[Pancreaticoduodenectomy combined with longitudinal pancreaticojejunostomy in the treatment of chronic pancreatitis: initial experience in 11 cases].

Objective: To investigate the surgical strategy for chronic pancreatitis complicated with suspected malignant lesions in the pancreatic head and pancreatolithiasis in the distal pancreas. Methods: This is a retrospective cohort study. Clinical data from 11 patients with chronic pancreatitis who underwent pancreaticoduodenectomy combined with longitudinal pancreaticojejunostomy(PD-L) were retrospectively collected(PD-L group) from the Department of Hepatobiliary Surgery of the First Affiliated Hospital of Xi'an Jiaotong University between December 2021 and September 2023. All patients were male with an age of (49.0±11.2) years(range:32 to 70 years). Their primary preoperative diagnoses included pancreatic lesions, chronic pancreatitis, pancreatolithiasis, and dilatation of the pancreatic duct. Data from 248 patients who underwent pancreaticoduodenectomy(PD) during the same period were retrospectively collected(PD group). There were 157 males and 91 females in the PD group, with an age of (61.5±10.8) years(range:27 to 82 years). Among them, 87 cases were diagnosed as pancreatic cancer or chronic pancreatitis. The propensity score matching method was used to reduce confounding bias between the two groups. The caliper value of 0.1 was used and the 1∶4 nearest neighbor matching method was used for the matching. Comparisons between the two groups were made using the independent sample t test, Mann-Whitney U test or χ2 test,respectively. Results: After complete excision of the specimen during pancreaticoduodenectomy, the key surgical step of PD-L was longitudinal pancreaticojejunostomy in the remaining pancreas. Intraoperative blood loss in the PD-L group was lower than that in the PD group [M(IQR)](300(200)ml vs. 500(500)ml, respectively; P<0.05). Similarly, hospitalization days(21.0(7.0)days vs. 25.0(8.5)days) and postoperative hospitalization days(13.0(8.0)days vs. 17.0(5.0) days) were also lower in the PD-L group compared to the PD group (P<0.05). There were no significant differences in the operation time and postoperative complication rate between the two groups(P>0.05). In the PD-L group, the postoperative follow-up time was 5(5)months(range: 3 to 21 months). One case was lost for follow-up. Abdominal pain was relieved in 10 patients. Additionally, abdominal distension and steatosis were alleviated in 8 cases. Furthermore, 5 cases of diabetes mellitus showed improved control of HbA1c and fasting blood glucose levels after surgery. Conclusions: PD-L treatment can be used to treat chronic pancreatitis complicated by suspected malignant lesions in the pancreatic head and pancreatolithiasis in the distal pancreas. PD-L also has advantages in removing stones from the pancreatic duct and evaporation of pancreatic fluid. However, due to the single-center design and the small sample size of this study, further practice and long-term follow-up are still necessary.

[Kinetics of immune activated T cells in aplastic anemia mouse model].

Objective: To explore the dynamic changes of donor derived T cells at different time points in the aplastic anemia mouse model. Methods: The aplastic anemia mouse model was induced and then the proportion of infiltrated donor derived T cells in spleen and bone marrow, expression of activation molecular markers, cell cycle and functional subsets were measured by flow cytometry at different time points to evaluate the functional status of T cells in different periods. Results: ①T cell immune-mediated aplastic anemia mouse model was successfully established by half lethal dose irradiation combined with major histocompatibility antigen (MHC) haploidentical lymph node cells infusion. ②The donor derived T cells began to infiltrate significantly in the spleen of aplastic anemia mouse from the 3rd day after transplantation and the ratio of CD4(+)/CD8(+) gradually inverted. After the 5th day, they gradually entered the bone marrow, predominated by CD8(+) cells. ③The expression peak of CD69 in donor CD4(+) cells was later than that in CD8(+) cells. The trend of CD25 expression in CD4(+) cells was the same as that in CD8(+) cells, but the expression level in CD8(+) cells was higher than CD4(+) cells. ④The proportion of donor CD4(+) cells in S/G(2)/M phase reached the peak in spleen, about 12%, within 3 days after transplantation, while a higher level in CD8(+) cells, which was about 20%. And the proportion of both CD4(+) and CD8(+) cells in S/G(2)/M phase increased again after entering bone marrow, which was continued to be higher in CD8(+) cells than that in CD4(+) cells after 3 days of transplantation. ⑤Immune activated T cells in the spleen rapidly differentiated into effector memory T cells (T(EM)) after a short central memory T cell (T(CM)) stage. After entering the bone marrow, some T(EM) differentiated into effector cells to further function. Conclusion: In the aplastic anemia mouse model, donor derived T cells activated rapidly after entering the allogenic recipient, reached its proliferation booming period and differentiated into T(EM) cells within 5 days. After 5 days, they began to enter the bone marrow to continue proliferate and damage hematopoiesis.

[Transmission routes of 2019-novel coronavirus (2019-nCoV)].

Since the outbreak of COVID-19 in Wuhan, China, at the end of 2019, it has demonstrated China's ability to identify unknown pathogens. At present, reports showed that the main transmission routes are respiratory droplets and indirect contact, other vertical transmission routes have yet to be confirmed. This review discusses the possible transmission routes of 2019-novel coronavirus (2019-nCoV), based on currently research, the main transmission routes are respiratory droplets and indirect contact, fecal-oral might bepossible, while aerosol, tear (conjunctival) and mother-to-fetus still have yet to be confirmed, providing a reference basis for 2019-nCoV prevention and control and public protection.

[Anemia status of Chinese rural women of reproductive age in 2012].

Objective: To study the hemoglobin concentration, anemia status and its determinant factors among Chinese rural women of reproductive age in 2012. Methods: This was a cross-sectional study. The data was obtained from the National Free Preconception Health Examination Project (NFPHEP). A total of 712 101 Chinese rural reproductive age women aged 21-49 years old who came from 193 counties of 30 provinces were included. The demographic characteristics were obtained from questionnaires. Hemoglobin concentration was measured using the cyanomethemoglobin method. The definition of anemia we used was recommended by World Health Organization, and was adjusted according to altitude level. The hemoglobin concentration level, the prevalence of anemia and its 95% CI was calculated. Determinant factors of anemia such as demographic characteristics and histories of pregnancy and miscarriage were analyzed using logistic regression. Results: In 2012, the level of hemoglobin concentration in Chinese rural women of reproductive age was (127.77±13.47) g/L, with the lowest in 21-24 years group, which was (127.54±13.54) g/L, and highest in 35-39 years group, which was (128.39±14.12) g/L. In terms of region, the hemoglobin concentration level was lowest in central south, which was (125.79±12.00) g/L, and highest in southwest, which was (129.91±14.37) g/L. The prevalence of anemia in Chinese rural women of reproductive age was 24.80%, with the highest seen in 21-24 years, which was 25.92% (95% CI: 25.74%-26.11%), and lowest in 30-34 years, which was 23.61% (95% CI: 23.37%-23.85%). The prevalence in northwest (28.31%, 95% CI: 28.01%-28.61%) was the highest among all regions, and the prevalence in east (20.88%, 95% CI: 20.68%-21.09%) was the lowest. Conclusions: The prevalence of anemia in Chinese rural reproductive age women was 24.80% in 2012. The anemia prevalence was higher among women who were young, had low educational level, and lived in northwest region.

Experimentally simulating quantum walks with self-collimated light.

In self-collimated photonic crystal, periodically arranged air holes of sub-wavelength scale provide flattened equi-frequency curves perpendicular to the ΓM direction, which allow light or photons propagating in a quasi-uniform medium without diffraction. Here we for the first time experimentally simulate four-step single-photon discrete time quantum walks with classical light in such a photonic crystal chip fabricated on silicon-on-insulator. Similarities between theoretical expectations and experimental results are higher than 0.98. The functional area is compact and can be extended to construct more complicated linear quantum circuits.

Screening and mutagenesis of a novel Bacillus pumilus strain producing alkaline protease for dehairing.

AIMS: To characterize and optimize a novel Bacillus pumilus strain isolated from biological waste which produces protease with excellent dehairing effect. This newly isolated strain could be utilized in the industrial leather dehairing process. METHODS AND RESULTS: Bacterial strains secreting proteases were screened from biological wastes. Positive clones were further characterized by analysing their efficacy in dehairing and effects on collagen integrity. Among 171 colonies tested, a strain BA06, identified as B. pumilus, was picked owing to its efficient dehairing capabilities with minimal impact on collagen. By combined mutagenesis using UV, N-methyl-N'-nitro-N-nitrosdguanidine and Co(60)-gamma-rays, this strain was further improved with regard to its alkaline protease production. The alkaline protease activity of the mutant strain SCU11was greatly improved up to 6000 U ml(-1), in comparison with its parent strain BA06 of 1200 U ml(-1). CONCLUSIONS: By using screening and mutagenesis methods, we have successfully created a B. pumilus strain that can produce high levels of alkaline proteases that are able to efficiently remove hair from skin with minimal damage on the collagen. SIGNIFICANCE AND IMPACT OF THE STUDY: This strain could be used in commercial alkaline protease production for leather dehairing.

Effect of resveratrol on peritoneal macrophages in rats with severe acute pancreatitis.

OBJECTIVE: The literature on resveratrol in severe acute pancreatitis (SAP) is limited though it has been widely studied in infections and trauma. The aim of this study was to investigate the inhibitory effect of resveratrol on inflammatory responses in a rat model of SAP. METHODS: Male Sprague-Dawley (SD) rats were randomly divided into 3 groups: SAP group, resveratrol group and control group. 4.0% sodium taurocholate was injected into the pancreatic duct to induce SAP. In the resveratrol group, resveratrol (10 mg/kg) was injected through penal vein 5 min after SAP was induced. The peritoneal macrophages of the rats were collected 3, 6 and 12 h after stimulus and then incubated for 24 h. The expression of nuclear factor kappa B (NF-kappaB) and inducible nitric oxide synthase (iNOS) in peritoneal macrophages was measured. The levels of tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1) and nitric oxide (NO) in culture medium of peritoneal macrophages and serum of rats were evaluated. RESULTS: Histological examination of pancreas indicated that the damage in the SAP group was more severe than that in the resveratrol group. The expression of NF-kappaB and iNOS in peritoneal macrophages was significantly higher in the SAP group than in the resveratrol group. The concentrations of TNF-alpha, IL-1 and NO in culture medium and serum were significantly elevated in the SAP group when compared with the resveratrol group. CONCLUSIONS: The inhibiting effect on the inflammatory response and the decreased expression of TNF-alpha, IL-1 and NO in peritoneal macrophages suggest resveratrol as a novel anti-inflammatory agent for reducing the severity of SAP.

Performance of large-size superconducting coil in 0.21T MRI system.

A high-temperature superconductor (HTS) was used on magnetic resonance imaging (MRI) receiver coils to improve image quality because of its intrinsic low electrical resistivity. Typical HTS coils are surface coils made of HTS thin-film wafers. Their applications are severely limited by the field of view (FOV) of the surface coil configuration, and the improvement in image quality by HTS coil is also reduced as the ratio of sample noise to coil noise increases. Therefore, previous HTS coils are usually used to image small in vitro samples, small animals, or peripheral human anatomies. We used large-size HTS coils (2.5-, 3.5-, and 5.5-in mean diameter) to enhance the FOV and we evaluated their performance through phantom and human MR images. Comparisons were made among HTS surface coils, copper surface coils, and cool copper surface coils in terms of the signal-to-noise ratio (SNR) and sensitivity profile of the images. A theoretical model prediction was also used to compare against the experimental result. We then selected several human body parts, including the wrist, feet, and head, to illustrate the advantage of HTS coil over copper coil when used in human imaging. The results show an SNR gain of 200% for 5.5-in HTS coil versus same size copper coils, while for 2.5- and 3.5-in coils it is 250%. We also address the various factors that affect the performance of large size HTS coils, including the coil-to-sample spacing due to cryogenic probe and the coil-loading effect.

Superconducting RF coils for clinical MR imaging at low field.

RATIONALE AND OBJECTIVES: A number of recent reports in the MRI literature have established that substantial signal-to-noise ratio (SNR) gains can be achieved with small samples or low resonance frequencies, through the use of high-quality factor high-temperature superconducting (HTS) RF receive coils. We show the application of HTS coils to the imaging of human subjects with improved SNR compared with copper coils. MATERIALS AND METHODS: HTS coils were constructed from 7.62-cm YBa2Cur3O7-delta thin films on LaAlO3 substrate and cooled in a liquid nitrogen cryostat. Human and phantom images were acquired on a 0.2-T scanner. The SNR improvements compared with equivalent-sized copper coils are reported. RESULTS: SNR gains of 2.8-fold and 1.4-fold were observed in images of a phantom acquired with an HTS coil versus a room temperature copper coil and a liquid nitrogen-cooled copper coil, respectively. Preliminary results suggest higher image quality can be obtained in vivo with an HTS coil compared with copper coil imaging. Images of human orbit, brain, temporomandibular joint, and wrist are presented. CONCLUSION: The experimental results show that benefits can be expected from application of HTS surface coils in human MR imaging with low-field scanners. These potential benefits justify the continued development of practical HTS coil imaging systems despite the considerable technical difficulties involved in cryostat and coil design.

Hepatitis C virus infection of human hepatoma cell line 7721 in vitro.

AIM: To establish a cell culture system with long-term replication of hepatitis C virus in vitro. METHODS: Human hepatoma cell line 7721 was tested for its susceptibility to HCV by incubating with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various phases during the culturing periods. The presence of HCV RNA, the expression of HCV antigens in cells and/or supernatant were examined by RTPCR, in situ hybridization and immunohistochemistry respectively. RESULTS: The intracellular HCV RNA was first detected on d2 after infection and then could be intermittently detected in both cells and supernatant over a period of at least three months. The expression of HCV NS3,CP10 antigens could be observed in cells. The fresh cells could be infected by supernatant from cultured infected cells and the transmission of viral genome from HCV-infected 7721 cells to PBMCs was also observed. CONCLUSION: The hepatoma line 7721 is not only susceptible to HCV but also supports its long-term replication in vitro.

[Population genetics of Chinese surnames. I. Surname frequency distribution and genetic diversity in Chinese].

This paper deals with the distributional characteristics of Chinese surnames and the factors affecting their distribution. Analysis of alpha and nu values for three periods in the last 1,000 years clearly reveals the distributional pattern of Chinese surnames. In China, communities with the same surname are widespread, especially in the central areas where there are more relatively isolated Y chromosome of the same source (communities with the same surname) and more surnames than in other areas (especially the South China). If each surname has a certain kind of mono-type Y-DNA, then, according to the distribution of surnames, there exist the most mono-type of Y-DNA in the central provinces where are the originating center of Chinese surnames. For the first time, an equation is constructed predicting the kind of Chinese surnames. It has been estimated that there are about 3,100 surnames present in use for the Han nationality.

MRI brain image segmentation by multi-resolution edge detection and region selection.

Combining both spatial and intensity information in image, we present an MRI brain image segmentation approach based on multi-resolution edge detection, region selection, and intensity threshold methods. The detection of white matter structure in brain is emphasized in this paper. First, a multi-resolution brain image representation and segmentation procedure based on a multi-scale image filtering method is presented. Given the nature of the structural connectivity and intensity homogeneity of brain tissues, region-based methods such as region growing and subtraction to segment the brain tissue structure from the multi-resolution images are utilized. From the segmented structure, the region-of-interest (ROI) image in the structure region is derived, and then a modified segmentation of the ROI based on an automatic threshold method using our threshold selection criterion is presented. Examples on both T1 and T2 weighted MRI brain image segmentation is presented, showing finer brain tissue structures.

Performance of a high-temperature superconducting probe for in vivo microscopy at 2.0 T.

The use of a high-temperature superconducting probe for in vivo magnetic resonance microscopy at 2 T is described. To evaluate the performance of the probe, a series of SNR comparisons are carried out. The SNR increased by a factor of 3.7 compared with an equivalent copper coil. Quantitative measures of the SNR gain are in good agreement with theoretical predictions. A number of issues that are unique to the application of HTS coils are examined, including the difficulty in obtaining homogenous excitation without degrading the SNR of the probe. The use of the HTS probe in transmit-receive mode is simple to implement but results in nonuniform excitation. The effect of using the probe in this mode of operation on the T1 and T2 contrast is investigated. Methods for improving homogeneity are explored, such as employing a transmit volume coil. It is found that the cost of using an external transmit coil is an increased probe noise temperature and a reduced SNR by approximately 30%. Other important aspects of the probe are considered, including the effect of temperature on probe stability. Three-dimensional in vivo imaging sets are acquired to assess the stability of the probe for long scans. High-resolution images of the rat brain demonstrate the utility of the probe for microscopy applications.

Combinations of three immunological assays for detecting anti-Toxoplasma IgG in the sera of patients infected with Toxoplasma gondii.

Enzyme-linked immunosorbent assay (ELISA), Dot-ELISA and Dot-immunogold silver staining (Dot-IGSS) were simultaneously used to detect the specific IgG against Toxoplasma gondii in 65 patients infected with the protozoa. The positive rates were 86.51%, 92.51% and 98.64%, respectively. When ELISA and Dot-ELISA results were put together, the positive rate increased to 95.38%. When Dot-IGSS results were combined with those of ELISA or Dot-ELISA, the positive rate was raised to 100%. The difference in positive rate between ELISA and Dot-IGSS was significant (x2 = 6.93, p < 0.01), but no statistically significant differences were found between ELISA and Dot-ELISA or between Dot-ELISA and Dot-IGSS. Paired comparison of the reacting intensities of the sera in the 3 assays showed the correlations were highly significant (p < 0.001), with r = 0.608 between Dot-IGSS and Dot-ELISA, r = 0.8194 between Dot-IGSS and ELISA and r = 0.517 between Dot-ELISA and ELISA. Hence combination of different serological assays may increase their sensitivity and specificity for detecting the anti-Toxoplasma antibodies.

Superconducting receiver coils for sodium magnetic resonance imaging.

We present the results from sodium magnetic resonance imaging (MRI) experiments using high-temperature superconducting (HTS) receiver coils. Sodium imaging has been shown to have great potential for the assessment of cell integrity but suffers from a substantially lower signal-to-noise ratio (SNR) than that of a hydrogen imaging. The use of an HTS receiver coil was found to significantly increase the SNR relative to an equivalent copper receiver coil at room temperature. The SNR gains afforded by HTS coils can also be used to decrease the imaging time.

Longitudinal study of the health of cotton workers.

OBJECTIVES: To follow up a group of newly employed workers in a cotton mill, and to report changes in symptoms over time. METHODS: A group of 110 mill workers at a cotton mill in Shijiazhuang, China, was investigated by questionnaire, skin testing, and spirometric measurements of airway responsiveness through forced expiratory volume in one second (FEV1). The workers were examined before starting work, at 10 weeks, and at one year. RESULTS: Decreases in FEV1 over shifts were small at 10 weeks and one year, and slightly higher among people with skin reactions to cotton dust extracts. Airway responsiveness, defined as the average decrease in FEV1 after 1.25 mg methacholine was increased at 10 weeks. It remained about the same after one year, except in the workers positive for the skin test, in whom it was further increased. Subjective symptoms of chest tightness and cough with phlegm increased progressively at 10 weeks and one year; nasal irritation remained unchanged and dry cough decreased between 10 weeks and one year. CONCLUSION: The results suggest that the airway inflammation caused by cotton dust increases with increasing exposure time and that the changes are more notable in workers with reactivity to cotton dust extract.

[Iris nodules, ocular findings and blood grouping in neurofibromatosis].

Through the analyses of 22 cases of neurofibromatosis (NF) patient ranging from 3 months to 63 yrs. old. We found that 4 cases had bilateral hearing loss and 2 of them were excluded from acoustic neuroma. The ocular appearance showed lid neurofibroma in 12 cases, orbital bone abnormalities in 4 cases, iris nodules in 20 cases (90%), congenital glaucoma (4 eyes) in 3 cases which showed abnormal gonioscopy in 3 eyes, lens opacity in 2 cases, mild and moderate myopia in 8 eyes, and high myopia in 7 eyes, occupying 16% of the total. 11 cases belong to 5 pedigrees showing autosomal dominant inheritance. The ABO and MN blood grouping of the NF cases and families in the pedigree showed that NF was more related to ABO than MN blood group. The ocular appearance, especially the shape and number of iris nodules in relation to age and diagnosis is discussed. The significance of 1 case of retinitis pigmentosa, 7 cases of high myopia in relation with NF should be further studied.