GABA-B Agonist Baclofen Normalizes Auditory-Evoked Neural Oscillations and Behavioral Deficits in the Fmr1 Knockout Mouse Model of Fragile X Syndrome

Fragile X syndrome is a genetic condition resulting from FMR1 gene mutation that leads to intellectual disability, autism-like symptoms, and sensory hypersensitivity. Arbaclofen, a GABA-B agonist, has shown efficacy in some individuals with FXS but has become unavailable after unsuccessful clinical trials, prompting interest in publicly available, racemic baclofen. The present study investigated whether racemic baclofen can remediate abnormalities of neural circuit function, sensory processing, and behavior in Fmr1 knockout mice, a rodent model of fragile X syndrome. Fmr1 knockout mice showed increased baseline and auditory-evoked high-frequency gamma (30-80 Hz) power relative to C57BL/6 controls, as measured by electroencephalography. These deficits were accompanied by decreased T maze spontaneous alternation, decreased social interactions, and increased open field center time, suggestive of diminished working memory, sociability, and anxiety-like behavior, respectively. Abnormal auditory-evoked gamma oscillations, working memory, and anxiety-related behavior were normalized by treatment with baclofen, but impaired sociability was not. Improvements in working memory were evident predominantly in mice whose auditory-evoked gamma oscillations were dampened by baclofen. These findings suggest that racemic baclofen may be useful for targeting sensory and cognitive disturbances in fragile X syndrome.

The Calculation of Robot Dynamics Using Articulated-Body Inertias

This paper describes a new method for calculating the acceleration of a robot in response to given actuator forces. The method is applicable to open-loop kinematic chains containing revolute and prismatic joints. The algorithm is based on recursive formulas involving quantities called articulated-body inertias, which represent the inertia properties of collections of rigid bodies connected together by joints allowing constrained relative motion between the bodies. A new, matrix-based notation is introduced to represent articulated-body inertias and other spatial quantities. This notation is used to develop the algorithm, and results in a compact representation of the equations. The new algorithm has a computational requirement that varies linearly with the number of joints, and its efficiency is compared with other published algorithms.

Position and Velocity Transformations Between Robot End-Effector Coordinates and Joint Angles

This paper describes efficient procedures for performing transformations from the position and velocity of the end effector to the corresponding joint angles and velocities, and vice versa, for a six-degree-of-freedom robot manipulator having three revolute joint axes intersecting at the wrist. Some attention is paid to the problems that arise when the manipulator's position is near a deadpoint.

Improvement of asthma control with a breath-actuated pressurised metred dose inhaler (BAI): a prescribing claims study of 5556 patients using a traditional pressurised metred dose inhaler (MDI) or a breath-actuated device

A relationship has been reported between sub-optimal inhaler technique and control of asthma symptoms. Randomised controlled trials and systematic reviews may fail to accurately represent this relationship, by excluding patients who are unable to correctly use the reviewed devices. Breath actuated inhalers (BAIs) are reported to be easier to use than metered dose inhalers (MDIs). This study uses a large primary care medical record database (DIN-LINK) to examine the 'real-life' clinical effectiveness of a BAI vs. traditional MDIs. A comparison is made between the quantity of asthma-related medication (beta2 agonist, oral steroids and antibiotics) and healthcare resource use required by children (0-12 years) and adults (13+ years) using either the BAI or an MDI over a 12-month period. Out of 5556 new asthma patients who met the inclusion criteria, 306 used a BAI and 5250 used a traditional MDI. Children and adults using the BAI received fewer prescriptions for all three medication types than those using a traditional MDI (children: beta2 agonists -18% P=0.036, oral steroids -88% P<0.05, antibiotics -68% P<0.05 and adults: beta2 agonists -10.9% P=0.179, oral steroids -51.2% P<0.05, antibiotics -19.5% P=0.276). All prescription results reached statistical significance, with the exception of beta2 agonist and antibiotic prescription numbers for adult patients. Children and adults using the BAI required less GP consultations for asthma (children -30.3%, P<0.05 and adults -22.9%, P<0.05) and less GP consultations for respiratory infections than those using a traditional MDI (children -35.2%, P=0.001 and adults -10.4%, P=0.236). Adults using the BAI required less outpatient appointments than adults using an MDI (-43.7%, P=0.166). All non-prescription resource results reached statistical significance with the exception of GP consultations for respiratory infections and outpatient visits in the adult group. In conclusion, children and adults using the BAI appear to have better asthma control than children and adults using an MDI as evidenced by fewer relief medication prescriptions and less healthcare resource use.

Involvement of the medial septum in stress-induced relapse to heroin seeking in rats

Intermittent footshock stress has been shown to reinstate extinguished drug-taking behaviour in rats, but the brain areas involved in this effect are to a large degree unknown. Here we studied the role of the septum in stress-induced reinstatement of heroin seeking. Rats were trained to self-administer heroin for 9-10 days (three 3-h sessions per day, 0.1 mg/kg per infusion). Following training, extinction sessions were given for 8-13 days by substituting saline for heroin, and then tests for reinstatement of heroin seeking were carried out. Reversible inactivation of the medial septum with tetrodotoxin (TTX; 1-5 ng, infused 25-40 min before the test sessions) reliably reinstated heroin seeking, mimicking the effect of 15 min of intermittent footshock. This effect of TTX was not observed after infusions made 1.5 mm dorsally into the lateral septum. In other experiments, it was found that infusions of a low, subthreshold dose of TTX (0.5 ng) into the medial septum, when combined with 2 min of footshock that in itself was ineffective, reinstated heroin seeking. Furthermore, electrical stimulation (400 microA pulses, 100 micros duration, 100 Hz frequency) of the medial septum during exposure to 10 min of intermittent footshock attenuated footshock-induced reinstatement of heroin seeking. These data suggest a role for the medial septum in stress-induced relapse to drug seeking. The septum is thought to be involved in neuronal processes underlying behavioural inhibition, thus we speculate that stressors provoke relapse by interfering with these processes.

Elective conventional colectomy in the era of laparoscopic surgery

Laparoscopic surgery, since its introduction into the general surgery, has reduced hospital stay. Can lessons learned from laparoscopic surgery about aggressive postoperative care be applied to elective conventional colectomy? Between August 1994 and February 1995, a prospective study was conducted on 24 consecutive patients undergoing elective conventional colectomy with primary anastomosis. A comparison of 30 consecutive patients in the 7 months immediately before this study were used as a historical control group. Both groups were comparable in age, indications for operation, type of operation, and operative time. The protocol consisted of an outpatient bowel prep, hospital admission on day of surgery, and intravenous metoclopramide starting before the operation and continued every 6 hours with diet started at 24 hours. Patients were discharged on regular diet after a bowel movement and were continued on oral metoclopramide for a total of 7 days. Hospital stay was reduced from 8 days (range 4-19 days) to 4 days (range 2-7 days) on the protocol P < 0.001). Hospital charges were also reduced by 20 per cent (from $18,450 to $14,586) (P = 0.066). Complication rate and postoperative emergency room visits as a measure of quality of care did not differ between the two groups. By implementing this protocol, hospital costs and length of stay for elective conventional colectomy were reduced without compromising patient care.

Laparoscopic training in residency program

The use of laparoscopy in general surgery has provided surgeons with a new approach to multiple procedures. New techniques are being developed daily. Laparoscopic training for surgical residents must be incorporated into their curriculum. To decrease the risks of training residents on patients and to decrease operative time, a program of videoscopic "bench" training exercises, to improve eye-hand coordination, was instituted for junior residents. Between July and September 1995, nine surgical residents participated in this proficiency videoscopic study. At the end of the study, there was a statistically significant improvement in the residents performance by an average of 37% (P = 0.0109). This program proved to be both effective and economical. It can be reproduced and easily incorporated into any surgical residency program.

Differences in the distribution and characteristics of tachykinin NK1 binding sites between human and guinea pig lung

1. The distribution and characteristics of tachykinin NK1 binding sites have been compared in human and guinea pig lung using quantitative in vitro receptor autoradiography with [125I]-Bolton Hunter-labelled substance P ([125I]-BH-SP). In addition, the effects on these sites of ovalbumin sensitization and challenge have been determined in guinea pig lung. 2. [125I]-BH-SP bound specifically and with high affinity to microvascular endothelium in both human and guinea pig lung, but to bronchial smooth muscle and pulmonary artery media in only guinea pig lung. 3. Specific binding of [125I]-BH-SP to guinea pig bronchial smooth muscle was positively correlated with airway diameter in the range 150-800 microns and was less dense in trachea than in main bronchi. 4. [125I]-BH-SP binding was inhibited by tachykinins with rank orders of affinity of SP > NKA > NKB (human microvessels) and SP > NKA = NKB (guinea pig bronchi and pulmonary arteries). NKA displayed a higher affinity for [125I]-BH-SP binding sites in human microvessels than in guinea pig tissues (P < 0.0001), indicating differences in selectivity for tachykinins between human and guinea pig NK1 receptors. 5. In both human and guinea pig lung, [125I]-BH-SP binding was inhibited by the specific tachykinin receptor antagonists FK888 (NK1 selective antagonist) and FK224 (mixed NK1/NK2 antagonist), with FK888 displaying equal affinity to SP and > 500 times higher affinity than FK224. SP, NKA, NKB and FK888 exhibited similar affinities for [125I]-BH-SP binding sites in both guinea pig arteries and bronchi. 6. Similar distributions, densities and characteristics of [I251]-BH-SP binding sites were demonstrated in oval bumin-sensitized and -challenged guinea-pig lung and in naive animals.7. Differences in the distribution and characteristics of NKI binding sites labelled with [125I]-BH-SP between guinea pig and human lung suggest limitations in the use of guinea pig models for studying roles of tachykinins in pulmonary disease. However, the similar microvascular distributions of NK,binding sites in human and guinea pig lung suggest that the selective tachykinin receptor antagonistsFK888 and FK224 may be useful in the management of airway inflammation in man.