Verbena officinalis essential oil and its component citral as apoptotic-inducing agent in chronic lymphocytic leukemia.

We evaluated the pro-apoptotic activity of Verbena officinalis essential oil and of its main component citral, on lymphocytes collected from normal blood donors and patients with chronic lymphocytic leukemia (CLL). The number of apoptotic cells was greater in CLL patients than in healthy subjects at all different times of incubation (4, 8 and 24 hours) for samples treated with Verbena officinalis essential oil (A) and citral (B) as well vs controls at different concentrations (0.1% and 0.01%). The greater pro-apoptotic ability was shown by both essential oil of Verbena officinalis and citral at lower concentrations (after 4 h A 0.1%: 17.8% vs 37.1%; A 0.01%: 15.8% vs 52%; B 0.1%: 18.4% vs 46.4%; B 0.01%: 15.8% vs 54.2%; after 8 h A 0.1%: 23% vs 38%; A 0.01%: 22.2% vs 55%; B 0.1%: 32% vs 42.2%; B 0.01%: 22% vs 54.3%; after 24 h A 0.1%: 5% vs 20.7%; A 0.01%: 25.8% vs 47.2%; B 0.1%: 18.4% vs 46.4%; B 0.01%: 15.8% vs 54.2%). Patients carrying deletion 17p13 (p53 mutation) showed a reduced ability to undergo apoptosis with respect to patients with other genomic aberrations or normal karyotype. The proapoptotic activity of Verbena officinalis essential oil and citral is thought to be due to a direct procaspase 3 activation. These data further support evidence that indicate natural compounds as a possible lead structure to develop new therapeutic agents.

Unilateral impairment of pupillary response to trigeminal nerve stimulation in cluster headache.

The pupillary constriction induced ipsilaterally by transcutaneous electrical nerve stimulation (TENS) of the infratrochlear nerve was measured, using an electronic pupillometer, in 26 episodic cluster headache (CH) and 15 migraine sufferers tested during an attack-free period and in 16 healthy controls. In controls, TENS gave rise to a miosis which was slow in onset and long-lasting in duration, and which was comparable to that mediated by tachykinins in animals. A similar miotic response was bilaterally observed in migraine patients and in CH patients examined during the inactive phase. In CH sufferers during the cluster period, TENS only elicited a normal pupillary constriction in the asymptomatic eye, whereas the resulting response in the symptomatic eye was markedly decreased. Although the exact mechanism underlying the dysfunction remains to be clarified, these results seem to indicate that ocular trigeminal pathways are involved in CH.

Behavioral outcome of posterior parietal cortex injury in the monkey.

Recent studies from our laboratory have characterized the response properties of trigeminal nociceptive neurons located in the posterior parietal cortex of awake monkeys, particularly in the rostral portion of the inferior parietal lobule and parietal operculum within the lateral sulcus. The stimulus intensity-response functions of some nociceptive neurons were significantly correlated to the stimulus intensity-escape frequency functions. The present study provides evidence that trauma to the posterior parietal cortex alters pain sensibility to the contralateral face. Although thermal pain tolerance was dramatically altered, the discriminative aspect of thermosensitivity may have remained intact. Our results complement the recent findings of clinical studies concerned with pain and damage to the posterior parietal cortex and of experimental studies concerned with painful stimulation and changes in regional cerebral blood flow. The role of the posterior parietal cortex in nociception and pain is discussed in relation to the first somatosensory area and to unilateral spatial neglect (inattention).

Tachykinin-like immunoreactivity in the mammalian urinary bladder: correlation with the functions of the capsaicin-sensitive sensory nerves.

The tachykinin-like immunoreactivity of the urinary bladder has been measured in various species by means of an antiserum (K12) having negligible cross-reactivity with substance P. The rank order for bladder content of tachykinin-like immunoreactivity was guinea-pig greater than mice greater than rat, similar to that found for substance P-like immunoreactivity. In all three species, both substance P- and tachykinin-like immunoreactivities were depleted by systemic capsaicin desensitization. The time course for depletion of substance P- and tachykinin-like immunoreactivities of the rat bladder following extrinsic denervation was almost superimposable. At reverse phase high pressure liquid chromatography, the major constituent of tachykinin-like immunoreactivity of the rat bladder co-eluted with neurokinin A. In vitro, the contractile response of the rat bladder to capsaicin (1 microM) was directly proportional to bladder tachykinin-like immunoreactivity while the response to field stimulation was not. In vivo, the volume threshold for reflex micturition was inversely proportional to bladder tachykinin-like immunoreactivity while amplitude of micturition contraction was not. Similar correlations were found in a previous study for substance P-like immunoreactivity. The contractile response to capsaicin or neurokinin A of the rat isolated bladder were significantly reduced by incubation with phenoxybenzamine at a concentration reported to produce a selective alkylation of neurokinin-2 receptors, while the response to substance P or KCl was unaffected. These findings indicate that multiple neurokinins co-exist in those bladder sensory nerves which are capsaicin-sensitive in adult rats. Both substance P- and tachykinin-like immunoreactivities in the rat bladder appear to be good functional markers of the sensory and "efferent" functions mediated by capsaicin-sensitive nerves, consistent with the hypothesis of a transmitter role for the corresponding peptides.

Regional differences in the motor response to capsaicin in the guinea-pig urinary bladder: relative role of pre- and postjunctional factors related to neuropeptide-containing sensory nerves.

Capsaicin induced a contraction of isolated strips from the guinea-pig urinary bladder which was more evident in the dome than in the neck and inhibited contractions induced by field stimulation, particularly in the neck. Both responses exhibited prompt desensitization and were tetrodotoxin-resistant, suggesting a specific action on transmitter release from sensory nerve terminals. Indeed, the contractile response in the dome was prevented by a substance P antagonist while the inhibitory response in the neck was prevented by immunoblockade with anticalcitonin gene-related peptide (CGRP) serum. Substance P produced a contraction of the guinea-pig bladder, being about 5 times more potent in the dome than in the neck, while CGRP inhibited the evoked contractions, being about 8 times more potent in the neck than in the dome. Further, the maximal effect of CGRP in the neck was almost double that in the dome. Substance P- and CGRP-like immunoreactivity were detected in both the dome and the neck with no regional differences for each peptide. CGRP-like immunoreactivity was 6.3 and 7.9 times higher than substance P-like immunoreactivity in the dome and the neck, respectively. Exposure to capsaicin evoked release of both substance P- and CGRP-like immunoreactivity from the dome and the neck. Peak CGRP-like immunoreactivity released by capsaicin was 12.3 and 8 times greater than substance P-like immunoreactivity in the dome and the neck, respectively. For each peptide, no difference was found in peak release in the dome vs neck. Total substance P-like immunoreactivity released from the neck was 25% lower than that released from the dome. The ability of CGRP to stimulate accumulation of 3',5' cyclic adenosine monophosphate in membranes prepared from the bladder muscle was greater in preparations from the neck than from the dome. These findings indicate that postjunctional mechanisms (type and number of receptors for sensory neuropeptides, coupling with second messengers) are a major determinant of the type of motor responses consequent of the release of sensory neuropeptides from capsaicin-sensitive nerves.

Secretion, pain and sneezing induced by the application of capsaicin to the nasal mucosa in man.

1. Topical application of capsaicin to the human nasal mucosa induced a burning sensation and sneezing. A dose-dependent seromucous nasal secretion was also observed. Capsaicin (75 micrograms) was more potent than methacholine (50 mg) in producing nasal secretion, while topical histamine (200 micrograms), substance P (135 micrograms) and calcitonin gene-related peptide (36 micrograms) did not induce rhinorrhea. 2. Pretreatment with either topical ipratropium bromide, systemic dexchlorpheniramine or indomethacin did not influence the effects induced by capsaicin. Topical pretreatment with lidocaine inhibited the painful sensation but failed to block the rhinorrhea. Desensitization to the effects of capsaicin occurred following 4-5 subsequent applications, and full recovery was observed within 30-40 days. 3. It is proposed that the effects of capsaicin in human nasal mucosa are due to excitation of primary afferent neurones that (a) convey burning and painful sensation, (b) evoke a sneezing reflex and (c) induce nasal secretion by releasing transmitter(s) from their peripheral terminals.

Peppers and pain. The promise of capsaicin.

Capsaicin, the most pungent ingredient in red peppers, has been used for centuries to remedy pain. Recently, its role has come under reinvestigation due to evidence that the drug acts selectively on a subpopulation of primary sensory neurons with a nociceptive function. These neurons, besides generating pain sensations, participate through an antidromic activation in the process known as neurogenic inflammation. The first exposure to capsaicin intensely activates these neurons in both senses (orthodromic: pain sensation; antidromic: local reddening, oedema etc.). After the first exposure, the neurons become insensitive to all further stimulation (including capsaicin itself). This evidence led to the proposal of capsaicin as a prototype of an agent producing selective analgesia. This perspective is radically different from previous 'folk medicine' cures, where the drug was used as a counter-irritating agent (i.e. for muscular pain). The new concept requires that capsaicin be repeatedly applied on the painful area to obtain the desensitisation of the sensory neurons. Following this idea, capsaicin has been used successfully in controlling pain in postherpetic neuralgia, diabetic neuropathy and other conditions of neuropathic pain. Furthermore, evidence indicates that capsaicin could also control the pain of osteoarthritis. Finally, repeated applications of the drug to the nasal mucosa result in the prevention of cluster headache attacks. On the basis of this evidence, capsaicin appears to be a promising prototype for obtaining selective analgesia in localised pain syndromes.

Kallidin applied to the human nasal mucosa produces algesic response not blocked by capsaicin desensitization.

Various kinins (dissolved in 50 microliters) were applied to the nasal mucosa of healthy human volunteers to test the algesic and proinflammatory effects of these peptides in an intact human tissue. [des-Arg9]-bradykinin (0.5 mumol) was found to be inactive, while bradykinin (0.05-0.5 mumol) and especially kallidin (0.005-0.5 mumol) induced: (a) a mild painful sensation described as burning and pricking (latency 30 s, duration 3-5 min), (b) perception of pulsatility and obstruction in the nasal cavity (onset 1 min, duration 6-8 min). Substance P (0.5 mumol) and neurokinin A (0.5 mumol) produced slight obstruction and weak pulsatile sensation but not pain. Capsaicin (0.05 nmol) produced pain and secretion of fluid, but not pulsatile sensation. The effects of kallidin were not affected by repeated (to induce desensitization) applications of capsaicin (0.5 mumol). Likewise, ipratropium bromide (80 mg in 100 microliters) did not affect responses to kallidin. In an intact human tissue, kallidin produces various effects, including an algesic response, that are apparently independent from activation of B1 receptors and from desensitization of capsaicin-sensitive primary afferents.

Simultaneous release of substance P- and calcitonin gene-related peptide (CGRP)-like immunoreactivity from isolated muscle of the guinea pig urinary bladder.

Capsaicin (10 microM) induced a tetrodotoxin (TTX)-resistant release of substance P (SP)- and calcitonin gene-related peptide (CGRP)-like immunoreactivity (LI) from muscle strips of the guinea pig isolated urinary bladder. A second application of capsaicin had no effect, indicating a specific effect on sensory nerves (desensitization). In functional experiments, capsaicin produced a phasic contraction of isolated bladder strips. This response was TTX-resistant, exhibited desensitization and was specifically antagonized by [D-Pro4, D-Trp7.9, Phe11] SP(4-11) a SP antagonist which also reduced, at a similar extent, the contraction induced by exogenous SP. These findings provide direct neurochemical and functional evidence for a transmitter role for a SP-like peptide(s) from peripheral sensory terminals in the guinea pig urinary bladder.

Beneficial effect of capsaicin application to the nasal mucosa in cluster headache.

Capsaicin application to human nasal mucosa was found to induce painful sensation, sneezing, and nasal secretion. All of these factors exhibit desensitization upon repeated applications. The acute effects induced by capsaicin (300 micrograms/100 microliters) application to the nasal mucosa were studied in healthy volunteers and cluster headache patients. These effects were not different in both nostrils of cluster headache patients as well as in the single nostril of healthy controls. Likewise, the time course of desensitization to the painful sensation and nasal secretion induced by capsaicin applied for five consecutive days in control subjects was almost superimposable to those observed in the nasal mucosa of cluster headache patients. The number of spontaneously occurring attacks was significantly reduced in the 60 days after the end of capsaicin treatment. Whether the beneficial effect induced by capsaicin application to the nasal mucosa could be ascribed to a specific action on sensory neurons remains unknown.

In vivo pupillary constrictor effects of substance P in man.

The ocular effects of substance P (SP) were studied in 13 normal volunteers. Various concentrations of SP (0.135, 1.35 and 135 micrograms per 100 microliters) were instilled into the conjunctival sac and pupillary area changes were evaluated by means of an electronic pupillometer. The ability of SP to modify the mydriasis induced by pretreatment with 1% homatropine eyedrops was also studied. The instillation of SP produced miosis in a dose-dependent manner without provoking any ocular disturbances. Furthermore, the highest concentration tested was unable to reduce the homatropine-induced mydriasis. These findings indicate that SP exerts a pupillokinetic action in humans which probably occurs via a receptor mechanism. Since muscarinic blockade is not overcome by the peptide instillation, the results do not clarify whether SP causes miosis acting on iris muscles and/or cholinergic fibres.

Does anisocoria by clonidine reflect a central sympathetic dysfunction in cluster headache?

Local pharmacological manipulations of both pupils in persons with cluster headache (CH) have shown a reduced pain-side sympathetic activity. It is difficult to determine if this sympathetic defect is localized in the nuclei of the CNS and/or in peripheral neurons that innervate the pupil. This study demonstrates that in a CH group 2% tyramine (an intraneuronal norepinephrine releaser) instillation into both eyes induces an asymmetric and bilateral mydriasis with the onset of anisocoria characterized by a pupillary diameter being less on the pain-side eye. In addition, intravenous administration of 0.10 mg clonidine, an inhibitor of central sympathetic activity, causes a bilateral miotic response, which is more marked on the pain-side eye. In a healthy control group, clonidine induces a symmetric and bilateral miosis but less intense than that observed in both eyes of CH sufferers. In CH patients, pretreatment with clonidine augments the degree of anisocoria induced by tyramine instillation, increasing the mydriatic response only in the pain-free-side pupil. The hypothesis of a permanent sympathetic defect of the pain-side pupil expressing itself as a reduced sympathetic tone of CNS nuclei and peripheral neurons that innervate the pupil is proposed.

Is the unresponsiveness to sumatriptan in cluster headache related to an alteration in the 5-HT receptors?

It is well established that cluster headache shows impaired functions at the neuroimmunomodulatory system level. Defects in the expression of receptors for 5-HT, IL-1 and IL-2 have been found in these patients. Sumatriptan, an agonist activity for 5-HT1D receptor, truncates cluster headache attack in 74% of patients. Flow cytometric analysis of monocytes expressing 5-HT receptor in cluster headache patients showed different trends clearly correlated with the clinical response to sumatriptan. Our findings strongly support the concept that cluster headache patients which are non-responders to sumatriptan could present a block in their 5-HT receptor expression possibly due to specific autoantibodies for this receptor site.

[Carcinoid associated with pancreatic heterotopia in Meckel's diverticulum. The clinical, morphological and ultrastructural aspects of a case]. / Carcinoide associato ad eterotopia pancreatica in diverticolo di Meckel. Aspetti clinici, morfologici ed ultrastrutturali di un caso.

A case of carcinoid tumor associated with pancreatic heterotopy in Meckel's diverticulum, in a 35 years old man is presented. The lesion was not grossly evident. The diagnosis was suspected on histological examination, and confirmed by electron microscopy.

Targeting regulatory T cells for anticancer therapy.

Regulatory T-cells (Tregs) comprise a group of either thymically derived or peripherally induced suppressor CD4+ cells involved in the control of effector T-cells against both self- and foreign-antigens. They are found increased in tumor tissues and are thought to be involved in pathogenesis of cancer by providing tumors with a mechanism to evade immune detection and destruction. Despite the fact that mechanisms of Tregs regulation are still in progress, efforts are made aiming to develop approaches to deplete or inhibit tumor-associated Tregs function. This could lead to restore antitumor immunity and emerging strategies for therapeutic vaccination, and immunotherapeutic targeting of Tregs with specific drugs are underway.

Analgesic effect of capsaicin in idiopathic trigeminal neuralgia.

Twelve informed and consenting patients were studied to determine the influence of capsaicin, the pungent component of the red pepper, on trigeminal neuralgia. All of these patients had idiopathic trigeminal neuralgia. These patients were followed up for 1 yr after the topical application over the painful area of 1.0 g of capsaicin three times a day for several days. Six patients had complete and four patients had partial relief of pain; the remaining two patients had no relief of pain. Of the 10 patients who were responsive to therapy, four had relapses of pain in 95-149 days. There were no relapses following the second therapy for the remainder of the year. We conclude that the topical application of capsaicin is frequently successful in relieving the pain from trigeminal neuralgia.

Idiopathic headache as a possible risk factor for phantom tooth pain.

Following tooth pulp extirpation, some subjects suffer from persistent pain which affects edentate sites in absence of any local pathology. As regards this peculiar pain, called phantom tooth pain (PTP), what is puzzling is the fact there is a low prevalence of PTP in a very large population showing identical conditions of tooth pulp extirpation. The present investigation indicates that PTP mainly affects migraine (M) and cluster headache (CH) sufferers, whereas it does not affect subjects who have a negative personal and family history for idiopathic headache (IH). These results circumscribe the presence of PTP to a specific section of the population. The present results, besides indicating that PTP may be the result of a peculiar neuronal predisposition relating to IH pathogenesis, suggests some practical therapeutic hints. In fact, successful anti- M and anti-CH prophylactic treatment greatly improve PTP syndrome.

Transcutaneous electrical stimulation applied to the infratrochlear nerve induces a homatropine-resistant miosis in humans.

1. Both high- and low-intensity transcutaneous electrical stimuli were applied to the emergence of the infratrochlear nerve in 18 healthy subjects. The effect on the size of the homolateral pupil was investigated. The width of the pupil was also measured when high-intensity transcutaneous electrical stimulation was applied to the contralateral side. 2. The high-intensity pulse resulted in constriction of the pupil when the stimulation was homolateral. The miosis was slow in onset (120 s latency) and long-lasting (80 s). No pupillary changes were detected after either ipsilateral low-intensity or contralateral high-intensity stimuli. 3. In 11 healthy subjects, the pupillary response to transcutaneous electrical stimulation was evaluated during iris parasympathetic blockade induced by homatropine eyedrops. The disappearance of the light reflex due to homatropine was considered an index of the parasympathetic blockade. Afterwards, a high-intensity pulse was transcutaneously delivered to the emergence of the infratrochlear nerve and the ipsilateral pupil size was measured. 4. A reduction in the pupillary size followed the electrical stimulation, still under the effect of homatropine which abolished the light reflex. The time course of this pupillary constriction was similar to that seen without the influence of homatropine. 5. The findings suggest that homolateral miosis, observed after unilateral high-intensity stimulation of the infratrochlear nerve, does not stem from cholinergic activation. It has been suggested that miosis induced by transcutaneous electrical stimulation may be due to an antidromic activation of the iris sensory fibres.