[Analysis of the progress in the field of oral microbiology and regenerative medicine from 2014 to 2023]

Objective: To analyze the trends in literature related to oral microbiology and regenerative medicine from 2014 to 2023. By identifying key research countries, institutions, and their collaboration networks, as well as exploring research hotspots and development directions, the study seeks to provide references for researchers and decision-makers in the field of oral microbiology and regenerative medicine, thereby guiding the direction of future research. Methods: Relevant literature was retrieved using the Web of Science Core Collection database, with data processing and analysis conducted using CiteSpace 6.2.R6 software. Time slicing, node type selection, and the application of the g-index (g-index) were used for filtering, analyzing countries, institutions, authors, journals, and keywords. Results: The volume of literature in the field of oral microbiology and regenerative medicine has steadily increased from 2014 to 2023, with the number of publications first exceeding one hundred in 2020 and reaching 134 in 2022, accompanied by a citation frequency of 3 363 times. China and the United States have been at the forefront in terms of the volume of publications, while the United States and Germany lead in terms of intermediary centrality. The research primarily spans disciplines such as oral medicine, interdisciplinary studies, materials science, and immunology. High-frequency keywords include stem cells, scaffold materials, and gut microbiota, while cluster analysis indicates that inflammation, drug delivery, and antimicrobial activity remain consistent research themes. In recent years, the research heat in "tissue regeneration""gut microbiota " and "maxillofacial surgery" has risen, suggesting these may become focal points of future research. Conclusions: Over the past decade, the volume of literature published in the fields of oral microbiology and regenerative medicine, along with their citation frequencies, has increased annually. The research focus has shifted over time. Understanding the interactions between oral and gut microbiomes is crucial for developing innovative regenerative treatment strategies.

[Surgical treatment for obstructive hypertrophic cardiomyopathy: a five-year single-center experience of 421 cases]

Objectives: To examine the short-term and mid-term effects of surgical treatment of obstructive hypertrophic cardiomyopathy (HCM) in one center. Methods: The perioperative data and short-term follow-up outcomes of 421 patients with obstructive HCM who received surgical treatment at Department of Cardiac Surgery, Zhongshan Hospital, Fudan University from January 2017 to December 2021 were analyzed retrospectively. There were 207 males and 214 females, aged (56.5±11.7) years (range: 19 to 78 years). Preoperative New York Heart Association (NYHA) classification included 45 cases of class Ⅱ, 328 cases in class Ⅲ, and 48 cases in class Ⅳ. Fifty-eight patients were diagnosed with latent obstructive HCM and 257 patients had moderate or more mitral regurgitation with 56 patients suffering from intrinsic mitral valve diseases. All procedures were completed by a multidisciplinary team, including professional echocardiologists involving in preoperative planning for proper mitral valve management strategies and intraoperative monitoring. A total of 338 patients underwent septal myectomy alone, and 59 patients underwent mitral valve surgery along with myectomy. A single transaortic approach was used in 355 patients, and a right atrial-atrial septal/atrial sulcus approach was used in 51 other patients. Long-handled minimally invasive surgical instruments were used for the procedures. Student t test, Wilcoxon rank sum test, χ² test or Fisher exact test were used to compare the data before and after surgery. Results: The aortic cross-clamping time of septal myectomy alone was (34.3±8.5) minutes (range: 21 to 94 minutes). Eighteen patients had intraoperative adverse events and underwent immediate reoperation, including residual obstruction (10 patients), left ventricular free wall rupture (4 patients), ventricular septal perforation (3 patients), and aortic valve perforation (1 patient). Four patients died during hospitalization, and 11 patients developed complete atrioventricular block requiring permanent pacemaker implantation. After discharge, 384 (92.1%) patients received a follow-up visit with a median duration of 9 months. All follow-up patients survived with significantly improved NYHA classifications: 216 patients in class Ⅰ and 168 patients in class Ⅱ (χ²=662.73, P<0.01 as compared to baseline). At 6 months after surgery, follow-up echocardiography showed that the thickness of the ventricular septum ((13.6±2.5) mm vs. (18.2±3.0) mm, t=23.51, P<0.01) and the peak left ventricular outflow tract gradient ((12.0±6.3) mmHg vs. (93.4±19.8) mmHg, 1 mmHg=0.133 kPa, t=78.29, P<0.01) were both significantly lower than baseline values. Conclusion: The construction of the surgical team (including echocardiography experts), proper mitral valve management strategies, identification and management of sub-mitral-valve abnormalities, and application of long-handled minimally invasive surgical instruments are important for the successful implementation of septal myectomy with satisfactory short-and medium-term outcomes.

Chemical constituents from salt lake-derived Streptomyces sp. QHA10

Two new alkaloids (1,2) and one new enoic acid (3), together with three known piericidins (4-6), were isolated from the liquid fermentation of the salt lake derived Streptomyces sp. QHA10. The structures of 1-3 were elucidated based on extensive spectroscopic data (NMR, HRESIMS) as well as single-crystal X-ray diffraction. Compound 3 showed potential anti-inflammatory activity by inhibiting the production of nitric oxide (NO) in lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophages with the IC₅₀ value of 24.5 μM.

Heteroexpression of Aspergillus nidulans laeA in Marine-Derived Fungi Triggers Upregulation of Secondary Metabolite Biosynthetic Genes

Fungi are a prospective resource of bioactive compounds, but conventional methods of drug discovery are not effective enough to fully explore their metabolic potential. This study aimed to develop an easily attainable method to elicit the metabolic potential of fungi using Aspergillus nidulans laeA as a transcription regulation tool. In this study, functional analysis of Aspergillus nidulans laeA (AnLaeA) and Aspergillus sp. Z5 laeA (Az5LaeA) was done in the fungus Aspergillus sp. Z5. Heterologous AnLaeA-and native Az5LaeA-overexpression exhibited similar phenotypic effects and caused an increase in production of a bioactive compound diorcinol in Aspergillus sp. Z5, which proved the conserved function of this global regulator. In particular, heteroexpression of AnLaeA showed a significant impact on the expression of velvet complex genes, diorcinol synthesis-related genes, and different transcription factors (TFs). Moreover, heteroexpression of AnLaeA influenced the whole genome gene expression of Aspergillus sp. Z5 and triggered the upregulation of many genes. Overall, these findings suggest that heteroexpression of AnLaeA in fungi serves as a simple and easy method to explore their metabolic potential. In relation to this, AnLaeA was overexpressed in the fungus Penicillium sp. LC1-4, which resulted in increased production of quinolactacin A.

[Comparison of myotomy and coronary artery bypass grafting in surgical treatment of symptomatic left anterior descending myocardial bridges]

Objective: To compare the effect of myotomy and coronary artery bypass grafting (CABG) to treat symptomatic myocardial bridges (MBs) of the left anterior descending artery (LAD). Methods: From January 2009 to December 2017, a total of 54 eligible patients [34 males, 20 females, with a median age of 60 (51, 64) years old] with symptomatic MBs of LAD who underwent myotomy (31 patients) or CABG (23 patients) at the Department of Cardiovascular Surgery of Zhongshan Hospital, Fudan University were included in the study. Surgical effect of the two groups were compared and multivariate logistic regression models were used to analyze the risk factors of major adverse cardiac events (MACE). Results: No significant differences between the two groups were observed with respect to age, gender, risk factors of coronary artery disease (CAD), symptoms, angiographic findings of MBs and preoperative cardiac status, and 0 surgery-associated death was observed. Among the 31 myotomy patients, 4 patients underwent off-pump myotomy (including one patient who underwent urgent conversion from off-pump to on-pump surgery due to massive hemorrhaging secondary to the right ventricular perforation), and the remaining 27 cases received myotomy under cardiopulmonary bypass with cardiac arrest. All 23 bypass surgery patients underwent off-pump CABG surgery with in situ left internal mammary artery (LIMA) grafting to the distal LAD. After LIMA grafting, the median graft flow was 14 (11, 20) ml/min. During a median follow-up of 26 months, 11 patients developed MACEs (7.4% for myotomy vs 40.9% for bypass surgery, P=0.007). Surgical strategy (CABG surgery vs myotomy) was an independent risk factor for MACE (OR=3.681, 95% CI: 1.812-8.685, P=0.011). Compared with myotomy, CABG surgery had a significantly higher incidence of adverse angiographic results (3.7% of residual compression vs 40.9% of LIMA graft failure, P=0.003). Among 10 CABG surgery patients with LAD-MBs and proximal coronary obstruction, all LIMA grafts were patent, though one case reported recurrent angina pectoris 2 years after the surgery which was relieved after drug therapy. Conclusions: For patients with symtomatic LAD-MBs, myotomy may be associated with favorable mid-term outcomes and angiographic results. However, CABG surgery should be recommended for those with concomitant proximal obstruction of LAD.

A new compound from the marine-derived Streptomyces sp. SS13M

As part of our efforts toward search for structurally new and bioactive natural products from marine-derived microorganisms, one new compound (1) was characterized from a marine-derived actinomycete Streptomyces sp. SS13M. The structure of new compound was elucidated by the analysis of HRESIMS, 1D, and 2D NMR spectroscopic data, and the absolute configuration was determined by ECD calculations.[Formula: see text].

Development of Al-TiCN nanocomposites via ultrasonic assisted casting route

This work provides a promising approach to achieve the uniform distribution of TiCN nanoparticles (NPs) in aluminum matrix via a combination of ultrasonic dispersion and fast cooling processing. Microstructure analysis demonstrates that as the cooling rate is increased, the NP distribution in the matrix varies from intergranular to intragranular at micro scale and the NP-matrix interface from incoherent to coherent at nano scale. An analytical model is proposed to unveil the effects of cooling rates on the behavior of NPs at the solidification front. The theoretical analysis reveals that the NP size and cooling rate are the two prominent factors determining the NP distribution during solidification of nanocomposites. The experimental results yield an insight into the understanding of NP-induced microstructural evolution and shed new light on the development of high-performance nanocomposites.

A new medermycin analog from the marine-derived actinomycetes Streptomyces sp. ZS-A45

A new medermycin analog (1) was isolated from the marine-derived actinomycetes Streptomyces sp. ZS-A45. The structure elucidation of compound 1 was determined by the HRESIMS and extensive NMR analysis. And compound 1 exhibited significant cytotoxicity against PC3 cell lines with IC₅₀ values of 0.81 ± 0.42 μm.

[Clinical outcomes of total arterial off-pump coronary revascularization in patients with left ventricular dysfunction]

Objective: To compare the advantages and disadvantages of total arterial revascularization (TAR) and conventional off-pump coronary artery bypass (OPCAB) grafting in patients with left ventricular dysfunction (LVD). Methods: Between January 2008 and March 2015, 76 patients who were scheduled to undergo selective OPCAB were selected for cardiac surgery in Zhongshan Hospital, Fudan University. The left ventricular ejection fraction of enrolled patients was less than 35%. Among those patients, 38 patients in TAR group underwent total arterial OPCAB with bilateral internal mammary artery, left and/or right radial artery, and another 38 patients in control group underwent conventional OPCAB with left internal mammary artery and great saphenous vein. The clinical data of all patients were collected. The follow-up was performed within 36 months. Results: There was no significant difference in preoperative clinical data between the two groups (all P>0.05). Additionally, there was no significant difference in the application rate of internal mammary artery, positive inotropic drugs and intra-aortic balloon pump (IABP) use between the two groups (all P>0.05). The operation time of TAR group was longer than that of control group [(278.3±31.2) min vs (196.7±19.1) min, P<0.01]. There was no significant difference in perioperative mortality between the two groups (5.3% vs 7.9%, P=0.64). The volume of operative drainage and blood transfusion in TAR group increased significantly at 24 hours after operation [(895.0±236.2) ml vs (585.4±172.5) ml, (656.3±84.4) ml vs (433.3±62.9) ml, both P<0.01]. There was no significant difference in perioperative complications such as heart, kidney and lung failure between the two groups (all P>0.05). At 12 months after operation, there were no significant differences in survival rate, cardiac death rate, angina recurrence, myocardial infarction, re-treatment rate of revascularization, re-hospitalization rate from cardiac insufficiency, graft patency rate, cardiac function and echocardiographic data between the two groups (all P>0.05). From 24 to 36 months after operation, all the above indexes in TAR group were better than those in control group except for echocardiographic data (all P<0.05). Conclusions: For LVD patients, the early clinical efficacy of the two surgical methods is similar, but for the long-term outcomes, the whole arterial OPCAB operation is obviously superior. However, the shortcomings of total arterial OPCAB are that operative drainage and the use of blood products increased significantly after operation.

Purmedermycins A and B, two novel medermycin derivatives from Streptomyces sp. SS17A

Purmedermycin A (1) and purmedermycin B (2), which were isolated from Streptomyces sp. SS17A, feature a rearranged and reconstructed C/D/E ring formed by the fusion of a tryptophan unit and medermycin or menoxymycin B, respectively, making them the first of a new type of medermycin.

Medermycin-Type Naphthoquinones from the Marine-Derived Streptomyces sp. XMA39

Four new medermycin-type naphthoquinones, strepoxepinmycins A-D (1-4), and one known compound, medermycin (5), were identified from Streptomyces sp. XMA39. Their structures were elucidated by analysis of HRESIMS, 1D and 2D NMR spectroscopic data, and ECD calculations. Among these compounds, strepoxepinmycin A (1) represents a rare 5,10-oxepindione ring system typically formed by a Baeyer-Villiger oxidation, and strepoxepinmycin B (2) is an isolation artifact derived from 1. Bioactivity evaluations of these compounds showed that compounds 3 and 4 exhibited cytotoxicity against HCT-116 and PC-3 cancer cell lines and 4 exhibited moderate inhibition of ROCK 2 protein kinase. In addition, all of the new compounds showed antibacterial activity against Escherichia coli and methicillin-resistant Staphylococcus aureus and antifungal activity against Candida albicans.

Bioactive Indolocarbazoles from the Marine-Derived Streptomyces sp. DT-A61

Nine new indolocarbazoles (1-9) were isolated from the marine-derived Streptomyces sp. DT-A61. Among them compounds 1-8 featured a hydroxy group at the C-3 or C-9 position. All purified compounds were identified by 1D and 2D NMR and HRESIMS data. The absolute configurations of 4-6, 8, and 9 were determined by electronic circular dichroism spectroscopic data. Compound 7 exhibited significant activity against human prostate PC-3 cancer cells with an IC₅₀ value of 0.16 μM. Compounds 1, 5, 6, and 9 showed moderate inhibition against the same cell line with IC₅₀ values of 8.0, 3.6, 3.1, and 5.6 μM. Compound 2 displayed a notable inhibitory effect against Rho-associated protein kinase (ROCK2) with an IC₅₀ value of 5.7 nM, which was similar to the positive control staurosporine (IC₅₀ 7.8 nM).

[Myocardial revascularization among patients with severe left ventricular dysfunction: a comparison between on-pump beating-heart and off-pump coronary artery bypass grafting]

Objective: To evaluate the impacts of an on-pump beating-heart versus an off-pump coronary artery bypass grafting (CABG) technique for surgical revascularization on the early clinical outcomes in patients with a left ventricular ejection fraction (EF) of 35% or less. Methods: A total of 216 consecutive patients with an echocardiographic estimated EF of 35% or less who underwent non-emergency, primary, isolated CABG from January 2010 to December 2014 at Department of Cardiovascular Surgery, Zhongshan Hospital, Fudan University were included in this study and were divided into either an OBCAB group (patients who received on-pump beating-heart CABG surgery, n=88) or an OPCAB group (patients who received off-pump CABG surgery, n=128). The early clinical outcomes were investigated and compared. The outcomes were compared between groups by t-test, χ² test or Fisher's exact test, when appropriate. Results: No significant differences emerged between the two groups in baseline characteristics of the entire cohort except for more patients with diabetes and a larger left ventricular endo-diastolic diameter in the OBCAB group. Patients in the OBCAB group compared to the OPCAB group had a similar in-hospital mortality (3.4% vs. 4.7%, P= 0.741). Mean EF, as measured preoperatively and early postoperatively (before discharge), significantly improved from (31.0±2.8)% to (35.6±2.9)% (t=10.61, P=0.000) in the OBCAB group and from (31.0±2.9)% to (34.8±3.3)% (t=9.68, P=0.000) in the OPCAB group, respectively. The improvement of mean LVEF in the OBCAB group was significantly higher than that in the OPCAB group ((4.7±0.2)% vs. (3.6±0.3)%, t=29.53, P=0.000). Patients in the OBCAB group compared to the OPCAB group had a significant higher early postoperative EF ((35.6±2.9)% vs.(34.8±3.3)%, t=1.892, P=0.034) but shared a similar baseline EF ((31.0±2.8)% vs. (31.0±2.9)%, t=0.012, P=0.930). Patients in the OBCAB group compared to the OPCAB group received a greater number of grafts and an increased amount of drainage during the first 24 h (3.7±0.8 vs. 2.8±0.6, t=9.442, P=0.000; (715±187) ml vs. (520±148) ml, t=8.544, P=0.000, respectively), without evidence of worse in-hospital mortality or major postoperative morbidity. Conclusion: The on-pump beating-heart technique may be an acceptable alternative to the off-pump technique for surgical revascularization in patients with an estimated EF of 35% or less.

Cyclizidine-Type Alkaloids from Streptomyces sp. HNA39

Eight new cyclizidine-type alkaloids (1-8) and one known alkaloid (9) were identified from the chemical investigations of a marine-derived actinomycete, Streptomyces sp. HNA39. Among these alkaloids, compounds 3, 7, and 8 contain a chlorine atom, and the known alkaloid, (+)-ent-cyclizidine (9), is now first reported as a natural product. Their structures were elucidated by extensive NMR-spectroscopic analysis and HRESIMS data. The absolute configurations of all of the compounds were established by ECD calculations. Cytotoxicity evaluations of all of the compounds showed that compound 2 exhibited significant activity against the PC3 and HCT116 human-cancer-cell lines with IC₅₀ values of 0.52 ± 0.03 and 8.3 ± 0.1 μM, respectively. Interestingly, compounds 2, 5, 7, and 8 exhibited moderate inhibition against the ROCK2 protein kinase with IC₅₀ values from 7.0 ± 0.8 to 42 ± 3 μM.

Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with a length of 5 μm, a maximum 13.8 times enhancement in the THz pulse energy (in ≤20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies (≤20 THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20–200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets with a length of 60 μm. Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results.

[PM2.5 and polluted gas exposure induced acute injury in rats'larynx membrane]

Objective:To study acute injury of rat's larynx membrane which were exposured to PM2.5 and polluted gas in serious air pollution. Method:Rats were divided into 3 groups of 5 animals each, the normal control group, gas exposured group, PM2.5 +gas exposured group. The control group served as the normal healthy control, rats of the gas exposured group had been exposured polluted gas in the A cabin, rats of PM2.5 +gas exposured group had been exposured PM2.5 and polluted gas in the B cabin. The total exposure time was six days. We collected specimen from 3 groups immediately after exposure. Histopathological changes in the rat's larynx membrane were assessed using hematoxylin and eosin staining(HE), the expression of IL-1β in laryngeal mucous membrane were assessed using immunohistochemical staining(IHC), and the ultrastructure changes were observed under TEM. Result:HE staining showed the rat's laryngeal mucosa cells in the normal control group had no obvious abnormalities, laryngeal mucosa of rats in the two experimental group had different degrees of cell proliferation, cell polarity change, etc. IHC staining showed that there's no obvious expression of IL-1β in laryngeal mucous membrane in the normal control group, and positive expression in the two experimental group. TEM showed the control group had no obvious abnormalities, the laryngeal mucosa cells in the two groups of experimental groups had been found irregular nucleus and damaged mitochondria. Conclusion:Exposed to PM2.5 and polluted gas in severe atmospheric pollution 6 days, the acute damage in rats laryngeal mucosa can be observed.

Sub GV/cm terahertz radiation from relativistic laser-solid interactions via coherent transition radiation

Broadband terahertz (THz) radiation with extremely high peak power, generated by the interaction of a femtosecond laser with a thin solid target, has been investigated via particle-in-cell simulations. The spatial (angular) and temporal profiles of the THz radiation reveal that it is caused by the coherent transition radiation emitted when laser-produced hot electrons pass through the front or rear surface of the target. Dependence of the THz radiation on laser and target parameters is studied; it is shown to have a strong correlation with hot electron production. The THz radiation conversion efficiency can be as high as a few times 10^{-3}. This radiation is not only a potentially high power THz source, but may also be used as a unique diagnostic of hot electron generation and transport in relativistic laser-solid interactions.

Publisher's Note: Sub GV/cm terahertz radiation from relativistic laser-solid interactions via coherent transition radiation [Phys. Rev. E 93, 063204 (2016)]

This corrects the article DOI: 10.1103/PhysRevE.93.063204.

Salmonella L-forms: formation in human bile in vitro and isolation culture from patients' gallbladder samples by a non-high osmotic isolation technique

Bacterial L-forms have always been considered as osmotic-pressure-sensitive cell-wall-deficient bacteria and isolation culture of L-forms must use media with high osmotic pressure. However, isolation culture of stable L-forms formed in humans and animals is very difficult because they have adapted to the physiological osmotic pressure condition of the host. We use a non-high osmotic isolation technique to isolate stable L-forms of Salmonella Typhi and Salmonella Paratyphi A from bile-inducer cultures in vitro and from patients' gallbladder specimens. Multiplex PCR assay for Salmonella-specific genes and nucleotide sequencing are used to identify the Salmonella L-forms in stable L-form isolates. Using this method, we confirmed that Salmonella Paratyphi A and Salmonella Typhi cannot be isolated from bile-inducer cultures cultured for 6 h or 48 h, but the L-forms can be isolated from 1 h to 45 days. In the 524 gallbladder samples, the positive rate for bacterial forms was 19.7% and the positive rate for Salmonella spp. was 0.6% by routine bacteriological methods. The positive rate for bacterial L-forms was 75.4% using non-high osmotic isolation culture. In the L-form isolates, the positive rate of Salmonella invA gene was 3.1%. In these invA-positive L-form isolates, four were positive for the invA and flic-d genes of Salmonella Typhi, and ten were positive for the invA and flic-a genes of Salmonella Paratyphi A.

Unprecedent aminophysalin from Physalis angulata

The 95% ethanol extract of the whole plant of Physalis angulata Linn. afforded one new skeletal physalin named aminophysalin A (1) and one new naturally occurring 5β-hydroxy-6a-chloro-5,6-dihydrophysalin B (2), together with five known physalins (3-7). Their structures were elucidated through MS, IR, NMR spectroscopy analyses and X-ray crystallography. Aminophysalin A (1) had an absolutely unusual structural feature in the chemistry of physalins with a nitrogen atom. Compounds 1-7 were evaluated for quinone reductase activities in hepa 1c1c7 cells. Physalin H (6) showed strong quinone reductase induction activity with IR (Induction ratio, QR induction activity) value of 3.74±0.02, using 4-bromoflavone as a positive control substance (2.17±0.01, 10 μg/mL), while compounds 1, 2, 3, 5 showed weak quinone reductase induction activity.

A preliminary study of chromium distribution in chromium-rich brewer's yeast cell by NAA

The purpose of this study was to assess the chromium (Cr) distribution in chromium-rich brewer's yeast cell. The chromium concentrations in the cell wall and protoplast fractions of the chromium-rich yeast were determined by neutron activation analysis (NAA). Moreover, the combined state of chromium and amino acid content in the Cr-rich brewer's yeasts was analyzed and measured. The experimental results indicate that the introduction of water-soluble chromium(III) salt as a component of the culture medium for yeasts results in a substantial amount of chromium absorbed through the cell wall by the yeast, among which 80.9% are accumulated in the protoplast. It implies that, under optimal conditions, yeasts are capable of accumulating large amounts of chromium and incorporating chromium into organic compounds.

Theoretical studies on cycloaddition reactions between keteniminium cations and olefins

The mechanisms of seven reactions between keteniminium cations and olefins have been theoretically explored at BHandHLYP/6-31G level. It is found that these seven reactions always form a relatively stable hydrogen-bonded type of ion-molecule complex first except for reactions 1d+2a and 1e+2a, which have no hydrogen atom attached to nitrogen atom in keteniminium cations. Some reactions take place via a concerted but unsynchronous mechanism, and the others are stepwise processes. The substituent effects are also studied. The data reveal that the electron-pushing substituents on keteniminium cations disfavor the reaction, and the electron-attracting substituents on keteniminium cations favor the reactions. The substituent effects on ethene are contrary to the former case.

Belladonna alkaloids-induced behavioral changes and amnesia on open-field and step-through in 18-, 28-, and 38-day-old mice

AIM

To study the age-related changes of atropine (Atr), scopolamine (Sco), anisodine (AT3), and anisodamine (Ani) on behaviors and memories.

METHODS

The behaviors and memories were measured with open-field test and step-through task. M-cholinergic receptors were determined by [3H] quinuclidinyl benzilate ([3H] QNB).

RESULTS

During acquisition session (d 1) the 18-, 28-, and 38-d-old mice pretreated with Atr, Sco, and AT3 (0.02, 0.2, 2, or 20 mg.kg-1, i.p.) in open-field test showed increase in walking counts by 26%-42%, but decrease in rearing, grooming, and defecating counts for 50%-92%, 67%-100%, and 75%-100%, respectively. On recall session (d 2) the walking and rearing behaviors in the 18- and 28-d-old mice receiving Atr, Sco, and AT3 on d 1 were higher than those in the mice receiving saline. But a lower grooming behavior on d 2 was found in the mice receiving the drugs on d 1. On d 1 Ani 20 mg.kg-1 reduced the rearing behavior by 50% in 18-d-old mice and defecation by 33%-36% in 18- and 28-d-old mice. All the 4 belladonna alkaloids increased the number of avoidance-response errors and decreased the retention latencies in step-through task. Bmax of [3H] QNB binding sites in frontal cortex and hippocampus regions in the 38-d-old mice increased 7% and 23% vs in the mice of 18 d of age, respectively.

CONCLUSION

1) The effects of the belladonna alkaloids on behaviors and memories in adult mice were weaker than those in young mice. 2) The belladonna alkaloids-induced amnesia on passive avoidance-response in step-through was more sensitive than behavioral changes and amnesia on open-field. 3) According to the lowest effective doses which insulted the behaviors or memories in young mice, Sco was about 10, 100, and 1000 times more potent than Atr, AT3, and Ani, respectively.