A comparison of morphine analgesic tolerance in male and female mice

Studies comparing morphine tolerance in males and females are rare, and all studies to date have utilized the rat. To generalize from findings with rats morphine tolerance was investigated in male and female mice using the tail-withdrawal test. Three and 7 days of systemic morphine injections produced significant but unequal rightward shifts in the morphine dose-response curve such that females displayed greater increases in analgesic ED(50) values when compared to males. In a separate experiment, males and females displayed similar reductions in morphine analgesic sensitivity when %MPE (maximum possible effect) and %total (area under the curve) were compared after 3 days of morphine. Differences in initial morphine sensitivity between sexes were not observed in either study. The data demonstrate that, in contrast to rats, female mice undergo greater reductions in morphine analgesia relative to males following chronic morphine, but this sex difference may depend on the method of assessing analgesia. Furthermore, the duration and/or cumulative dose of morphine treatment does not affect the expression of sex differences in morphine tolerance.     

Morphine tolerance after chronic intracerebroventricular injection in male and female mice

We compared morphine analgesia ED(50) values of male and female mice prior to (Day 1) and after (Day 4) 3 days of intracerebroventricular morphine injections. Increases in ED(50) values from Day 1 to Day 4, indicating tolerance, were of similar magnitude in both sexes. The data suggest that spinal opioid analgesic mechanisms, acting alone or in synergy with supraspinal loci, may contribute to pharmacodynamic explanations of sex differences in systemic morphine tolerance.     

Assessment of acute and chronic morphine dependence in male and female mice

The present study compared male and female mice for frequency of naloxone-precipitated jumping and naloxone ED(50) values, two common indices of physical dependence, following acute and chronic morphine administration. Both sexes displayed a positive dose-response relationship between acute morphine and naloxone doses and jumping frequency. There was a significant main effect of sex, with mean jumping frequencies greater in males. The naloxone ED(50) estimate was also fourfold lower in males, indicating greater withdrawal sensitivity than females. Jumping frequencies were similar in male and female saline-treated control mice, discounting initial sex differences as a significant factor in the unequal magnitude and sensitivity in acute morphine dependence between sexes. In contrast, males and females displayed similar mean withdrawal jumping frequencies and naloxone ED(50) values after 3 days of morphine injections. Sex difference in withdrawal jumping was also not observed when morphine treatment was increased to 7 days via daily injection or continuous subcutaneous infusion. The present study demonstrates the development of greater physical dependence in male relative to female mice following acute but not chronic morphine administration.     

The Neuman Systems Model Institute: testing middle-range theories

The credibility of the Neuman systems model can only be established through the generation and testing of Neuman systems model-derived middle-range theories. However, due to the number and complexity of Neuman systems model concepts/concept interrelations and the diversity of middle-range theory concepts linked to these Neuman systems model concepts by researchers, no explicit middle-range theories have yet been derived from the Neuman systems model. This article describes the development of an organized program for the systematic study of the Neuman systems model. Preliminary work, already accomplished, is detailed, and a tentative plan for the completion of further preliminary work as well as beginning the actual research conduction phase is proposed.     

Surgical relevance of the lateral costotransverse ligament in relation to the dorsal root ganglion

The lateral costotransverse ligament, a short band that stabilizes the costovertebral joint, is found in close proximity to the dorsal root ganglion. This ligament is an important surgical landmark during tumor resections or nerve blocks in the paravertebral space. The purpose of this study was to quantitatively and qualitatively describe the morphology of the lateral costotransverse ligament and its relation to the dorsal root ganglion at all levels of the thoracic spine. The thoracic spines of eight embalmed cadavers were dissected bilaterally. The length, width, and thickness of the ligament were measured. The distance from the inferolateral aspect of the ligament to the lateral aspect of the dorsal root ganglion was also measured. Three bilateral groups of lateral costotransverse ligaments, top (on ribs 1–2), middle (on ribs 3–10), and bottom (on ribs 11–12), were compared based on anatomic distinctions between the costotransverse joints, which can influence ligament morphology. Among the three groups, the differences between the length, width, and thickness were not statistically significant. However, the distance from the lateral costotransverse ligament to the dorsal root ganglion differed significantly (P = 0.000), with the middle group having the longest distance, and the bottom group having the shortest distance. This finding can help clinicians and surgeons avoid iatrogenic injuries of neural structures during thoracic spine surgery, or when performing nerve blocks in the paravertebral space.     

3D detection and extraction of bladder tumors via MR virtual cystoscopy

Purpose

This paper proposes a pipeline for the detection and extraction of 3D regions of bladder tumors via MR virtual cystoscopy.

Methods

After the acquisition of volumetric bladder images with a high-resolution T2-weighted 3D sequence, the inner and outer surfaces of the bladder wall were segmented simultaneously by a coupled directional level-set method. Based on the Laplacian method, a potential field was built up between two surfaces so that the thickness of each voxel within the bladder wall was estimated. To detect bladder abnormalities, four volume-based morphological features, including bent rate, shape index, wall thickness, and a novel morphological feature, which reflects bent rate difference between the inner and outer surfaces, were extracted. The combination of these four features was used to detect seeds on the inner surface by using selected filtering criterion. Then all points on streamlines started from detected seeds formed 3D candidate regions. Finally the fuzzy c-means clustering with spatial information (sFCM) was used to extract tumors from surrounding bladder wall tissues in candidate regions.

Results

The proposed pipeline was evaluated by a database of MR bladder images acquired from ten patients with bladder cancer. To find an optimal feature combination for tumor detection, the performance of different combinations of these features was evaluated with different filtering criteria. With the combination of all four features, the computer-aided detection pipeline shows a high performance of 100 % sensitivity with 2.3 FPs/case. Comparing with tumor regions delineated by radiological experts, the average overlap ratio of tumor regions extracted by sFCM is 86.3 %.

Conclusions

The experimental result demonstrates the feasibility of the proposed pipeline on the detection and extraction of bladder tumors. It may provide an effective way to achieve the goal of evaluating the whole bladder for tumor detection and local staging.

     

A Lyme disease case study and individualized healthcare plan.

The Atlantic and Pacific coasts are the boundaries of Lyme disease with the Northeastern and Midwestern regions of the United States continuing to report the majority of cases. New reported cases of Lyme disease doubled from 1991 to 2001 according to statistics published by the Centers for Disease Control and Prevention. Within that population are more children between the ages of 5 and 9. The younger the child, the more difficult it is to diagnose Lyme disease. Children under the age of 19 are at high risk for Lyme disease because of the amount of time spent in outdoor activities during the late spring and summer. These months correlate with the tick breeding cycle and the peak time for outdoor recreational activities. Lyme disease can pose serious health risks in late stage illness. A Lyme disease case study on a school-age child provides comprehensive assessment data, interventions, and educational information for parents. A template of an individualized healthcare plan using standardized language is a guide for school nurses. The value of school nurses as guardians of the public's health is addressed.     

Polyanalgesic Consensus Conference—2012: Recommendations on Trialing for Intrathecal (Intraspinal) Drug Delivery: Report of an Interdisciplinary Expert Panel

Introduction: Trialing for intrathecal pump placement is an essential part of the decision‐making process in placing a permanent device. In both the United States and the international community, the proper method for trialing is ill defined. Methods: The Polyanalgesic Consensus Conference (PACC) is a group of well‐published experienced practitioners who meet to update the state of care for intrathecal therapies on the basis of current knowledge in the literature and clinical experience. Anexhaustive search is performed to create a base of information that the panel considers when making recommendations for best clinical practices. This literature, coupled with clinical experience, is the basis for recommendations and for identification of gaps in the base of knowledge regarding trialing for intrathecal pump placement. Results: The panel has made recommendations for the proper methods of trialing for long‐term intrathecal drug delivery. Conclusion: The use of intrathecal drug delivery is an important part of the treatment algorithm for moderate to severe chronic pain. It has become common practice to perform a temporary neuroaxial infusion before permanent device implantation. On the basis of current knowledge, the PACC has developed recommendations to improve care. The need to update these recommendations will be very important as new literature is published.