The pathophysiology of the chronic pain cycle.

The diagnosis and treatment of chronic pain is an area in which the field of medicine is failing to offer the best possible care to patients. This article presents a clinically driven view of the condition with an emphasis on active recognition and intervention. Defining aspects of chronic pain, including the emotional and psychologic components, are introduced with regard to recognition and diagnosis.

Evaluation of conflict of interest in economic analyses of new drugs used in oncology.

Context: Recent studies have found that when investigators have financial relationships with pharmaceutical or product manufacturers, they are less likely to criticize the safety or efficacy of these agents. The effects of health economics research on pharmaceutical company revenue make drug investigations potentially vulnerable to this bias.

Objective: To determine whether there is an association between pharmaceutical industry sponsorship and economic assessment of oncology drugs.

Subcutaneous phaeohyphomycosis: overview and case report.

Phaeohyphomycosis describes a heterogenous group of mycotic infections caused by pigmented fungi. Previously uncommon to the United States, the number of case reports in the American literature has steadily increased over the past two decades. This has been attributed to the ever increasing number of immunocompromised individuals as well as an influx of immigrants from areas where these opportunistic fungi are more commonly found.

Temporal correlation analysis of penumbral dynamics in focal cerebral ischemia.

A novel temporal correlation technique was used to map the first-pass transit of iodinated contrast agents through the brain. Transit profiles after bolus injections were measured with dynamic computed tomography (CT) scanning (1 image/s over 50 s). A rabbit model of focal cerebral ischemia (n = 6) was used, and dynamic CT scans were performed at 30, 60, 90, and 120 min postocclusion.

Nerve growth factor-induced sprouting of mature, uninjured sympathetic axons.

The infusion of nerve growth factor (NGF) into the lateral ventricle of the mature rat brain elicits a sprouting response from axons associated with the intradural segment of the internal carotid artery. Using electron microscopic techniques, we observed a three-fold increase in the total number of perivascular axons. This NGF-elicited response is characterized by a dramatic reduction in glial cell ensheathment similar to that observed during development and by the presence of profiles devoid of organelles that may represent newly formed sprouts.

A unique presentation of non-Hodgkin's lymphoma in the foot.

Non-Hodgkin's lymphoma of the foot is a relatively uncommon pedal neoplasm. The authors discuss the etiology, incidence, histology, morphology, metastatic rate, and treatment of this entity. Non-Hodgkin's lymphomas rarely present as destructive lesions of bone; when they do, they usually involve the axial skeleton or proximal long bones.

NGF-induced remodeling of mature uninjured axon collaterals.

Accumulation of nerve growth factor (NGF) within the rat hippocampus following septal denervation is thought to contribute to sympathetic axon ingrowth. However, intraventricular NGF infusion, which results in elevated hippocampal NGF, fails to elicit such sprouting, although it increases innervation of the extracerebral vasculature. To determine whether or not NGF would stimulate sympathohippocampal sprouting, we infused NGF after sprouting was initiated.

Intracerebral NGF infusion induces hyperinnervation of cerebral blood vessels.

The use of intracerebral NGF (nerve growth factor) infusions as a therapeutic tool to prevent the degeneration of cholinergic neurons in humans suffering from Alzheimer's disease has recently been suggested. In the present study, intracerebroventricular infusion of nerve growth factor into the adult rat brain was found to induce axonal sprouting of mature, uninjured axons associated with the intradural segment of the internal carotid artery. Following NGF infusion, a three-fold increase in the total number of axons associated with the vessel wall was observed when compared with vehicle-infused animals.

Intraventricular NGF infusion in the mature rat brain enhances sympathetic innervation of cerebrovascular targets but fails to elicit sympathetic ingrowth.

The ability of peripheral axons to regenerate long distances in the peripheral nervous system (PNS) is well documented; however, examples of axonal elongation within the adult mammalian central nervous system (CNS) are rare. One example of axonal growth in the mature brain is the sprouting of sympathetic axons into the hippocampal formation following disruption of the septohippocampal pathway. A current hypothesis is that elevated hippocampal NGF levels, secondary to loss of retrograde transport by septal neurons, elicits sympathetic ingrowth, In this study, we sought to determine whether elevation of hippocampal NGF activity without septal denervation is sufficient to elicit sympathetic sprouting.

Putative gliotoxin, alpha-aminoadipic acid, fails to kill hippocampal astrocytes in vivo.

The putative gliotoxic compound, alpha-aminoadipic acid (AAA), has previously been reported to be a glial-selective toxin exerting its effects both in vivo and in vitro. This study sought to examine the effects of this compound on adult rat hippocampal astrocytes in vivo. Fourteen adult male Sprague-Dawley rats were injected with high concentrations of either the L-isomer or the racemic mixture of AAA into the dorsal hippocampal formation or corpus striatum.