAGE separated 15 major protein bands from saliva samples, and Western blot analysis indicated significant binding of the S. mutans fimbria preparation to a 52-kDa salivary protein. The major fimbria-binding salivary protein was isolated by preparative electrophoresis. The ability of the S. mutans fimbria preparation to bind to the purified salivary protein was confirmed by Western blot analysis and ELISA. Incubation of the purified salivary protein with the S. mutans fimbria preparation significantly neutralized binding of the salivary protein-fimbria complex to saliva-coated surfaces. The salivary protein, whole saliva, and commercial amylase reacted similarly with antiamylase antibody in immunoblots. A purified 65-kDa fimbrial protein was demonstrated to bind to both saliva and amylase. These data indicated that the S. mutans fimbria preparation and a purified fimbrial protein bound to whole-saliva-coated surfaces and that amylase is the major salivary component involved in the binding.

[Accident risk in epilepsy]. / Unfallrisiko bei Epilepsien.

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).

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.

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.

Natural history of androgenetic alopecia.

Twenty-two men with patterns III-Va androgenetic alopecia were entered into a 10-month study aimed at establishing information on the natural progression of hair loss over a period of time typical of studies of hair growth promoters. The methodology employed was the same as that in published clinical trials of topical minoxidil, but the men refrained from application of either active drug or vehicle to their scalps. As one of the potential explanations for the observed 'placebo-effect' seen in non-vellus hair counts in the topical minoxidil trials was a learning curve of novice hair counters, we were particularly interested in evaluating this in our 'no-treatment' trial. To that end, both a novice (Observer I) and an experienced (Observer II) hair counter independently performed the hair counts. There was a mean decline in the number of vertex target area non-vellus hairs (-17.2 +/- 80.3 for Observer I and -26.6 +/- 63.5 for Observer II) at the end of 10 months; this was not significant. The novice's hair counts were lower than the experienced observer's counts at baseline, and the difference remained relatively constant during the study. Without the application of a placebo, there was no increase in hair growth, making it unlikely that the methods of hair counting led to the 'placebo-effect' seen in prior topical minoxidil studies.