[Analysis of the efficacy and safety of coblation and pulsed radiofrequency in the treatment of cervicogenic headache].

Objective: To explore the efficacy and safety of coblation and pulsed radiofrequency on cervicogenic headache (CEH). Methods: A total of 118 patients with CEH who underwent coblation or pulsed radiofrequency in the Department of Pain Management at Xuanwu Hospital, Capital Medical University from August 2018 to June 2020 was retrospectively collected. Patients were divided into the coblation group (n=64) and the pulsed radiofrequency group (n=54) according to different surgical methods. In the coblation group, there were 14 males and 50 females, aged 29-65 (49.8±10.2) years, while in the pulse radiofrequency group, there were 24 males and 30 females, aged 18-65 (41.7±14.8) years. Visual analogue scale (VAS) score, postoperative numbness in the affected areas and other complications were recorded and compared between the two groups at preoperative 3 d, and 1 month, 3 months and 6 months postoperatively. Results: The VAS score of the coblation group was (7.16±0.91), (3.67±1.13), (1.59±0.91), (1.66±0.84) and (1.56±0.90) before operation, and 3 days, 1 month, 3 months and 6 months after surgery. Likewise, the VAS score of the pulsed radiofrequency group was (7.01±0.78), (1.58±0.88), (1.57±0.94), (3.71±1.08) and (6.92±0.83) at the aforementioned time points. There were statistically significant differences of VAS scores between the coblation group and the pulsed radiofrequency group at 3 days, 3 months and 6 months postoperatively (all P<0.001). Intra-group comparison revealed that VAS scores in the coblation group were significantly lower than those before surgery at all time points after surgery (all P<0.001), while VAS scores in the pulsed radiofrequency group were significantly decreased at 3 days, 1 month and 3 months after surgery (P<0.001). The incidence of numbness was 72% (46/64), 61% (39/64), 6% (4/64) and 3% (2/62) in the coblation group and 7% (4/54), 7% (4/54), 2% (1/54) and 0 (0/54) in the pulsed radiofrequency group, respectively. At 3 days and 1 month after surgery, the incidence of numbness in the coblation group was higher than those in the pulsed radiofrequency group (both P<0.001). In the coblation group, one patient developed pharyngeal discomfort 3 days after surgery, which disappeared spontaneously 1 week after surgery without special treatment. One patient developed vertigo after getting up in the morning at 3 days postoperatively, and the possibility of transient cerebral ischemia was considered. In the pulsed radiofrequency group, one patient developed nausea and vomiting after operation, but spontaneous remission was observed after one hour without special treatment. Conclusions: Both coblation and pulsed radiofrequency are effective and safe in the treatment of CEH. But the VAS scores at 3 and 6 months after coblation is significantly lower than those of pulsed radiofrequency ablation group, and the efficacy is better in those undergoing coblation.

Radiofrequency thermocoagulation combined with pulsed radiofrequency helps relieve postoperative complications of trigeminal neuralgia.

Trigeminal neuralgia is a sudden, severe condition characterized by stabbing and recurrent pain. Radiofrequency thermocoagulation (RFT) and pulsed radiofrequency (PRF) are common surgical interventions used to treat trigeminal neuralgia. This study aimed to investigate the therapeutic effects and associated complications of a combination of RFT and PRF in the treatment of trigeminal neuralgia. Computed tomography-guided percutaneous RFT of the Gasserian ganglion was performed on 80 patients with trigeminal neuralgia. Patients were randomly assigned to either group A (RFT at 70°C) or group B (RFT at 75°C). Patients in each group were divided into 2 subgroups, receiving percutaneous RFT (240 s) with or without PRF (42°C, 2 Hz, 240 s). Six months later, pain relief and complication status were evaluated. There was no significant difference in visual analogue scores among groups with RFT at 70° or 75°C, with or without PRF. Data showed that facial numbness and postoperative masticatory muscle weakness recovered more rapidly in patients receiving combined RFT and PRF treatment. Decreased corneal reflex was relieved to a significantly greater extent in groups receiving PRF than those without. Thus, compared to the use of RFT at 75°C alone, the combination of PRF and RFT helped eliminate postoperative complications, such as facial numbness, masticatory muscle weakness, and decreased corneal reflex, indicating that it could be useful for surgically treating trigeminal neuralgia.

Anoxia induces thermotolerance in the locust flight system.

Heat shock and anoxia are environmental stresses that are known to trigger similar cellular responses. In this study, we used the locust to examine stress cross-tolerance by investigating the consequences of a prior anoxic stress on the effects of a subsequent high-temperature stress. Anoxic stress and heat shock induced thermotolerance by increasing the ability of intact locusts to survive normally lethal temperatures. To determine whether induced thermotolerance observed in the intact animal was correlated with electrophysiological changes, we measured whole-cell K(+) currents and action potentials from locust neurons. K(+) currents recorded from thoracic neuron somata were reduced after anoxic stress and decreased with increases in temperature. Prior anoxic stress and heat shock increased the upper temperature limit for generation of an action potential during a subsequent heat stress. Although anoxia induced thermotolerance in the locust flight system, a prior heat shock did not protect locusts from a subsequent anoxic stress. To determine whether changes in bioenergetic status were implicated in whole-animal cross-tolerance, phosphagen levels and rates of mitochondrial respiration were assayed. Heat shock alone had no effect on bioenergetic status. Prior heat shock allowed rapid recovery after normally lethal heat stress but afforded no protection after a subsequent anoxic stress. Heat shock also afforded no protection against disruption of bioenergetic status after a subsequent exercise stress. These metabolite studies are consistent with the electrophysiological data that demonstrate that a prior exposure to anoxia can have protective effects against high-temperature stress but that heat shock does not induce tolerance to anoxia.

Heat shock-induced thermoprotection of action potentials in the locust flight system.

There is increasing evidence that heat shock (HS) has long-term effects on electrophysiological properties of neurons and synapses. Prior HS protects neural circuitry from a subsequent heat stress but little is known about the mechanisms that mediate this plasticity and induce thermotolerance. Exposure of Locusta migratoria to HS conditions of 45 degrees C for 3 h results in thermotolerance to hitherto lethal temperatures. Locust flight motor patterns were recorded during tethered flight at room temperature, before and after HS. In addition, intracellular action potentials (APs) were recorded from control and HS motoneurons in a semi-intact preparation during a heat stress. HS did not alter the timing of representative depressor or elevator muscle activity, nor did it affect the ability of the locust to generate a steering motor pattern in response to a stimulus. However, HS did increase the duration of APs recorded from neuropil segments of depressor motoneurons. Increases in AP duration were associated with protection of AP generation against failure at subsequent elevated temperatures. Failure of AP generation at high temperatures was preceded by a concomitant burst of APs and depolarization of the membrane. The protective effects of HS were mimicked by pharmacological blockade of I(K+) with tetraethylammonium (TEA). Taken together, these findings are consistent with a hypothesis that HS protects neuronal survival and function via K+ channel modulation.

A new approximate analytical approach for dispersion relation of the nonlinear Klein-Gordon equation.

A novel approach is presented for obtaining approximate analytical expressions for the dispersion relation of periodic wavetrains in the nonlinear Klein-Gordon equation with even potential function. By coupling linearization of the governing equation with the method of harmonic balance, we establish two general analytical approximate formulas for the dispersion relation, which depends on the amplitude of the periodic wavetrain. These formulas are valid for small as well as large amplitude of the wavetrain. They are also applicable to the large amplitude regime, which the conventional perturbation method fails to provide any solution, of the nonlinear system under study. Three examples are demonstrated to illustrate the excellent approximate solutions of the proposed formulas with respect to the exact solutions of the dispersion relation. (c) 2001 American Institute of Physics.

Potential inhibitors of S-adenosylmethionine-dependent methyltransferases. 7. Role of the ribosyl moiety in enzymatic binding of S-adenosyl-L-homocysteine and S-adenosyl-L-methionine.

A series of 2',3'-acyclic analogues of S-adenosyl-L-homocysteine were synthesized and evaluated as inhibitors of S-adenosyl-L-methionine-dependent methyltransferases. The 2',3'-acyclic analogues were prepared by periodate oxidation of the corresponding ribonucleosides, followed by reduction of the intermediate dialdehydes with sodium borohydride. These 2',3'-acyclic ribonucleosides were inactive as inhibitors of histamine N-methyltransferase, catechol O-methyltransferase, phenylethanolamine N-methyltransferase, and hydroxyindole O-methyltransferase. These results suggest that the rigidity of the ribosyl ring of S-adenosyl-L-homocysteine is crucial to its enzymatic bindings.

Affinity labeling of histamine N-methyltransferase by 2',3'-dialdehyde derivatives of S-adenosylhomocysteine and S-adenosylmethionine. Kinetics of inactivation.

S-Adenosyl-L-methionine (AdoMet), S-adenosyl-L-homocysteine (L-AdoHcy), and related ribonucleosides have been oxidized with periodic acid to the corresponding 2',3'-dialdehydes. Both AdoMet dialdehyde and L-AdoHcy dialdehyde were observed to rapidly and irreversibly inactivate histamine N-methyltransferase (HMT). Equally active as an irreversible inhibitor was S-adenosyl-D-homocysteine dialdehyde (D-AdoHcy dialdehyde), which is consistent with the known affinity of HMT for S-adenosyl-D-homocysteine (D-AdoHcy). Other analogues of AdoHcy dialdehyde (S-adenosyl-L-cysteine dialdehyde, S-adenosyl-L-homocysteine sulfoxide dialdehyde, and adenosine dialdehyde) also produced irreversible inactivation of HMT, but at predictably slower rates. The corresponding acyclic 2',3'-ribonucleosides, which were obtained by NaBH4 reduction of the ribonucleosides dialdehydes, were found to be very weak, reversible inhibitors of HMT. Kinetic analysis of the inactivation of HMT produced by L-AdoHcy dialdehyde, AdoMet dialdehyde, and D-AdoHcy dialdehyde suggested mechanisms involving the formation of dissociable enzyme-inhibitor complexes prior to irreversible inactivation. Studies using L-[2,8-3H] AdoHcy dialdehyde revealed that incorporation of radioactivity into HMT closely paralleled the loss of enzyme activity. The results of these studies indicate that L-AdoHcy dialdehyde, D-AdoHcy dialdehyde, and AdoMet dialdehyde are affinity labeling reagents for HMT.

Antitumor agents XXIII: Helenalin, and antitumor principle from Anaphalis morrisonicola HAY.

A chloroform extract of the whole plant of Anaphalis morrisonicola HAY, showed significant antitumor activity against Ehrlich ascites carcinoma, Walker 256 carcinosarcoma, and P-388 lymphocytic leukemia. Systematic fractionation of the extract led to isolation and characterization of helenalin, a pseudoguaianolide, as the major active principle.