Chronic State (chronic + state)

Distribution by Scientific Domains
Medical Sciences60%

Selected Abstracts

Activation of the basal forebrain by the orexin/hypocretin neurones

ACTA PHYSIOLOGICA, Issue 3 2010
E. Arrigoni
Abstract The orexin neurones play an essential role in driving arousal and in maintaining normal wakefulness. Lack of orexin neurotransmission produces a chronic state of hypoarousal characterized by excessive sleepiness, frequent transitions between wake and sleep, and episodes of cataplexy. A growing body of research now suggests that the basal forebrain (BF) may be a key site through which the orexin-producing neurones promote arousal. Here we review anatomical, pharmacological and electrophysiological studies on how the orexin neurones may promote arousal by exciting cortically projecting neurones of the BF. Orexin fibres synapse on BF cholinergic neurones and orexin-A is released in the BF during waking. Local application of orexins excites BF cholinergic neurones, induces cortical release of acetylcholine and promotes wakefulness. The orexin neurones also contain and probably co-release the inhibitory neuropeptide dynorphin. We found that orexin-A and dynorphin have specific effects on different classes of BF neurones that project to the cortex. Cholinergic neurones were directly excited by orexin-A, but did not respond to dynorphin. Non-cholinergic BF neurones that project to the cortex seem to comprise at least two populations with some directly excited by orexin-A that may represent wake-active, GABAergic neurones, whereas others did not respond to orexin-A but were inhibited by dynorphin and may be sleep-active, GABAergic neurones. This evidence suggests that the BF is a key site through which orexins activate the cortex and promote behavioural arousal. In addition, orexins and dynorphin may act synergistically in the BF to promote arousal and improve cognitive performance. [source]

Inflamed adipose tissue, insulin resistance and vascular injury

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 8 2008
Christian X. Andersson
Abstract Type 2 diabetes is the most common metabolic disorder today and has reached epidemic proportions in many countries. Insulin resistance and inflammation play a central role in the pathogenesis of type 2 diabetes and are present long before the onset of the disease. During this time, many of the complications associated with type 2 diabetes are initiated. Of major concern is the two- to fourfold increase in cardiovascular morbidity and mortality in this group compared to a nondiabetic population. Obesity, characterized by enlarged fat cells, and insulin resistance are, like type 2 diabetes, associated with impaired adipogenesis and a low-grade chronic inflammation that to a large extent emanates from the adipose tissue. Both these processes contribute to unfavourable alterations of the circulating levels of several bioactive molecules (adipokines) that are secreted from the adipose tissue, many of which have documented inhibitory effects on insulin sensitivity in the liver and peripheral tissues and, in addition, have negative effects on the cardiovascular system. Here we review current knowledge of the adipose tissue as an endocrine organ, the local and systemic effects of a chronic state of low-grade inflammation residing in the adipose tissue, and, in particular, the effects of inflammation and circulating adipokines on the vascular wall. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Malingering, Perceptions of Illness, and Compensation Seeking in Whiplash Injury: A Comparison of Illness Beliefs Between Individuals in Simulated Compensation Scenarios and Litigation Claimants,

JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 11 2006
Maggie Linnell
This paper compares beliefs about whiplash injury between individuals in simulated compensation/no compensation scenarios and actual litigant claimants. Comparisons between simulators and the clinical sample revealed that chronic patients reported significantly more symptoms than all simulator groups. The beliefs of the real compensation claimants in the acute phase of the condition were similar to those in the ,injury only' simulator group. The analyses identified a trend towards beliefs in the expected timeline of the illness becoming more negative with time, whilst feelings of control over the symptoms improve. The paper discusses indicators of malingering behavior and the possible involvement of litigation and treatment processes in the transition to a chronic state of ill health. [source]

Soluble cellular adhesion molecules, selectins, VEGF and endothelin-1 in patients with Wuchereria bancrofti infection and association with clinical status

PARASITE IMMUNOLOGY, Issue 1-2 2005
P. Esterre
SUMMARY Lymphatic filariasis, a mosquito-transmitted disease commonly known as Bancroftian filariasis, is characterized by debilitating pathology linked to the progression of lymphoedema to a chronic state of elephantiasis. We performed longitudinal measurements of endothelial adhesion and angiogenic molecules in 63 Polynesian patients living in an hyperendemic focus of Wuchereria bancrofti. Decreased serum concentrations of soluble (s-) L selectin (CD62L) were noticed in sera of of patients with chronic conditions (hydrocele and elephantiasis). Chyluria was associated with increased vascular endothelial growth factor (VEGF) levels, whereas elephantiasis presented a high endothelin-1 (ET-1) profile. By contrast, increased serum concentrations of soluble intercellular (sICAM-1, CD54), but not of vascular cell (sVCAM-1, CD106), adhesion molecules were observed in sera of patients with bacterial lymphangitis used as controls. These trends are consistent with the increased permeability of vascular structures, a major clinical feature observed in acute lymphatic pathology (of bacterial or filarial origin), and of fundamental differences in the pathogenesis of hydrocele and elephantiasis. Using markers correlated with the clinical status (high ET-1 and VEGF levels for elephantiasis and chyluria, respectively; low CD62L levels for hydrocoele and elephantiasis) it should be possible to monitor disease progression in lymphatic filariasis. [source]

Chronic cerebrospinal venous insufficiency and multiple sclerosis

ANNALS OF NEUROLOGY, Issue 3 2010
Omar Khan MD
A chronic state of impaired venous drainage from the central nervous system, termed chronic cerebrospinal venous insufficiency (CCSVI), is claimed to be a pathologic phenomenon exclusively seen in multiple sclerosis (MS). This has invigorated the causal debate of MS and generated immense interest in the patient and scientific communities. A potential shift in the treatment paradigm of MS involving endovascular balloon angioplasty or venous stent placement has been proposed as well as conducted in small patient series. In some cases, it may have resulted in serious injury. In this Point of View, we discuss the recent investigations that led to the description of CCSVI as well as the conceptual and technical shortcomings that challenge the potential relationship of this phenomenon to MS. The need for conducting carefully designed and rigorously controlled studies to investigate CCVSI has been recognized by the scientific bodies engaged in MS research. Several scientific endeavors examining the presence of CCSVI in MS are being undertaken. At present, invasive and potentially dangerous endovascular procedures as therapy for patients with MS should be discouraged until such studies have been completed, analyzed, and debated in the scientific arena. ANN NEUROL 2010;67:286,290 [source]