Recent Approaches to Design and Analysis of Electrical Impedance Systems for Single Cells Using Machine Learning

Individual cells have many unique properties that can be quantified to develop a holistic understanding of a population. This can include understanding population characteristics, identifying subpopulations, or elucidating outlier characteristics that may be indicators of disease. Electrical impedance measurements are rapid and label-free for the monitoring of single cells and generate large datasets of many cells at single or multiple frequencies. To increase the accuracy and sensitivity of measurements and define the relationships between impedance and biological features, many electrical measurement systems have incorporated machine learning (ML) paradigms for control and analysis. Considering the difficulty capturing complex relationships using traditional modelling and statistical methods due to population heterogeneity, ML offers an exciting approach to the systemic collection and analysis of electrical properties in a data-driven way. In this work, we discuss incorporation of ML to improve the field of electrical single cell analysis by addressing the design challenges to manipulate single cells and sophisticated analysis of electrical properties that distinguish cellular changes. Looking forward, we emphasize the opportunity to build on integrated systems to address common challenges in data quality and generalizability to save time and resources at every step in electrical measurement of single cells.

[Effect of prolonged inhalation of nitric oxide on chronically hypoxic rats]

OBJECTIVE

To explore the effect of prolonged nitric oxide (NO) inhalation on chronically hypoxic rats.

METHODS

Male Wistar rats were randomly divided into 3 groups: 1) room-air control (C); 2) hypoxia (H); 3) hypoxia with the inhalation of 20 ppm NO(2NH). RV/LV + S, mPAP and the histopathology of the lung were examined. Plasma levels of ET-1 and cGMP were detected by radioimmunoassay.

RESULTS

1. Hypoxia caused marked elevation in mPAP and RV/LV + s (both P < 0.001 vs Group C). NO significantly reduced mPAP and RV/LV + S; 2. Hypoxia raised the percentage of intra-acinar muscular artery (MA) and lowered that of nonmuscular artery (NAM). MA decreased from 35.2% to 16.8% in Group 2NH; NMA increased from 43.6% to 64.8% in Group 2NH, 3. The plasma level of ET-1 increased and that of cGMP droped significantly in Group H(both P < 0.001 vs Group C). NO resulted in a marked reduction in the plasma ET-1 and an increase in plasma cGMP; 4. Inhalation of NO had no effect on methemoglobin and lung index in hypoxic rats.

CONCLUSIONS

Prolonged inhalation of 20 ppm NO can attenuate hypoxic pulmonary hypertension and inhibit the hypertrophy of the pulmonary vascular smooth muscle and the right ventricle NO, when inhalated at a concentration of 20 ppm for a long duration, will cause no toxicity in chronically hypoxic rats.

[The effect of nitric oxide administration on pateints with pulmonary hypertension: a dose-response study]

OBJECTIVE

To explore the dose-response relationship in patients with pulmonary hypertension after inhalation of nitric oxide (NO).

METHODS

The effect of various concentrations (20, 40, 60 and 80 ppm) of NO on hemodynamics and cardiac function in 16 patients with pulmonary hypertension was studied with right heart catheterization.

RESULTS

Pulmonary artery pressure and pulmonary vascular resistance reduced significantly after inhalation of various concentrations (20, 40, 60 and 80 ppm) of NO. The vascular response to NO was not concentration-dependant with a maximal effect obtained at 20 ppm. At inhalation of low dose of NO (20 ppm), the mean pulmonary artery pressure and pulmonary vascular resistance dropped by 26.5% and 40.3% (P < 0.0001), respectively. With the increase of inhaled NO concentration, pulmonary artery pressure and pulmonary vascular resistance did not decline.

CONCLUSION

The best concentration of inhaled NO was not more than 20 ppm in the patients of this study.

[Effects of an extract of salviae miltiorrhizae (764-3) on structural remodeling of intra-acinar pulmonary artery in pulmonary hypertension due to chronic hypoxia and monocrotaline in rats]

OBJECTIVE

To investigate the effects of an extract of salviae miltiorrhizae (764-3) on the percentage of intra-acinar muscular artery (MA), partal MA(PMA) and nonmuscular MA(NMA) and collagen deposition in the media of MA in rats with hypoxia and MCT-induced pulmonary hypertension.

METHOD

Wistar rats were divided into 12 groups. The hypobaric hypoxic 51 kPa (1 kPa = 7.5 mmHg) and MCT (60 mg/kg intraperitoneal injection) rats were treated with 764-3 (20 mg/kg), beta-aminopropionitrile (BAPN, 150 mg/kg) and 764-3 (40 mg/kg), respectively. At each time point, the hemodynamic and morphological parameters were measured.

RESULT

After hypoxia for 2 weeks, the percentage of MA increased (P < 0.001), of NMA decreased (P < 0.001) and of PMA no obvious change; and after 4 weeks, the above changes became to be more striking and the collagen content in the media of MA increased (P < 0.001). The MCT-treated rats had more severe changes than the hypoxic rats. Both 764-3 and BAPN could inhibit the changes, decreased the collagen content and BAPN was more effective than 764-3(P < 0.05).

CONCLUSION

764-3 can partially inhibit collagen deposition in pulmonary arterioles attenuate hypoxia and MCT-induced pulmonary hypertension, reduce the percentage of MA, and has a moderate influence on collagen deposition as compared with BAPN.

[Risk factors of chronic obstructive pulmonary disease in patients with chronic bronchitis]

OBJECTIVE

To explore the risk factors of chronic obstructive pulmonary disease (COPD) in patients with chronic bronchitis in following-up 8 years.

METHODS

The baseline survey of the study was carried out on 1,999 patients with chronic bronchitis screened out from 67,251(15 years or more) rural people in 1992. In 2000, 1,114 patients were reexamined by simple random sampling method.

RESULTS

869 (78.0% of 1,114) with complete data entered analysis of this study. Smoking, and family history of COPD were associated significantly positively with the decrement per capita yearly of FEV1(forced expiratory volume in the first second) and/or FEV1/FVC (forced vital capacity) ratio. Ex-smoking decreased the decrement of lung function in smokers. The accumulative incidence of COPD was associated positively with smoking and family history of COPD and negatively with baseline FEV1 and FEV1/FVC. The relative risk of COPD was not significantly different between non-smokers and ex-smokers.

CONCLUSION

For Chinese rural patients with chronic bronchitis, aging, smoking, family history of COPD, lower pulmonary function are independent risk factors of COPD while sex is not one. Ex-smoking can almost decrease the relative risk of COPD to the approximative risk level of non-smoking.

[Effect of 764-3 on ventricular collagen deposition in pulmonary hypertension induced by chronic hypoxia and monocrotaline in rats]

OBJECTIVE

To observe the effect of 764-3 on ventricular collagen deposition in pulmonary hypertension induced by chronic hypoxia or monocrotaline (MCT) in rats.

METHODS

Wistar rats were divided into 10 groups. The hypobaric hypoxia group received 764-3 20 mg/kg once daily subcutaneously and the MCT group treated with 764-3 40 mg/kg once daily. The hemodynamic and biochemical parameters were measured.

RESULTS

At the time of 2 weeks and 4 weeks after treated with hypoxia or MCT, the pulmonary arterial pressure (PAP) of rats raised significantly and the right ventricular collagen content (RVCC) increased markedly. 764-3 could reduce the raised PAP induced either by hypoxia or MCT. It could lower the elevated RVCC of hypobaric hypoxia group at 2 weeks from 76.3 +/- 13.3 to 59.4 +/- 11.4 (P < 0.01), and the RVCC of MCT group lowered from 293.4 +/- 73.9 to 210.1 +/- 37.6(P < 0.01).

CONCLUSION

764-3 could partially prevent right ventricular collagen deposition induced by hypoxia and has therapeutic effect on that induced by MCT.

[Study on susceptible risk factors for COPD in smokers]

OBJECTIVE

To explore the susceptible risk factors for COPD in smokers.

METHODS

154 patients with COPD (FEV1/FVC < 70%) were recruited as the case group whose smoking index (average cigarettes a day times smoking years) was > or = 300 and there was no complaint of chronic respiratory symptoms. The control group included 154 smokers pair-matched in age(+/- 3 years) gender, residence, absence of COPD (FEV1/FVC > or = 75%) and respiratory symptoms. 23 never-smoking subjects with FEV1/FVC > or = 75% and no respiratory symptoms served as healthy control. The following parameters were evaluated: questionaire, physical examination, ECG, chest X-ray, lung function test, methacholine provocation test of bronchial responsiveness and serum levels of elastase activity, alpha 1-AT activity, MDA, PIIIP, IgE and IgG.

RESULTS

The positive rate of bronchial hyperresponsiveness was 78% in the case group, PC20 = (1.4 +/- 1.6) g/L; but 28% in the matched group were positive, PC20 = (2.7 +/- 2.3) g/L, (P < 0.001). No one was found hyperresponsive in the healthy control group. There were no differences in serum PIIIP and IgE between the case and the control groups, but they were markedly higher than those in the healthy control. Serum alpha 1-AT activity, room condition, occupational exposure, smoking habit (deep inhalation), cigarettes with or without filter tip, parents with bronchitis and(or) emphysema history, brothers or sisters with bronchitis history were correlated with COPD, OR being 2.33, 2.00, 1.64, 1.88, 1.76 and 3.67, respectively. Logistic regression revealed that alpha 1-AT activity, bronchial hyperresponsiveness, room condition and occupational exposure, smoking habit and respiratory disease history in family were related to COPD.

CONCLUSIONS

alpha 1-AT deficiency may be a risk factor for COPD susceptible smokers. There may be relationship between bronchial hyperresponsiveness and developing COPD, but whether it is the cause or result of COPD needs further study. Smoking may induce elevation of serum PIIIP and IgE, but both of them are not directly related to COPD. Room condition, occupational exposure, smoking habit, and respiratory disease history in family may be associated with COPD in smokers.

[Preliminary studies on chemical constituents and pharmacological action of Eclipta prostrata L]

OBJECTIVE

To study the pharmacologically active components of Eclipta prostrata.

METHOD

The components were extracted by alcohol and isolated by silica gel column and subjected to pharmacological screening.

RESULT

Four compounds were isolated from E. prostrata, of which two were identified as stigmasterol and alpha-terthienyl.

CONCLUSION

alpha-Terthienyl was isolated from the plant for the first time. The EtOAc part of alcoholic extraction exhibits significant hepatoprotective activity against carbon terachloride-induced liver injury in rats.

[Changes of serum elastase, alpha 1-antitrypsin, procollagen III peptide and malonaldehyde in smokers with and without chronic obstructive pulmonary diseases]

OBJECTIVE

Serum elastase, alpha(1)-antitrypsin (alpha(1)-AT), procollagen III peptide (PIIIP) and malonaldehyde (MDA) were studied in smokers with and without chronic obstructive pulmonary disease (COPD) to explore the roles of these factors in COPD induced by smoking.

METHODS

A design of 154-pair case-control study was used. alpha(1)-AT, MDA and PIIIP were determined with colorimetric method, fluo-spectrophotometric method and radio-immunological assay, respectively, in non-smoker control and smokers with and without COPD.

RESULTS

Serum PIIIP content was increased in smokers and alpha(1)-AT decreased significantly in patients with COPD.

CONCLUSION

Decreased alpha(1)-AT may be a susceptible factor in the development of COPD caused by smoking.

[Strain screening and fermentation conditions of a novel heparinase-producing strain]

The novel heparinase-producing bacterial strain Corynebacterium sp. was screened and isolated from soil. The optimum medium composition is (g/L): Trypticase 20, NaCl 1, K2HPO4 2.5, MgSO4 0.5, Heparin 2, maltose 20, pH 6.5. The optimum growth temperature was 27 degrees C while, maximum enzyme production was achieved at temperature 31 degrees C. When cultured at a rotating shaker at 30 degrees C for 24 hours, 200 r/min, 40 mL medium in 500 mL flask, the Production of heparinase reached 1700 u/L.

[Purification and characterization of beta-N-acetyl hexosaminidase from Aspergillus tamarii]

A beta-N-acetylhexosaminidase from mycelium-free culture filtrate of Asp tamarii S215 was purified to PAGE homogenous by ammonium sulfate and polyethylene glycol fractionation precipitation followed by Sephadex G-50 desalt, DEAE-Sephadex A-25 chromatography, hydroxyapatite chromatography and DEAE-Sephadex A-25 rechromatography with 170-fold purification and 24.7% recovery. The ratio of the beta-GlcNAcase and beta-GalNAcase was 2.5 and remained constant throughout the purification. The Mr estimated with concentration gradient PAGE was 140,000 and subunit Mr determined with SDS-PAGE was 72,000, the number of subunit were 2. The pI was 4.2 determined by PAGIEF. The optimum pH was 5.5-6.5 and 5.0-6.0 for beta-GlcNAcase and beta-GalNAcase respectively with stable pH range 5.5-8.3 for both. The optimum temperature was 60 degrees C for beta-GlcNAcase and beta-GalNAcase. The residual activity of beta-GlcNAcase was 52.7% after treated at 50 degrees C for 8 h and it was 44.9% for beta-GalNAcase. The residual activities of both were down to 1% after treated at 62 degrees C for 10 min. The activity was slightly activated by Mn2+ or Fe2+, while strongly inhibited by Hg2+ and slightly by Ag+, Cu2+, Pb2+, Cd2+ or Zn2+. Analyses of amino acids composition showed that the beta-HexNAcase contained about 24.2% acidic amino acids and 14.9% basic amino acids and only 0.6% methionine.

Association between isolated diastolic hypertension and cardiovascular events: a systematic review and meta-analysis of prospective cohorts

Background

Isolated diastolic hypertension (IDH) is a subtype of hypertension, which is defined as systolic blood pressure (SBP) &lt;140 mmHg and diastolic blood pressure (DBP) ≥90 mmHg by 2018 European Society of Cardiology (ESC) guideline and 2019 National Institute for Health and Care Excellent (NICE). Whereas some previous studies have demonstrated the significant association between IDH and cardiovascular (CV) events, some have not.

Purpose

To assess the association between IDH and the risk of CV events, CV mortality, and all-cause mortality.

Methods

We conducted a systematic search for publications using Medline, Embase, and the Cochrane Library from inception through March 2021 for prospective cohort studies exploring the association between IDH and CV events, CV mortality, and all-cause mortality. Relative risks (RR) or hazard ratios were extracted from the selected studies. Random effect models with inverse variance weighting were used to calculate the pooled RR and 95% confidence interval (CI). The primary outcome was a composite of total CV events including CV mortality. The secondary outcomes were CV mortality and all-cause mortality. We defined the IDH as SBP &lt;140 mmHg and DBP ≥90 mmHg, reference group as BP less than 140/90mmHg.

Results

Overall, 15 studies were identified including 1049587 participants (5.5% IDH). For the primary outcome, IDH was significantly associated with risk of CV events (RR, 1.40 [95% CI, 1.18–1.66], p&lt;0.001). The increased risk of CV events was also observed in subgroup analyses based on age (less or more than 50) and sex. However, in further stratified analysis based on geographical region, only the Asia population showed a significant association with increased risk of CV events, whereas results were null in Europe and North America populations. For the secondary outcomes, IDH was significantly associated with increased CV mortality (RR [95% CI], 1.41 [1.12–1.78], p&lt;0.001) but not with all-cause mortality (RR [95% CI], 1.13 [0.86–1.48], p=0.378). The sensitivity analysis showed the overall results did not vary significantly after exclusion of any one study.

Conclusions

IDH is associated with increased risk of CV events and CV mortality. Further, more large-scale prospective epidemiological cohorts are needed to confirm our conclusion.

Funding Acknowledgement

Type of funding sources: None. Primary outcomeSecondary outcomes

Down-regulation of IL-12, not a shift from a T helper-1 to a T helper-2 phenotype, is responsible for impaired IFN-gamma production in mammary tumor-bearing mice

Altered cytokine production has been implicated in the down-regulation of cell-mediated immunity in mice bearing large mammary tumors. In several diseases, an imbalance between helper T lymphocytes Th1 and Th2 and their cytokines has been suggested as a contributing factor. In this study, although IFN-gamma from splenic T cells of D1-DMBA-3 mammary tumor-bearing mice was greatly diminished, other cytokine levels remained unchanged, indicating no clear shift between the Th1, Th2, or Th3 phenotypes. The IFN-gamma levels can be restored in vitro by addition of rIL-12 to cultured splenocytes from tumor bearers. Furthermore, IL-12 production is greatly down-regulated in macrophages from tumor-bearing mice as detected by ELISA, and this correlates with diminished expression of IL-12 p40 chain RNA. The mammary tumor used in our studies produces several factors, including granulocyte macrophage-CSF, PGE2, and phosphatidyl serine, that can affect the immune system. Addition of these tumor-derived factors in vitro to macrophages from normal mice resulted in decreased levels of IL-12 protein in cultures treated with PGE2 or phosphatidyl serine. These results indicate that the down-regulation of T cell-produced IFN-gamma in this tumor model is the result of decreased IL-12 production caused by tumor-derived factors and not a shift from the Th1 to the Th2 phenotype.

[The comprehensive treatment of varicosis of lower extremity with chronic ulcer of leg]

From Oct. 1993 to Dec. 1995, nineteen refractory cases with varicosis and chronic ulcer of lower limb were treated. The average age of these patients was sixty-eight, the disease history was more than 20 years. The size of the ulcer of the leg ranged from the minimum of 10 cm x 8 cm to the maximum of 30 cm x 15 cm. All of them had once received saphenectomy and split skin graft without ulcer healing before they were admitted in our department. Both venography and ultrasonography showed superficial venous valve incompetence. The following comprehensive treatment was adopted. Firstly, myoplasty around popliteal vein was done. Secondly, phlebexairesis and phleborrhaphy were done for the variciform veins through minor incision. Then through debridement of the ulcer was performed. Delayed split skin graft was exerted one week later. The result showed that all the cases were successful: the ulcer was healed and there was no recurrence of varicosis.

Construction of La-tPA vector and expression in the mammary gland of transgenic mice

Expression vectors of long acting human tissue plasminogen activator (La-tPa) in the mammary gland was constructed using the promoters of sheep beta-lactoglobulin gene (BLG, 5 kb) containing the first and the second introns obtained by PCR. Transgenic mice were established by microinjection. 540 fertilized eggs were injected and 6 transgenic mice were screened out from the offspring by PCR and Southern Blot analysis. The foreign gene integrating rate was 32%. The expression of La-tPA in mammary glands of transgenic mice was confirmed by milk assay and Northern blot analysis. Expression level of La-tPA reached 6 ug/ml in milk of transgenic mice.