Case of Mitral Valve Prolapse - Associated Sudden Cardiac Death in Pregnancy.

BACKGROUND Mitral valve prolapse (MVP) is a frequent echocardiographic finding that can be accompanied by symptoms ranging from a benign course to occasionally catastrophic complications, such as heart failure, and rarely, sudden cardiac death. Female sex, younger age, physiological or psychological stress, electrical instability, and changes in the structure of the mitral apparatus all seem to be risk factors for fatal ventricular arrhythmias in patients with MVP. We report a case of MVP-related cardiac arrest in a pregnant woman, which is rarely reported. CASE REPORT A 34-year-old woman who had collapsed at home from cardiac arrest was transported to the hospital. She had no history of cardiac diseases and was 8 weeks pregnant. Premature ventricular complexes and sinus tachycardia were observed on the 12-lead electrocardiogram as she arrived at the Emergency Department. The second cardiac arrest she experienced while in the hospital was observed to be from torsades de pointes. Further investigations revealed severe mitral valve regurgitation due to posterior leaflet prolapse and regional hypokinesis of the inferior wall and interventricular septum. CONCLUSIONS Ventricular arrhythmia is a frequent finding of mitral valve regurgitation. However, it rarely results in serious consequences. Malignant arrhythmic mitral valve regurgitation can result in sudden cardiac death; therefore, physicians need to be aware of patients with MVP who exhibit characteristics of a potential high-risk profile in order to avoid tragic outcomes.

Knowledge and Attitude Related to Hepatitis C among Medical Students in the Oral Direct Acting Antiviral Agents Era in Vietnam.

BACKGROUND: Medical students play important frontline roles in the prevention, early detection, and treatment of hepatitis C. This study investigated knowledge and attitudes toward hepatitis C among 5th- and 6th-year medical students and possible associated factors. METHODS: A cross-sectional survey was conducted among 2000 students from eight medical universities using a self-administered structured questionnaire. RESULTS: The mean knowledge and attitude scores for hepatitis C were 20.1 ± 4.0 (out of 26) and 10.6 ± 2.9 (out of 20), respectively. Approximately, three-quarters (74.4%) of the participants had a good knowledge score, but only a small proportion (3.1%) obtained a good attitude score. Although the participants had fairly high knowledge about the causes, consequences, and transmission routes of hepatitis C, there were important gaps in their knowledge about hepatitis C screening and treatment. In multivariate analysis, female students, 5th-year students, and students from the central provinces had significantly higher knowledge and attitude scores. There was a low positive correlation between knowledge and attitude scores. CONCLUSION: This study points out the need to update the medical training curriculum to improve the knowledge and attitude of students about hepatitis C infection.

Knowledge, Attitudes and Practices toward Hepatitis B Virus Infection among Students of Medicine in Vietnam.

BACKGROUND: Building capacity in hepatitis B virus prevention and management for medical students and health professionals is one of the pillars of the national viral hepatitis control strategy. METHODS: A cross-sectional study was conducted at eight medical universities from the northern, central and southern regions of the country between May and November 2020 using a systematic random sampling technique. RESULTS: Among 2000 participants, 84.2% reported they had been tested for hepatitis B and 83.9% had received the hepatitis B vaccine. The mean knowledge, attitude, practice score was 40.2 out of 54 (74.4%) with only 19.9% of the study participants obtaining a good score. In multivariate analysis, fifth year students, students from central universities, students who had tested positive for hepatitis B and students who had received hepatitis B vaccine or had encountered patients with chronic hepatitis B had significantly higher knowledge score (p < 0.05). The study showed lack of trust in the hepatitis B vaccine safety and lack of confidence in providing counselling, testing and management of patients with chronic hepatitis B. CONCLUSION: Findings from our research emphasized an immediate need to improve the medical schools' training curriculum in Vietnam to enable students' readiness in hepatitis B prevention and management.

Ginseng Saponins in Different Parts of Panax vietnamensis.

Chemical and pharmacological studies of Panax vietnamensis (Vietnamese ginseng; VG) have been reported since its discovery in 1973. However, the content of each saponin in different parts of VG has not been reported. In this study, 17 ginsenosides in the different underground parts of P. vietnamensis were analyzed by HPLC/evaporative light scattering detector (ELSD). Their contents in the dried rhizome, radix, and fine roots were 195, 156, and 139 mg/g, respectively, which were extremely high compared to other Panax species. The content of protopanaxatriol (PPT)-type saponins were not much different among underground parts; however, the content of protopanaxadiol (PPD)- and ocotillol (OCT)-type saponins were greatly different. It is noteworthy that the ginsenoside pattern in the fine roots is different from other underground parts. In particular, despite the content of PPD-type saponins being the highest in the fine roots, which is similar to other Panax species, the total content of saponins was the lowest in the fine roots, which is different from other Panax species. The ratios of PPT : PPD : OCT-type saponins were 1 : 1.7 : 7.8, 1 : 1.6 : 5.5, and 1 : 4.8 : 3.3 for the rhizome, radix, and fine roots, respectively. OCT-type saponins accounted for 36-75% of total saponins and contributed mostly to the difference in the total saponin content of each part.

Effects of steaming on saponin compositions and antiproliferative activity of Vietnamese ginseng.

BACKGROUND: Steaming of ginseng is known to change its chemical composition and biological activity. This study was carried out to investigate the effect of different steaming time-scales on chemical constituents and antiproliferative activity of Vietnamese ginseng (VG). METHODS: VG was steamed at 105°C for 2-20 h. Its saponin constituents and antiproliferative activity were studied. The similarity of chemical compositions between steamed samples at 105°C and 120°C were compared. RESULTS: Most protopanaxadiol and protopanaxatriol ginsenosides lost the sugar moiety at the C-20 position with 10-14 h steaming at 105°C and changed to their less polar analogues. However, ocotillol (OCT) ginsenosides were reasonably stable to steaming process. Antiproliferative activity against A549 lung cancer cells was increased on steaming and reached its plateau after 12 h steaming. CONCLUSION: Steaming VG at 105°C showed a similar tendency of chemical degradation to the steaming VG at 120°C except the slower rate of reaction. Its rate was about one-third of the steaming at 120°C.

Processed Vietnamese ginseng: Preliminary results in chemistry and biological activity.

BACKGROUND: This study was carried out to investigate the effect of the steaming process on chemical constituents, free radical scavenging activity, and antiproliferative effect of Vietnamese ginseng. METHODS: Samples of powdered Vietnamese ginseng were steamed at 120°C for various times and their extracts were subjected to chemical and biological studies. RESULTS: Upon steaming, contents of polar ginsenosides, such as Rb1, Rc, Rd, Re, and Rg1, were rapidly decreased, whereas less polar ginsenosides such as Rg3, Rg5, Rk1, Rk3, and Rh4 were increased as reported previously. However, ocotillol type saponins, which have no glycosyl moiety at the C-20 position, were relatively stable on steaming. The radical scavenging activity was increased continuously up to 20 h of steaming. Similarly, the antiproliferative activity against A549 lung cancer cells was also increased. CONCLUSION: It seems that the antiproliferative activity is closely related to the contents of ginsenoside Rg3, Rg5, and Rk1.

The central and basolateral amygdala are critical sites of neuropeptide Y/Y2 receptor-mediated regulation of anxiety and depression.

Anxiety is integrated in the amygdaloid nuclei and involves the interplay of the amygdala and various other areas of the brain. Neuropeptides play a critical role in regulating this process. Neuropeptide Y (NPY), a 36 aa peptide, is highly expressed in the amygdala. It exerts potent anxiolytic effects through cognate postsynaptic Y1 receptors, but augments anxiety through presynaptic Y2 receptors. To identify the precise anatomical site(s) of Y2-mediated anxiogenic action, we investigated the effect of site-specific deletion of the Y2 gene in amygdaloid nuclei on anxiety and depression-related behaviors in mice. Ablating the Y2 gene in the basolateral and central amygdala resulted in an anxiolytic phenotype, whereas deletion in the medial amygdala or in the bed nucleus of the stria terminalis had no obvious effect on emotion-related behavior. Deleting the Y2 receptor gene in the central amygdala, but not in any other amygdaloid nucleus, resulted in an added antidepressant-like effect. It was associated with a reduction of presumably presynaptic Y2 receptors in the stria terminalis/bed nucleus of the stria terminalis, the nucleus accumbens, and the locus ceruleus. Our results are evidence of the highly site-specific nature of the Y2-mediated function of NPY in the modulation of anxiety- and depression-related behavior. The activity of NPY is likely mediated by the presynaptic inhibition of GABA and/or NPY release from interneurons and/or efferent projection neurons of the basolateral and central amygdala.

CaV1.3 L-type Ca2+ channels modulate depression-like behaviour in mice independent of deaf phenotype.

Mounting evidence suggests that voltage-gated L-type Ca2+ channels can modulate affective behaviour. We therefore explored the role of CaV1.3 L-type Ca2+ channels in depression- and anxiety-like behaviours using CaV1.3-deficient mice (CaV1.3-/-). We showed that CaV1.3-/- mice displayed less immobility in the forced swim test as well as in the tail suspension test, indicating an antidepressant-like phenotype. Locomotor activity in the home cage or a novel open-field test was not influenced. In the elevated plus maze (EPM), CaV1.3-/- mice entered the open arms more frequently and spent more time there indicating an anxiolytic-like phenotype which was, however, not supported in the stress-induced hyperthermia test. By performing parallel experiments in Claudin 14 knockout mice (Cldn14-/-), which like CaV1.3-/- mice are congenitally deaf, an influence of deafness on the antidepressant-like phenotype could be ruled out. On the other hand, a similar EPM behaviour indicative of an anxiolytic phenotype was also found in the Cldn14-/- animals. Using electroretinography and visual behavioural tasks we demonstrated that at least in mice, CaV1.3 channels do not significantly contribute to visual function. However, marked morphological changes were revealed in synaptic ribbons in the outer plexiform layer of CaV1.3-/- retinas by immunohistochemistry suggesting a possible role of this channel type in structural plasticity at the ribbon synapse. Taken together, our findings indicate that CaV1.3 L-type Ca2+ channels modulate depression-like behaviour but are not essential for visual function. The findings raise the possibility that selective modulation of CaV1.3 channels could be a promising new therapeutic concept for the treatment of mood disorders.

Effect of neuropeptide Y Y2 receptor deletion on emotional stress-induced neuronal activation in mice.

In different behavioral paradigms including the elevated plus maze (EPM), it was observed previously that deletion of the neuropeptide Y Y2 receptor subtype results in potent suppression of anxiety-related and stress-related behaviors. To identify neurobiological correlates underlying this behavioral reactivtiy, expression of c-Fos, an established early marker of neuronal activation, was examined in Y2 receptor knockout (Y2(-/-)) vs. wildtype (WT) mice. Mice were placed on the open arm (OA) or closed arm (CA) of the EPM for 10 min and the effect on regional c-Fos expression in the brain was investigated. The number of c-Fos positive neurons was significantly increased in both WT and Y2(-/-) lines after OA and CA exposure in 51 of 54 regions quantified. These regions included various cortical, limbic, thalamic, hypothalamic, and hindbrain regions. Genotype influenced c-Fos responses to arm exposures in 6 of the 51 activated regions: the cingulate cortex, barrel field of the primary somatosensory cortex, nucleus accumbens, dorsal lateral septum, amygdala and lateral periaqueductal gray. These differences in neuronal activity responses to the novel environments were more pronounced after OA than after CA exposure. Mice lacking Y2 receptors exhibited reduced neuronal activation when compared to WT animals in response to the emotional stressors. Reduced neuronal excitability in the identified brain areas relevant to the processing of motivated, explorative as well as anxiety-related behaviors is suggested to contribute to the reduced anxiety-related behavior observed in Y2(-/-) mice.

Conditional CRF receptor 1 knockout mice show altered neuronal activation pattern to mild anxiogenic challenge.

RATIONALE: Regional-specific corticotropin-releasing factor receptor 1 (CRF-R1) knockout mice have been generated recently as a tool to dissociate CNS functions modulated by this receptor. In these mice, CRF-R1 function is postnatally inactivated in the anterior forebrain including limbic brain structures but not in the pituitary leading to normal activity of the hypothalamic-pituitary-adrenocortical (HPA) axis under basal conditions and reduced anxiety-related behavior in the light-dark box and the elevated plus maze (EPM) as compared to wild-type (WT) mice (Müller et al., Nat Neurosci 6:1100-1107, 2003). OBJECTIVE: To identify neurobiological correlates underlying this reduced anxiety-like behavior, the expression of c-Fos, an established marker for neuronal activation, which was examined in response to a mild anxiogenic challenge. MATERIALS AND METHODS: Mice were placed for 10 min on the open arm (OA) of the EPM, and regional c-Fos expression was investigated by immunohistochemistry. RESULTS: OA exposure enhanced c-Fos expression in both conditional CRF-R1 knockout and WT mice in a number of brain areas (39 of 55 quantified), including cortical, limbic, thalamic, hypothalamic, and hindbrain regions. The c-Fos response in conditional CRF-R1 knockout animals was reduced in a restricted subset of activated neurons (4 out of 39 regions) located in the medial amygdala, ventral lateral septum, prelimbic cortex, and dorsomedial hypothalamus. CONCLUSIONS: These results underline the importance of limbic CRF-R1 in modulating anxiety-related behavior and suggest that reduced neuronal activation in the identified limbic and hypothalamic key structures of the anxiety circuitry may mediate or contribute to the anxiolytic-like phenotype observed in mice with region-specific deletion of forebrain CRF-R1.