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At least 1,423 records · Page 79Linked to original sources
PubMed2006

Management of pseudoaneurysms in the intracranial segment of the internal carotid artery with covered stents specially designed for use in the intracranial vasculature: technical notes.

Vascular diseases like aneurysms, pseudoaneurysms and direct high-flow carotid-cavernous fistulas on the intracranial segment of the internal carotid artery are usually managed through transarterial embolization with detachable coils or balloons. Utility of covered stents has been reported with good results in the treatment of selective cases. But the current generation of covered stents for coronary use is rather stiff and difficult to navigate in tortuous vessels particularly in the intracranial vasculature. Herein, we report on the use and technical respects of balloon-expanded covered stents specially designed for intracranial vasculature in the treatment of two pseudoaneurysms secondary to the successful obliteration of direct CCFs on the intracranial segment of the internal carotid artery. This is the first report of covered stents specially developed for use in intracranial vasculature.

Adult↗
PubMed2006

Species-specific population structure in rock-specialized sympatric cichlid species in Lake Tanganyika, East Africa.

Species richness and geographical phenotypic variation in East African lacustrine cichlids are often correlated with ecological specializations and limited dispersal. This study compares mitochondrial and microsatellite genetic diversity and structure among three sympatric rock-dwelling cichlids of Lake Tanganyika, Eretmodus cyanostictus, Tropheus moorii, and Ophthalmotilapia ventralis. The species represent three endemic, phylogenetically distinct tribes (Eretmodini, Tropheini, and Ectodini), and display divergent ecomorphological and behavioral specialization. Sample locations span both continuous, rocky shoreline and a potential dispersal barrier in the form of a muddy bay. High genetic diversity and population differentiation were detected in T. moorii and E. cyanostictus, whereas much lower variation and structure were found in O. ventralis. In particular, while a 7-km-wide muddy bay curtails dispersal in all three species to a similar extent, gene flow along mostly continuous habitat appeared to be controlled by distance in E. cyanostictus, further restricted by site philopatry and/or minor habitat discontinuities in T. moorii, and unrestrained in O. ventralis. In contrast to the general pattern of high gene flow along continuous shorelines in rock-dwelling cichlids of Lake Malawi, our study identifies differences in population structure among stenotopic Lake Tanganyika species. The amount of genetic differentiation among populations was not related to the degree of geographical variation of body color, especially since more phenotypic variation is observed in O. ventralis than in the genetically highly structured E. cyanostictus.

Animals↗
PubMedDate not supplied

Changes in perceived health of children with congenital heart disease after attending a special sports camp.

Sports camps for children with cardiac anomalies have existed for many years. However, no formal evaluation of the benefits of attending such camps has been undertaken heretofore. We assessed potential changes in the self-perceived health of children with congenital heart disease who attended a special sports camp. Thirty-one children with cardiac anomalies attended a 3-day multisports camp. Sixteen children, all of whom were 10 years or older, literate, and Dutch- or French-speaking, completed the Child Health Questionnaire (CHQ-CF87) before and after attending the camp. The scores of the children were compared with those of healthy peers by calculating mean standardized differences. After attendance at the sports camp, the children achieved significant improvements in the self-perception of their physical functioning, role functioning due to emotional problems, role functioning due to behavioral problems, mental health, and general behavior. The children's self-esteem and general behavior after the camp were significantly better than that of their healthy counterparts. We conclude that children with congenital heart disease who participate in activities at special sports camps may reap benefits in terms of their subjective health status. Although further research is needed, we recommend the participation in sport activities by children with heart defects, and more specifically their participation in sports camps.

Adolescent↗
PubMed2003

Trends in incidence and prevalence of specialized intestinal metaplasia, barrett's esophagus, and adenocarcinoma of the gastroesophageal junction.

Most available information on the epidemiology of Barrettacute;s esophagus (BE) relates to patients with long segments (> 3 cm) of specialized intestinal metaplasia (SIM). Its prevalence is 3% in patients undergoing endoscopy for reflux symptoms and 1% in those undergoing endoscopy for any clinical indication. The latter prevalence is similar to the 1% found in autopsy series. A "silent majority" with BE remain unrecognized in the general population. BE is more common in men, and the prevalence rises with age. Recent endoscopic series document a rise in the diagnosis of endoscopically apparent short segments (< 3 cm) of BE (SSBE). The prevalence of SSBE in both unselected and reflux patients is 8% to 12%. Specialized intestinal metaplasia at the cardia, below a normal-appearing squamocolumnar junction, has been reported to vary from 6% to 25% in patients presenting for upper endoscopy. Unlike patients with long segment Barrett's esophagus (LSBE), the role of gastroesophageal reflux disease in the pathogenesis of SSBE and SIM of the cardia is controversial. Recent data suggest that the etiology of SIM of the cardia might be secondary to Helicobacter pylori infection, although the role of other environmental factors cannot be ruled out. The incidence of adenocarcinoma of the esophagus and esophagogastric juction (EGJ) has been increasing over the past 15 years in Western countries. Surgical series and population-based studies show that by 1994 adenocarcinomas of the esophagus accounted for half of all esophageal cancer among white men. LSBE and SSBE predispose to the development of adenocarcinoma of the esophagus and EGJ. The role of SIM of the cardia as a precursor lesion for EGJ adenocarcinoma is still unclear. The prevalences of dysplasia in LSBE and SSBE are around 6% and 8%, respectively. The incidence of adenocarcinoma in patients with LSBE is about 1 in 100 patient-years. Cancer risk for SSBE and SIM at the cardia is unknown. Smoking and obesity increase the risk for esophageal and EGJ adenocarcinomas.

Adenocarcinoma↗
PubMed2006

Postsurgical infections are reduced with specialized nutrition support.

OBJECTIVE: The objective was to examine the relationship between pre-, peri-, and postoperative specialized nutritional support with immune-modulating nutrients and postoperative morbidity in patients undergoing elective surgery. METHODS: Studies were identified by searching MEDLINE, review article bibliographies, and abstracts and proceedings of scientific meetings. All randomized clinical trials in which patients were supplemented by the IMPACT formula before and/or after elective surgery and the clinical outcomes reported were included in the meta-analysis. Seventeen studies (n=2,305), 14 published (n=2,102), and 3 unpublished (n=203), fulfilled the inclusion criteria. Ten studies (n=1,392) examined the efficacy of pre- or perioperative IMPACT supplementation in patients undergoing elective surgery, whereas 7 (n=913) assessed postoperative efficacy. Fourteen of the studies (n=2,083) involved gastrointestinal (GI) surgical patients. Postoperative complications, mortality, and length of stay in hospital (LOS) were major outcomes of interest. RESULTS: IMPACT supplementation, in general, was associated with significant (39%-61%) reductions in postoperative infectious complications and a significant decrease in LOS in hospital by an average of 2 days. The greatest improvement in postoperative outcomes was observed in patients receiving specialized nutrition support as part of their preoperative treatment. In GI surgical patients, anastomotic leaks were 46% less prevalent when IMPACT supplementation was part of the preoperative treatment. CONCLUSION: This study identifies a dosage (0.5-1 l/day) and duration (supplementation for 5-7 days before surgery) of IMPACT that contributes to improved outcomes of morbidity in elective surgery patients, particularly those undergoing GI surgical procedures. The cost effectiveness of such practice is supported by recent health economic analysis. Findings suggest preoperative IMPACT use for the prophylaxis of postoperative complications in elective surgical patients.

Adjuvants, Immunologic↗
PubMed2002

Mammalian ear specializations in arid habitats: structural and functional evidence from sand cat (Felis margarita).

To test whether structural specializations of sand-cat ears are adaptations to their desert habitats we measured structural and acoustic features of their ears. The area of the external ear's pinna flange is similar to that of domestic cat. The dimensions of the ear canal are about twice domestic cat's, as is the volume of the middle-ear air space. The magnitude of the acoustic input-admittance at the tympanic membrane is about five times larger than that of domestic cat; both the middle-ear cavities and the ossicular chain contribute to the increase. Structure-based models suggest the acoustic admittance looking outward through the external ear is generally larger for sand cat than for domestic cat; the radiation power-efficiency is also larger in sand cat for frequencies below 2 kHz. Hearing sensitivity (estimated from measurements and model calculations) in sand cat is predicted to be about 8 dB greater than in domestic cat for frequencies below 2 kHz. Analysis of attenuation of sound in deserts implies that the increased sensitivity extends sand cat's hearing range beyond domestic cat by 0.4 km at 0.5 kHz. Thus, the structural specializations may provide habitat-specific survival value.

Acoustic Stimulation↗
PubMed2006

Specializations in the lumbosacral vertebral canal and spinal cord of birds: evidence of a function as a sense organ which is involved in the control of walking.

Birds are bipedal animals with a center of gravity rostral to the insertion of the hindlimbs. This imposes special demands on keeping balance when moving on the ground. Recently, specializations in the lumbosacral region have been suggested to function as a sense organ of equilibrium which is involved in the control of walking. Morphological, electrophysiological, behavioral and embryological evidence for such a function is reviewed. Birds have two nearly independent kinds of locomotion and it is suggested that two different sense organs play an important role in their respective control: the vestibular organ during flight and the lumbosacral system during walking.

Animals↗
PubMed2000

Infantile head injury, with special reference to the development of chronic subdural hematoma.

An infantile head injury has unique features in that infants are totally helpless and dependent on their parents, and biomechanical characteristics of the skull and brain are very different from those of other age groups. The authors reviewed a total of 16 infant head injury patients under 12 months of age who were treated in our hospital from 1989 to 1997. Birth head injury was excluded. The most common age group was 3-5 months. Early seizures were noted in 7 cases, and motor weakness in 6. Three patients with acute intracranial hematoma and another 3 with depressed skull fracture were operated on soon after admission. Chronic subdural hematomas (SDHs) developed in 3 infants. Initial CT scans showed a small amount of SDH that needed no emergency operation. Resolution of the acute SDH and development of subdural hygroma appeared on follow-up CT scans within 2 weeks of injury. Two of these infants developed early seizures. Chronic SDH was diagnosed on the 68th and 111th days after the injuries were sustained, respectively. The third patient was the subject of close follow-up with special attention to the evolution of chronic SDH in view of our experience in the previous 2 cases, and was found to have developed chronic SDH on the 90th day after injury. All chronic SDH patients were successively treated by subduro-peritoneal shunting. In conclusion, the evolution of chronic SDH from acute SDH is relatively common following infantile head injury. Infants with head injuries, especially if they are associated with acute SDH and early development of subdural hygroma, should be carefully followed up with special attention to the possible development of chronic SDH

Chronic Disease↗
PubMed2005

The duration of postoperative ileus after elective colectomy is correlated to surgical specialization.

AIM: Postoperative ileus is an important factor of complications following gastrointestinal procedures. Its pathophysiology and the parameters, which may impact on its duration, remain unclear. The aim of this study was to measure the role of various clinical determinants on restoration of intestinal function after elective colorectal surgery. METHODS: From July 2002 to September 2003, all patients who underwent laparotomy for colectomy (laparoscopic resections excluded) with either an ileotransverse, colocolic, or high colorectal anastomosis were entered in this prospective study. The intervals in hours between the end of the surgical procedure and passing of flatus (PG) and passing of stool (PS) were recorded by an independent investigator. PG and PS were eventually correlated with the following parameters: type of colectomy, early removal of nasogastric tube (NGT), mechanical bowel preparation (MBP), type of underlying disease, systemic administration of opiates, and surgical training (colorectal fellowship or other). RESULTS: One hundred twenty-four patients were entered in this study. Four patients (3.2%) developed septic complications (3 anastomotic leaks and 1 intraabdominal abscess) and were excluded from the analysis. Median age in this population was 68 (range 30-95) years. Mean duration of postoperative ileus was 70+/-28 h (PG) and 99+/-34 h (PS). The type of colectomy, underlying disease, MBP, and early NGT removal failed, in univariate analysis, to correlate with the duration of postoperative ileus. By contrast, time intervals PG and PS were statistically shorter in the group of patients treated by a colorectal surgeon [56+/-23 vs 74+/-28 h (PG); 82+/-26 vs 103+/-35 h (PS), p=0.004], as well as in patients who received systemic opiates for less than 2 days [64+/-27 vs 75+/-28 h (PG), p=0.04; 88+/-32 vs 108+/-33 h (PS), p=001]. CONCLUSION: Restoration of normal intestinal function after elective open colectomy takes 3 (PG) to 4 (PS) days. In our series, specialized training in colorectal surgery has a positive impact on the duration of postoperative ileus. Surgical specialization should be considered an important parameter in future clinical trials aiming to minimize postoperative ileus.

Adult↗
PubMed1999

Measurement of clinical change caused by knee replacement. Conventional score or special change indexes?

Clinical change may be measured with specific indexes of change or with the difference between single-state examinations. Change scores and transition indexes are the special indexes of change analysed in this study. At the 10-year follow-up of compartmental replacements, the conformity between subsequent Hospital for Special Surgery overall scores and the patient's opinion of change from before knee replacement was 0.54. This was judged to be unacceptable. It is recommended that a transitional index be included in the clinical evaluation systems used for knee replacement.

Aged↗
PubMed2001

Endosomes: multipurpose designs for integrating housekeeping and specialized tasks.

In most cells the endocytic system is organized following a common concept that allows for the integrative handling of a variety of housekeeping functions. In addition, variations on the general scheme provide for specialized endosome-based pathways that occur only in specific cell types. The diversity of endosomal functions is not only reflected by characteristic molecular compositions, but also mirrored in their morphological organization. In this review we will first describe the general outline of the endocytic system by combining kinetic, morphological, molecular, and functional definitions. In the second part, adaptations of endosomes that allow their functioning in specialized processes, such as antigen presentation, synaptic vesicle formation, and glucose transport, will be addressed.

Animals↗
PubMed2006

Improved perceived health status persists three months after a special sports camp for children with congenital heart disease.

INTRODUCTION: Although summer and sports camps for children with congenital heart disease are organized in many countries and regions, empirical data on the effects of such camps is limited. OBJECTIVES: The aim of the present study was to investigate changes in the perceived health status and habitual physical activities in children attending a special sports camp. MATERIALS AND METHODS: In this longitudinal study, 25 children with congenital heart disease who participated in a three-day multi-sports camp were included. The perceived health status was measured using the Child Health Questionnaire-Child Form, CHQ-CF87, completed by the child at the start of the camp (T1), at the end of the camp (T2), and 3 months after the camp concluded (T3). Habitual physical activities were assessed by means of a modified version of the Baecke questionnaire, which was completed by one of the parents at T1 and T3. RESULTS: During the sports camp, we observed significant improvements in the children's perception of their physical functioning, role-physical functioning, general health, role-emotional functioning, self-esteem, mental health, and general behavior. For physical functioning, role-emotional functioning, and family activities, high scores persisted three months after the sports camp concluded. The habitual physical activities (sport and leisure time) of the children remained unchanged. DISCUSSION AND CONCLUSION: In conclusion, we propose that a special sports camp for children with congenital heart disease may improve specific dimensions of subjective health status. Our study confirms a previous report on the benefits of such camps for afflicted children. If these findings can be further corroborated in other settings, participation in sport camps should be advocated as a simple, noninvasive means to promote healthier children.

Adolescent↗
PubMed1997

Filamentous contacts: the ultrastructure and three-dimensional organization of specialized non-synaptic interneuronal appositions in thalamic relay nuclei.

Filamentous contacts are non-synaptic interneuronal junctions characteristic of thalamic relay nuclei. Symmetrical filamentous contacts occur between two dendrites, two somata or a dendrite and a soma; asymmetrical filamentous contacts occur between axon terminals and dendrites, or occasionally somata, chiefly between the large specific afferent axon terminals of the synaptic glomeruli and the shafts of relay cell dendrites. Both are arranged as extensive net-like (reticular) specializations. The strands of the network enclose fenestrae of variable shape and size and, in perpendicular thin sections, appear as stretches of slightly widened intercellular space containing an electron-dense material and bounded by plasma membranes, the cytoplasmic surfaces of which are coated by electron-dense material into which microfilaments appear to insert. The lamina of cytoplasmic material in dendrites and somata is thicker than that in axon terminals and contains distinct electron-dense sub-units. Regular synaptic junctions may be situated like islands within the territory of an asymmetrical filamentous contact, and small spot-like close membrane appositions resembling gap junctions are occasionally seen in the fenestrae adjacent to the strands of both varieties of contact. Bundles of neurofilaments running in different directions, but in a plane parallel to the plasma membrane, are prominent on either side of the symmetrical filamentous contact and on the dendritic side of the asymmetrical variety. The agranular reticulum also exhibits differences between the contact types. Because of their highly specialized ultrastructure and specific distribution, filamentous contacts probably do not serve a purely adhesive function. Their possible role in the establishment and maintenance of orderly connections between cells is discussed but not favoured. Filamentous contacts probably mediate some form of intercellular communication, possibly involving gap junctions.

Intercellular Junctions↗
PubMed2002

Elimination of plant toxins by herbivorous woodrats: revisiting an explanation for dietary specialization in mammalian herbivores.

Constraints on rates of detoxification and elimination of plant toxins are thought to be responsible for limiting dietary specialization in mammalian herbivores. This hypothesis, known as the detoxification limitations hypothesis, suggests that most mammalian herbivores are generalists to avoid overdosing on toxins from a single plant species. The hypothesis also predicts that the few mammalian specialists that exist should have adaptations for rapid detoxification and elimination of plant secondary compounds. We took a pharmacological approach to test whether specialists eliminate toxins from the bloodstream faster than generalists. We compared elimination rate and total exposure of alpha-pinene in closely related dietary specialist and generalist woodrats, Neotoma stephensi and N. albigula, respectively. Animals were orally gavaged with alpha-pinene, a plant secondary compound present in the natural diets of both woodrat species. We collected venous blood at 3, 6, 10, 15, and 20 min post-ingestion of alpha-pinene. Blood was analyzed for alpha-pinene concentration using gas chromatography. We found that specialist and generalist woodrats did not differ in elimination rates of alpha-pinene. However, specialists had lower exposure levels of alpha-pinene than generalists due to lower initial delivery of alpha-pinene to the general circulation. The levels of alpha-pinene detected in the bloodstream of specialists were 4.7-5.3x lower over all time intervals than generalists. Thus, specialists encounter a functionally lower dose of toxin than generalists. We suggest that the lower exposure level of specialist woodrats may be due to mechanisms in the gut that decrease toxin absorption. Regardless of mechanism, lower exposure to plant toxins may allow specialists to forage on diets with high toxin concentrations thereby facilitating dietary specialization.

Absorption↗
PubMed2003

Differential host use in two highly specialized ant-plant associations: evidence from stable isotopes.

Carbon and nitrogen stable isotopes were used to examine variation in ant use of plant resources in the Cecropia obtusifolia / Azteca spp. association in Costa Rica. Tissue of ants, host plants and symbiotic pseudococcids were collected along three elevation transects on the Pacific slope of Costa Rica's Cordillera Central, and were analyzed for carbon and nitrogen isotopic composition. Worker carbon and nitrogen signatures were found to vary with elevation and ant colony size, and between Azteca species groups. Ants in the A. constructor species group appear to be opportunistic foragers at low elevations, but rely more heavily on their host plants at high elevations, whereas ants in the A. alfari species group consume a more consistent diet across their distribution. Further, isotope values indicate that both ant species groups acquire more nitrogen from higher trophic levels at low elevation and when ant colonies are small. Provisioning by the host is a substantial ecological cost to the interaction, and it may vary, even in a highly specialized association. Nonetheless, not all specialized interactions are equivalent; where interaction with one ant species group appears conditional upon the environment, the other is not. Differential host use within the Cecropia-Azteca association suggests that the ecological and evolutionary benefits and costs of association may vary among species pairs.

Altitude↗
PubMed2004

A critical evaluation of intrapopulation variation of delta13C and isotopic evidence of individual specialization.

Individual variation in the diet of consumers is common in many ecological systems and has important implications for the study of population dynamics, animal behavior, and evolutionary or ecological interactions. Ecologists frequently quantify the niche of a population by intensive analyses of gut contents and feeding behaviors of consumers. Inter-individual differences in delta13C signature can indicate long term differences in feeding behavior, often unattainable by a single snapshot analysis of gut contents. If a consumer's food sources have unique delta13C signatures, then the intrapopulation variation in delta13C may be useful for quantifying diet variation and detecting isotopic evidence of individual specialization. However, intrapopulation variation in delta13C can underestimate or overestimate dietary variation, and therefore is not directly equivalent to a dietary based niche. In this paper we show that intrapopulation variability of delta13C in consumers critically depends on the isotopic range and distribution of food sources. Our analyses fundamentally challenge how we interpret the intrapopulation isotopic variance of delta13C, and how we evaluate isotopic evidence of individual specialization.

Animals↗
PubMed2004

The relationship between specialization and local abundance: the case of helminth parasites of birds.

Positive relationships are commonly observed between the abundance of a species in a locality and the frequency of its occurrence among localities on a larger scale. This pattern may not hold for parasitic organisms when the average abundance of a parasite among its hosts is related to the number of host species in which it occurs, because of the additive investment in specific adaptations to counter host immune responses required for each host species in a parasite's repertoire. For a rigorous test of the hypothesis that there is a trade-off between the number of host species that can be successfully exploited and the average abundance of parasites in those hosts, one needs to take into account the phylogenetic (or taxonomic) distances among the host species used by a parasite. Differences in immune responses are likely to increase with increasing phylogenetic distances. The trade-off hypothesis was tested in a comparative analysis of 393 species of trematodes, cestodes and nematodes parasitic in birds surveyed from the same geographical area, using an index of host specificity that measures the average taxonomic distances between a parasite's known host species. After correcting for the influences of parasite phylogeny and other potential confounding variables, mean abundance was negatively correlated with the average taxonomic distance among host species for nematodes, and with the variance in taxonomic distances among hosts for cestodes. In the case of trematodes, these variables covaried positively. The trade-off between average infection success and how taxonomically distant a parasite's host species are from each other was only found in two of the three groups of helminths investigated, possibly because of compensating features in trematodes, such as their ability to multiply asexually in intermediate hosts. These results provide empirical evidence consistent with the hypothesis that specialization allows greater local adaptation and therefore greater local population abundance, supporting key predictions regarding the evolution of ecological specialization.

Analysis of Variance↗
PubMed2002

Laparoscopic cholecystectomy: quality of care and benchmarking. Results of a single-institution specialized in laparoscopy compared with those of a nationwide study in Switzerland.

BACKGROUND: Quality control is an important issue in surgery. Therefore, we assessed the outcome of laparoscopic cholecystectomies (LC) performed at our institution specialized in laparoscopic surgery in order to do a benchmarking. METHODS: The perioperative courses of the first 1000 LCs performed in Aarberg hospital were recorded, analyzed, and compared with the results of a recent study including 10, 174 patients published by the Swiss Association of Laparoscopic and Thoracoscopic Surgery (SALTS). RESULTS: The following quality indicators were compared with the corresponding SALTS rates: primary conversion rate 1.5% (SALTS 8.2%; p <0.01); conversion rate for intraoperative complications 6.5% (63.8%; p <0.01); intraoperative complication rate 22.2% (34.4%; p <0.01); postoperative morbidity rate 8.1% (10.4%; n.s.); in-hospital mortality rate 0.1% (0.2%; n.s.); and reoperation rate 0.8% (1.7%; n.s.). CONCLUSIONS: LC has reached a high quality level in its widespread use, but in a small specialized center even a higher quality level can be achieved. Favorable results seem to depend on structural advantages of a surveyable unit in association with a continuously motivated surgical team.

Adolescent↗