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PubMed2005

Fatigue and regulation of the hypothalamo-pituitary-adrenal axis in multiple sclerosis.

BACKGROUND: Fatigue is a common and disabling symptom in patients with multiple sclerosis (MS). Underlying mechanisms postulated so far have involved localization of brain lesions and abnormalities of the neuroendocrine system and cytokine regulation. OBJECTIVE: To investigate the relationship between fatigue and the hypothalamo-pituitary-adrenal (HPA) axis in patients with MS. DESIGN: A prospective survey. SETTING: Outpatient and inpatient study at the Max Planck Institute of Psychiatry, Munich, Germany. PATIENTS: Thirty-one patients with clinically definite MS, a relapsing-remitting disease course, and without MS-specific treatment. INTERVENTIONS: Assessment of fatigue with 3 questionnaires: the Fatigue Severity Scale (FSS), the Modified Fatigue Impact Scale (MFIS), and the Visual Analog Scale. Assessment of HPA axis regulation with the combined dexamethasone-corticotropin releasing hormone (Dex-CRH) test. RESULTS: The FSS score was significantly correlated with the MFIS score. Patients with fatigue had significantly elevated adrenocorticotropin (ACTH) levels in the combined Dex-CRH test. CONCLUSIONS: In contrast to results for chronic fatigue syndrome, where a hyporeactivity of the HPA axis has been shown, MS patients with fatigue exhibited a higher activity of the HPA axis than those without fatigue, as evidenced by significantly increased ACTH concentrations. Proinflammatory cytokines, known to be elevated in patients with MS, may cause both HPA axis alterations and fatigue.

Adrenocorticotropic Hormone↗
PubMed1992

Comparison of Hensen's node and retinoic acid in secondary axis induction in the early chick embryo.

Retinoic acid (RA) and Hensen's node, the organizer center in the chick embryo, have been shown to have polarizing activity when applied or grafted into the chick limb bud. Here we investigate and compare the effects of RA and grafted Hensen's node on the early chick embryo. Anion exchange beads soaked with RA at concentrations ranging from 5 to 100 ng/ml and implanted on the anterior side or on the left side of the host anteroposterior axis of a stage 4 chick embryo in ovo have the ability to induce secondary axis formation, while beads soaked with RA of the same concentration and implanted on the right side or on the posterior side of the host axis are unable to induce the secondary axis. All of the induced axes contain trunk-tail structures. Hensen's node from quail embryos implanted into the early chick blastoderm could also cause the formation of secondary axes in addition to self-differentiation of the graft into a secondary axis. Both RA and grafted Hensen's node caused the inhibition of forebrain development with an increase in hindbrain development and the host heart to loop in an abnormal direction. The results support the hypothesis that Hensen's node is a source of RA which is involved in early embryogenesis. Alternatively, RA might stimulate the formation of Hensen's nodal properties in adjacent tissue.

Animals↗
PubMed1989

Pretranslational control of the levels of glyoxysomal protein gene expression by the embryonic axis in maize.

Previous studies showed that the expression of catalase-2 (CAT-2) and other glyoxysomal proteins is independently controlled in the scutella of intact maize seedlings. In this study, removal of the embryonic axis prior to seed imbibition dramatically decreased the amounts of all but two of the 19 immunologically detectable glyoxysomal proteins in the scutellum, including CAT-2. The temporal expression profile of CAT-2 was also altered. Removal of the axis after seeds were fully imbibed (24 hr) had little effect on the subsequent pattern of expression of CAT-2. The effect of axis removal was specific for glyoxysomal enzymes and caused relatively little change in the population of stainable scutellar proteins. In vitro translation studies and nucleic acid hybridization with a gene-specific cloned probe (for Cat2) revealed that the mRNA levels for glyoxysomal proteins were sharply lowered by axis removal. This study provides evidence that a signal may be released from the embryonic axis during imbibition, leading to the expression of a set of glyoxysomal enzymes by enhancing either the transcription of their genes or transcript stability.

Catalase↗
PubMed1992

Is the anterior-posterior axis of the fetus specified before implantation in the mouse?

The mouse conceptus is generally held to be radially symmetrical about its embryonic-abembryonic axis from the blastocyst stage until the primitive streak appears at the beginning of gastrulation. However, this notion has been challenged by recent observations on conceptuses sectioned in utero which suggest that the blastocyst is already bilaterally symmetrical when it begins to implant. Accordingly, the blastocyst has been assigned an anterior-posterior axis which appears to persist through gastrulation and is claimed to coincide with the anterior-posterior axis of the future fetus in both orientation and polarity. In the present investigation the relationship between these two axes was examined in conceptuses dissected from the uterus early in gastrulation so that it could be determined more accurately than is possible in situ. The anterior-posterior axis of the conceptus and nascent fetus were found to be either parallel or antiparallel to each other, suggesting that while the orientation of the fetal axis may be specified at the blastocyst stage its polarity is not.

Animals↗
PubMed2003

Comparison of right ventricular volume measurements between axial and short axis orientation using steady-state free precession magnetic resonance imaging.

PURPOSE: To compare right ventricular (RV) volume measurements and their reproducibility between axial and short axis orientation acquisition techniques. MATERIALS AND METHODS: Measurements of RV volumes from data sets acquired in axial and short axis orientations were compared in 20 normal subjects. The observer variabilities were assessed and the left ventricle (LV) and RV stroke volumes (SV) were compared. RESULTS: There was a significant and systematic difference in the EDV and ESV volumes between the axial and short axis methods. The latter method resulted in larger volumes (mean bias EDV 7.5 +/- 13.2, 4.7% difference; ESV 7.2 +/- 8.6, 10.7% difference). The axial method had lower intra- and interobserver variability than the short axis method. The standard deviation of the difference (SDD) and the limits of agreement were consistently lower for the axial method. The mean differences between LV and RV stroke volumes expressed as mean +/- 1 SD (r(2) =correlation coefficient) were: axial 7.6 +/- 9.1 (r(2) = 0.93); and short axis 7.4 +/- 10.8 (r(2) = 0.90). CONCLUSION: There is a significant systematic difference between volumes measured using the two different orientations. The axial orientation resulted in better inter- and intraobserver reproducibility.

Adult↗
PubMed1994

Velocity invariance of preferred axis of motion for single spot stimuli in simple cells of cat striate cortex.

Directional tuning for motion of a long bar and a spot was compared quantitatively over a wide range of velocities in 23 simple cells of cat striate cortex whose "on" and "off" receptive field subregions had been mapped with optimally oriented, stationary flash-presented bars. Tuning curves were derived using stimuli whose polarity of contrast was appropriate for the dominant receptive field subregion of each cell (i.e. light stimuli for on-subregions and dark stimuli for off-subregions); stimulus sweep was centred accurately on the centre of that subregion. Bar stimuli were of optimal width, and spot diameter was equal to the width of the bars. In all simple cells, preferred axis of motion for a long bar was invariant with velocity, being orthogonal to preferred orientation, as assessed with a stationary flash-presented bar. In 20 of 23 simple cells, preferred axis for spot motion was approximately orthogonal to that for bar motion (i.e., parallel to preferred orientation) at all velocities tested, including those just above threshold for spot stimuli. However, tuning for the spot became sharper as velocity was increased, due to an increase in response to the spot moving along the preferred axis and a decrease in response to spot motion along other axes, including the preferred axis for the bar. Both preferred and upper cut-off velocity were consistently higher for spot than for bar motion. The remaining 3 simple cells showed no response to spot motion at any velocity, and their preferred axis of motion for the shortest bar which evoked a consistent response was the same as the long bar.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Bilateral comparison of femoral bone density and hip axis length from single and fan beam DXA scans.

Dominant/nondominant differences in bone mineral density (BMD) have been observed in the upper extremities. However for the proximal femur, the distinction between dominant and nondominant hips is not clear. The purpose of this study is to evaluate left/right variations in femoral BMD and hip axis length (HAL) in both single beam and fan beam dual x-ray absorptiometry (DXA) scans. A total of 36 women aged 41-76 years (average age 60 +/- 10 years) received single beam and fan beam DXA scans of both proximal femora with a Hologic QDR-2000 scanner. Femoral BMD and hip axis length were determined for each scan. Left/right and single beam/fan beam correlations were determined and differences were evaluated using a two-way analysis of variance. Femoral BMD at corresponding measurement regions in opposing femora were highly correlated (r = 0.81-0.96). No significant left/right differences were detected. At the femoral neck, the mean BMD difference (+/- standard deviation) was 1.5% +/- 4.7% in a single beam mode and -0.6% +/- 6.3% in fan beam mode. Though mean values of femoral BMD were equivalent, the observed individual left/right differences were occasionally large (as high as 26% in the femoral neck). The hip axis length of the left and right hips were highly correlated and statistically equivalent. However, hip axis length using fan beam was significantly larger (7.5%) than the single beam measurement with a larger observed variation. We conclude that measurement of a single proximal femur will usually be sufficient for clinical evaluation of BMD and/or hip axis length.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed2006

Insulin like growth factors axis and growth disorders.

The growth hormone-insulin like growth factor (GH-IGF) axis plays a crucial role in the regulation of growth. Initially considered to be a mediator of growth hormone actions, IGF axis has been established as an independent endocrine system with wide array of actions. Recent advances have led to tremendous increase in the clinical utility of the IGF axis. IGF-based investigations (IGF1 and IGF binding protein 3) are now replacing GH-based investigations for evaluation and monitoring of disorders of the GH-IGF axis. IGF therapy has been successfully utilized in growth hormone insensitivity syndrome and GHD type 1B. The possibility of IGF axis as therapeutic options is being explored in wide variety of disorders like hypoxic-ischemic encephalopathy, Alzheimer's disease and psoriasis.

Body Height↗
PubMedDate not supplied

Concomitant infusion of ovine corticotropin-releasing hormone does not prevent suppression of the hypothalamus-pituitary-adrenal axis by dexamethasone in male rats.

Glucocorticoids (GCs) suppress the hypothalamus-pituitary-adrenal (HPA) axis at various sites including hypothalamus, pituitary and extrahypothalamic brain. Previous studies have shown that corticotropin-releasing hormone (CRH) and vasopressin facilitate the recovery of HPA axis suppressed by GCs. In this study, we investigate whether the concomitant continuous infusion of CRH may prevent the suppression of HPA axis by GCs. Groups of male Wistar rats weighing 140 to 160 g were implanted subcutaneously with Alzet osmotic pump for delivery of dexamethasone (DEX), 2 micrograms/h and/or CRH, 0.66 microgram/h. Control rats were implanted with sialistic tube of similar size. Rats were decapitated 3 or 7 days after osmotic pump implantation. In spite of the suppression of plasma corticosterone, the body weight (BW), adrenal weight (AW), plasma corticotropin (ACTH) and pituitary ACTH content of rats treated with DEX for 3 days were not significantly different from those of control rats. Concomitant infusion of ovine CRH (oCRH) and DEX for 3 days caused impaired BW gain, adrenal atrophy in addition to further reduction of plasma corticosterone. Treatment with DEX and/or oCRH for 7 days caused further suppression of HPA axis as shown by reduced pituitary ACTH content. In conclusion, simultaneous infusion of oCRH and DEX does not prevent and may even worsen HPA axis suppression by DEX.

Adrenal Glands↗
PubMed2003

Role of the hypothalamic-pituitary-adrenal axis in reinstatement of cocaine-seeking behavior in squirrel monkeys.

RATIONALE: Stress has been suggested to play a role in relapse to cocaine-seeking behavior. An important physiological system activated by stress is the hypothalamic-pituitary-adrenal (HPA) axis; however, evidence for a role of HPA axis activation in cocaine relapse has been contradictory. OBJECTIVES: This study examined the effects of pharmacological stimulation of the HPA axis on reinstatement of drug-seeking behavior and salivary cortisol levels in a non-human primate model of cocaine relapse. In addition, the effect of corticotropin releasing hormone type 1 receptor (CRH-R1) blockade on cocaine priming-induced reinstatement was investigated. METHODS: Squirrel monkeys were trained to self-administer cocaine under a second-order schedule in which behavior was maintained by IV drug injections and a drug-paired visual stimulus. A period of extinction was then imposed during which saline was substituted for cocaine and the stimulus was omitted. Subsequently, monkeys were tested for reinstatement of cocaine seeking following priming injections of drugs. During reinstatement tests, the drug-paired stimulus was restored. Salivary cortisol levels were determined to measure the effects of drug treatments on the HPA axis activity. RESULTS: Priming with corticotropin releasing hormone (10 and 50 microg/kg), adrenocorticotropic hormone (1 microg/kg), or cortisol (1-10 mg/kg) did not induce significant reinstatement of cocaine seeking. All of these treatments, however, resulted in a significant increase in salivary cortisol. In contrast, priming injections of cocaine (0.1-1.0 mg/kg) dose-dependently induced reinstatement of drug seeking, but did not increase salivary cortisol. The CRH-R1 antagonist CP-154,526 (10 mg/kg, IV) did not modulate cocaine priming-induced reinstatement of drug seeking, but attenuated CRH-induced increases in salivary cortisol. CONCLUSIONS: The results suggest that activation of the HPA axis is neither necessary nor sufficient for reinstatement of cocaine-seeking behavior in this non-human primate model of cocaine relapse.

Adrenocorticotropic Hormone↗
PubMed2003

Vergence-mediated changes in the axis of eye rotation during the human vestibulo-ocular reflex can occur independent of eye position.

The aim of this study was to determine whether vergence-mediated changes in the axis of eye rotation in the human vestibulo-ocular reflex (VOR) would obey Listing's Law (normally associated with saccadic eye movements) independent of the initial eye position. We devised a paradigm for disassociating the saccadic velocity axis from eye position by presenting near and far targets that were centered with respect to one eye. We measured binocular 3-dimensional eye movements using search coils in ten normal subjects and 3-dimensional linear head acceleration using Optotrak in seven normal subjects. The stimuli consisted of passive, unpredictable, pitch head rotations with peak acceleration of approximately 2000 degrees /s(2 )and amplitude of approximately 20 degrees. During the pitch head rotation, each subject fixated straight ahead with one eye, whereas the other eye was adducted 4 degrees during far viewing (94 cm) and 25 degrees during near viewing (15 cm). Our data showed expected compensatory pitch rotations in both eyes, and a vergence-mediated horizontal rotation only in the adducting eye. In addition, during near viewing we observed torsional eye rotations not only in the adducting eye but also in the eye looking straight ahead. In the straight-ahead eye, the change in torsional eye velocity between near and far viewing, which began approximately 40 ms after the start of head rotation, was 10+/-6 degrees /s (mean +/- SD). This change in torsional eye velocity resulted in a 2.4+/-1.5 degrees axis tilt toward Listing's plane in that eye. In the adducting eye, the change in torsional eye velocity between near and far viewing was 16+/-6 degrees /s (mean +/- SD) and resulted in a 4.1+/-1.4 degrees axis tilt. The torsional eye velocities were conjugate and both eyes partially obeyed Listing's Law. The axis of eye rotation tilted in the direction of the line of sight by approximately one-third of the angle between the line of sight and a line orthogonal to Listing's plane. This tilt was higher than predicted by the one-quarter rule. The translational acceleration component of the pitch head rotation measured 0.5 g and may have contributed to the increased torsional component observed during near viewing. Our data show that vergence-mediated eye movements obey a VOR/Listing's Law compromise strategy independent of the initial eye position.

Adult↗
PubMed1998

The hypothalamic-pituitary-adrenal stress axis in fibromyalgia and chronic fatigue syndrome.

HPA axis abnormalities in FM, CFS, and other stress-related disorders must be placed in a broad clinical context. We know that interventions providing symptomatic improvement in patients with FM and CFS can directly or indirectly affect the HPA axis. These interventions include exercise, tricyclic anti-depressants, and serotonin reuptake inhibitors. There is little direct information as to how the specific HPA axis perturbations seen in FM can be related to the major symptomatic manifestations of pain, fatigue, sleep disturbance, and psychological distress. Since many of these somatic and psychological symptoms are present in other syndromes that exhibit HPA axis disturbances, it seems reasonable to suggest that there may be some relationship between basal and dynamic function of the HPA axis and clinical manifestations of FM and CFS.

Adrenocorticotropic Hormone↗
PubMed2002

Celiac axis stenosis in pancreatic head resection for chronic pancreatitis.

BACKGROUND AND AIMS: To determine the outcome of pancreatic head resection for chronic pancreatitis in the presence of celiac axis stenosis or occlusion we analyzed the blood supply of the upper abdominal organs in 11 patients before and after surgery. PATIENTS AND METHODS: Between March 1994 and April 2000 we performed 145 pancreatic head resections for chronic pancreatitis. Preoperatively 11 patients showed celiac axis stenosis at angiography. All 11 patients underwent duplex ultrasonography postoperatively and 8 had magnetic resonance angiography during follow-up. RESULTS: In two cases division of the median arcuate ligament was performed to reestablish hepatic artery blood flow. No further revascularization procedures of the celiac axis were necessary. Postoperative duplex ultrasonography and magnetic resonance angiography showed normal blood flow in five patients. Four patients still had an occlusion or a significant celiac axis stenosis, and two had a stenosis only during expiration. At follow-up nine patients were completely free of abdominal pain (82%), and all had gained weight postoperatively, ranging from 5 to 16 kg. CONCLUSIONS: Our data suggest that celiac axis stenosis infrequently causes complications in pancreatic head resection for chronic pancreatitis and therefore does not represent a contraindication for this procedure. Nevertheless the hepatopedal blood flow must be confirmed by palpation or duplex ultrasonography after pancreatic head resection in these patients.

Celiac Artery↗
PubMed1981

Two-dimensional echocardiographic evaluation of discrete subaortic stenosis from the apical long axis view.

M-mode standard two-dimensional (2DE) left parasternal long axis echocardiographic examination of the left ventricular outflow tract (LVOT) was evaluated exclusively with respect to its utility in identifying discrete subaortic stenosis (SUB-AS). Important details of the anatomy of the subaortic area may also be obtained from 2DE apical long axis imaging. According, 18 patients with discrete SUB-AS were prospectively evaluated by M-mode and 2DE. The M-mode findings included narrowing of the LVOT and early systolic closure of the aortic valve. However, these findings were variable and highly dependent upon scan speed, fluid flow dynamics, and beam angulation. 2DE findings varied using the standard long axis view at the left parasternal border, depending upon the type of obstruction present. A discrete membrane produced linear echoes adjacent and parallel to the interventricular septum beneath the aortic valve. Fibromuscular obstruction produced a localized dense ridge of echoes in the LVOT. These findings were not apparent in five patients studied. In these patients, the 2DE apical long axis view was employed to image the subaortic area. From this tomographic corss-section a fibrous membrane was imaged as a linear echo parallel to the aortic valve. The membrane extended across the LVOT from the ventricular septum to the anterior leaflet of the mitral valve. The 2DE apical long axis view therefore provides an additional approach in the evaluation of patients with discrete SUB-AS.

Adolescent↗
PubMed1975

Left axis deviation and left anterior hemiblock among 8,000 Japanese-American men.

Electrocardiographic patterns of left axis deviation and left anterior hemiblock, defined by a frontal plane QRS axis of minus 30 degrees to minus 44 degrees and minus 45 degrees to minus 90 degrees, respectively, with normal QRS duration, were found to be fairly common (2.6 and 1.5 percent, respectively) in a community population of 8,000 Japanese-American men aged 45 to 69 years. More than 60 percent of men with these electrocardiographic patterns had no other cardiovascular abnormalities, and the incidence of fatal or nonfatal coronary heart disease and stroke in this group during observation periods of 3 to 6 years was not significantly different from that of control normal men. A significant association was found between these electrocardiographic patterns and the prevalence of hypertension, myocardial infarction and stroke. However, the association of myocardial infarction with left anterior hemiblock appeared to be coincidental and was attributed largely to the similarity of the electrocardiographic manifestations of left anterior hemiblock and inferior wall myocardial infarction. Men with left axis deviation were fatter and had higher blood pressure than the control population. No such difference could be demonstrated for men with left anterior hemiblock although this group was significantly older than control subjects and men with left axis deviation. The results of our study suggest that there are qualitative differences between the causative mechanisms and clinical features of left axis deviation and those of left anterior hemiblock.

Age Factors↗
PubMed1981

Pantographic evaluation of cephalometric hinge axis.

Some commercial positioner manufactures supply clear acetate prescription forms for ordering hinge axis-oriented tooth positioners. These prescription froms assume that the patient's hinge axis is located in the "center of the condylar head." The author, suspecting that this generality could not be axiomatic, investigated fifteen persons, using pantographic hinge-axis-locating equipment, and compared the actual "tatto hinge axis" with the center of condyle as seen on lateral cephalograms. According to pantographic findings, there is a greater than 50 percent chance that the terminal hinge axis is located below and behind the cephalometric "center of the condyle."

Adolescent↗
PubMed1977

Surgical treatment of the celiac axis compression syndrome.

Six patients with symptomatic celiac axis compression syndrome are reported on. Four were treated surgically with arterial reconstruction. None of these four patients was benefited more than temporarily by the corrective surgery. One patient had an abdominal exploration and highly selective vagotomy unrelated to the celiac axis and is symptom-free ten months after surgery. One patient had no surgery and remains symptomatic. Angiographic evaluation in all patients demonstrated that despite high grade stenosis of the celiac axis, there was no radiographically discernible reduction in constrast flow to the celiac axis because of well developed collaterals from the superior mesenteric artery. These results indicate that compression of the celiac axis may be merely an incidental angiographic finding, so this syndrome needs cautious evaluation.

Adult↗
PubMed1995

Down-regulation of the hypothalamo-pituitary-adrenal axis reduces brain damage and number of seizures following hypoxia/ischaemia in rats.

Several reports suggest that the activity of the hypothalamo-pituitary-adrenal axis (HPA-axis) is increased following hypoxia/ischaemia and that this might be associated with increased neuronal vulnerability. The main goal of this study was to examine the effects of down-regulation of the HPA-axis on the hypoxia/ischaemia-induced (1) rise of plasma corticosterone levels, (2) seizures, and (3) brain damage. Down-regulation of the HPA-axis was induced by prolonged corticosterone treatment lasting until 24 h before hypoxia/ischaemia exposure. When compared to 8 days vehicle (sesame oil)-treated animals (CONT), 8 days daily corticosterone (40 mg/animal)-treated animals (CORT) showed significantly reduced adrenal-and thymus weight. Shortly after hypoxia/ischaemia plasma corticosterone levels in CORT animals were significantly reduced (17.30 micrograms/dl +/- 3.50) when compared to CONT animals (54.80 micrograms/dl +/- 7.78). This correlated with the brain damage which is expressed as the ratio between the damaged area and the total area. The total brain damage was significantly less in CORT-treated animals (28% +/- 11%) than in CONT animals (69% +/- 2%). Following hypoxia/ischaemia the number of seizures was significantly reduced in CORT animals (56 +/- 26) when compared to CONT animals (217 +/- 50). We conclude that prolonged corticosterone treatment resulting in down-regulation of the HPA-axis leads to (1) lower plasma corticosterone levels during hypoxia/ischaemia, (2) a reduction in brain damage following hypoxia/ischaemia, and (3) less hypoxia/ischaemia-induced seizures.

Adrenal Glands↗