Machine-learning intervention progress in the field of organic waste composting: Simulation, prediction, optimization, and challenges

Aerobic composting stands as a widely-adopted method for treating organic solid waste (OSW), simultaneously producing organic fertilizers and soil amendments. This biologically-driven biochemical reaction process, however, presents challenges due to its complex non-linear metabolism and the heterogeneous nature of the solid medium. These characteristics inherently limit the simulation accuracy and efficiency optimization in aerobic composting. Recently, significant efforts have been made to simulate and control composting process parameters, as well as predicting and optimizing composting product quality. Notably, the integration of machine learning (ML) in aerobic composting of organic waste has garnered considerable attention for its applicability and predictive capability in exploring the complex non-linear relationships of organic waste composting parameters. Despite numerous studies on ML applications in OSW composting, a systematic review of research findings in this field is lacking. This study offers a systematic overview of the application level, current status, and versatility of ML in OSW composting. It spans various aspects, such as compost maturity, environmental pollutants, nutrients, moisture, heat loss, and microbial metabolism. The survey reveals that ML-intervention predominantly focuses on compost maturity and environmental pollutants, followed by nutrients, moisture, heat loss, and microbial activity. The most commonly employed predictive models and optimization algorithms are artificial neural networks (47%) and genetic algorithms (10%). These demonstrate high prediction accuracy and maximize composting efficiency in the simulation and prediction of organic waste composting, alongside regulation of key parameters. Deep neural networks and ensemble learning models prove effective in achieving superior predictive performance by selecting feature variables in compost maturity and pollutant residue prediction of organic waste composting in a simpler and more objective manner.

[Characteristics of baseline viral load before antiretroviral therapy in newly reported HIV-infected patients in Tianjin, 2019-2022]

Objective: To understand the baseline viral load (VL) of newly reported HIV- infected patients before antiretroviral therapy and related factors in Tianjin. Methods: Data were obtained from the China Disease Control and Prevention Information System, and the study subjects were HIV-infected patients before the first antiretroviral therapy in Tianjin from 2019 to 2022, and the information about their socio-demographic characteristics, baseline CD4+T lymphocyte (CD4) counts before antiretroviral therapy and baseline VL test results were collected, the baseline high VL was defined as ≥100 000 copies/ml. The effect of different factors on viral load were analyzed. Software SPSS 24.0 was used for statistical analysis. Results: A total of 1 296 newly reported HIV-infected patients were included in the study, in whom 15.89% (206/1 296) had high baseline VL, and multifactorial logistic regression analysis showed that those with history of STD (aOR=1.45, 95%CI:1.00-2.08) were more likely to have high baseline VL. Compared with those with baseline CD4 counts <200 cells/μl, those with baseline CD4 counts 200-350 cells/μl (aOR=0.40, 95%CI: 0.27-0.57), 351-500 cells/μl (aOR=0.32, 95%CI: 0.20-0.49), and >500 cells/μl (aOR=0.30, 95%CI: 0.18-0.49) were less likely to have high baseline VL. Conclusions: The proportion of HIV-infected patients with high baseline VL before antiretroviral therapy was low in Tianjin during 2019-2022. History of STD and baseline CD4 counts <200 cells/μl were associated with high baseline VL in HIV-infected patients, to which close attention needs to be paid in AIDS prevention and control.

Novel perspective on qualitative assessment of swine manure compost maturity using organic carbon density fractions

Mature compost is safe and stable, yet quality assessments are challenging owing to current maturity indicators' limitations. This study employed density fractionation to separate organic carbon into light and heavy fractions, offering a new perspective for assessing maturity. Results showed that light fraction organic carbon progressively transitioned into heavy fraction during composting, reducing the proportion of total organic carbon from 82.82% to 44.03%, while heavy fraction organic carbon increased to 48.58%. During the first seven days, the reduction rate of light fraction organic carbon decreased slowly, while the increase rate of heavy fraction declined sharply, levelling off thereafter. Light/heavy fraction organic carbon ratio was significantly correlated with existing maturity indicators (carbon/nitrogen ratio, humic acid/fulvic acid ratio, biological growth-related indicators), with the ratio below 1.33 serving as a potential compost maturity marker. Thus, given its simplicity and reliability, organic carbon density fractions is an innovative indicator for compost maturity assessments.

Histone crotonylation of peripheral blood mononuclear cells is a potential biomarker for diagnosis of colorectal cancer

BACKGROUND

Blood-based tests have public appeal in screening cancers due to their minimally invasive nature, ability to integrate with other routine blood tests, and high compliance. This study aimed to investigate whether certain epigenetic modulation of peripheral blood mononuclear cells (PBMCs) could be a biomarker of colorectal cancer (CRC).

RESULTS

Western blotting of histones in the PBMCs from 40 colorectal cancer patients and 40 healthy controls was performed to identify the crotonylation sites of proteins. The correlation of crotonylation with tumor staging and diagnostic efficacy were analyzed. Crotonylation of H2BK12 (H2BK12cr) was identified significantly upregulated in the PBMCs of CRC patients compared to healthy controls, and were closely related to distant metastasis (P = 0.0478) and late TNM stage (P = 0.0201). Receiver operator characteristic curve (ROC) analysis demonstrated that the area under curve (AUC) of H2BK12cr was 0.8488, the sensitivity was 70%, and the specificity was 92.5%. The H2BK12cr parameter significantly increased the diagnostic effectiveness of CRC compared with the commercial carcinoembryonic antigen assays.

CONCLUSIONS

The H2BK12cr level in PBMCs of CRC patients has a potential to be a biomarker for distinguishing CRC patients from healthy controls with the advantages of easy operation and high diagnostic efficacy.

Sympathetic nerve infiltration promotes stomach adenocarcinoma progression via norepinephrine/β2-adrenoceptor/YKL-40 signaling pathway

Objective

This study aimed to address the status, role, and mechanism of sympathetic nerve infiltration in the progression of stomach adenocarcinoma (STAD).

Methods

Sympathetic nerve and its neurotransmitter NE, β-ARs, and associated signaling molecules in the STAD tissues and the adjacent tissues from 46 STAD patients were examined using immunostaining, HPLC, and western blotting. The effects and mechanisms of β2-AR activation on the proliferation, migration and invasion of AGS and SGC-7901 gastric cancer (GC) cell lines were examined using CCK-8, transwell, and western blotting assays. Correlations between genes and STAD survival were analyzed using bioinformatics.

Results

Striking sympathetic nerve infiltration, elevations of NGF, TrkA, GAP43, TH, S100, NE, β2-AR, YKL-40, syndecan-1, MMP9, CD206, and CD31 were observed in the STAD tissues compared to the adjacent tissues. Activation of β2-AR in the two GC cell lines significantly amplified the expressions of NGF, YKL-40, MMP9, syndecan-1, p-STAT3 and p-ERK, and increased GC cell proliferation, migration and invasion. Bioinformatic analyses revealed positive correlations of NGF, β2-AR, syndecan-1, and macrophage infiltration, respectively, with low survival of STAD, of β2-AR respectively with STAT3, ERK1/2 (MAPK1/3), YKL-40, MMP9, and syndecan-1, and of YKL-40 with MMP9.

Conclusion

Sympathetic nerves significantly infiltrated into human STAD tissues as a result of high NGF and TrkA expressions; elevated NE led to overactivation of β2-AR-STAT3/ERK-YKL-40 signaling pathway, and finally caused cancer cell growth and invasion, M2 macrophage infiltration, angiogenesis, matrix degradation and STAD metastasis and progression.

[Regulatory mechanism of deferoxamine on macrophage polarization and wound healing in mice with deep tissue injury]

Objective: To investigate the effects of deferoxamine on macrophage polarization and wound healing in mice with deep tissue injury (DTI) and its mechanism. Methods: The experimental research methods were adopted. Fifty-four male C57BL/6J mice of 6-8 weeks old were divided into DTI control group, 2 mg/mL deferoxamine group, and 20 mg/mL deferoxamine group according to random number table, with 18 mice in each group. DTI was established on the back of mice by magnet compression method. From post injury day (PID) 1, mice were injected subcutaneously with 100 µL normal saline or the corresponding mass concentration of deferoxamine solution every other day at the wound edge until the samples were collected. Another 6 mice without any treatment were selected as normal control group. Six mice in each of the three DTI groups were collected on PID 3, 7, and 14 to observe the wound changes and calculate the wound healing rate. Normal skin tissue of mice in normal control group was collected on PID 3 in other groups (the same below) and wound tissue of mice in the other three groups on PID 7 and 14 was collected for hematoxylin-eosin (HE) staining to observe the tissue morphology. Normal skin tissue of mice in normal control group and wound tissue of mice in the other three groups on PID 7 were collected, and the percentages of CD206 and CD11c positive area were observed and measured by immunohistochemical staining, and the mRNA and protein expressions of CD206, CD11c, and inducible nitric oxide synthase (iNOS) were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction and Western blotting, respectively. Normal skin tissue of mice in normal control group and wound tissue of mice in DTI control group and 20 mg/mL deferoxamine group were collected on PID 3, 7, and 14, and the protein expressions of signal transducer and activator of transcription 3 (STAT3) and interleukin-10 (IL-10) were detected by Western blotting. The sample number in each group at each time point in the above experiments. The RAW264.7 cells were divided into 50 μmol/L deferoxamine group, 100 μmol/L deferoxamine group, 200 μmol/L deferoxamine group, and blank control group, which were treated correspondingly, with 3 wells in each group. The positive cell percentages of CD206 and CD86 after 48 h of culture were detected by flow cytometry. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and least significant difference test. Results: On PID 7, the wound healing rates of mice in 2 mg/mL and 20 mg/mL deferoamine groups were (17.7±3.7)% and (21.5±5.0)%, respectively, which were significantly higher than (5.1±2.3)% in DTI control group (P<0.01). On PID 14, the wound healing rates of mice in 2 mg/mL and 20 mg/mL deferoamine groups were (51.1±3.8)% and (57.4±4.4)%, respectively, which were significantly higher than (25.2±3.8)% in DTI control group (P<0.01). HE staining showed that the normal skin tissue layer of mice in normal control group was clear, the epidermis thickness was uniform, and skin appendages such as hair follicles and sweat glands were visible in the dermis. On PID 7, inflammation in wound tissue was obvious, the epidermis was incomplete, and blood vessels and skin appendages were rare in mice in DTI control group; inflammatory cells in wound tissue were reduced in mice in 2 mg/mL and 20 mg/mL deferoxamine groups, and a few of blood vessels and skin appendages could be seen. On PID 14, inflammation was significantly alleviated and blood vessels and skin appendages were increased in wound tissue of mice in 2 mg/mL and 20 mg/mL deferoxamine groups compared with those in DTI control group. On PID 7, the percentages of CD206 positive area in wound tissue of mice in 2 mg/mL and 20 mg/mL deferoxamine groups were significantly higher than that in DTI control group (P<0.01), the percentage of CD206 positive area in wound tissue of mice in DTI control group was significantly lower than that in normal skin tissue of mice in normal control group (P<0.01), the percentage of CD206 positive area in wound tissue of mice in 20 mg/mL deferoxamine group was significantly higher than that in normal skin tissue of mice in normal control group (P<0.01). The percentages of CD11c positive area in wound tissue of mice in 2 mg/mL and 20 mg/mL deferoxamine groups were significantly lower than those in DTI control group and normal skin tissue in normal control group (P<0.05 or P<0.01), and the percentage of CD11c positive area in normal skin tissue of mice in normal control group was significantly higher than that in DTI control group (P<0.05). On PID 7, the CD206 mRNA expressions in the wound tissue of mice in 2 mg/mL and 20 mg/mL deferoxamine groups were significantly higher than that in DTI control group (P<0.01), but significantly lower than that in normal skin tissue in normal control group (P<0.01); the CD206 mRNA expression in wound tissue of mice in DTI control group was significantly lower than that in normal skin tissue in normal control group (P<0.01). The mRNA expressions of CD11c and iNOS in wound tissue of mice in 2 mg/mL and 20 mg/mL deferoamine groups were significantly lower than those in DTI control group (P<0.01). The mRNA expressions of CD11c in the wound tissue of mice in DTI control group, 2 mg/mL and 20 mg/mL deferoamine groups were significantly higher than that in normal skin tissue in normal control group (P<0.01). Compared with that in normal skin tissue in normal control group, the mRNA expressions of iNOS in wound tissue of mice in 2 mg/mL and 20 mg/mL deferoamine groups were significantly decreased (P<0.01), and the mRNA expression of iNOS in wound tissue of mice in DTI control group was significantly increased (P<0.01). On PID 7, the protein expressions of CD206 in the wound tissue of mice in 2 mg/mL and 20 mg/mL deferoamine groups were significantly higher than those in DTI control group and normal skin tissue in normal control group (P<0.01), and the protein expression of CD206 in wound tissue of mice in DTI control group was significantly lower than that in normal skin tissue in normal control group (P<0.01). The protein expressions of CD11c and iNOS in wound tissue of mice in 2 mg/mL and 20 mg/mL deferoamine groups were significantly lower than those in DTI control group (P<0.01). The protein expressions of CD11c and iNOS in wound tissue of mice in DTI control group were significantly higher than those in normal skin tissue in normal control group (P<0.01). The CD11c protein expressions in wound tissue of mice in 2 mg/mL and 20 mg/mL deferoamine groups were significantly higher than those in normal skin tissue in normal control group (P<0.05 or P<0.01). The protein expression of iNOS in wound tissue of mice in 2 mg/mL deferoamine group was significantly lower than that in 20 mg/mL deferoamine group and normal skin tissue in normal control group (P<0.05). On PID 3, 7, and 14, the protein expressions of STAT3 and IL-10 in wound tissue of mice in 20 mg/mL deferoxamine group were significantly higher than those in DTI control group (P<0.05 or P<0.01), and the protein expressions of STAT3 were significantly higher than those in normal skin tissue in normal control group (P<0.05 or P<0.01). On PID 7 and 14, the protein expressions of IL-10 in wound tissue of mice in 20 mg/mL deferoxamine group were significantly higher than those in normal skin tissue in normal control group (P<0.01). On PID 3, 7, and 14, the protein expressions of IL-10 in wound tissue of mice in DTI control group were significantly lower than those in normal skin tissue in normal control group (P<0.05 or P<0.01). After 48 h of culture, compared with those in blank control group, the CD206 positive cell percentages in 100 μmol/L and 200 μmol/L deferoamine groups were significantly increased (P<0.01), while the CD86 positive cell percentages in 100 μmol/L and 200 μmol/L deferoamine groups were significantly decreased (P<0.01). Conclusions: Deferoxamine can promote the polarization of macrophages toward the anti-inflammatory M2 phenotype and improve wound healing by enhancing the STAT3/IL-10 signaling pathway in DTI mice.

A Numerical Simulation Method Considering Solid Phase Transformation and the Experimental Verification of Ti6Al4V Titanium Alloy Sheet Welding Processes

A prediction model of the welding process of Ti-6Al-4V titanium alloy was established by using the finite element method, which was used to evaluate the phase composition, residual stress and deformation of the welded joints of Ti-6Al-4V sheets with different processes (including tungsten inert gas welding, TIG, and laser beam welding, LBW). The Ti-6Al-4V structures of TIG welding and LBW are widely used in marine engineering. In order to quantitatively study the effects of different welding processes (including TIG welding and LBW) on the microstructure evolution, macro residual stress and deformation of Ti6Al4V titanium alloy sheets during welding, a unified prediction model considering solid-state phase transformation was established based on the ABAQUS subroutine. In this paper, LBW and TIG welding experiments of 1.6 mm thick Ti-6Al-4V titanium alloy sheets were designed. The microstructure distribution of the welded joints observed in the experiment was consistent with the phase composition predicted by the model, and the hardness measurement experiment could also verify the phase composition and proportion. From the residual stress measured by experiment and the residual stress and deformation calculated by finite element simulation of LBW and TIG weldments, it is concluded that the effect of phase transformation on residual stress is mainly in the weld area, which has an effect on the distribution of tensile and compressive stress in the weld area. The overall deformation of the welded joint is mainly related to the welding process, and the phase transformation only affects the local volume change of the weld seam. Importantly, the phase composition and residual stress, which are scalar fields, calculated by the established model can be introduced into the numerical analysis of structural fracture failure as input influence factors.

Minimally invasive surgery for suspected early-stage ovarian cancer; a cost-effectiveness study

OBJECTIVE

While there are a number of benefits to minimally invasive surgery (MIS) for women with ovarian cysts, there is an increased risk of ovarian capsule rupture during the procedure, which could potentially seed the abdominal cavity with malignant cells. We developed a decision model to compare the risks, benefits, effectiveness and cost of MIS versus laparotomy in women with ovarian masses.

DESIGN

Cost-effectiveness study POPULATION: Hypothetical cohort of 10 000 women with ovarian masses who were undergoing surgical management.

METHODS

The initial decision point in the model was performance of surgery via laparotomy or a MIS approach. Model probabilities, costs and utility values were derived from published literature and administrative data sources. Extensive sensitivity analyses were conducted to assess the robustness of the findings.

MAIN OUTCOME MEASURES

The primary outcome was the cost-effectiveness of MIS versus laparotomy for women with a pelvic mass measured by incremental cost-effectiveness ratios (ICERs).

RESULTS

MIS was the least costly strategy at $7,732 per women on average, compared with $17,899 for laparotomy. In our hypothetical cohort of 10 000 women, there were 64 cases of ovarian rupture in the MIS group and 53 in the laparotomy group, while there were 26 cancer-related deaths in the MIS group and 25 in the laparotomy group. MIS was more effective than laparotomy (188 462 QALYs for MIS versus 187 631 quality adjusted life years [QALYs] for laparotomy). Thus, MIS was a dominant strategy, being both less costly and more effective than laparotomy. These results were robust in a variety of sensitivity analyses.

CONCLUSION

MIS constitutes a cost-effective management strategy for women with suspicious ovarian masses.

TWEETABLE ABSTRACT

MIS is a cost-effective management strategy for women with suspicious ovarian masses.

Emerging roles of non-histone protein crotonylation in biomedicine

Crotonylation of proteins is a newly found type of post-translational modifications (PTMs) which occurs leadingly on the lysine residue, namely, lysine crotonylation (Kcr). Kcr is conserved and is regulated by a series of enzymes and co-enzymes including lysine crotonyltransferase (writer), lysine decrotonylase (eraser), certain YEATS proteins (reader), and crotonyl-coenzyme A (donor). Histone Kcr has been substantially studied since 2011, but the Kcr of non-histone proteins is just an emerging field since its finding in 2017. Recent advances in the identification and quantification of non-histone protein Kcr by mass spectrometry have increased our understanding of Kcr. In this review, we summarized the main proteomic characteristics of non-histone protein Kcr and discussed its biological functions, including gene transcription, DNA damage response, enzymes regulation, metabolic pathways, cell cycle, and localization of heterochromatin in cells. We further proposed the performance of non-histone protein Kcr in diseases and the prospect of Kcr manipulators as potential therapeutic candidates in the diseases.

[An overview on the opioid substitution therapy service model]

When facing the worldwide abuse of opioid substance, one of the effective responses is opioid substitution therapy (OST). However, different OST service patterns may affect the therapeutic outcome. Using the System Engineering Initiative for Patient Safety (SEIPS) model, we can analyze the factors that affecting the outcomes of patients from the perspective work system. In this paper, SEIPS model is used to describe the existing OST service model. According to the operation mechanism of the methadone maintenance treatment in China and the existing OST service model, some suggestions are put forward to carry out effective OST service in the country.

Uterine leiomyosarcoma: a review of recent advances in molecular biology, clinical management and outcome

Uterine leiomyosarcoma (LMS) are rare but aggressive tumours with poor clinical outcomes regardless of stage. Most tumours are identified by histopathology at time of surgery, and pre-operative diagnosis remains a clinical challenge. Management of early-stage LMS relies on surgical resection. Cytotoxic chemotherapy remains the mainstay of therapy for advanced-stage, recurrent or metastatic LMS, and includes single or combination doxorubicin-, ifosfamide- or gemcitabine-based regimens. Recent interest in genetic biomarkers led to developments of targeted therapies for LMS, although more research is needed to understand the molecular complexities underlying LMS to guide the development of novel treatment strategies.

TWEETABLE ABSTRACT

The diagnosis and treatment of uterine LMS is challenging. Novel biomarkers offer hope for future therapies.

Measurement and validation of frailty as a predictor of outcomes in women undergoing major gynaecological surgery

OBJECTIVE

Frailty is the loss of physical or mental reserve that impairs function, often in the absence of a defined comorbidity. Our aim was to determine whether a modified frailty index (mFI) correlates with morbidity and mortality in patients undergoing hysterectomy.

DESIGN

Retrospective cohort study.

SETTING

Hospitals across the USA participating in the National Surgical Quality Improvement Program (NSQIP).

SAMPLE

Patients who underwent hysterectomy from 2008 to 2012.

METHODS

An mFI was calculated using 11 variables in NSQIP. The associations between mFI and morbidity and mortality were assessed. Model fit statistics (c-statistics) were utilised to evaluate the ability of mFI to distinguish outcomes.

MAIN OUTCOME MEASURE

Wound infection, severe complications and mortality.

RESULTS

A total of 66 105 patients were identified. Wound complications increased from 2.4% in patients with an mFI of zero to 4.8% in those with mFI ≥ 0.5 (P < 0.0001). Similarly, severe complications increased from 0.98% to 7.3% (P < 0.0001), overall complications rose from 3.7% to 14.5% (P < 0.0001) and mortality increased from 0.06% to 3.2% (P < 0.0001) for patients with a frailty index of zero compared with those with an index of ≥ 0.5. Versus chance, the goodness-of-fit c-statistics suggested that mFI increases the ability to detect wound complications by 11.4%, severe complications by 22.0% and overall complications by 11.0%.

CONCLUSIONS

The mFI is easily reproducible from routinely collected clinical data and predictive of outcomes in patients undergoing hysterectomy. Frailty may be useful in the preoperative risk assessment of women undergoing gynaecological surgery.

TWEETABLE ABSTRACT

Frailty may be useful in the preoperative risk assessment of women undergoing gynaecological surgery.

A nonsense mutation in exon 3 results in the HLA-B null allele B*5127N

A new HLA-B null allele has been identified within the B*51 group by combined serological and molecular typing of an Italian Caucasoid family. Serological data indicated that the proband typed homozygous for A2 and B60. Confirmatory typing using sequence specific oligonucleotide hybridization (SSPOH) detected a second B allele within the B*51 group. Allele specific typing (SSP) for B*51 subtypes, including the known B*5111N allele, was performed, and typing results were consistent with B*5101, suggesting the presence of a new null variant. Cloning and sequencing of this allele identified a B*5101 variant with a nonsense mutation in exon 3. This new null allele has been designated B*5127N. The combined use of serologic and DNA-based typing methods facilitates the identification of null and low-expression alleles. An overview of null alleles of class I HLA is presented.

Fluorometric and mass spectrometric analysis of nonenzymatic glycosylated albumin

Albumin is the major transport protein in blood and intramolecular movement contributes to this function. Nonenzymatic glycosylation (NEG) of albumin occurs in diabetes and, in this study, fluorometric methods were used to determine the effect of increasing levels of NEG upon intramolecular movement in human serum albumin. Low levels of NEG significantly reduced and left-shifted Trp fluorescence, reduced quenching by acrylamide and inhibited penetration of bis-ANS, while these changes became only modestly more pronounced at higher levels of NEG. Mass spectrometry of tryptic and CNBr NEG-HSA fragments identified potential glycosylation sites and demonstrated only late glycosylation of the C- and N-terminal regions of the protein. Similar changes in diabetes may contribute to altered transport function in these patients.

A multiple-capillary electrophoresis system for small-scale DNA sequencing and analysis

A five-capillary system has been developed for DNA sequencing and analysis. The post-column fluorescence detector is based on a sheath-flow cuvette. The instrument provides uniform and continuous illumination of the samples. The cuvette virtually eliminates cross-talk in the fluorescence signal between capillaries. Discrete single-photon counting avalanche photodiodes provide high efficiency light detection. The instrument has detection limits (3sigma) of 130 +/- 30 fluorescein molecules injected onto each capillary. Over 650 bases of sequence at 98.8% accuracy were generated in 100 min at 50 degrees C from M13mp18. Separation and detection of short tandem repeats proved efficient and accurate with the use of internal standards for direct comparison of migration times between capillaries.

Inhibition of microvascular endothelial apoptosis in tissue explants by serum albumin

Plasma factors appear to inhibit endothelial cell (EC) apoptosis in vivo so that flow influences microvascular form. The identity of these factors has not, however, been established. Earlier, we reported that apoptosis in isolated, serum-deprived human EC is inhibited by albumin (Alb). Here, we demonstrate likely biological relevance of this to vascular remodelling in experiments with tissue explants. Rat skin explants were incubated in medium M199 with or without serum, bovine Alb, or human Alb. EC in paraffin sections of explants were labelled by lectin histochemistry and the relative proportion of apoptotic was EC determined. Apoptosis was confirmed by transmission electron microscopy and terminal deoxynucleotidyl transferase labelling. Serum-free culture induced EC apoptosis (P < 0.02) and this was strongly inhibited by Alb at physiological concentrations (P < 0.01). This was not a nonspecific protein effect, as mercaptoethanol denaturation destroyed the activity and ovalbumin was not protective. Also, protection was not due to serum contaminants, as recombinant human Alb had activity identical to that of native material. The dose response was identical for all Alb preparations tested, with maximal activity at physiological concentrations. Protection was not limited to rat tissue as similar results were obtained with human gingival explants. These data support a role for Alb as a plasma antiapoptotic factor for EC in tissues.

Activation energy of the separation of DNA sequencing fragments in denaturing noncross-linked polyacrylamide by capillary electrophoresis

We present the mobility of DNA sequencing fragments as a function of temperature in 5%T, 0%C noncross-linked polyacrylamide and at an electric field of 150 V/cm. The mobility of the fragments follows the Arrhenius equation. The activation energy for migration of a fragment through the polymer decreases monotonically with fragment length. The data were also analyzed in terms of the biased reptation model; the onset of biased reptation with stretching occurs for longer fragments as the temperature increase. These results are quite different from those observed for separation of DNA in cross-linked gels and represent a fundamental difference in the physics of the cross-linked and noncross-linked polyacrylamide.

[Effect of shashen maidong decoction on gastric motility in vivo]

Effect of Shashen Maidong Decoction (SSMDD) on the gastric motility of mice and rats was observed in vivo. Results showed that the gastric phenol red excretion rate of mice could be reduced markedly by SSMDD given in various dosages (23 g.kg-1.d-1, 9 g.kg-1.d-1 or 23 g.kg-1.d-1 for 5 days successively), P < 0.05. By administration of 9 g.kg-1.d-1 or 23 g.kg-1.d-1 could antagonize the acceleration of gastric emptying induced by neostigmine in mice (P < 0.05, P < 0.01). 7 g/kg of SSMDD by gastrogavage could inhibit the frequency and amplitude of contraction of fundic longitudinal muscle using strain gauge transducer in rats, but the effect was not obvious on that of antral circular muscle. By water-ballon method, it was observed that SSMDD 3.5 g/kg or 7 g/kg intraduodenal perfusion could slow down the frequency and decrease the amplitude of gastric peristalsis, 7 g/kg could inhibit significantly the gastric hypermotility induced by subcutaneous injection of indomethacin (40 mg/kg), but had no obvious effect on the gastric hypermotility induced by intramuscular injection of reserpine (0.4 mg.kg-1.d-1 x 4 d).

Use of non-cross-linked polyacrylamide for four-color DNA sequencing by capillary electrophoresis separation of fragments up to 640 bases in length in two hours

Four-color DNA cycle sequencing was performed on an M13mp18 template using dye-labeled primers. Sequencing fragments were separated by capillary electrophoresis at 60 degrees C and at an electric field of 150 V/cm. The sieving medium was 5%T, non-cross-linked polyacrylamide in 7 M urea. The use of high temperature for the separation reduces formation of secondary structures in the sequencing fragments, generating a sequence that is free of compressions without the use of strongly denaturing gels. The use of high temperatures also increases the separation rate compared with room-temperature operation. Fragments up to 640 bases are separated in less than 2 h.

[Initial cost-benefit analysis of chest fluoroscopy in synthetic clue investigation on tuberculosis]

Body surface exposure to X-ray radiation was measured in those with synthetic clue investigation on tuberculosis. The results showed body surface exposure in them appeared a logarithmic normal distribution with a geometric mean of 0.19 mC/kg and was higher than that with fluoroscopy in routine check-ups. The late effect of X-ray radiation showed 0.52 hours of an average life-span cut. But, based on prevalence, mortality and cure rate of chemotherapy for tuberculosis in Jiangsu Province, chest fluoroscopy in synthetic clue investigations brought an average prolongation of 45.8 hours per person in life-span of those X-rayed. Comparison of life-span showed synthetic clue investigation was an adequate method in active tuberculosis case-finding from the viewpoint of radiation protection.

[Effect of xiao chaihu decoction on experimental alkaline reflux gastritis in rats]

The effects of Xiao Chaihu Decoction (XCHD) on alkaline reflux gastritis and gastric secretion in rats was observed.

RESULTS

(1) 5g/kg, 20 g/kg of XCHD might markedly inhibit the gastric lesion induced by gastric feeding of sodium taurocholate; (2) 5g/kg, 20g/kg of XCHD might significantly prevent the gastric lesion induced by gastric feeding of intestinal juice; (3) On chronic reflux gastritis model induced by spring-expanded pylorus after 4 or 8 weeks, 4g/kg-20g/kg of XCHD might lower the incidence of gastritis, and reduce the intragastric bile acid; (4) 5g/kg and 20g/kg of XCHD might significantly inhibit the secretion of gastric juice and acid as well as the activity of pepsin. The results suggested that XCHD had anti-reflux gastritis effect.

Superior vena cava syndrome as a complication of permanent transvenous endocardial pacing: report of a case

Superior vena cava syndrome as a complication of permanent transvenous endocardial pacing is unusual. We herein report on a 71-year-old woman who presented with progressive swelling of the face, neck, thorax and upper limbs two months after implantation of a permanent transvenous endocardial pacing device for sinus node dysfunction. Superior vena cava syndrome was diagnosed by venography. Acute heart failure and respiratory failure developed before her scheduled operation. She expired despite vigorous cardiopulmonary resuscitation.

[Effects of 3 Chinese medical prescriptions on alkaline reflux gastritis in rats]

The experimental alkaline reflux gastritis in rats was established after 9 weeks of anastomosis between stomach and jejunum. The experiment shows that xiangsha liujunzi decoction, xiaochaihu decoction and dahuang gancao decoction all help to inhibit edema, hyperamia and extravasted blood, as well as depress inflammatory infiltration and hyperplasia. The number of intestinal metaplasia in the group treated with xiangsha liujunzi decoction is decreased. All the three prescriptions are not able to lower the contents of bile acid in the stomach.

Local effect of substance P on colonic motor activity in different experimental states

We studied the effects of close intra-arterial injections of substance P on colonic motor activity in the conscious state, during anesthesia, and during acute laparotomy. In the conscious state, with enteric nerves intact, substance P stimulated postsynaptic cholinergic neurons to induce a large amplitude and long duration contraction. This response was blocked by prior close intra-arterial injection of atropine and tetrodotoxin (TTX) but not hexamethonium. Hexamethonium and TTX given alone, close intra-arterially, induced a series of short-duration contractions. Prior close intra-arterial administration of hexamethonium significantly enhanced the colonic motor response to substance P. After blockade of nerve conduction by TTX, substance P induced a series of short-duration contractions with characteristics different from those when the nerves were functioning. Anesthesia alone had little effect on the colonic motor response to substance P, but laparotomy inhibited it significantly. Laparotomy similarly inhibited the contractile response to bethanechol. Gut handling had no further effect on this inhibition. We conclude that in the conscious state substance P acts preferentially on postsynaptic cholinergic neurons to contract colonic circular muscle. When the intrinsic nerves are blocked, substance P may act directly on the smooth muscle to induce circular muscle contractions with characteristics different from those induced when nerves are intact. Substance P also has a weak inhibitory motor effect by its action on presynaptic neurons that synapse on postganglionic intrinsic inhibitory neurons. Anesthetic doses of barbiturates have no major effects on the neuromuscular response to substance P, but laparotomy significantly inhibits the smooth muscle response and selectively blocks some neurons.