Salty taste: the paradoxical taste

Taste is a basic sensation to get attracted toward nutritious foods or avoid possible harmful substances. The basic taste qualities in humans consist of sweet, bitter, umami, salty, and sour. Basically, sweet and umami tastes make food attractive, whereas bitter and sour tastes make it avoidable. Salty taste comprises basic salty and high salt taste.The basic salty taste is known as amiloride-sensitive salty taste, which is inhibited by amiloride, but the high salt taste is not sensitive to amiloride. Moreover, high salt taste can also cause avoidance behavior in human beings. Sodium, one of the most important cations in the body fluids of vertebrates, controls the volume of total body fluids and is a risk factor for cardiovascular diseases, such as hypertension. The concentration of sodium in body fluids must be under delicate control. A distinction between the salty taste and high salt taste would be a contributing mechanism to control the volume and/or osmolarity of body fluids.

Distribution of adeG, adeB, adeE, adeY, abeM, and adeJ Efflux Pump Genes in Clinical Isolates of Acinetobacter Species from Korea

BACKGROUND: The aim of the present study was to determine the frequency of six efflux pump genes in Acinetobacter clinical isolates collected from South Korean hospitals. METHODS: In this study, we used a total of 339 Acinetobacter strains, comprising 279 Acinetobacter calcoaceticus–Acinetobacter baumannii (ACB) complex and 60 non-ACB complex strains. We performed specific PCR assays to detect adeG, adeB, adeE, adeY, abeM, and adeJ, transporter genes of the multidrug efflux pumps AdeFGH, AdeABC, AdeDE, AdeXYZ, AbeM, and AdeIJK, respectively. RESULTS: Frequencies of six efflux pump genes varied according to the species of Acinetobacter. Frequencies of adeE, abeM, and adeJ between A. baumannii group and A. nosocomialis group were found to be significantly different. Significant differences were found in the frequencies of adeB, adeE, adeY, and adeJ among the susceptible A. baumannii (SAB), multidrug-resistant A. baumannii (MDRAB), and extensively drug-resistant A. baumannii (XDRAB) groups within the 154 strains of A. baumannii. The frequencies of efflux pump genes in imipenem-susceptible and imipenem-nonsusceptible groups were significantly different for adeB, adeY, and adeJ. The frequencies of efflux pump genes in ciprofloxacin-susceptible and ciprofloxacin-nonsusceptible groups were significantly different for adeB and adeY. No significant difference was found in the frequency of efflux pump genes among groups sampled from different regions of Korea, across 86 strains of A. baumannii collected in 2012. CONCLUSIONS: The frequencies of six efflux pump genes obtained in this study demonstrate the fundamental epidemiological feature of efflux pump genes in Korean Acinetobacter clinical isolates.

Primary Myelofibrosis with MPL S505N Mutation: The First Case Reported in Korea

MPL mutation is an important molecular marker in myeloproliferative neoplasms (MPN). Although MPL W515 is a hot spot for missense mutations in MPN, MPL S505 mutations have been reported in both familial and non-familial MPN. A 72-year-old male visited the hospital, complaining mainly of dizziness and epistaxis. Leukocytosis, anemia, thrombocytopenia, tear drop cells, nucleated RBCs, and myeloblasts were observed in both complete blood cell counts and peripheral blood smears. Bone marrow aspiration failed due to dilution with peripheral blood. BM biopsy indicated hypercellular marrow, megakaryocytic proliferation with atypia, and grade 3 reticulin fibrosis. Conventional cytogenetics results were as follows: 46,XY,del(13)(q12q22)[19]/46,XY[1]. Molecular studies did not detect JAK2 V617F, BCR/ABL translocation, JAK2 exon 12, and CALR exon 9 mutations. The MPL S505N mutation was verified by colony PCR and Sanger sequencing following gene cloning. Based on the above findings, a diagnosis of overt primary myelofibrosis (PMF) was indicated. Mutation studies of buccal and T cells were not conducted. Further, family members were not subjected to mutation studies. Therefore, we were unable to determine whether this mutation was familial or non-familial. Six months after the first visit to the hospital, the patient died due to pneumonia and sepsis. Thrombotic symptoms or major bleeding events did not develop during the survival period following diagnosis of PMF. To the best of our knowledge, this may be the first reported case of PMF with the MPL S505N mutation in Korea.

Comparison of the Utility of dnaJ and 16S rDNA Sequences for Identification of Clinical Isolates of Vibrio Species

BACKGROUND: Among the many Vibrio species that can cause infections in humans, several species can cause a fatal outcome. Therefore, accurate identification of Vibrio species is very important. Since some species show atypical phenotypic features, selecting an appropriate molecular method is necessary to avoid misdiagnosis. METHODS: Vibrio clinical isolates (N=53) and reference strains (N=8) were used in this study. We analyzed the following sequences for identification: dnaJ gene, 16S rDNA, gyrase B (gyrB) V. vulnificus-specific sequence, gyrB V. navarrensis-specific sequence, and V. vulnificus hemolysin gene PCR (Vvh PCR). We performed phylogenetic analysis of the 16S rDNA, dnaJ, and gyrB sequences. Final identification was based on the combined results of all tests described above. Concordance of the 16S rDNA and dnaJ sequence analysis was measured using the Chi-square test. RESULTS: The 61 Vibrio strains were identified as follows, in descending order: V. vulnificus (78.69%), V. parahaemolyticus (6.56%), V. navarrensis (4.92%), V. mimicus (1.64%), V. cholera (1.64%), V. furnissii (1.64%), V. alginolyticus (1.64%), and Grimontia hollisae (1.64%). The accuracy rates of the dnaJ gene and 16S rDNA sequence for identification were 91.80% and 86.89%, respectively. The 16S rDNA and dnaJ sequences showed a concordance rate of 0.45, which indicates moderate agreement. CONCLUSIONS: Our results suggest that analysis of the dnaJ sequence may be a useful method for the identification of clinical isolates of Vibrio species, especially for distinguishing between closely related Vibrio species.

Assessment of Efflux Activity Using H33342 Accumulation in Tigecycline-Resistant Acinetobacter baumannii Clinical Isolates / 대한임상미생물학회지

BACKGROUND: Tigecycline resistance has emerged recently and has shown diverse mechanisms. The aim of this study was to assess the role of efflux activity in tigecycline resistance in 120 clinical isolates of A. baumannii using two methods: the H33342 accumulation assay and adeB real-time reverse transcriptase polymerase chain reaction. In addition, we analyzed the correlation between the expression level of adeB and H33342 accumulation level. METHODS: A. baumannii clinical isolates was divided into tigecycline-resistant (49 strains), intermediate (40 strains), and susceptible (31 strains) groups. The H33342 accumulation was measured in the absence or presence of the efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Real-time RT-PCR was performed to determine the relative expression of the adeB gene in A. baumannii clinical isolates. RESULTS: The level of H33342 accumulation in the resistant group was relatively lower than those in the other groups. The addition of CCCP caused a significantly increased fold change in H33342 accumulation in the tigecycline-resistant group. Significant difference in the fold change level in H33342 accumulation was found between tigecycline-susceptible and resistant isolates. Those findings support the role of efflux pumps of which substrates are H33342 in the resistance of tigecycline. Significant differences in the relative expression levels of adeB were shown between tigecycline-susceptible and resistant groups also. CONCLUSION: The results showed that several efflux pumps of which substrates were H33342 can contribute to tigecycline resistance. The adeB overexpression can also contribute to tigecycline resistance. It is possible that efflux pumps other than adeB efflux pumps contribute to tigecycline resistance because there was no correlation between fold change level in H33342 accumulation and adeB expression level.

Effects of acidic pH on voltage-gated ion channels in rat trigeminal mesencephalic nucleus neurons

The effects of acidic pH on several voltage-dependent ion channels, such as voltage-dependent K⁺ and Ca²⁺ channels, and hyperpolarization-gated and cyclic nucleotide-activated cation (HCN) channels, were examined using a whole-cell patch clamp technique on mechanically isolated rat mesencephalic trigeminal nucleus neurons. The application of a pH 6.5 solution had no effect on the peak amplitude of voltage-dependent K⁺ currents. A pH 6.0 solution slightly, but significantly inhibited the peak amplitude of voltage-dependent K⁺ currents. The pH 6.0 also shifted both the current-voltage and conductance-voltage relationships to the depolarization range. The application of a pH 6.5 solution scarcely affected the peak amplitude of membrane currents mediated by HCN channels, which were profoundly inhibited by the general HCN channel blocker Cs⁺ (1 mM). However, the pH 6.0 solution slightly, but significantly inhibited the peak amplitude of HCN-mediated currents. Although the pH 6.0 solution showed complex modulation of the current-voltage and conductance-voltage relationships, the midpoint voltages for the activation of HCN channels were not changed by acidic pH. On the other hand, voltage-dependent Ca²⁺ channels were significantly inhibited by an acidic pH. The application of an acidic pH solution significantly shifted the current-voltage and conductance-voltage relationships to the depolarization range. The modulation of several voltage-dependent ion channels by an acidic pH might affect the excitability of mesencephalic trigeminal nucleus neurons, and thus physiological functions mediated by the mesencephalic trigeminal nucleus could be affected in acidic pH conditions.

In Vitro Interactions of Antibiotic Combinations of Colistin, Tigecycline, and Doripenem Against Extensively Drug-Resistant and Multidrug-Resistant Acinetobacter baumannii

BACKGROUND: Acinetobacter baumannii infections are difficult to treat owing to the emergence of various antibiotic resistant isolates. Because treatment options are limited for multidrug-resistant (MDR) A. baumannii infection, the discovery of new therapies, including combination therapy, is required. We evaluated the synergistic activity of colistin, doripenem, and tigecycline combinations against extensively drug-resistant (XDR) A. baumannii and MDR A. baumannii. METHODS: Time-kill assays were performed for 41 XDR and 28 MDR clinical isolates of A. baumannii by using colistin, doripenem, and tigecycline combinations. Concentrations representative of clinically achievable levels (colistin 2 microg/mL, doripenem 8 microg/mL) and achievable tissue levels (tigecycline 2 microg/mL) for each antibiotic were used in this study. RESULTS: The colistin-doripenem combination displayed the highest rate of synergy (53.6%) and bactericidal activity (75.4%) in 69 clinical isolates of A. baumannii. Among them, thedoripenem-tigecycline combination showed the lowest rate of synergy (14.5%) and bacteri-cidal activity (24.6%). The doripenem-tigecycline combination showed a higher antagonistic interaction (5.8%) compared with the colistin-tigecycline (1.4%) combination. No antagonism was observed for the colistin-doripenem combination. CONCLUSIONS: The colistin-doripenem combination is supported in vitro by the high rate of synergy and bactericidal activity and lack of antagonistic reaction in XDR and MDR A. baumannii. It seems to be necessary to perform synergy tests to determine the appropri-ate combination therapy considering the antagonistic reaction found in several isolates against the doripenem-tigecycline and colistin-tigecycline combinations. These findings should be further examined in clinical studies.

The Effect of Aroma Inhalation Method on the Preoperative Anxiety of Abdominal Surgical Patients / 성인간호학회지

PURPOSE: The study was done to analyze the effects of aroma inhalation method on preoperative anxiety of abdominal surgical patients. METHODS: The research design was a nonequivalent control group non-synchronized design. The data were collected from July 25 to October 21, 2005 at C Medical Center in Seoul. The patients were divided into two group of 24 subjects each. In order for measuring the all patient's anxiety before operation and aroma inhalation, Spidlberger(1975) trait anxiety, VAS(visual analogue scale) state anxiety, blood pressure, pulse rate were taken. After experimental group was taken aroma inhalation, VAS state anxiety, blood pressure, pulse rate were measured for two group. RESULTS: After aroma inhalation, VAS state anxiety level, systolic blood pressure, diastolic blood pressure, pulse rate of the experimental group were decreased significantly than those of control group(p = .000, p = .000, p = .030. p = .000). CONCLUSION: The aroma inhalation method can be considered an effective nursing intervention that relieves the preoperative anxiety of abdominal surgical patients and stabilizes vital signs.

The Effect of Aroma Inhalation Method on the Preoperative Anxiety of Abdominal Surgical Patients / 성인간호학회지

PURPOSE: The study was done to analyze the effects of aroma inhalation method on preoperative anxiety of abdominal surgical patients. METHODS: The research design was a nonequivalent control group non-synchronized design. The data were collected from July 25 to October 21, 2005 at C Medical Center in Seoul. The patients were divided into two group of 24 subjects each. In order for measuring the all patient's anxiety before operation and aroma inhalation, Spidlberger(1975) trait anxiety, VAS(visual analogue scale) state anxiety, blood pressure, pulse rate were taken. After experimental group was taken aroma inhalation, VAS state anxiety, blood pressure, pulse rate were measured for two group. RESULTS: After aroma inhalation, VAS state anxiety level, systolic blood pressure, diastolic blood pressure, pulse rate of the experimental group were decreased significantly than those of control group(p = .000, p = .000, p = .030. p = .000). CONCLUSION: The aroma inhalation method can be considered an effective nursing intervention that relieves the preoperative anxiety of abdominal surgical patients and stabilizes vital signs.

Effects of Ethosuximide on the Pilocarpine Induced Seizure in Rat Model of Neuronal Migration Disorder

Cortical malformation-associated epileptic seizures are resistant to conventional anticonvulsant drugs. Relatively little research has been conducted on the effects of antiepileptic drugs (AEDs) on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate (MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of ethosuximide (ETX) in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injected control animals. Field potential recordings were used to monitor the amplitude and number of population spikes, and paired pulse inhibition in response to stimulation of the commissural pathway. Pharmaco-resistance was tested by measuring seizure latencies after pilocarpine administration (320 mg/kg, i.p.) with and without pre-treatment with ETX. Pre-treatment with 300 mg of ETX significantly prolonged the latency to the status epilepticus (SE) in both control and MAM-treated groups. Pre-treatment with ETX 100mg and ETX 200 mg had little effect in MAM-exposed rats. However, ETX 200 mg prolonged the latency to the SE in control groups. Spontaneous field potential and secondary after-discharges were higher for MAM-treated rat in comparison with control rats injects with ETX. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard ETX assessed in vivo. These data suggest that ETX do not prolong seizure latencies in MAM-rats exposed to pilocarpine.

Changes of CA1 Excitability in Rats after Prenatal Methylazoxymethanol Treatment

Experimentally induced cortical disorganization exhibits many anatomical features which are characteristic of cortical malformations in children with early-onset epilepsy. We used an immunocytochemical technique and extracellular field potential recordings from the dorsal hippocampus to determine whether the excitability of the CA1 pyramidal cells was enhanced in rats with experimentally induced hippocampal dysplasia. Compared with control rats, the MAM-treated rats displayed a decrease of paired pulse inhibition. When GABAA receptor antagonists were blocked with 10microM bicuculline, the amplitude of the second population spike of the MAM-treated of rats was similar to that of the first population spike, as was in the control rats. The MAM-treated rats had fewer somatostatin and parvalbumin-immunoreactive neurons than the control rats. These results suggest that the enhanced neuronal responsiveness of the in vivo recording of the CA1 in this animal model may involve a reduction of CA1 inhibition.

Effect of Soy Isoflavone Supplementation and Exercise on Serum Lipids in Postmenopausal Women

To elucidate the effect of soy isoflavone supplementation and exercise on serum lipids in normolipidemic and mildly hyperlipidemic postmenopausal period, 54 women residing in Seoul area were recruited. The subjects were divided into 4 groups: control group (n = 13), isoflavone group (n = 14), exercise group (n = 14), isoflavone + exercise group (n = 13). The control group was given placebo capsules, isoflavone group was given soy isoflavone supplements (90 mg/day), exercise group was given placebo capsules and exercised 3 times/week, over 30 min/time, and isoflavone + exercise group took soy isoflavone supplement and exercised. The duration of study were 8 weeks. The average age of the subjects was 57.0 years, 56.0 years, 54.4 years, and 55.2 years, respectively. There were no significant differences among the four groups in terms of height, weight, and body mass index. There were no significant differences among the four groups in terms of serum, total cholesterol, HDL-cholesterol. But the subjects indicated a significant difference in serum LDL-cholesterol (110.5 mg/day in before versus 74.6 mg/day in after) in the isoflavone + exercise group at the levels of p < 0.05. In conclusion, the isoflavone supplementation and exercise may be helpful to decrease serum lipids of normolipidemic and mildly hyperlipidemic postmenopausal women.

Interhemispheric Modulation on Afferent Sensory Transmission to the Ventral Posterior Medial Thalamus by Contralateral Primary Somatosensory Cortex

Single unit responses of the ventral posterior medial (VPM) thalamic neurons to stimulation were monitored in anesthetized rats during activation of contralateral primary somatosensory (SI) cortex by GABA antagonist. The temporal changes of afferent sensory transmission were quantitatively analyzed by poststimulus time histogram (PSTH). Mainly, afferent sensory transmission to VPM thalamus was facilitated (15 neurons of total 23) by GABA antagonist (bicuculline) applied to contralateral cortex, while 7 neurons were suppressed. However, when ipsilateral cortex was inactivated by GABA agonist, musimol, there was significant suppression of afferent sensory transmission of VPM thalamus. This suppressed responsiveness by ipsilateral musimol was not affected by bicuculline applied to contralateral cortex. These results suggest that afferent transmission to VPM thalamus may be subjected to the interhemispheric modulation via ipsilateral cortex during inactivation of GABAergic neurons in contralateral SI cortex.