Bone metastases in biliary cancers: A multicenter retrospective survey.

•Natural history of biliary cancers metastatic to bone•The role of skeletal events in patients with biliary cancer•Biliary cancer and bone metastases: role of bisphosphonates.

Effects of focal vibration on bone mineral density and motor performance of postmenopausal osteoporotic women.

AIM: This randomized double blind controlled study is aimed at determining the effect of repeated vibratory stimuli focally applied to the contracted quadriceps muscles (repeated muscle vibration=rMV) on bone mineral density, leg power and balance of postmenopausal osteoporotic women. METHODS: The study has been conducted on 40 voluntary postmenopausal osteoporotic women, randomised at 2 groups for rMV treatment and for control. The treatment group underwent rMV (100Hz, 300-500 µm; three applications per day, each lasting 10-minutes, for 3 consecutive days) applied to voluntary contracted quadriceps (VC=vibrated and contracted group). The control group, received a sham stimulation on contracted quadriceps (NV=non vibrated group). Bone mineral density T-score of proximal femur of the participants, was evaluated in two weeks before and 360 days after intervention; body balance and explosive leg power were measured 1 day before, 30 days and 360 days after treatment. RESULTS: VC group T-score at one year didn't change significantly relative to baseline values (pretreatment: -2.61±0.11, post-treatment -2.62±0.13); conversely in NV subjects T-score decreased significantly from -2.64 ± 0.15 SD down to -2.99 ± 0.28 SD. A significant improvement of balance and explosive leg power was observed only in VC group at 30 and 360 days after the intervention. CONCLUSION: We conclude that rMV is a safe, short-lasting and non-invasive treatment that can significantly and persistently improve muscle performance and can effectively counteract progressive demineralisation in postmenopausal and osteoporotic women.

Focal vibration of quadriceps muscle enhances leg power and decreases knee joint laxity in female volleyball players.

AIM: This double-blind randomized controlled study aims at determining the effect of repeated muscle vibration (rMV) on explosive and reactive leg power and on knee laxity of female volleyball players. METHODS: Eighteen voluntary volleyball athletes, belonging to the same senior regional level team (age=22.7 ± 3 years, height=180.3 ± 5 cm, mass= 64 ± 4 kg) were assigned to three groups (N.=6) for vibration on contracted quadriceps (VC), vibration on relaxed muscle (VR), and sham vibration (NV), respectively. Intervention consisted in 3 rMV sessions performed in 3 consecutive days. In each session, 100 Hz, 300-500 µm amplitude vibratory stimuli were bilaterally delivered to the quadriceps in three consecutive 10-minutes applications. Explosive and reactive leg power and knee joint laxity were evaluated 1 day before, and 1, 30, and 240 days after intervention. RESULTS: In VC group, explosive and reactive leg power increased respectively by ~16% and ~9% at 1 day, by ~19% and ~11% at 30 days and by ~26% and ~13% at 240 days, concomitantly knee laxity decreased by ~6%, ~15% and ~18% at the same times. These changes were significantly larger than in the other groups, in which leg power increment and knee joint laxity reduction remained close to ~3%, ~5% and ~10% at 1, 30 and 240 days, respectively. CONCLUSION: Combined bilateral voluntary contraction and rMV of the quadriceps muscles is a short-lasting, non-invasive technique that can significantly and persistently improve muscle performance and knee laxity in volleyball women players.

Central distribution of nociceptive intradental afferent nerve fibers in the rat.

The central distribution of intradental afferent nerve fibers was investigated by combining electron microscopic observations with a selective method for inducing degeneration of the A delta- and C-type afferent fibers. Degenerating terminals were found on the proprioceptive mesencephalic trigeminal neurons and on dendrites in the neuropil of the trigeminal motor nucleus after application of capsaicin to the rat's lower incisor tooth pulp. The results give anatomical evidence of new sites of central projection of intradental A delta- and C-type fibers whereby the nociceptive information from the tooth pulp can affect jaw muscle activity.

Improvement of posture stability by vibratory stimulation following anterior cruciate ligament reconstruction.

Surgical reconstruction of the anterior cruciate ligament (ACL) may reduce, but it does not always eliminate, knee and body instability because of a persisting proprioceptive deficit. In order to enhance body stability, a new protocol of treatment has been proposed consisting of mechanical vibration (100 Hz frequency and < 20 microm amplitude) of the quadriceps muscle in the leg that has undergone ACL reconstruction. In our trials, stimulation was performed when the quadriceps muscle was kept isometrically contracted. Treatment was started one month after surgery. Vibration was applied for short periods over three consecutive days. Nine months after treatment, postural stability was re-evaluated with the subjects standing on one leg with open and with closed eyes. The postural stability of the subjects having undergone vibration treatment, standing on the operated leg was significantly improved one day after treatment when evaluated as mean of speed and elliptic area of the center of pressure. The improvement persisted and increased during the following weeks. Peak torques of the operated leg extensor muscles also increased and reached values close to that of the leg, which had not been operated. Conversely, the balance of the untreated subjects standing on the operated leg did not improve and the restoration of the extensor muscle peak torque was poor. It is concluded that short lasting proprioceptive activation by vibration may lead to a faster and more complete equilibrium recovery probably by permanently changing the network controlling knee posture.

Selective deafferentation of hand cutaneous territory is followed by changes in fibre type distribution of a forearm muscle in the horse.

Based on previous observations that capsaicin can selectively damage group III and IV afferents and induce muscle fibre transformation, we hypothesized that eliminating, by means of capsaicin, the group III and IV afferents of a peripheral territory it could lead to a fibre transformation in a muscle involved in the flexor reflexes of the same peripheral territory. Therefore, capsaicin was injected into the palmar nerves of the forelimb of the horse to investigate if eliminating group III and IV afferents from the hand of the horse a muscle fibre transition would occur in the flexor carpi radialis (FCR) muscle, which is involved in the flexor reflexes of the finger itself. 120 days after capsaicin injection, type I slow fibres increased and type IIA fast fibres decreased. We presume that the long lasting deafferentation of the ergo-nociceptive fibres causes a plastic remodelling in the central nervous system and indirectly influences the motoneuron excitability via short or long loop-pathways enhancing their tonic discharge.

Capsaicin-sensitive muscle afferents modulate the monosynaptic reflex in response to muscle ischemia and fatigue in the rat.

The role of muscle ischemia and fatigue in modulating the monosynaptic reflex was investigated in decerebrate and spinalized rats. Field potentials and fast motoneuron single units in the lateral gastrocnemious (LG) motor pool were evoked by dorsal root stimulation. Muscle ischemia was induced by occluding the LG vascular supply and muscle fatigue by prolonged tetanic electrical stimulation of the LG motor nerve. Under muscle ischemia the monosynaptic reflex was facilitated since the size of the early and late waves of the field potential and the excitability of the motoneuron units increased. This effect was abolished after L3-L6 dorsal rhizotomy, but it was unaffected after L3-L6 ventral rhizotomy. By contrast, the monosynaptic reflex was inhibited by muscle fatiguing stimulation, and this effect did not fully depend on the integrity of the dorsal root. However, when ischemia was combined with repetitive tetanic muscle stimulation the inhibitory effect of fatigue was significantly enhanced. Both the ischemia and fatigue effects were abolished by capsaicin injected into the LG muscle at a dose that blocked a large number of group III and IV muscle afferents. We concluded that muscle ischemia and fatigue activate different groups of muscle afferents that are both sensitive to capsaicin, but enter the spinal cord through different roots. They are responsible for opposite effects, when given separately: facilitation during ischemia and inhibition during fatigue; however, in combination, ischemia enhances the responsiveness of the afferent fibres to fatigue.

The role of capsaicin-sensitive muscle afferents in fatigue-induced modulation of the monosynaptic reflex in the rat.

1. The role of group III and IV afferent fibres of the lateral gastrocnemious muscle (LG) in modulating the homonymous monosynaptic reflex was investigated during muscle fatigue in spinalized rats. 2. Muscle fatigue was induced by a series of increasing tetanic electrical stimuli (85 Hz, 600 ms) delivered to the LG muscle nerve. Series consisted of increasing train numbers from 1 to 60. 3. Potentials from the spinal cord LG motor pool and from the ventral root were recorded in response to proprioceptive afferent stimulation and analysed before and during tetanic muscle activations. Both the pre- and postsynaptic waves showed an initial enhancement and, after a '12-train' series, an increasing inhibition. 4. The enhancement of the responses to muscle fatiguing stimulation disappeared after L3-L6 dorsal root section, while a partial reflex inhibition was still present. Conversely, after section of the corresponding ventral root, there was only a reduction in the inhibitory effect. 5. The monosynaptic reflex was also studied in animals in which a large number of group III and IV muscle afferents were eliminated by injecting capsaicin (10 mM) into the LG muscle. As a result of capsaicin treatment, the fatigue-induced inhibition of the pre- and postsynaptic waves disappeared, while the response enhancement remained. 6. We concluded that the monosynaptic reflex inhibition, but not the enhancement, was mediated by those group III and IV muscle afferents that are sensitive to the toxic action of capsaicin. The afferents that are responsible for the response enhancement enter the spinal cord through the dorsal root, while those responsible for the inhibition enter the spinal cord through both the ventral and dorsal roots.

Partial transformation from fast to slow muscle fibers induced by deafferentation of capsaicin-sensitive muscle afferents.

Mechanical and histochemical characteristics of the lateral gastrocnemius (LG) muscle of the rat were examined 21 days after capsaicin injection into the LG muscle. The capsaicin caused a decrease in generation rate of twitch and tetanic tension and an increase in fatigue resistance of LG muscle. The histochemical muscle fiber profile evaluated by myosin adenosine triphosphatase and reduced nicotinamide adenine dinucleotide tetrazolium reductase methods showed an increase of type I and IIC fibers and a decrease of the type IIB in whole muscle, and a decrease of the IIA, IIX fibers in the red part accompanied by their increase in the white part. Therefore the capsaicin treatment, which selectively eliminated fibers belonging to the III and IV groups of muscle afferents, induced muscle fiber transformation from fast contracting fatiguing fibers to slowly contracting nonfatiguing ones.

Central projections and entries of capsaicin-sensitive muscle afferents.

The entry pathway and central distribution of A delta and C muscle afferents within the central nervous system (CNS) were investigated by combining electron microscopy and electrophysiological analysis after intramuscular injection of capsaicin. The drug was injected into the rat lateral gastrocnemius (LG) and extraocular (EO) muscles. The compound action potentials of LG nerve and the evoked field potentials recorded in semilunar ganglion showed an immediate and permanent reduction in A delta and C components. The morphological data revealed degenerating unmyelinated axons and terminals in the inner sublamina II and in the border of laminae I-II of the dorsal horn at L4-L5 and C1-C2 (subnucleus caudalis trigemini) spinal cord segments. Most degenerating terminals were the central bouton (C) of type I and II synaptic glomeruli. Furthermore, degenerating peripheral axonal endings (V2) presynaptic to normal C were found. Since V2 were previously found degenerated after cutting the oculomotor nerve (ON) or L4 ventral root, we conclude that some A delta and C afferents from LG and EO muscles entering the CNS by ON or ventral roots make axoaxonic synapses on other primary afferents to promote an afferent control of sensory input.

Tenotomy prevents the functional improvement of a muscle reinnervated with a chronically severed nerve.

During the early stages of nerve implantation, we followed the dynamic properties of the lateral gastrocnemius muscle of the rat, reinnervated with an acutely or chronically severed peroneal nerve. The aim of this study was to ascertain whether 1) the better functional recovery of a muscle reinnervated by a chronically severed foreign nerve is present from the onset of reinnervation, and 2) whether such functional improvement is due to the conditioning lesion effect. Our results indicate that better functional recovery is already apparent one week after nerve implantation, and it is due to the conditioning lesion effect, since tenotomy prevents such improvement. The tenotomy effect underlines the fact that some environmental factors concerning the target tissue, and not only the predegenerated nerve, are involved in the conditioning effect.

Effects of capsaicin in the motor nerve.

The injection of capsaicin into the lateral gastrocnemius (LG) muscle of the rat induced an immediate and sustained reduction in the A delta and C components of the compound action potential (CAP) of the LG motor nerve. Conversely, the drug did not immediately affect the CAP wave belonging to fast-conducting fibers or the motor responses to LG nerve stimulation. It seems that capsaicin only affects the group III and IV afferents of LG nerve. However, a week after the injection the capsaicin also altered the motor responses, as shown by the threshold enhancement and amplitude reduction of the muscle twitch and by the decrease of the A alpha-beta CAP components. This late motor impairment was attributed to a central depression following a reduction of capsaicin-sensitive neuron input into the CNS. However, this motor effect was transient since the LG nerve regained the preinjection excitability level in a week and the muscle twitch amplitude reached the control value in a month.

L-acetylcarnitine enhances functional muscle re-innervation.

The efficacy of L-acetylcarnitine and L-carnitine treatment on motor re-innervation was analyzed by evaluating different muscular parameters describing functional muscle recovery after denervation and re-innervation. The results show that L-acetylcarnitine markedly enhances functional muscle re-innervation, which on the contrary is unaffected by L-carnitine. The medial gastrocnemius muscle was denervated by cutting the nerve at the muscle entry point. After 20 days the sectioned nerve was resutured into the medial gastrocnemius muscle, and the extent of re-innervation was monitored 45 days later. L-acetylcarnitine-treated animals show significantly higher twitch and tetanic tensions of re-innervated muscle. Furthermore the results, obtained by analysing the twitch time to peak and tetanic contraction-relaxation times, suggest that L-acetylcarnitine mostly affects the functional re-innervation of slow motor units. The possible mechanisms by which L-acetylcarnitine facilitates such motor and nerve recovery are discussed.

Increased prevalence of neurologic complications among insulin dependent diabetic patients of Algerian origin.

This study was undertaken to ascertain a clinical impression that the prevalence of complications is higher in insulin-dependent Algerian diabetics than in their European counterparts. Forty-one Algerian patients under regular follow-up for 2 years or more were closely matched to 41 French insulin dependent diabetics with regard to sex (34M/7F) and duration of disease (10.5 +/- 1 year; range 2 -32 years). Insulin dose, number of injections, arterial blood pressure, glycemia, glycosylated haemoglobin, cholesterolemia and triglyceridemia were similar in the two groups. The age at the time of diagnosis of diabetes was higher in the Algerian group (28.7 +/- 1.9 vs 21.4 +/- 1.7) as was the number of smokers (23/41 vs 12/41). No difference was noted between the two groups with respect to the prevalence of retinopathy (absent, simple, proliferative): 25, 12, and 4 vs 29, 9, and 3 or nephropathy (absent, incipiens, patent): 30, 6, 5 for the Algerians and 35, 3, 2 for the French. This suggest that long term metabolic control was relatively identical in the two groups. The incidence of neuropathy rated as absent, moderate (abolished reflexes, impaired pallesthesia, cardiac neuropathy) or severe was significantly higher in the Algerians (13, 16 and 12) as compared to the French (28, 10 and 3) p less than 0.01. Severe neuropathy in the Algerian group was often multiple (8/12), serious and early. The only difference between the neuropathic and non-neuropathic Algerian subgroups was the duration of disease (13.2 +/- 2.2 vs 7.3 +/- 0.01; p less than 0.01). Since there were apparently no acquired nutritional factors, an ethnic predisposition of Algerians to develop neuropathy seems likely.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of atrophy on the efficiency of muscle reinnervation.

The effectiveness of motor reinnervation carried out after an interval of 20 days between nerve transection and reimplantation onto a foreign muscle was studied in the rat. Sixty days after reimplantation the compound action potential, the maximal indirect twitch and tetanic tensions, and weight loss were evaluated. The functional data demonstrated an incomplete recovery which differed from the complete functional restoration observed in an acutely denervated muscle reinnervated with a chronically severed nerve. Time-dependent changes induced in the muscle by denervation seem therefore to influence the efficacy of motor reinnervation.

Telethermographic findings after transcutaneous electrical nerve stimulation.

The purpose of this study was to determine whether some types of transcutaneous electrical nerve stimulation cause local vasodilation. The amount of vascular perfusion was monitored using telethermography to gauge the skin temperature of the area to which TENS was applied. We studied the effects of four different modalities of TENS (intensities of 1.5 and 3 times the sensory threshold and frequencies of 3 pulses per second [pps] and 100 pps), delivered through small and large electrodes (1.5 cm and 4 cm in diameter), on 10 healthy subjects. Stimulation at 3 times the sensory threshold produced local hyperthermia, which was maximal when a current of 100 pps was delivered through small electrodes. Because any physical or chemical effects of the current could be eliminated as causes of hyperthermia, the rise in skin temperature was considered to be a result of increased vascular perfusion. The results of the study demonstrate that some types of TENS cause local vasodilation. This effect may represent another mechanism by which such techniques provide pain relief, particularly in the treatment of myofascial syndromes.

Neural nature of the time-dependent factor(s) involved in motor reinnervation.

The influence of a time interval between nerve transection and reimplantation into a foreign muscle on the effectiveness of reinnervation was studied in the rat. We evaluated the weight loss and the maximal twitch and tetanic tensions developed by the reinnervated muscle upon nerve stimulation 60 days after reimplantation (i) of an acutely severed nerve onto an acutely denervated muscle; (ii) of a chronically (20 days) severed nerve onto an acutely denervated muscle, and (iii) of an acutely severed nerve onto a chronically denervated muscle. The best recovery was obtained when a chronically severed nerve was implanted into an acutely denervated muscle. We conclude that a neural time-dependent factor(s) is involved in motor reinnervation.

Role of the interval between axotomy and nerve suture on the success of muscle reinnervation: an experimental study in the rabbit.

The influence of the time interval between nerve transection and neurorrhaphy on motor and sensory reinnervation was studied experimentally in the rabbit. We evaluated the maximal tetanic tension, the amplitude of the compound action potential, and the retrograde transport of horseradish peroxidase 30 and 60 days after neurorrhaphy carried out at 0, 10, or 20 days after transection of the nerves to the medial and lateral gastrocnemius and soleus muscles. The results showed that the suture 20 days after transection was followed by a more precocious motor reinnervation, whereas the outgrowth of motor axons past the suture was not affected by the time interval between transection and neurorrhaphy. On the contrary, the best regrowth of afferent axons was obtained after an interval of 10 days between transection and suture. We conclude that the time interval did not influence motor axon growth, but was involved in the operation of mechanism(s) involved in the reestablishment of impulse conduction and/or synaptic efficacy. In contrast, the time interval appeared to be related to factors involved directly in the axonal elongation of afferent fibers.