Tumor vascular signals in renal masses: detection with Doppler US

The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.     

Fictive motor patterns in chronic spinal cats.

1. Fictive motor patterns were recorded in hind leg nerves of 10 adult chronic spinal cats (spinalized at T13). Four of these animals had been trained to step with their hind legs on a treadmill (late-spinal animals), whereas the remainder received no training and were examined a short time after spinalization (early-spinal animals). 2. A fictive pattern resembling the locomotor pattern for stepping was evoked in all animals in response to stimulation of the skin of the perineal region. (2-[2,6-Dichloroaniline]-2-imidazoline) hydrochloride (Clonidine) at doses ranging from 100 to 500 micrograms/kg iv facilitated the production of this pattern, particularly in early-spinal animals. 3. The fictive locomotor pattern in late-spinal animals was more complex than that occurring in early-spinal animals. In the latter the pattern consisted of an alternation of activity in flexor and extensor nerves, and changing leg position did not qualitatively alter the pattern, whereas in late-spinal animals the relative durations of the bursts in different flexors were usually not the same, and the pattern of flexor activity was dependent on leg position. 4. Moving the legs from extension to flexion progressively decreased the duration of flexor bursts, increased the cycle period, and decreased the ease with which the pattern could be evoked in both early- and late-spinal animals. 5. 1-beta-3,4-Dihydroxyphenylalanine (DOPA)/Isonocotinic acid 2-[(2-benzylcarbamoyl)ethyl]hydrazide (Nialamide) treatment following Clonidine in early-spinal animals increased the complexity of flexor burst activity. This, and other observations, indicates that DOPA and Clonidine do not have strictly identical actions on the locomotor pattern generator. 6. Stimulation of the paws in late-spinal animals produced two patterns of activity distinctly different from the locomotor pattern. of activity distinctly different from the locomotor pattern. One was a short sequence of high-frequency rhythmic activity (at approximately 8 c/s) in response to gently stimulating one paw with a water jet, and the other was a slow rhythm in flexor nerves in response to squeezing the paw. 7. The main conclusion of this investigation is that three distinctly different fictive motor patterns can be generated in chronic spinal cats depending on the method and site of stimulation. These patterns correspond to three different behaviors (locomotion, paw shake, and rhythmic leg flexion) that can be elicited in behaving chronic spinal cats in response to the same stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)     

An intracellular study of muscle primary afferents during fictive locomotion in the cat

1. Presynaptic activity of identified primary afferents from flexor, extensor, and bifunctional hindlimb muscles was studied with intra-axonal recordings during fictive locomotion. Fictive locomotion appeared spontaneously in decorticate cats (n = 9), with stimulation of the mesencephalic locomotor region (n = 4), and in spinal cats injected with clonidine or nialamide and L-DOPA (n = 4). Representative flexor and extensor muscle nerves, recorded to monitor the locomotor pattern and dorsal rootlets of the sixth and seventh lumbar segments, were recorded simultaneously to monitor dorsal root potentials (DRPs). 2. From responses to muscle stretches and, in some instances, twitch contractions of the parent muscle, 75% of the single units examined were putatively identified as spindle afferents (40/53). On the basis of conduction velocity and stimulation threshold, 73% of these were further classified as group I fibers (29/40), the rest as group II fibers. 3. All units (n = 53 with resting potential more negative than -45 mV) showed fluctuations of their membrane potential (up to 1.5 mV) at the rhythm of the fictive locomotion. Subsequent averaging of these fluctuations over several cycles revealed that 89% of all units displayed a predominant wave of depolarization during the flexor phase, followed by a trough of repolarization. In 79% of the units, there was also a second, usually smaller, depolarization during the extensor phase. The relative size of each wave of depolarization could vary with different episodes of fictive locomotion in the same unit and among various afferents from the same muscle in the same experiment. 4. The firing frequency of some afferents from the ankle flexor tibialis anterior (5/16) and the bifunctional muscle posterior biceps-semitendinosus (4/15) was phasically modulated along the fictive step cycle. The maximum frequency always occurred during the flexor phase, i.e., during the largest depolarization of the unit. Because of the absence of phasic sensory input in the curarized animal, we assume that the phasic discharges were generated within the spinal cord and antidromically propagated. Phasic firing was never encountered in afferents from extensor muscles such as triceps surae (0/15) and vastus lateralis (0/4). 5. The results demonstrate that the pattern of rhythmic depolarization accompanying fictive locomotion is similar for the majority of flexor, extensor, and bifunctional group I (and possibly group II) muscle spindle primary afferents. They further indicate that there is a specific phasic modulation of antidromic firing for some flexor and bifunctional muscle spindle afferents.(ABSTRACT TRUNCATED AT 400 WORDS)     

Blood vessel location time by Anopheles stephensi (Diptera: Culicidae).

Probing behavior of Anopheles stephensi Liston is characterized by the following: the first probe is longer than subsequent ones, the probability of blood location rises initially and then falls, and blood vessel location is deterministic. The overall probing behavior of An. stephensi, therefore, is similar to that of Aedes aegypti (L.); i.e., differences between them were quantitative and may be accounted for by different levels of salivary apyrase and different experimental vertebrate hosts.     

Clinical and molecular overlap in overgrowth syndromes

Here, we report the clinical and molecular analysis of 75 patients with overgrowth and mental retardation, including 45 previously reported cases [Rio et al., 2003; Baujat et al., 2004]. Two groups are distinguished: group I corresponding to patients with recognizable overgrowth syndromes (Sotos syndrome (SS), Weaver syndrome (WS), Beckwith-Wiedemann syndrome, Simpson-Golabi-Behmel syndrome (SGBS), and del(22)(qter) syndrome) (60 cases) and group II corresponding to unclassified cases (15 patients). We investigated NSD1 and GPC3 deletions or mutations, 11p15 abnormalities, and 22qter deletions. Surprisingly, in Group I, two SS patients had 11p15 abnormalities and two patients with Beckwith-Wiedemann syndrome had NSD1 aberrations. In group II, two cases of del(22)(qter) were identified but neither NSD1, 11p15, nor GPC3 abnormalities were detected. These results emphasize the clinical and molecular overlap in overgrowth conditions.     

Event-related potentials (ERPs) in ecstasy (MDMA) users during a visual oddball task

Ecstasy is the common name for a drug mainly containing a substance identified as 3,4-methylenedioxymethamphetamine (MDMA). It has become popular with participants in “raves”, because it enhances energy, endurance and sexual arousal, together with the widespread belief that MDMA is a safe drug [Byard, R.W., Gilbert, J., James, R., Lokan, R.J., 1998. Amphetamine derivative fatalities in South Australia. Is “ecstasy” the culprit? Am. J. Forensic Med. Pathol. 19, 261–265]. However, it is suggested that this drug causes a neurotoxicity to the serotonergic system that could lead to permanent physical and cognitive problems.In order to investigate this issue, and during an ERP recording with 32 channels, we used a visual oddball design, in which subjects (14 MDMA abusers and 14 paired normal controls) saw frequent stimuli (neutral faces) while they had to detect as quickly as possible rare stimuli with happy or fearful expression.At a behavioral level, MDMA users imply longer latencies than normal controls to detect rare stimuli. At the neurophysiological level, ERP data suggest as main result that the N200 component, which is involved in attention orienting associated to the detection of stimulus novelty (e.g. [Campanella, S., Gaspard, C., Debatisse, D., Bruyer, R., Crommelinck, M., Guérit, J.M., 2002. Discrimination of emotional facial expression in a visual oddball task: an ERP study. Biol. Psychol. 59, 171–186]), shows shorter latencies for fearful rare stimuli (as compared to happy ones), but only for normal controls. This absence of delay was interpreted as an attentional deficit due to MDMA consumption.     

Contribution of cutaneous inputs from the hindpaw to the control of locomotion. I. Intact cats

The goal of this study was to evaluate the role of hindpaw cutaneous feedback in the control of locomotion, by cutting some (in one cat) or all (in 2 cats) cutaneous nerves bilaterally at ankle level. Kinematic and electromyographic (EMG) recordings were obtained before and for several weeks after denervation during level and incline (15 degrees up and down) treadmill walking. Ladder walking and ground reaction forces were also documented sporadically. Early after the denervation (1-3 days), cats could not walk across a ladder, although deficits were small during level treadmill walking. Increased knee flexion velocity caused a 14% reduction in swing phase duration. EMG activity was consistently increased in knee, ankle, and toe flexors, and in at least one knee or ankle extensor. The adaptive changes during walking on the incline were much reduced after denervation. Ladder walking gradually recovered within 3-7 wk. By this time, level treadmill walking kinematics had completely returned to normal, but EMG activity in flexors remained above control. Incline walking improved but did not return to normal. Mediolateral ground reaction forces during overground walking were increased by 200%. It is concluded that in intact cats, cutaneous inputs contribute more to demanding situations such as walking on a ladder or on inclines than to level walking. Active adaptive mechanisms are likely involved given that the EMG locomotor pattern never returned to control level. The companion paper shows on the other hand that when the same cats are spinalized, these cutaneous inputs become critical for foot placement during locomotion.     

Rhythmic fluctuations of dorsal root potentials and antidromic discharges of primary afferents during fictive locomotion in the cat

1. This study examines rhythmical activity of primary afferents occurring during "fictive" locomotion in decorticate paralyzed cats. Oscillations of the dorsal root potential (DRP) at the frequency of the locomotor rhythm have been observed at the lumbosacral and cervical levels. In addition, rhythmic antidromic discharges of primary afferent units have been recorded from the proximal stumps of cut dorsal root filaments. A detailed study of the relationships between the DRP fluctuations, the antidromic discharges, and the locomotor activity monitored by recording extensor and flexor muscle nerves is presented. 2. Typical DRP recordings from both lumbosacral and cervical levels show two negative waves (N1 and N2) separated by positive troughs (P1 and P2) in each locomotor cycle. Linear regression analyses indicate that the first negative wave (which generally has the largest amplitude) is related to the flexor activity whereas the second is related to the extensor activity. The relative amplitude of the two negative waves may vary without apparent concomitant changes in the recorded flexor or extensor motor nerves. The positive troughs occur respectively close to the period of transition between flexor and extensor activities and between extensor and flexor activities. 3. DRPs of similar period and amplitude can be observed in different ipsilateral roots recorded simultaneously. The DRPs recorded bilaterally from the same segment have the same periodicity but are out-of-phase. Point-to-point variations of amplitude in bilaterally recorded roots are not correlated. This suggests that the polarization of primary afferents on one side is mainly related to the locomotor events on that side. DRPs have been recorded in cats spinalized at Th13 and injected with nialamide and l-DOPA. This suggests that although the supraspinal contribution may be important, at least part of the DRPs may result from locomotor activity within the spinal cord itself. 4. A salient finding in our experiments was that of rhythmic antidromic unit discharges in the proximal stump of cut dorsal root filaments. Of the 194 units recorded, 19% (37/194) discharged in distinct bursts occurring at fixed times in the locomotor cycle. The majority of the units discharged either one burst during the period of flexor or extensor activity or one burst during one of the two periods of transition. Three units discharged two bursts per locomotor cycle. The frequency of the antidromic discharges of some units in one limb were also found to be modulated by stimulation of the skin or passive manipulation of the limbs.(ABSTRACT TRUNCATED AT 400 WORDS)     

Occupational stress in migraine is weekend headache a myth or reality?

To determine whether or not the frequency of migraine attacks increased at weekends in employed patients and if so, whether or not this was related to the type of migraine, 35 female patients prospectively recorded the presence or absence of migraine attacks daily over a six-week period. They were also asked to estimate the frequency with which emotional factors predisposed to their migraine attacks and to provide details of their occupation. A diagnosis of common (migraine without aura) or classical migraine (migraine with aura) was made according to both the criteria of the Ad Hoc Committee on the Classification of Headache and those of the International Headache Society. Eleven percent and 6% of patients, respectively, felt that emotional factors "usually" or "always" predisposed to migraine attacks. There was no significant increase in the frequency of migraine attacks at weekends in either the total group or in the employed patients. Similarly, the type of migraine made no difference to the results. There was therefore no evidence for a delayed onset of migraine at weekends related to the weekday stress of employment.     

Elevated interleukin-6 in schizophrenia

Interleukin 6 (IL-6) levels have been shown to be increased in a number of autoimmune disorders and have recently been shown to be elevated in the serum of schizophrenic patients. Given the involvement of the CNS in schizophrenia, levels of interleukin-6 in the CSF are also of interest. Thus, we examined levels of both CSF and serum IL-6 concomitantly to determine if these levels were different from control values. In addition, we examined these measures in patients both on and off antipsychotic drugs to determine if any medication or exacerbation effects may account for the difference from controls. CSF IL-6 was measured by ELISA in 61 drug-free male schizophrenic (DSM-IIIR) patients and 25 well-screened healthy male control subjects. Serum IL-6 was measured in 43 of the 61 patients, and in 16 control subjects. Serum IL-6 was significantly higher in the schizophrenic patients compared to control subjects. CSF IL-6 was also higher in the patients, but the difference was not statistically significant. Paired data showed no medication or exacerbation effects on CSF IL-6, but plasma IL-6 significantly decreased in patients that experienced an exacerbation after medication withdrawal. The results indicate that IL-6 levels may be altered in schizophrenia. The relative decrease in exacerbated patients following haloperidol withdrawal may be indicative of a compensatory response of plasma IL-6 levels to relapse.