HOXC11-SRC-1 regulation of S100beta in cutaneous melanoma: new targets for the kinase inhibitor dasatinib.

BACKGROUND: Cutaneous melanoma is an aggressive disease. S100beta is an established biomarker of disease progression; however, the mechanism of its regulation in melanoma is undefined. METHODS: Expression of HOXC11 and SRC-1 was examined by immunohistochemistry and immunofluorescence. Molecular and cellular techniques were used to investigate regulation of S100beta, including, western blot, qPCR, ChIP and migration assays. RESULTS: Expression levels of the transcription factor HOXC11 and its coactivator SRC-1 were significantly elevated in malignant melanoma in comparison with benign nevi (P<0.001 and P=0.017, respectively, n=80), and expression of HOXC11 and SRC-1 in the malignant tissue associated with each other (P<0.001). HOXC11 recruitment to the promoter of S100beta was observed in the primary melanoma cell line SKMel28. S100beta expression was found to be dependant on both HOXC11 and SRC-1. Treatment with the Src/Abl inhibitor, dasatinib, reduced HOXC11-SRC-1 interaction and prevented recruitment of HOXC11 to the S100beta promoter. Dasatinib inhibited both mRNA and protein levels of S100beta and reduced migration of the metastatic cell line MeWo. CONCLUSION: We have defined a signalling mechanism regulating S100beta in melanoma, which can be modulated by dasatinib. Profiling patients for expression of key markers of this network has the potential to increase the efficacy of dasatinib treatment.

Increased growth hormone response to dopamine infusion in insulin-dependent diabetic subjects: indication of possible blood-brain barrier abnormality.

To test the hypothesis that cerebral capillaries, which share the embroyologic and morphologic characteristics of retinal capillaries, might have the same abnormal permeability in diabetic patients, we investigated the growth hormone response to a small amount of peripherally administered dopamine (1.5 microgram/kg.min). Consistent with the known exclusion of systemic dopamine from brain parenchyma, no rise was observed in 12 normal subjects. In 10 of 12 juvenile-onset, insulin-dependent diabetic patients, however, a substantial growth hormone rise occurred (peak value, 19.2 +/- 3.0 ng/ml [mean +/- SE]). Comparision of metabolic and cardiovascular responses to the infusion in both groups did not suggest that higher circulating levels of dopamine had been achieved in the diabetics. Other growth hormone stimuli (apomorphine in decreasing amounts, glucagon, and graded physical exercise) failed to indicate that hypothalamic hypersensitivity could account for the consistent rise. We postulate that an abnormal permeability of the blood-brain barrier in the diabetic patients permitted exposure of the hypothalamic structures regulating growth hormone secretion to a greater fraction of the infused dopamine.

Interpretation of the HJ interval of the normal ballistocardiogram based on the principle of conservation of momentum and aortic ultrasonic Doppler velocity measurements during left ventricular ejection.

The principle of conservation of momentum and the observation that blood acceleration in the ascending aorta is approximately constant during ventricular ejection was applied to develop a new interpretation of the HI and IJ intervals of the normal ballistocardiogram. The results indicate that the acceleration (A), velocity (V), and displacement (D) of the ballistocardiogram in the HI and IJ phases may be expressed by a set of equations which, when evaluated numerically, give theoretical acceleration, velocity, and displacement curves. The theoretical A, V, and D curves corresponded closely to those observed on the normal ballistocardiogram record during the HJ interval.

Quantitative ascending aortic Doppler blood velocity in normal human subjects.

We have developed digital, Apple II microcomputer-based methods for the numerical analysis of pulsed, range-gated, ultrasonic Doppler blood velocity signals. These methods were then used to analyse Doppler data recorded every 5 ms from the ascending aorta via the suprasternal notch in normal subjects ranging in age from 3 to 62 years. Normal values for peak velocity, the integral of velocity over the time of systole, and the rate of change of velocity in early ejection are reported. It was found that, after an initial step increase, the velocity of blood flow in early ejection increased in a linear manner in more than two thirds of the individual beats analysed. The time for which the linear acceleration in the aorta was constant (circa 50 ms) was unrelated to the age or size of the subject.

Simultaneous Doppler blood velocity measurements from aorta and radial artery in normal human subjects.

We used two independent, pulsed, range-gated, ultrasonic, Doppler blood velocity meters to record blood velocities in the aorta and a peripheral artery in 32 normal subjects aged 8 to 62 years. Aortic signals were obtained from an unfocussed transducer in the suprasternal notch using a 2.25 MHz instrument. Simultaneous tracings were obtained from the radial or posterior tibial artery using an 8 MHz instrument. The audio Doppler signals were subjected to spectral analysis and mean velocity was calculated at 5 ms intervals during 11 successive heart beats at each site. The increase in mean velocity at the start of systole in the aorta followed a linear pattern for the first 45 ms of ejection in two thirds of the beats, irrespective of the age or size of the subject. A similar linear velocity increase in early systole was seen in the peripheral arterial signals after a delay due to the time taken for the flow wave to pass to the periphery. Thus the constant acceleration seen in aortic blood velocity tracings is transmitted to peripheral arteries in an attenuated and delayed but undistorted form.

A transmission line model of the normal aorta and its branches.

A computer model of the aorta and its branches was made based on a simulation of an electrical transmission line using T elements. The model represented the aorta, with branches to the arms and legs and a branch to the head. The values for the capacitance and inductance of each T element could be specified, and a linearly increasing left ventricular pressure was used to drive the model. Transmission line equations were used to select values for the components, and an attempt was made to simulate the results of measurements of blood velocity in the aorta and peripheral arteries of normal subjects. The values obtained with the model showed a close relation to those in experimental studies. The results support the hypothesis that the arterial bed can be well represented by a "lossless" branched transmission line, with impedances matched at each branch and terminated with resistances that give a reflection coefficient of 0.5. A driving function, in which a linearly increasing left ventricular pressure provided a transient input to an aortic root of relatively low impedance, gave the best simulation of the experimental results.

Doppler blood velocity in the pulmonary artery of infants, children, and adults.

A pulsed, range gated, directional, ultrasonic, Doppler blood velocity meter was used to record signals from the pulmonary artery in 52 normal subjects ranging in age from less than 1 week to over 30 years. Signals were obtained from an unfocused transducer in the second or third left intercostal space using a 2.25 MHz instrument. The increase in mean velocity at the start of systole followed a linear pattern for at least the first 45 ms of ejection, irrespective of the age or size of the subject. The value for the acceleration at the start of systole decreased during childhood, reaching less than half that in the aorta in adults, and the duration of the linear increase in velocity increased. The pulmonary arterial signals in newborn infants closely resembled those in the aorta. The range of frequencies seen in the sample volume in the adult pulmonary arterial signals was greater than that in the aorta, whereas in infants it was indistinguishable from that in the aorta.

Cardiac valve orifice equation independent of valvular flow intervals: application to mitral valve area computation in mitral stenosis and comparison with the Gorlin formula and direct anatomical measurements.

An orifice equation is developed which relates the effective mitral valve area (A), the average mitral valve pressure gradient (dP), the cardiac output (Q) and the heart frequency (f) through considerations of momentum conservation across the mitral valve. The form of the new equation is A = (4.75 X 10(-5)Qf/dP, where A, Q, and dP are expressed in cm2, ml X min-1 and mmHg respectively. Mitral valve areas computed with the new orifice formula are found to correlate with those computed by the Gorlin formula in conditions of equilibrium associated with the resting state at a level of r = 0.95, SE = 0.15 cm2, with autopsy measurements at a level of r = 0.85, SE = 0.18 cm2 and with direct anatomical measurements of excised valves at a level of r = 0.78, SE = 0.41 cm2. The results suggest that the new formula may be considered as an independent orifice equation enjoying a similar domain of validity as the Gorlin formula. The new equation offers the possibility of deriving additional useful haemodynamic relationships when used in combination with established cardiological formulas.

Pyogenic infection of the sacroiliac joint. Case reports and review of the literature.

Three cases of pyogenic sacroiliitis are described, and the English literature from 1878 to 1990 reviewed, for a total of 166 cases. In 1 patient the source of infection was identified at the site of an intravenous line; 1 patient had 2 risk factors for developing the disease (pregnancy and intravenous drug use); and a third patient had no source of infection and no associated risk factors. The diagnosis of pyogenic sacroiliitis was made in each patient by history, physical examination, and positive skeletal scintigraphy or computed tomography of the sacroiliac joint. The infectious agent causing septic arthritis was identified by fine-needle aspiration of the sacroiliac joint under fluoroscopic guidance. Two of the 3 patients also had an open biopsy of the sacroiliac joint--one to confirm the organism causing septic arthritis, and the other for surgical drainage of the infected sacroiliac joint. Cultures from all 3 patients grew organisms uncommon for this disease, and all were treated for 6 weeks with intravenous antibiotics. In all patients pain diminished after treatment. Pyogenic sacroiliitis is a relatively rare condition (1-2 cases reported/year) that may be clinically difficult to diagnose unless the clinician is familiar with the disease. A prompt diagnosis can prevent significant morbidity and reduce serious complication. Major predisposing factors include intravenous drug use, trauma, or an identifiable focus of infection elsewhere, but 44% of patients have no predisposing or associated factors identified. Most patients present with an acute febrile illness with pain in the buttocks and pain on movement that stresses the affected sacroiliac joint. There is no specific blood test which points to the diagnosis of pyogenic sacroiliitis, although the erythrocyte sedimentation rate may be greater than 100 mm/hr. The diagnostic procedure of choice is bone scan with attention to the early perfusion phase, which usually localizes the affected sacroiliac joint. Unilateral involvement is the rule. In patients whose blood cultures fail to reveal a causative organism, fluoroscopic guided fine-needle aspiration of the sacroiliac joint under general anesthesia may help to identify the organism. If all cultures are negative, open biopsy of the sacroiliac joint may be required. Open biopsy should also be done if sequestration or an abscess is formed, or if the patient fails to respond to antibiotic therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Partial deficiency of carnitine palmityltransferase: physiologic and biochemical consequences.

Deficiency of muscle carnitine palmityltransferase (CPT), first described in 1973 by DiMauro and associates, is proving to be one of the principal causes of recurrent paroxysmal myoglobinuria. In this disease, oxidation of lipid substrates is impaired, because CPT is necessary for the transport of long-chain fatty acids through the inner mitochondrial membrane. As a result, patients depend excessively on carbohydrate metabolism as a source of energy for muscular work.

Noninvasive measurement of cardiac function during exercise, using resaturation curves.

The resaturation curve, a noninvasive indicator-dilution test using an ear oximeter to detect rates of change in arterial oxygen saturation during breathing of various concentrations of oxygen, was used to assess cardiac performance in normal subjects and in 108 patients with cardiac valvular disease. Measurements made during exercise included the time constant of resaturation (tau) and beat-to-beat changes in arterial oxygen saturation (the left heart clearance fraction). At maximum rates of voluntary work, patients had a significantly reduced clearance fraction and longer tau than normal subjects. Clearance fraction and tau improved in patients after aortic valve replacement; deterioration occurred in tau and clearance fraction over time in patients treated medically, as compared to normal subjects who showed little change during a ten-year period. Clearance fraction and tau correlated with hemodynamic data obtained during cardiac catheterization. The resaturation curve provides an objective measure of cardiac impairment that can be readily repeated during follow-up of patients with heart disease.

Distortion of chest wall and work of diaphragm in preterm infants.

Chest wall distortion is common in infants and is especially visible in preterm infants. It has been suggested that this distortion increases the volume displacement of the diaphragm during inspiration, which may be associated with muscular fatigue and apnea. We studied 10 preterm infants who had no evidence of lung disease, investigating the effect of chest wall distortion on the volume displacement and work of the diaphragm. The volume changes of the respiratory system were partitioned using an inductance plethysmograph. The minute volume displacement and the work of the diaphragm were calculated using the partitioned abdominal volume change and the gastric and esophageal pressures. The paradoxical movement of the chest wall lasted an average of 36% of inspiration. The minute volume displacement of the diaphragm ranged from 72 to 176% of the minute pulmonary ventilation, and diaphragmatic work ranged from 94 to 793% of that performed on the lungs. The amount of chest wall distortion, as reflected by the duration of the paradoxical chest wall movement, the minute volume excursion, or work of the diaphragm, was not related to the mechanical properties of the lungs. This estimated work load may represent a significant expenditure of calories in these infants and may contribute to the development of diaphragmatic fatigue, apnea, and a prolonged need for mechanical ventilation.

Dynamics of chest wall in preterm infants.

The chest wall of the preterm infant has visible paradoxical movement during breathing, because of its greater flexibility than those of older children and adults. We studied the dynamics of the chest wall in 10 preterm infants to describe the interaction of the chest wall volume, as partitioned by the inductance plethysmograph, and the transthoracic and abdominal pressures. There was considerable hysteresis between the chest wall volume and the transthoracic pressure, and it had linear pressure-volume behavior during airway occlusion, late inspiration, and early expiration. The slope of this pressure-volume relationship, or the instantaneous chest wall compliance, averaged 0.89 +/- 0.16 and 0.94 +/- 0.18 ml/cmH2O for the respiratory effort during airway occlusion and early expiration, respectively. The dynamic compliance was considerably greater, averaging 7.8 +/- 2.3 ml/cmH2O. This resistive pressure-volume behavior was not related to the absolute value of or the rate of development of the esophageal or abdominal pressures. This additional degree of freedom of motion of the chest wall suggests that its linkage to the diaphragm is flexible, which provides a braking force for expiration and allows free movement of the diaphragm for breathing movements before birth.

Spatial and temporal resolution of aortic Doppler blood velocity signals in normal human subjects.

We have used digital, microcomputer-based methods for the numerical analysis of pulsed, range-gated, ultrasonic Doppler blood velocity signals recorded with an axially aimed transducer from the ascending aorta of normal subjects. We investigated the spatial, temporal and amplitude resolution of our methods for recording and analysis, comparing aortic signals with test signals from a sine wave function generator. The spatial resolution of our system was found to be adequate in spite of the use of a relatively large sample volume. The temporal resolution was significantly influenced by the rate of change of velocity which affected the results of discrete fast Fourier transform analysis. The rate of increase in aortic blood velocity at the start of ejection was linear, following an initial jump in velocity. The amplitude resolution was affected by fluctuations in the amplitude of the Doppler signals. We conclude that our methods do not exaggerate the bluntness of the aortic velocity profile or the linearity of the increase in blood velocity at the start of left ventricular ejection.

Doppler ultrasonic investigation of Raynaud's phenomenon: effect of temperature on blood velocity.

We have used spectral analysis of signals from a pulsed, range-gated Doppler ultrasonic instrument to make quantitative measurements of arterial blood flow velocity in the hands of normal subjects and persons with Raynaud's phenomenon. We measured the peak velocity during the cardiac cycle and the time integral of the velocity signal over the cardiac cycle. This latter parameter gives a sensitive indication of the degree of vasoconstriction in response to cold. Our preliminary results, based on findings in 13 subjects, suggest that Doppler ultrasound can differentiate persons with Raynaud's phenomenon from normal subjects.

Comparison of methods of recording and analysis of Doppler blood velocity signals in normal subjects.

Doppler blood velocity signals were recorded from the aorta and pulmonary artery in normal adults, children and premature infants, using three different pulsed, range-gated instruments. The tracings analyzed by three independent methods of spectral analysis with axially aimed transducers showed velocity patterns with a narrow range of frequencies (blunt velocity profile) with a constant acceleration of blood flow in early systole. A similar velocity pattern was seen in the premature infant's aorta in which the transducer beam was larger than the vessel insonated. We conclude that the normal velocity pattern in the central circulation is close to blunt, and that tracings obtained with transducers that insonate varying proportions of the vessel give similar signals.

Non-invasive ultrasonic cardiac output measurement in intensive care unit.

A non-invasive method for measuring cardiac output utilizing M-mode echography and pulsed Doppler ultrasound is described. Measurements were obtained in 26 of 29 randomly selected, mechanically ventilated patients. These values were compared with simultaneously measured cardiac outputs by thermodilution. There was a statistically significant linear relationship between Cardiac Output measured by Doppler (DCO) and Thermodilution (TDCO): DCO = 0.86 TDCO + 0.29 l/min (r = 0.96, n = 26, SEE = 0.45 l/min) over the range of 1.75-8.5 l/min. DCO had the additional advantage of measuring peak flow velocity and maximal blood flow acceleration during early systole, indices of left ventricular pumping ability. Ultrasonic monitoring of cardiac output may be an important supplement to invasive methods in critical care.

Quantitative assessment of peripheral arterial obstruction in Raynaud's phenomenon: development of a predictive model of obstructive arterial cross-sectional area and validation with a Doppler blood flow study.

The objective of this study was to develop a method for the analytical assessment of arterial obstruction in conditions of Raynaud's phenomenon capable of providing diagnostic criteria. Numerous attempts have been made to determine and quantify arterial obstruction in terms of Doppler ultrasound measurements of arterial blood velocity. Absent from these methods is a formulation that allows an assessment of arterial obstruction based on the obstructed area as derived from direct measurement. The authors used spectral analysis of velocity signals from a pulsed, range-gated Doppler ultrasonic instrument to make quantitative measurements of arterial blood flow velocity in hands of normal subjects and persons with Raynaud's phenomenon. They measured the peak and mean velocity during the cardiac cycle and the time integral of the velocity signal over the cardiac cycle. These measurements for two distinct hemodynamic states induced by temperature changes allowed them to calculate the fractional change in arterial cross-sectional area produced by the change in temperature through the application of a hydraulic model of digital arterial circulation. They found an equation expressing fractional obstructed area expressed as: dA/A = 2 (dD - taudv - vtau)/(D + vdtau), where D is the time integral of the velocity signal; tau is the blood flow interval, v is the blood velocity; and dD, dtau and dv are the differences in D, tau, and v at two different hemodynamic states produced by two different temperature states. Their findings suggest that over a temperature range of 35 degrees-25 degrees C, normal subjects experience 0.05/ degrees C reduction in cross-sectional area while Raynaud subjects experience a reduction of 5.8%/degrees C. The results, based on findings in 13 subjects, suggest that Doppler ultrasound can differentiate persons with Raynaud's phenomenon from normal subjects. Additionally, the hydraulic model appears to offer the potential of assessing relative stenotic area in other arterial obstructive diseases.