Structure-activity relationship of 99mTc complexes of phenylenediamine-thiol-thioether ligands (PhAT) to brain uptake in rats.

A novel class of ligands, phenylenediamine-thiol-thioether (PhAT), was synthesized, and their 99mTc complexes were evaluated for potential use as a functional brain imaging agent. The ligands reacted with Na99mTcO4 and SnCl2 to form single, stable, neutral, and lipophilic 99mTc complexes. Several of these complexes showed significant brain uptake and retention in rats. In particular, the S-ethyl, allyl, and propargyl derivatives had high initial brain uptake (0.88, 0.99, and 0.82% dose/g at 5 min, respectively) and good retention (0.71, 0.75, and 0.67% dose/g at 30 min). The structure-activity relationship of alkyl, alkenyl, and alkynyl thioether derivatives is reported.

Medial frontal cortex involvement in PTSD symptoms: a SPECT study.

The regional cerebral blood flow (rCBF) responses to a combat stress-related auditory stimulus was examined in Vietnam veterans diagnosed with posttraumatic stress disorder (PTSD). Based on prior data in healthy subjects, we hypothesized that the medial prefrontal cortex may be involved in the processing of stress responses. Twelve male veterans diagnosed with PTSD, 11 age-matched, combat-exposed subjects without PTSD, and 12 healthy control subjects were studied with single-photon emission tomography and the blood flow tracer [99mTc]-HMPAO. Subjects were studied twice, while listening to combat sounds or white noise. Significant increases in the blood flow to the medial prefrontal cortex were observed in PTSD patients, but not in the control groups, which correlated at trend levels with psychophysical measures of stress response. These data support the involvement of the medial prefrontal cortex in the pathophysiology of PTSD, possibly mediating some of its symptoms.

Central acetabular fracture-dislocation secondary to an epileptic seizure in a chronic renal patient.

An unusual mechanism of injury for a central acetabular fracture-dislocation is reported in a patient with chronic renal insufficiency. The combination of renal osteodystrophy and an epileptic seizure resulted in such an injury as a complication of renal dialysis. Skeletal traction and a prolonged period of non-weight bearing produced a satisfactory result.

Conversion of external arteriovenous hemodialysis shunt to internal fistula.

The preservation of arteriovenous (AV) access site is important to long-term survival of patient's requiring maintenance hemodialysis life-support therapy. Patients with chronic renal failure and uremia who are not suited for immediate application of a subcutaneous AV fistula or arteriovenous graft and who require an initial Teflon-Silastic AV shunt to initiate urgent hemodialysis need not lose these vessels when the AV shunt is removed. After venous maturation, these patients should have a subcutaneous AV fistula created from the uninfected, unclotted shunt before infection or clotting would cause loss of these vessels.

Delayed traumatic arteriovenous fistula following hemodialysis vascular catheterization.

Arteriovenous fistula formation is a rare complication of percutaneous femoral vein cannulation for hemodialysis. Symptoms and physical findings may be elusive and the lesion can proceed unnoticed for extended periods of time. This complication is easily managed with surgical repair following rapid clinical and angiographic diagnosis. It is the purpose of this paper to report a case of delayed arteriovenous fistula formation 7 months following percutaneous insertion of an acute hemodialysis catheter into the femoral vein.