Type and treatment of toxic mushroom poisoning in Korea

To eat unidentified or misidentified mushrooms taken from the wild can be very dangerous. In the vast majority of toxic mushroom ingestions in Korea, the mushroom was incorrectly identified. In general, poisoning of toxic mushrooms can be classified into seven types according to the toxins that they contain; amatoxin, gyromitrin, coprine, muscarine, ibotenic acid-muscimol, psilocybin-psilocin and gastrointestinal irritants. When clinicians care for a patient who ingested a toxic mushroom, it is very important to identify what kind of mushroom may have caused a patient's illness. But, in clinical practice, accurate botanical identification of the mushroom can be very difficult. Therefore, for estimating the caused mushroom and adequate treatment of poisoning, clinicians should know the type and treatment of toxic mushroom poisoning.

Muscarinic antibodies and heart rate responses to dynamic exercise and to the Valsalva maneuver in chronic chagasic patients / Anticorpos muscarínicos e resposta da frequência cardíaca ao exercício dinâmico e a manobra de Valsalva na doença de Chagas crônica

We have studied the cardiac chronotropic responses to the Valsalva maneuver and to dynamic exercise of twenty chronic chagasic patients with normal left ventricular function and no segmental wall abnormalities by two-dimensional echocardiogram. The absolute increase in heart rate of the patients (Δ = 21.5 ± 10 bpm, M±SD) during the maneuver was significantly diminished when compared to controls (Δ = 31.30 ± 70, M±SD, p = 0.03). The minimum heart rate (58.24 ± 8.90 vs. 62.80 ± 10, p = 0.68) and the absolute decrease in heart rate at the end of the maneuver (Δ = 38.30 ± 13 vs. Δ = 31.47 ± 17, p = 0.10) were not different from controls. The initial heart rate acceleration during dynamic exercise (Δ = 12 ± 7.55 vs. Δ = 19 ± 7.27, M±SD, p = 0.01) was also diminished, but the heart rate recovery during the first ten seconds was more prominent in the sero-positive patients (Median: 14, Interquartile range: (9.75-17.50 vs. 5(0-8.75, p = 0.001). The serum levels of muscarinic cardiac auto-antibodies were significantly higher in the chagasic patients (Median: 34.58, Interquartile Range: 17-46.5, Optical Density) than in controls (Median: 0, Interquartile Range: 0-22.25, p = 0.001) and correlated significantly and directly (r = 0.68, p = 0.002) with early heart rate recovery during dynamic exercise. The results of this investigation indirectly suggest that, the cardiac muscarinic auto-antibodies may have positive agonist effects on parasympathetic heart rate control of chagasic patients.

Foram estudadas as respostas cronotrópicas cardíacas à manobra de Valsalva e ao exercício dinâmico de vinte pacientes chagásicos com função ventricular esquerda normal e sem alterações da contractilidade segmentar por ecocardiografia bidimensional. O aumento absoluto da frequência cardíaca dos pacientes (Δ = 21,5 ± 10 bpm, M ± DP) durante a manobra de Valsalva foi significativamente menor quando se comparava ao grupo controle (Δ = 31,30 ± 70, p = 0,03). A frequência cardíaca mínima (58,24 ± 8,90 vs 62,80 ± 10, p = 0,68) e a diminuição da frequência cardíaca absoluta no final da manobra (Δ = 38,30 ± 13 vs Δ = 31,47 ± 17, p = 0,10) não foram diferentes em comparação com o grupo controle. A aceleração inicial da frequência cardíaca durante o exercício dinâmico (Δ = 12 ± 7,55 vs Δ = 19 ± 7,27, p = 0,01) também foi menor, mas a recuperação da frequência cardíaca, durante os primeiros dez segundos, foi maior no grupo sero-positivos [mediana:14 (intervalo interquartil: 9,75-17,50) vs 5 (0 - 8,75), p = 0,001]. Os níveis séricos de auto-anticorpos muscarínicos cardíacos foram significativamente maiores nos pacientes chagásicos do que no grupo controle [(mediana: 34,58 densidade óptica (intervalo interquartil 17 - 46,5) vs (mediana: 0, intervalo interquartil 0 - 22,25) p = 0,001] e a correlação é significativa e direta (r = 0,68, p = 0,002) com o início da recuperação da frequência cardíaca durante o exercício dinâmico. Os resultados desta investigação sugerem que indiretamente, os auto-anticorpos muscarínicos cardíacos, podem ter ação agonista positiva sobre o controle parassimpático da frequência cardíaca dos pacientes chagásicos.

Recent advances in the treatment of organophosphorous poisonings

Organophosphorous compounds have been employed as pesticides and chemical warfare nerve agents. Toxicity of organophosphorous compounds is a result of excessive cholinergic stimulation through inhibition of acetyl cholinesterase. Clinical manifestations include cholinergic syndromes, central nervous system and cardiovascular disorders. Organophosphorous pesticide poisonings are common in developing worlds including Iran and Sri Lanka. Nerve agents were used during the Iraq-Iran war in 1983-1988 and in a terrorist attack in Japan in 1994-1995. Following decontamination, depending on the severity of intoxication the administration of atropine to counteract muscarinic over-stimulation, and an oxime to reactivate acetyl cholinesterase are indicated. Supportive and intensive care therapy including diazepam to control convulsions and mechanical respiration may be required. Recent investigations have revealed that intravenous infusion of sodium bicarbonate to produce mild to moderate alkalinization is effective. Gacyclidine; an antiglutamatergic compound, was also proved to be beneficial in conjunction with atropine, pralidoxime, and diazepam in nerve agent poisoning. Intravenous magnesium sulfate decreased hospitalization duration and improved outcomes in patients with organophosphorous poisoning. Bio-scavengers including fresh frozen plasma or albumin have recently been suggested as a useful therapy through clearing of free organophosphates. Hemofiltration and antioxidants are also suggested for organophosphorous poisoning. Recombinant bacterial phosphotriesterases and hydrolases that are able to transfer organophosphorous-degrading enzymes are very promising in delayed treatment of organophosphorous poisoning. Recently, encapsulation of drugs or enzymes in nanocarriers has also been proposed. Given the signs and symptoms of organophosphorous poisoning, health professionals should remain updated about the recent advances in treatment of organophosphorous poisoning poisonings

Nicotine-evoked cytosolic Ca2+ increase and cell depolarization in capillary endothelial cells of the bovine adrenal medulla

Endothelial cells are directly involved in many functions of the cardiovascular system by regulating blood flow and blood pressure through Ca2+ dependent exocitosis of vasoactive compounds. Using the Ca2+ indicator Fluo-3 and the patch-clamp technique, we show that bovine adrenal medulla capillary endothelial cells (B AMCECs) respond to acetylcholine (ACh) with a cytosolic Ca2+ increase and depolarization of the membrane potential (20.3±0.9 mV; n=23). The increase in cytosolic Ca2+ induced by 10µM ACh was mimicked by the same concentration of nicotine but not by muscarine and was blocked by 100 µM of hexamethonium. On the other hand, the increase in cytosolic Ca2+ could be depressed by nifedipine (0.01 -100 µM) or withdrawal of extracellular Ca2+. Taken together, these results give evidence for functional nicotinic receptors (nAChRs) in capillary endothelial cells of the adrenal medulla. It suggests that nAChRs in B AMCECs may be involved in the regulation of the adrenal gland's microcirculation by depolarizing the membrane potential, leading to the opening of voltage-activated Ca2+ channels, influx of external Ca2+ and liberation of vasoactive compounds.

Acetylcholine Induces Hyperpolarization Mediated by Activation of K (Ca) Channels in Cultured Chick Myoblasts

Our previous report demonstrated that chick myoblasts are equipped with Ca2+-permeable stretch- activated channels and Ca2+-activated potassium channels (KCa), and that hyperpolarization-induced by KCa channels provides driving force for Ca2+ influx through the stretch-activated channels into the cells. Here, we showed that acetylcholine (ACh) also hyperpolarized the membrane of cultured chick myoblasts, suggesting that nicotinic acetylcholine receptor (nAChR) may be another pathway for Ca2+ influx. Under cell-attatched patch configuration, ACh increased the open probability of KCa channels from 0.007 to 0.055 only when extracellular Ca2+ was present. Nicotine, a nAChR agonist, increased the open probability of KCa channels from 0.008 to 0.023, whereas muscarine failed to do so. Since the activity of KCa channel is sensitive to intracellular Ca2+ level, nAChR seems to be capable of inducing Ca2+ influx. Using the Ca2+ imaging analysis, we were able to provide direct evidence that ACh induced Ca2+ influx from extracellular solution, which was dramatically increased by valinomycin-mediated hyperpolarization. In addition, ACh hyperpolarized the membrane potential from -12.5+/-3 to -31.2+/-5 mV by generating the outward current through KCa channels. These results suggest that activation of nAChR increases Ca2+ influx, which activates KCa channels, thereby hyperpolarizing the membrane potential in chick myoblasts.

Muscarine M2 Receptor-mediated Presynaptic Inhibition of GABAergic Transmission in Rat Meynert Neurons

Cholinergic modulation of GABAergic spontaneous miniature inhibitory postsynaptic currents (mIPSCs) by the activation of muscarine receptors was investigated in mechanically dissociated rat nucleus basalis of the Meynert neurons using the conventional whole-cell patch recording configuration. Muscarine (10microM) reversibly and concentration-dependently decreased mIPSC frequency without affecting the current amplitude distribution. Muscarine action on GABAergic mIPSCs was completely blocked by 1microM methoctramine, a selective M2 receptor antagonist, but not by 1microM pirenzepine, a selective M1 receptor antagonist. NEM (10microM), a G-protein uncoupler, attenuated the inhibitory action of muscarine on GABAergic mIPSC frequency. Muscarine still could decrease GABAergic mIPSC frequency even in the Ca2+-free external solution. However, the inhibitory action of muscarine on GABAergic mIPSCs was completely occluded in the presence of forskolin. The results suggest that muscarine acts presynaptically and reduces the probability of spontaneous GABA release, and that such muscarine-induced inhibitory action seems to be mediated by G-protein-coupled M2 receptors, via the reduction of cAMP production. Accordingly, M2 receptor-mediated disinhibition of nBM neurons might play one of important roles in the regulation of cholinergic outputs from nBM neurons as well as the excitability of nBM neurons themselves.

The Effects on Pain Relief of Intraarticular Tramadol and Neostigmine after Knee Arthroscopic Surgery / 대한마취과학회지

BACKGROUND: Evidence has accumulated that tramadol hydrochloride can produce relief of moderate to severe pain across the range of acute and chronic pain states by combining a synergistically weak opioid and a monoaminergically mediated antinociceptive mechanism. Neostigmine can produce antinociceptive effects by interacting with muscarine receptors in peripheral tissues. This study was designed to determine whether intraarticular tramadol results in better analgesic effect and whether tramadol and neostigmine would provide superior analgesia to tramadol alone, after knee arthroscopic surgery. METHODS: Forty-five ASA class 1 or 2 patients undergoing arthroscopic knee surgery were randomly allocated to three treatment groups. All patients received general anesthesia with nitrous oxide, O2 and inhalational agents. When the surgical procedure was completed, the study drug was injected into the patient's knee joint through the arthroscope. Patients in group 1 (n = 15) received 30 ml of 0.5% mepivacaine; patients in group 2 (n = 15) received tramadol 50 mg and 30 ml of 0.5% mepivacaine; patients in group 3 (n = 15) received a combination of tramadol 50 mg, neostigmine 100 micro gram and 30 ml of 0.5% mepivacaine. Postoperative pain was assessed using the visual analogue scale (VAS) at 1, 2, 4, 6, 12 and 24 hours after the intraarticular injection. RESULTS: There were no significant differences among the three groups in the 1 to 2 hour postoperative period and groups 2 and 3 showed significantly lower VAS score than group 1 from 4 to 24 hours postoperatively. CONCLUSIONS: It is concluded that after knee arthroscopy, intraarticular injection of tramadol had a good analgesic effect, whereas neostigmine added to tramadol did not show superior analgesic effects over tramadol alone.

The Effects on Pain Relief of Intraarticular Tramadol and Neostigmine after Knee Arthroscopic Surgery / 대한마취과학회지

BACKGROUND: Evidence has accumulated that tramadol hydrochloride can produce relief of moderate to severe pain across the range of acute and chronic pain states by combining a synergistically weak opioid and a monoaminergically mediated antinociceptive mechanism. Neostigmine can produce antinociceptive effects by interacting with muscarine receptors in peripheral tissues. This study was designed to determine whether intraarticular tramadol results in better analgesic effect and whether tramadol and neostigmine would provide superior analgesia to tramadol alone, after knee arthroscopic surgery. METHODS: Forty-five ASA class 1 or 2 patients undergoing arthroscopic knee surgery were randomly allocated to three treatment groups. All patients received general anesthesia with nitrous oxide, O2 and inhalational agents. When the surgical procedure was completed, the study drug was injected into the patient's knee joint through the arthroscope. Patients in group 1 (n = 15) received 30 ml of 0.5% mepivacaine; patients in group 2 (n = 15) received tramadol 50 mg and 30 ml of 0.5% mepivacaine; patients in group 3 (n = 15) received a combination of tramadol 50 mg, neostigmine 100 micro gram and 30 ml of 0.5% mepivacaine. Postoperative pain was assessed using the visual analogue scale (VAS) at 1, 2, 4, 6, 12 and 24 hours after the intraarticular injection. RESULTS: There were no significant differences among the three groups in the 1 to 2 hour postoperative period and groups 2 and 3 showed significantly lower VAS score than group 1 from 4 to 24 hours postoperatively. CONCLUSIONS: It is concluded that after knee arthroscopy, intraarticular injection of tramadol had a good analgesic effect, whereas neostigmine added to tramadol did not show superior analgesic effects over tramadol alone.