[The evaluation of training program "resident team leader in the Department of General Internal Medicine" at Peking Union Medical College Hospital]

Objective: To evaluate senior resident training program "resident team leader in the Department of General Internal Medicine" at Peking Union Medical College Hospital. Methods: We surveyed the residents or the fellows who had been selected as resident team leaders and received the training from October 2014 to September 2018 on their comments and suggestions. Results: Twenty-two rotated senior residents who were selected as team leaders in the Department of General Internal Medicine completed the survey. Almost all (21/22, 95.5%) of the respondents reported that they learnt more in general as team leaders by Visual Analog Scale (VAS). The mean VAS scores of clinical skills were 7.23±1.27, 7.86±1.32 in teaching abilities, 8.14±0.89 in leadership evaluation. Scales as chief resident assistants were 8.44±1.26. Sixteen respondents (72.7%) considered that pre-job training by attending doctors was necessary. Another 8 (36.4%) respondents addressed their demands on training of teaching skills. Conclusions: The senior resident training program "resident team leader in the Department of General Internal Medicine" improves the competency of rotated senior residents. It is a valuable pilot study on senior resident training and worthy of further application in other departments and hospitals.

[The 468th case: periodic fever, abdominal pain, small intestinal ulcers, NOD2 gene mutation]

Fever and abdominal pain are common symptoms and could be main manifestations in patients with autoinflammatory diseases. A 48-year-old female patient was admitted with recurrent fever and abdominal pain for 9 years. Serum level of inflammatory markers synchronously fluctuated with fever, and returned to normal when fever subsided. The periodic episodes of fever occurred every 1 to 4 months and failed to respond to empirical antibiotics. Whole exome sequencing showed heterozygous mutation of NOD2 gene q902k, leading to the final diagnosis of autoinflammatory disease. Corticosteroid and tripterygiumglycosides were effective for the disease remission.

[Analysis of eight-year follow-up data of plateau workers by color doppler echocardiography]

Objective: To analyze the heart rate changes and risk factors, as a result of high altitude. Methods: Retrospective analysis of echocardiographic data of plateau workers at a railway maintenance company from 2006 to 2013. The survival curve method was used to analyze the abnormal rate of the heart. Kaplan-Meier method and Cox proportional hazards regression model were used to analyze the influencing factors. Results: In the first occurrence of cardiac abnormalities, the main types of abnormalities were right atrium enlargement (53.47%) , right ventricle enlargement (17.36%) , and tricuspid regurgitation (16.67%) . Cox regression analysis showed that workplace altitude and first physical examination age are two influencing factors of cardiac abnormalities, and their relative risk was 1.661 and 1.039. At high altitudes (3 600~4 000 m) , nearly 40% of workers heart has not changed. But this adaptation does not observed in the ultra-high altitudes (≥4 000 m) . Conclusion: There are individual differences in human adaptability to high altitude. We should take more stringent measures of health care for older people and those who work at more than 4000m. And we should abide by the rotation system for railways that are suitable for the plateau.

[Study on the relationship between age-related hearing loss and cognitive impairment]

Objective: To investigate the correlation between age-related hearing loss and cognitive impairment. Methods: 201 elderly patients, who were admitted to the Department of Otorhinolaryngology of Peking University People's Hospital from March 1, 2017 to March 31, 2017, were evaluated with hearing screening and the Montreal Cognitive Assessment Scale. Among them, 101 were female and 100 were male, aged 60-90 years old. Taking the cognitive level as the dependent variable, and taking the age, sex, education, occupation, marital status, residence, and average hearing loss (average hearing threshold of 500, 1 000, 2 000, and 4 000 Hz), as well as the length of conscious hearing loss as the independent variables, the single factor analysis and multivariate linear regression analysis were used to screen the main factors affecting the cognitive level of the elderly. Results: Of the 201 elderly patients, 39 had normal hearing, 65 had mild hearing loss, 80 had moderate hearing loss, 16 had severe hearing loss, and 1 had profound hearing loss. The average degree of hearing loss was the influencing factor of cognitive impairment, and it mainly affected the directional force and abstract ability in the cognitive domains (P<0.05); The age, self-reported hearing loss, years of education, marital status, past ear diseases, and hypertension were relatively independent factors that affected the cognitive level(P<0.05). Conclusions: Age-related hearing loss is the risk factor for the cognitive impairment, especially for abstraction and orientation, in the elderly. The self-reported hearing loss is an independent risk factor for cognitive impairment.

Incoherently coupled two-color vector dark solitons in self-defocusing media

We investigate the stability of incoherently coupled two-color vector dark and grey solitons in a nonlinear self-defocusing media. We employ the variational technique to derive approximate solutions of the two-color vector dark solitons. The relations between the soliton parameters and the representation of the transverse velocities of the vector solitons are analytically obtained. We also demonstrate numerically the propagation dynamics of the two-color vector solitons, which shows that the two-color vector dark and grey solitons with different wavelengths are always unstable.

Modeling of resonantly pumped mid-infrared Pr3+-doped chalcogenide fiber amplifier with different pumping schemes

We propose a model for resonantly pumped Pr³⁺-doped chalcogenide fiber amplifiers, which includes excited state absorption and the full spectral amplified spontaneous emission spanning from 2 μm to 6 μm. Based on this model, the observed near- and mid-infrared photoluminescence generated from Pr³⁺-doped chalcogenide fiber is explained. Then the output properties of a 4.1 μm resonantly pumped Pr³⁺-doped chalcogenide fiber amplifier are simulated in both co- and counter-pumping schemes. Results show that the 4.1 μm counter-pumped fiber amplifier can achieve a power conversion efficiency (PCE) of over 62.8% for signal wavelengths ranging from 4.5 μm to 5.3 μm. This is, to our best knowledge, the highest simulated PCE for a Pr³⁺-doped chalcogenide fiber amplifier.

Heterogeneous to homogeneous melting transition visualized with ultrafast electron diffraction

The ultrafast laser excitation of matters leads to nonequilibrium states with complex solid-liquid phase-transition dynamics. We used electron diffraction at mega-electron volt energies to visualize the ultrafast melting of gold on the atomic scale length. For energy densities approaching the irreversible melting regime, we first observed heterogeneous melting on time scales of 100 to 1000 picoseconds, transitioning to homogeneous melting that occurs catastrophically within 10 to 20 picoseconds at higher energy densities. We showed evidence for the heterogeneous coexistence of solid and liquid. We determined the ion and electron temperature evolution and found superheated conditions. Our results constrain the electron-ion coupling rate, determine the Debye temperature, and reveal the melting sensitivity to nucleation seeds.

Determination of Oleandrin in Blood and Liver Samples by LC-MS/MS

OBJECTIVES

To develop a liquid chromatography-tandem mass spectrometry （LC-MS/MS） analytical method for the determination of oleandrin in blood and liver tissues, which could be applied to the cases of death caused by oleander poisoning.

METHODS

Blood or liver tissues underwent a liquid-liquid extraction （LLE） using ethyl acetate, and the extract was separated on an Agilent ZORBAX SB-C₁₈ column and eluted with a gradient of acetonitrile and 20 mmol/L ammonium acetate （containing 0.1% formic acid）. Oleandrin was detected using electrospray positive ionization （ESI+） with multiple-reaction monitoring （MRM） mode.

RESULTS

Oleandrin showed excellent linearity in both blood and liver samples in the corresponding linear range （r>0.995 0）, with detection limits 1 ng/mL and 2 ng/g, respectively, extraction recovery rates greater than 70.50%, both intra- and inter-day precisions less than 10.71%, accuracies 98.42%-111.63%, and matrix effects 91.52%-106.39%. The method was successfully applied to a case of suspected oleander poisoning. Oleandrin was detected in the blood, urine, liver tissues, bile, stomach wall tissues and stomach contents of the cadaver, with the content ranging from 65.5 to 29 600.0 ng/mL （ng/g）.

CONCLUSIONS

The method developed in this study is simple and convenient to operate with good selectivity, and is suitable for the analysis of oleandrin in biological samples such as blood and liver tissues, which can provide technical support for forensic identification and clinical diagnosis and treatment of oleander poisoning.

[Identification of New Designer Benzodiazepine Diclazepam in Drug Facilitated Sexual Assault]

OBJECTIVES

To identify the new designer drugs which are totally unknown and not in the routine testing list by the technologies such as high-resolution mass spectrometry in drug facilitated sexual assault, in order to solve the problem in actual cases.

METHODS

The milky fluid from an actual case was extracted and analyzed using LC-QE, ¹H-NMR and GC-MS, respectively. The accurate masses and cluster ions isotope patterns of unknown compound were obtained by LC-QE. The molecular formula was confirmed as C₁₆H₁₂C₂N₂O based on the protons number of ¹H-NMR. The isomers diclazepam and 4-chlorodiazepam were separated and detected with GC-MS.

RESULTS

The new designer benzodiazepine as diclazepam in the milky fluid was identified. The results provided direct evidence for the investigation and qualitative analysis of such cases.

CONCLUSIONS

The combined application of various methods, including LC-QE, ¹H-NMR and GC-MS, can be used to detect unknown new psychoactive substances.

Genome-wide association study reveals novel genes for the ear size in sheep (Ovis aries)

Variations in ear size can be observed in livestock such as sheep; however, the genetic basis of variable ear size in sheep is still poorly understood. To investigate causative genes associated with ear size in sheep, a genome-wide association study was performed in 115 adult Duolang sheep with different-sized floppy ears using the Ovine Infinium HD BeadChip. We found 38 significant SNPs at the genome-wide or chromosome-wise 5% significance level after Bonferroni correction. The most significant association (P = 1.61 × 10^-6 ) was found at SNP rs402740419, located in the DCC gene, which plays a critical role in ear development. Also, we observed two additional significant SNPs, rs407891215 in PTPRD and rs407769095 in SOX5, both of which are functionally associated with ear developmental processes. Our results are useful for future sheep breeding and provide insights into the genetic basis of ear size development in sheep and other livestock.

[Analysis of Arsenic Compounds in Blood and Urine by HPLC-ICP-MS]

OBJECTIVES

To establish an analysis method for the detection of 6 arsenic compounds [AsC, AsB, As（Ⅲ）, DMA, MMA and As（V）] in blood and urine by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry （HPLC-ICP-MS）, and apply it to real cases.

METHODS

Triton was used to damage cells, and then EDTA·2Na·2H2O was used to complex arsenic compounds in cells, and sonication and protein deposition by acetonitrile were performed for sample pretreatment. With the mobile phase consisted of ammonium carbonate and ultrapure water, gradient elution was performed for obtaining the arsenic compounds in samples, which were analysed by ICP-MS with Hamilton PRP-X100 column.

RESULTS

The limits of detection in blood were 1.66-10 ng/mL, while the lower limits of quantitation in blood ranged from 5 to 30 ng/mL. The limits of detection in urine were 0.5-10 ng/mL, while the lower limits of quantitation in urine were 5-30 ng/mL. The relative standard deviation of inter-day and intra-day precisions was less than 10%. This method had been successfully applied to 3 cases.

CONCLUSIONS

This study has established an analysis method for detecting 6 common arsenic compounds in blood and urine, which can be used to detect the arsenic compounds in the blood and urine from arsenic poisoning cases as well as the patients under arsenic treatment.

[Clinical analysis of multiple myeloma-associated amyloidosis]

Objective: To investigate the clinical features and survival of multiple myeloma-associated amyloidosis patients. Methods: Twenty three multiple myeloma-associated amyloidosis patients were retrospectively analyzed from January 2009 to December 2016. Results: The overall response rate(ORR)was 65.2% and the remission rate (sCR+ CR) was 21.7%. The median progression-free survival(PFS) was fourteen months(1-63), and the median overall survival(OS)was fifteen months(3-63). The early death rate (death rate within one year)was 33.3%. The median OS of patients(n=9)with the performance status(PS) score >2 was seven months(1-15), and the median OS of patients(n=14)with the PS score ≤2 was thirty months(10-63). There was a statistically significant difference in OS(P<0.05); the median PFS and OS of the patients (n=15) who responded to inductive treatment were seventeen months(2-63) and twenty four months (4-63)respectively, and the median PFS and OS of the patients (n=8)who did not respond to inductive treatment were three months(1-8) and eleven months (3-15) respectively. There was a statistically significant difference in PFS and OS(P<0.05). There was a statistically significant difference in PFS and OS between patients treated with remission (n=5)and those who did not(n=18) (P<0.05). Conclusions: The multiple myeloma-associated amyloidosis patients had a high early death rate and short survival time. Early identification and effective treatment are the preconditions for improving the poor prognosis.

[Strategy for minimally invasive cochlear implantation and residual hearing preservation]

In the past few decades, considerable development was achieved in the cochlear implantation following the emergence of innovative electrode array and advances in minimally invasive surgery. Minimally invasive technique led to a better preservation of residual low-frequency hearing. The loss of residual hearing was caused by complicated factors. According to previous studies, a slower and stable speed of electrode insertion and the use of perioperative steroids were demonstrated to have a positive impact on hearing preservation. The selection of electrode array or its insertion approaches didn't show any distinctive benefits in hearing preservation.

[Presented with subarachnoid hemorrhage and then blood culture negative infective endocarditis: a case report and literature review]

The patient, a 43-year-old man, had paroxysmal headache three months ago, and he had complained the left occipital sharp pain, which could be alleviated by itself, with alalia and the right side of the upper limb numbness. Head computed tomography (CT) revealed a left temporal lobe intraparenchymal hemorrhage with the left side of the subarachnoid hemorrhage in small quantities. Digital subtraction angiography (DSA) revealed a suspicious aneurysm on the left internal carotid artery siphon. He had intermittent fever 1 month ago, with maximum body temperature 39 °C. He suffered headache again 20 days ago, with pain nature, duration and the way of easing up similar to the earlier onset. General examination demonstrated 2/6 grade blowing systolic murmurs at apex area. Neurological examination revealed that Babinski's sign was positive on the right side. Echocardiographic found an anterior mitral valve ve-getation on the 4th day in hospital. So his clinical diagnosis was infective endocarditis with cerebral embolism. He received vancomycin treatment immediately. His three blood cultures remained negative in hospital. His blood specimens were sent to Chinese Center for Disease Control and Prevention, indirect immunofluorescence method (IFA) IgG antibody detection revealed that the Bartonella henselae IgG antibody was positive. Therefore the clinical diagnosis was Bartonella endocarditis complicated with subarachnoid hemorrhage and cerebral embolism. Bartonella, an intracellular fastidious, gram-negative bacilli, was first documented as a cause of endocarditis in 1993 and since then has been increasingly recognized as an important etiology of infective culture-negative endocarditis. In cases of documented Bartonella endocarditis, the Infectious Diseases Society of America (IDSA) guidelines recommended 2 weeks of gentamicin plus 6 weeks of doxycycline treatment, to achieve a higher cure rate.

[Identification of Methamphetamine Abuse and Selegiline Use： Chiral Analysis of Methamphetamine and Amphetamine in Urine]

OBJECTIVES

To study the content variation of selegiline and its metabolites in urine, and based on actual cases, to explore the feasibility for the identification of methamphetamine abuse and selegiline use by chiral analysis.

METHODS

The urine samples were tested by chiral separation and LC-MS/MS method using CHIROBIOTIC™ V2 chiral liquid chromatography column. The chiral analysis of methamphetamine and amphetamine were performed on the urine samples from volunteers of selegiline use and drug addicts whom suspected taking selegiline.

RESULTS

After 5 mg oral administration, the positive test time of selegiline in urine was less than 7 h. The mass concentrations of R（-）-methamphetamine and R（-）-amphetamine in urine peaked at 7 h which were 0.86 μg/mL and 0.18 μg/mL and couldn't be detected after 80 h and 168 h, respectively. The sources of methamphetamine and amphetamine in the urine from the drug addicts whom suspected taking selegiline were analysed successfully by present method.

CONCLUSIONS

The chiral analysis of methamphetamine and amphetamine, and the determination of selegiline's metabolites can be used to distinguish methamphetamine abuse from selegiline use.

Minimizing the t1-noise when using an indirect 1H high-resolution detection of unlabeled samples

The most utilized through-space correlation ¹H-{X} methods with proton indirect detection use two consecutive transfers, ¹H → X and then X → ¹H, with the evolution time t₁ in the middle. When the X isotope is not 100% naturally abundant (NA), only the signal of the protons close to these isotopes is modulated by the ¹H-X dipolar interactions. This signal is theoretically disentangled with phase-cycling from the un-modulated one. However, this separation is never perfect and it may lead to t₁-noise in case of isotopes with very small NA, such as ¹³C or even worse ¹⁵N. One way to reduce this t₁-noise is to minimize, 'purge', during t₁ the un-modulated ¹H magnetization before trying to suppress it with phase-cycling. We analyze experimentally several sequences following the HORROR condition, which allow purging the ¹H transverse magnetization. The comparison is made at three spinning speeds, including very fast ones for ¹H resolution: 27.75, 55.5 and 111 kHz. We show (i) that the efficiency of this purging process increases with the spinning speed, and (ii) that the best recoupling sequences are the two simplest ones: XY and S₁ = SR2¹₂. We then compare the S/N that can be achieved with the two most used ¹H-{X} 2D methods, called D-HMQC and CP-CP. The only difference in between these two methods is that the transfers are done with either two π/2-pulses on X channel (D-HMQC), or two Cross-Polarization (CP) transfers (CP-CP). The first method, D-HMQC, is very robust and should be preferred when indirectly detecting nuclei with high NA. The second method, CP-CP, (i) requires experimental precautions to limit the t₁-noise, and (ii) is difficult to use with quadrupolar nuclei because the two CP transfers are then not efficient nor robust. However, CP-CP is presently the best method to indirectly detect isotopes with small NA, such as ¹³C and ¹⁵N.