TrkA-expressing trigeminal sensory neurons display both neurochemical and structural plasticity despite a loss of p75NTR function: responses to normal and elevated levels of nerve growth factor.

In neural crest-derived sensory ganglia, approximately half of the neuronal population expresses the transmembrane trkA receptor that is required for neuronal binding of target-derived nerve growth factor (NGF). These same neurons also express the p75 neurotrophin receptor (NTR) that increases the affinity of trkA for NGF. Depleting p75NTR expression reduces both the survival of trkA-positive sensory neurons and their afferent innervation of peripheral targets. In this investigation, we assessed the neurochemical and structural plasticity of trigeminal sensory neurons in p75NTR-deficient mice in response to either normal or elevated levels of NGF during postnatal development and into adulthood. Although p75NTR-deficient mice have 30% fewer trigeminal neurons, levels of trkA mRNA expression are modestly elevated in these mutant mice as compared to control mice. The density of central afferent axons and local levels of NGF are, however, comparable between mutant and control animals. Thus, despite the survival of fewer trigeminal neurons, neither ganglionic levels of trkA mRNA expression nor the density of central afferent projections are depleted in p75NTR-deficient mice. In response to elevated levels of NGF protein, transgenic mice with and without p75NTR expression display both increased levels of trkA mRNA expression and a greater density of trigeminal central afferent axons as compared to control mice. These data further reveal that an absence of p75NTR function in trigeminal sensory neurons does not diminish their capacity for NGF-dependent plasticity, namely trkA mRNA expression and collateral growth of central afferent axons.

The role of human resources in supporting reengineering.

To ensure the successful reengineering of a large, complex, unionized, urban teaching hospital, communication, education, and employee participation are key aspects. Human Resources-designed training supports the transition in concert with reengineering management, organizational development, labor relations, and external consultants. Education improves patient care and raises employee self-esteem as new teams focus together on excellence.

Interventional radiologic treatment of complications following gastric bypass surgery for morbid obesity.

Complications of gastric bypass surgery include leakage from the gastrojejunal anastomosis with abscess formation and anastomotic stenosis. Using interventional radiologic techniques, we have treated 18 patients with such complications following surgery for morbid obesity, with clinical success in 11. Procedures included 9 abdominal abscess drainages and 7 balloon dilatations of stenotic or occluded gastrojejunal anastomoses. Eight of 9 abscesses resolved completely; 3 of 7 balloon dilatations resulted in long-term clinical improvement. We describe the techniques used as well as problems encountered in these patients.

Steel occlusion coils: pretreatment with thrombin.

Stainless steel vascular occlusion coils provide a convenient and effective means for occluding large vessels. Occasionally, coagulopathies or extremely high-flow states delay or preclude the formation of an effective thrombus around this device. A technique is described for pretreating these coils with a thrombin solution. This pretreatment assures a prompt and effective occlusion of the target vessel.

Infantile hemangioendothelioma: angiographic features and factors determining efficacy of hepatic artery embolization.

The angiographic features of infantile hepatic hemangioendothelioma are discussed as well as the role of hepatic artery embolization in its management when more conservative measures have failed. A unique case with portal vein supply of the tumor is presented, and the impact of this angiographic feature is discussed.

Technical refinements in percutaneous nephroureterolithotomy.

Percutaneous nephrostolithotomy and ureterolithotomy is now widely accepted as the preferred method of managing symptomatic upper urinary tract calculi. The success of these procedures depends on an optimally oriented, percutaneously established nephrocutaneous track. These nephrostomies are often technically difficult if the collecting system is unobstructed or if calculi interfere with percutaneous manipulations. Several technical refinements have been developed that have aided in the performance of over 200 such nephrostomies as well as percutaneous ureterolithotomy. These include the use of externally applied abdominal compression to distend the collecting system after intravenous administration of contrast material for renal puncture, distend the ureter beyond an obstructing ureteral calculus to aid in percutaneous extraction, and relocate ptotic kidneys back into the renal fossa to optimize renal access; targeting on an opaque caliceal calculus for nephrostomy puncture; use of a saline flush to confirm proper nephrostomy needle placement; and an accelerated method of track dilatation with semirigid fascial dilators. The value of air as contrast for postprocedural nephrostography is also discussed.

Rectourethrocutaneous fistula in Crohn disease.

Fistulae from the gastrointestinal tract to the urinary tract are a well-known complication of Crohn disease. The majority of these are ileovesical. On rare occasion, patients with perianal complications of regional ileitis or granulomatous colitis may develop rectourethrocutaneous fistulae. The authors have encountered 2 such patients and add them to the 3 previously reported cases in the English literature. Retrograde urethrography and voiding cystourethrography established the diagnosis.

Subjective assessment and cardiovascular response to ischemic pain in young, healthy women users and non-users of oral contraceptives.

PIP: Due to the fact that oral contraceptives (OCs) can alter the pain threshold and since evidence of possible concomitant changes in the cardiovascular response to pain is still missing, an investigation of the response of heart rate (HR), blood pressure (BP), and systolic time interval (STI) to ischemic pain in OC users and nonusers was conducted. The objective was to explore also the existence of correlations, if any, between subjective and hemodynamic responses. 26 women students volunteered for the study. 12 of the women used a combination of estrogen-progestogen OCs (users) and 14 did not (nonusers). The women were healthy and of similar height, weight, age, and strength. 4 users and 3 nonusers smoked cigarettes. Ischemic pain was induced by blanching the dominant arm with an Esmarck bandage, inflating an upper arm cuff at 250 torr, and having the subject exercise the ischemic hand by pulling the ergometer springload of 5.4 kg 15 times in 75 seconds according to a rigid time schedule. Following the exercise, pain levels were estimated by the subjects on a numbered visual scale in color. The 2 groups differed statistically in cardiovascular variables. At rest the users had higher HR and shorter preejection period (PEP) than the nonusers. The Wilcoxon rank-sum test showed no difference between users and nonusers as to the intensity of perceived pain. In the user group a significant positive correlation between pain and preejection period time index (PEPI) and the PEP/LVET (left ventrical ejection time) ratio was observed. These correlations were not significant in the nonusers. Both hypertension and heart disease occur more often in OC users than in nonusers. In the sample the 2 groups were not distinguished at rest by differences in BP, but they did differ in the cardiac variables of HR and PEP. Users had more rapid HR and shorter PEP than the nonusers, implying a comparatively more active cardiac state.^ieng

Patient access to medical records on a psychiatric inpatient unit.

The authors studied the effects of patient access to medical records during hospitalization in a psychiatric unit of a community general hospital. Questionnaires were completed by about 20 staff and 88 patients, and records were compared with those from an earlier period to note any changes in the written record. Patients reported feeling better informed and more involved in their treatment, and staff said that they became more thoughtful about their notes in the chart. The availability of staff seems crucial to this process and facilitates the working alliance.