Electrophoretic manipulation of single DNA molecules in nanofabricated capillaries.

We demonstrate the use of nanofabricated capillaries, integrated as part of a microfluidic structure, to study the electrophoretic behaviour of single, fluorescently-labelled, molecules of DNA as a function of capillary size. The nanocapillaries, fabricated using a focused ion beam, have cross-sections down to 150 x 180 nm. Control of single-molecule direction and velocity was achieved using voltage manipulation. DNA mobility was found to increase with decreasing cross-section, which we interpret in terms of reduced electro-osmotic counter-flow. Such nanofabricated capillaries as part of larger fluidic structures have great potential for biotechnology, particularly single molecule manipulation and analysis.

Somatic, affective, and pain characteristics of chronic TMD patients with sexual versus physical abuse histories.

AIMS: This study examined whether temporomandibular disorder (TMD) patients with sexual versus physical abuse histories differ in their pain report, psychological distress, and somatic symptoms. METHODS: Participants were 114 female TMD patients. The sample was divided into 3 groups based on abuse history: sexual abuse, physical abuse, or no abuse. Abuse histories were assessed with a structured clinical interview. Measures used included the McGill Pain Questionnaire, the State-Trait Anxiety Inventory, the Beck Depression Inventory, and the Pennebaker Inventory of Limbic Languidness. Group differences were analyzed by analysis of variance and Bonferroni post hoc comparisons. RESULTS: Temporomandibular disorder patients with a history of physical abuse reported significantly more pain, anxiety, and depressive symptoms than did patients with a history of sexual abuse or no history of abuse. Furthermore, the results suggest that TMD patients with a sexual abuse history are not significantly different from patients with no abuse history across the domains studied. CONCLUSION: Based on the differences found, it can be argued that assessment of physical abuse histories by appropriately trained clinicians should be a routine part of any multimodal assessment of female chronic TMD patients.

Trafficking of Glut4-green fluorescent protein chimaeras in 3T3-L1 adipocytes suggests distinct internalization mechanisms regulating cell surface glut4 levels.

Insulin stimulates glucose transport in adipose and muscle tissue by stimulating the movement ('translocation') of an intracellular pool of glucose transporters (the Glut4 isoform) to the plasma membrane. We have engineered a series of chimaeras between Glut4 and green fluorescent protein (GFP) from Aequoria victoria and expressed these proteins in 3T3-L1 adipocytes by microinjection of plasmid cDNA. In the absence of insulin, GFP-Glut4 is localized intracellularly within a perinuclear compartment and multiple intracellular punctate structures. In response to insulin, chimaeric GFP-Glut4 species exhibit a profound redistribution to the cell surface with kinetics comparable with the endogenous protein. The intracellular localization of GFP-Glut4 overlaps partially with compartments labelled with Texas Red transferrin, but is largely distinct from intracellular structures identified using Lysotracker-Red(R). K(+)-depletion resulted in the accumulation of GFP-Glut4 at the cell surface, but to an lesser extent than that observed in response to insulin. In contrast with native Glut4, removal of the insulin stimulus or treatment of insulin-stimulated cells with phosphatidylinositol 3'-kinase inhibitors did not result in re-internalization of the chimaeric GFP-Glut4 from the plasma membrane, suggesting that the recycling properties of this species differ from the native Glut4 molecule. We suggest that the recycling pathway utilized by GFP-Glut4 in the absence of insulin is distinct from that used to internalize GFP-Glut4 from the plasma membrane after withdrawal of the insulin stimulus, which may reflect distinct pathways for internalization of endogenous Glut4 in the presence or absence of insulin.

Predicting treatment compliance following facial pain evaluation.

The purpose of this study was to document compliance to treatment follow-up for facial pain patients referred for outside services. In addition, we generated a multidimensional model of the psychosocial constructs associated with chronic pain to determine whether these factors were predictive of compliance across recommended therapy modalities or with an overall measure of compliance. These constructs included pain report, depressive symptoms, anxiety, cognitive coping strategies, and physical activity reduction. The sample consisted of 80 facial pain patients evaluated at a tertiary care, facial pain clinic at a large university medical center. Compliance ratings ranged from 93% to 50% and are consistent with the literature that indicates that compliance differs across treatment modality. Furthermore, compliance rates were lower for the more nontraditional facial pain treatments performed by physical therapists or psychologists. Depression was negatively associated with compliance to medication changes, therapeutic injections, and splint therapy, but not psychological counseling or physical therapy. Increased pain was only associated with physical therapy. Measures of psychological distress (depression and anxiety) and pain were predictive of the overall measure of compliance. These results suggest that psychological distress can be a barrier for positive patient outcomes through reduced treatment compliance.

Neoadjuvant chemotherapy and radiotherapy for inoperable head and neck cancer: the LSU-Shreveport experience.

A retrospective review of 8 years of treatment in 2 hospitals in Shreveport showed that neoadjuvant chemotherapy with radiotherapy was performed in 39 patients with inoperable, locally advanced head and neck cancer. Twenty-two individuals treated by definitive radiotherapy alone served as historical controls. The cumulative survival rate at 4 years was 34% in patients managed by neoadjuvant chemotherapy with radiotherapy and 7% in patients treated by radiotherapy only. With the exception of greater acute toxicity seen in patients receiving neoadjuvant chemotherapy with radiotherapy, differences in locoregional failure, distant metastasis, and late complication rates were not observed between the patient groups.

Compartment-ablation studies of GLUT4 distribution in adipocytes: evidence for multiple intracellular pools.

The available data suggest that GLUT4 does populate the recycling endosomal system to some extent, but that a large proportion of the intracellular GLUT4 resides in a compartment that is devoid of transferrin receptors and may have properties more akin to specialized secretory vesicles. The study of the nature and biogenesis of this compartment will provide important insight into the mechanism by which insulin stimulates glucose transport. Further study of the role of the synaptobrevins in these distinct subcellular compartments will probably shed further light on the mechanism by which insulin stimulates GLUT4 translocation.

Transfusion therapy in sickle cell disease patients: methods and acute indications.

Management of transfusion therapy in sickle cell disease patients with acute complications is often made difficult because of confusing indications, a variety of methods, disparate goals, and varying needs for maintenance transfusion. In priapism, acute chest syndrome, many major surgical procedures, toxemia of pregnancy, and cerebrovascular accidents, the target hemoglobin A level should be made as close to 100% as possible by mechanized red blood cell exchange. If mechanized exchange is unavailable, manual exchange should be instituted. Hemoglobin A should be maintained at greater than 60% to 70% by periodic simple transfusion until patients are fully recovered. Stroke patients should undergo maintenance transfusions for at least 3 years and perhaps 5 to 12 years. Physicians and patients should be aware of the transfusion-related risks of hepatitis and HIV infection. Alloimmunization and iron overload should be minimized in patients requiring frequent transfusions and chelation therapy should be utilized for iron overload.

Comparison of three techniques on time to awakening, time to orientation and incidence of nausea and vomiting using alfentanil in balanced anesthesia in an outpatient surgical setting.

Maximizing patient safety and comfort while minimizing adverse sequelae are continuing anesthetic challenges. The purpose of this study was to examine three anesthetic techniques utilizing alfentanil with regard to time to awakening, time to orientation and incidence of nausea and vomiting. Surgical procedures were limited to knee arthroscopy, laparoscopy and dental extractions. Unpremedicated ASA I/II outpatients (n = 74) between the ages of 18 and 59 were randomly assigned to one of three groups: Group I: alfentanil + 67% N2O + 33% O2 Group II: alfentanil + 67% N2O + 33% O2 + droperidol 0.015 mg/kg Group III: alfentanil + 100% O2 + 0.7% isoflurane Anesthesia was induced with alfentanil 40 micrograms/kg, atracurium 0.4 mg/kg, thiamylal 4 mg/kg and 100% O2 and was maintained according to group assignment. The anesthetic was supplemented as clinically indicated with incremental boluses of alfentanil 10 micrograms/kg. Upon completion of surgery, muscle relaxation was reversed with edrophonium 0.75 mg/kg and atropine 0.015 mg/kg. Analyses indicated that the three groups were comparable in terms of potentially confounding variables including gender, race, surgical procedure, age, percent of ideal body weight, case length and dose of alfentanil in micrograms/kg/hr. Time to awakening was significantly shorter in the two N2O groups by approximately 1.5 minutes, as compared to the O2 and isoflurane group (p = .0060). Time to orientation was significantly shorter in the N2O groups by approximately 1.5 minutes also, as compared to the O2 and isoflurane group (p = .0142). The two N2O groups did not differ significantly in either measure. The incidence of vomiting in the postanesthesia recovery room (PARR) indicated a significant difference (p = .0317) among groups with vomiting occurring 45.8% of the time in Group I, 28.8% of the time in Group II and 8% of the time in Group III. Total emetic score (nausea and vomiting) in the PARR indicated a significant difference (p = .03) among groups with symptoms occurring 50% of the time in Group I, 28% of the time in Group II, and 16% of the time in Group III.

The response of plant mitochondria to media of high solute content.

The state-3 rate of respiration of potato tuber mitochondria is inhibited by concentrations of KCl or NaCl above 125 mM, and by concentrations of sucrose, lactose, or maltose above 500 mM, but not at all by mannitol, glucose, glycine, or proline up to a concentration of 1500 mM in the medium. Mitochondria from cauliflower, beetroot, cucumber, rock melon, and watermelon behave very similarly to those from potato tuber. The variable response to different solutes proves that the reduction in respiration is not a simple function of the chemical potential of water in the medium. Disruption of potato mitochondria by ultrasonic vibration does not relieve the inhibition of succinate oxidation caused by KCl or sucrose. However, treatment with detergent abolishes completely the inhibition of respiration by sucrose. Inhibition of succinate dehydrogenase [Succinate:PMS, oxidoreductase (EC.1.3.99.1)] and malate dehydrogenase [L-Malate:NAD oxidoreductase (EC.1.1.1.37)] activities by sucrose is less than the inhibition of succinate- and malate-dependent oxygen uptake by the potato mitochondria. Limited substrate uptake and, alternatively, reduced electron flow as a consequence of a direct effect of solute on the mitochondrial membrane are considered as possible mechanisms of inhibition.