Mode structure of coupled L3 photonic crystal cavities.

We investigate the energy splitting, quality factor and polarization of the fundamental modes of coupled L3 photonic crystal cavities. Four different geometries are evaluated theoretically, before experimentally investigating coupling in a direction at 30◦ to the line of the cavities. In this geometry, a smooth variation of the energy splitting with the cavity separation is predicted and observed, together with significant differences between the polarizations of the bonding and anti-bonding states. The controlled splitting of the coupled states is potentially useful for applications that require simultaneous resonant enhancement of two transitions.

Design and fabrication of three-dimensional scaffolds for tissue engineering of human heart valves.

We developed a new fabrication technique for 3-dimensional scaffolds for tissue engineering of human heart valve tissue. A human aortic homograft was scanned with an X-ray computer tomograph. The data derived from the X-ray computed tomogram were processed by a computer-aided design program to reconstruct a human heart valve 3-dimensionally. Based on this stereolithographic model, a silicone valve model resembling a human aortic valve was generated. By taking advantage of the thermoplastic properties of polyglycolic acid as scaffold material, we molded a 3-dimensional scaffold for tissue engineering of human heart valves. The valve scaffold showed a deviation of only +/-3-4% in height, length and inner diameter compared with the homograft. The newly developed technique allows fabricating custom-made, patient-specific polymeric cardiovascular scaffolds for tissue engineering without requiring any suture materials.

Sublay or onlay incisional hernia repair along with abdominoplasty: which is better? Long-term results.

PURPOSE: Estimation and comparison of results after incisional hernia repair (IHR) modo onlay or sublay with abdominoplasty in patients who lost the weight following Roux-en-Y Gastric Bypass (RYGB). Analysis and comparison of changes in quality of life (QL) of these patients prior to RYGB, before and after simultaneous IHR and abdominoplasty. METHODS: Clinical analysis involved 40 patients with abdominal disfigurement (following RYGB and massive weight loss) after one-time IHR sublay method with abdominoplasty-group 1 or IHR onlay method with abdominoplasty-group 2. We evaluated postoperative results and long-term QL changes (DAS24, SF-36 scales). RESULTS: We noted abnormal wound healing (2), pneumonia (3) and dysesthesia (3) in patients from group 1, and abnormal wound healing (2), seroma (2), pneumonia (2), and dysesthesia (4) in group 2. Quality of life was improved in the functional, esthetic and psychological aspects. CONCLUSIONS: One stage incisional hernia repair by onlay as well as sublay method with abdominoplasty are safe surgical methods improving the functioning of patients after major weight loss following RYGB. Sublay hernia repair and abdominoplasty was connected with longer time of the: operation, drainage, analgesic agents use, time to mobilization and to full oral diet than the onlay method. Significant improvement of the quality of life was noted after every subsequent step of surgical treatment in both groups. Reduction of the risk of BMI re-growth after bariatric surgery is related to the need for constant, specialized care for these patients at every stage of follow-up after bariatric surgery.

The repair of incisional hernia following Roux-en-Y gastric bypass-with or without concomitant abdominoplasty?

BACKGROUND: Incisional hernia, found in up to 25% of patients, is a typical complication of open bariatric surgery. METHODS: Open Roux-en-Y gastric bypass (RYGB) was performed in 204 patients. They have been followed-up for at least 6 months. Thirty-two patients in whom incisional hernia was diagnosed were divided into two groups-they were scheduled for hernia repair or hernia repair with abdominoplasty. The surgery was performed, on average, 20 months after RYGB operation. Fourteen patients [mean body mass 86.4 kg, mean body mass index (BMI) 30.0 kg/m(2)] have had hernias repaired. The mean duration of hospital stay was 7.2 days. Hernia repair along with abdominoplasty was performed in 18 patients with mean body mass 89.4 kg and BMI 31.5 kg/m(2). The mean duration of hospital stay was 8.7 days. RESULTS: Both examined groups were similar in body mass, BMI, age, and duration of hospital stay (p > 0.05), as well as gender distribution. The wound infection was diagnosed in six patients. CONCLUSION: The simultaneous abdominoplasty does not prolong the time of hospital stay of the patients undergoing incisional hernia repair. Infection is the most frequent complication of incisional hernia repair.

Polarized quantum dot emission from photonic crystal nanocavities studied under moderesonant enhanced excitation.

We study the linear polarization of the emission from single quantum dots embedded in an "L3" defect nanocavity in a two-dimensional photonic crystal. By using narrow linewidth optical excitation in resonance with higher-order modes, we are able to achieve strong quantum dot emission intensity whilst reducing the background from quantum dots in the surrounding lattice. We find that all the dots observed emit very strongly linearly polarized light of the same orientation as the closest mode, despite the fact that these quantum dots may be spectrally detuned by several times the mode linewidth. We discuss the coupling mechanisms which may explain this behavior.

Obstructive sleep apnoea syndrome in morbidly obese children with tibia vara.

Morbid obesity and its association with obstructive sleep apnoea syndrome have been increasingly recognised in children. Orthopaedic surgeons are often the primary medical contact for older children with tibia vara, which has long been associated with obesity, but are unfamiliar with the evaluation and treatment of sleep apnoea in children. We reviewed all children with tibia vara treated surgically at one of our institutions over a period of five years. Thirty-seven patients were identified; 18 were nine years of age or older and 13 of these (72%) had morbid obesity and a history of snoring. Eleven children were diagnosed as having sleep apnoea on polysomnography. The incidence of this syndrome in the 18 children aged nine years or older with tibia vara, was 61%. All these patients required pre-operative non-invasive positive-pressure ventilation; tonsillectomy and adenoidectomy were necessary in five (45%). No peri-operative complications related to the airway occurred. There is a high incidence of sleep apnoea in morbidly obese patients with tibia vara. These patients should be screened for snoring and, if present, should be further evaluated for sleep apnoea before corrective surgery is undertaken.

Progress in the molecular genetic analysis of trichome initiation and morphogenesis in Arabidopsis.

Arabidopsis trichomes are large unicellular structures that develop on the surface of most shoot-derived organs. In leaves, the number, spacing and shape of trichomes is tightly regulated, and this process has been used as an experimental system to study the control of cell fate and pattern formation. The control of trichome initiation is complex: both the potential of a cell to adopt the trichome cell fate and an intricate signaling pathway determine the pattern of trichome initiation events. Several important new results suggest that trichome initiation and morphogenesis are redundantly regulated by both positive and negative factors. A testable model for the control of trichome initiation is presented.

cot1: a regulator of Arabidopsis trichome initiation.

In Arabidopsis, the timing and spatial arrangement of trichome initiation is tightly regulated and requires the activity of the GLABROUS1 (GL1) gene. The COTYLEDON TRICHOME 1 (COT1) gene affects trichome initiation during late stages of leaf development and is described in this article. In the wild-type background, cot1 has no observable effect on trichome initiation. GL1 overexpression in wild-type plants leads to a modest number of ectopic trichomes and to a decrease in trichome number on the adaxial leaf surface. The cot1 mutation enhances GL1-overexpression-dependent ectopic trichome formation and also induces increased leaf trichome initiation. The expressivity of the cot1 phenotype is sensitive to cot1 and 35S::GL1 gene dosage, and the most severe phenotypes are observed when cot1 and 35S::GL1 are homozygous. The COT1 locus is located on chromosome 2 15.3 cM north of er. Analysis of the interaction between cot1, try, and 35S::GL1 suggests that COT1 is part of a complex signal transduction pathway that regulates GL1-dependent adoption of the trichome cell fate.

Subdural hematomas of arterial origin.

Three cases of acute subdural hematoma related to bleeding aneurysm or arteriovenous malformation are presented. Various possible arterial sources of bleeding that may lead to subdural hematoma are reviewed. The complex cause and effect relationship between the presence of aneurysm or arteriovenous malformation and the occurrence of subdural hematoma in a head-injured patient is discussed. The pitfalls of reliance on the computed tomogram as a sole diagnostic test in the evaluation of head-injured patients or of unconscious patients with no available history are emphasized.

Hippocampal vasopressin release evoked by N-methyl D-aspartate (NMDA) microdialysis.

Hippocampus is a brain structure containing vasopressin (AVP) fibers and specific binding sites for this peptide. There is growing evidence that AVP and its metabolites participate in glutamate-mediated plasticity of the hippocampus. The aim of the present study was to evaluate the influence of NMDA on AVP release in the rabbit hippocampus. Caudate nucleus was chosen as the reference structure. The mentioned brain structures were simultaneously microdialyzed with 0.9 % NaCl solution. AVP was determined in the outflowing fluid by radioimmunoassay. The mean basal AVP content in the fluid outflowing from the hippocampus was significantly greater than that from the caudate nucleus. The addition of K(+) into the fluid perfusing the probes implanted into the hippocampus and caudate nucleus significantly increased AVP release into the extracellular fluid of both brain structures. NMDA applied into the mentioned brain structures increased AVP release only from the hippocampus but not from the caudate nucleus. Our findings indicate a role which NMDA receptors play in AVP release into the extracellular fluid of the hippocampus.

Automatic patient registration in computer assisted maxillofacial surgery.

In this paper, a new approach for patient registration in computer assisted maxillofacial surgery is presented. The method uses a unique structure of markers embedded in a reference frame for the automatic detection of the coordinate system of the medical imaging data during the surgical intervention. With the new method, the inaccurate and time consuming process of manually identifying markers in the data volume and manually teaching them to a navigation system can be replaced. The method and algorithms for the automatic marker detection are described in this paper. Experiments with 45 data sets of patients proove the robustness, usability and safety of the new method. The method has been integrated into the navigation system RoboDent for dental implant surgery.

The Lesbian Internalized Homophobia Scale: a rational/theoretical approach.

This article reports the development and psychometric properties of a new scale that measures internalized homophobia in lesbians: the Lesbian Internalized Homophobia Scale (LIHS). This 52-item measure was developed using a rational/theoretical approach of test construction and includes five subscales. Research findings, based on a sample of 303 female participants, supported the reliability and validity of the LIHS in assessing internalized homophobia in lesbians. Implications for research and practice are discussed.

Plasma glucose after stomach or jejunum glucose infusion in Roux-en-Y gastric bypass patients--a possible implication for early satiety mechanism.

BACKGROUND: Morbidly obese patients undergoing gastric bypass surgery experience early satiety soon after the surgery; the mechanism of this effect is poorly understood. As blood glucose concentration plays a role in appetite regulation in humans, we hypothesized that after gastric bypass surgery glucose absorbed mainly in jejunum leads to a greater rise in plasma glucose that if it is ingested in stomach. MATERIAL AND METHODS: 24 non-diabetes morbidly obese patients (15 women, 9 men, mean age [± SD] 35.6 ± 11.9 years, body weight 140.7 ± 33.1 kg, BMI 46.8 ± 8.3 kg/m²) undergoing Roux-en-Y gastric bypass surgery were given 10 ml of 40% glucose solution to the stomach before its size reduction and to the jejunum after gastro-jejunal anastomosis was formed. RESULTS: After jejunal infusion blood glucose increased more rapidly and was ∼30% higher than after stomach infusion. Moreover, this increase was less pronounced in more obese patients. CONCLUSION: In patients after Roux-en-Y gastric bypass surgery glucose absorbed in jejunum leads to greater rise in plasma glucose concentration than if it is ingested in stomach. This phenomenon may help explain satiety feeling occurring early in gastric bypass surgery patients.

Effects of age, weight, hormones, and hibernation on breeding success in boreal toads (Bufo boreas boreas).

The goals of this study were to test the effects of exogenous hormones and hibernation on breeding behavior and gamete release by boreal toads (Bufo boreas boreas). Each year, a subset of 77 toads was hibernated and then paired with hibernated or nonhibernated mates and treated with luteinizing hormone releasing hormone analogue (LHRHa), human chorionic gonadotropin (hCG), or left untreated. Amplexus and egg and sperm production were recorded. At 1 yr of age, only 19% of pairs exhibited amplexus, and no sperm or eggs were produced. At 2 and 3 yr of age, most male toads treated with LHRHa exhibited amplexus (56.9% and 100%, respectively). Among 2-yr-old males, amplexus was more prevalent (P<0.05) in those that were hibernated than in those that were nonhibernated (54.0% and 33.3%, respectively), but most males in each group (93.3% and 75%, respectively) produced sperm in response to LHRHa treatment. Only one 2-yr-old and two 3-yr-old females produced eggs. At 4 yr of age, eight females produced eggs, but two died from egg retention. More nonhibernated than hibernated females developed eggs (7 of 10 vs. 1 of 10, P<0.05). Mean (+/-SD) weight of female toads producing eggs (58.9 +/- 11.9g) was greater (P<0.05) than that of nonproducing females (43.6 +/- 7.0g). Similarly, four of seven nonhibernated females (58.8+/-8.3g) produced eggs at 5 yr of age. All eggs were produced by females treated once with LHRHa. Number of eggs per female varied (141 to 3307), and development to tadpoles was low (0 to 36.5%), although tadpoles did become toadlets. In conclusion, male and female boreal toads matured at 2 and 4 yr of age, respectively, and heavier females were more likely to produce eggs. To enhance breeding success, males should be hibernated and treated with LHRHa. In contrast, female productivity was enhanced by improving their body condition instead of subjecting them to hibernation prior to LHRHa treatment.

Randomized clinical trial of postoperative hernia prophylaxis in open bariatric surgery.

BACKGROUND: Postoperative hernia following bariatric procedures is more common than in other groups of surgical patients, and remains a serious problem. Gastric bypass is the most often performed bariatric procedure and, despite the increasing popularity of a laparoscopic approach, many morbidly obese patients are still offered open procedures. The aim of this study was to assess the effects of prophylactic polypropylene mesh in morbidly obese patients undergoing gastric by-pass surgery. METHODS: The study randomized 74 patients undergoing open Roux-en-Y gastric bypass into two groups: wound closure with (n = 36) or without (n = 38) a polypropylene mesh. Mean(s.d.) body mass and body mass index in the mesh group were 137.3(24.5) kg and 46.2(7.1) kg/m(2) and in the non-mesh group were 139.0(24.9) kg and 46.8(7.6) kg/m(2) respectively. In the non-mesh group, the wound was closed with a polypropylene suture. Patients in the mesh group had in addition a polypropylene mesh inserted in a sublay manner. RESULTS: Patients were followed up for at least 6 (range 6-38) months. Hernia developed in eight patients in the non-mesh group but in none in the mesh group. The duration of hospital stay was similar in both groups: mean(s.d.) 8.4(3.2) and 10.3(5.9) days (P = 0.092). There were no serious complications in either group. CONCLUSION: The use of a mesh prevented hernia development and did not lengthen hospital stay.

Tissue engineering of vascular conduits: fabrication of custom-made scaffolds using rapid prototyping techniques.

BACKGROUND: The technique of stereolithography, which automatically fabricates models from X-ray computed tomography or magnetic resonance imaging (MRI) data linked to computer-aided design programs, has been applied to the fabrication of scaffolds for tissue engineering. We previously reported on the application of stereolithography in scaffold fabrication of a trileaflet heart valve. In our current experiment we demonstrate a new technique for the fabrication of custom-made conduits for the potential replacement of a coarcted aortic segment. METHODS AND RESULTS: In this experiment the image data derived from a 12-year-old male patient with aortic coarctation scanned by MRI were processed by a computer-aided design program to reconstruct the aortic arch with isthmus stenosis three dimensionally. By defining the stenotic section and the adjacent normal vessel a custom-made nonstenotic descending aorta was reconstructed to replace the stenosed part. The rapid prototyping technique was used to establish stereolithographic models for fabricating biocompatible and biodegradable vascular scaffolds with the anatomic structure of the recalculated human descending aorta through a thermal processing technique. CONCLUSION: Our results suggest that the re-creation and reproduction of complex vascular structures by computer-aided design techniques may be useful to fabricate custom-made polymeric scaffolds for the tissue engineering of living vascular prostheses.

GLABROUS1 overexpression and TRIPTYCHON alter the cell cycle and trichome cell fate in Arabidopsis.

Cellular competence, initiation cues, and inhibition signals control the distribution of trichomes on the Arabidopsis leaf. The GLABROUS1 (GL1) gene has a dual role in that it is required for trichome initiation, but GL1 overexpression reduces trichome number. We have found that a mutation in the TRIPTYCHON (TRY) gene partially suppresses the GL1 overexpression phenotype but not in a way that indicates that TRY directly controls an epidermal inhibition pathway. Surprisingly, cauliflower mosaic virus 35S::GL1 try plants contain a subclass of trichomes derived from the subepidermal layer. Altered cell cycle control was also detected in 35S::GL1 and try plants. A mutation in TRY led to increased epidermal and mesophyll cell number, a reduction in endoreduplication in the epidermis, and an increase in endoreduplication in trichomes. GL1 overexpression also reduced endoreduplication levels in both the epidermis and trichomes; however, in the presence of try, it synergistically enhanced trichome endoreduplication. Interactions with the COTYLEDON TRICHOME1 (COT1) gene indicate that GL1 and TRY control trichome development and may be involved in cell cycle control during leaf development.

Calmodulin isoforms differentially enhance the binding of cauliflower nuclear proteins and recombinant TGA3 to a region derived from the Arabidopsis Cam-3 promoter.

Many stimuli increase cytoplasmic Ca2+ concentrations as an early signal transduction event and alter the patterns of nuclear gene transcription, but the mechanisms by which Ca2+ signals are transduced to the nucleus are not known. This article shows that at least four DNA binding proteins from cauliflower nuclear extracts are also calmodulin (CaM) binding proteins. CaM enhances the binding of these proteins to a C/G-box sequence element in the Arabidopsis Cam-3 promoter. Binding to the C/G-box is enhanced preferentially by the CaM isoform encoded by Cam-3. However, it is not clear whether the effect is mediated directly by CaM or indirectly through the activity of a CaM-regulated protein phosphatase. CaM also binds recombinant TGA3 and enhances its binding to the same Cam-3 promoter element. These results are consistent with the idea that a Ca(2+)-mediated signalling pathway eliciting some changes in gene expression may consist of CaM, or a structurally related Ca2+ binding protein, and transcription factors.

[Correlations between arrhythmias and left ventricular function at rest and during stress in patients with postinfarct aneurysm]. / Zusammenhang zwischen Rhythmusstörungen und linksventrikulärer Funktion in Ruhe und unter Belastung bei Patienten mit postinfarziellem Aneurysma.

The results (clinical, hemodynamic, and angiographic data) of 197 patients with left ventricular anterior wall aneurysm were evaluated at rest and during exercise (bicycle ergometer) 6 months after the acute infarction. Using the technique of digital subtraction angiography, left ventricular volumes were estimated after injection of contrast medium into the pulmonary artery and measuring of pulmonary artery pressure. In 136 patients a programmed right ventricular stimulation was performed additionally. The patients were divided into the following groups: patients with (VT+) and without (VT-) ventricular arrhythmias in history. Group VT- was subdivided in patients with positive (RV+) or negative (RV-) result of right ventricular stimulation. In group VT+ chamber volumes were greater and ejection fraction was smaller than in group VT-. At rest the results of subgroup RV+ were similar to group VT+, but during exercise similar to group RV-. These results show that left ventricular function at rest and during exercise is much more impaired in patients with spontaneous and by stimulation-induced arrhythmias than in patients without these arrhythmias. The conclusions for clinical practice of these findings are not yet clear, concerning, for example, the prophylactic use of antiarrhythmic measurements in patients without spontaneous but with induced arrhythmias. Further investigations (long-term follow-ups of these patients) will be necessary.