Acceleration of Yeast Autolysis by Addition of Fatty Acids, Ethanol and Alkaline Protease

BACKGROUND

Autolysate products from yeast origin are very interesting for food, feed, cosmetic, pharmaceutical, and fermentation industries. The lysis process greatly influences the quality and efficiency of the final autolysates.

OBJECTIVES

Here, we have compared four lysis methods based on autolysis, plasmolysis (with ethanol 1.5% (v/v) and coconut fatty acids 1% (w/w)) and hydrolysis (with alkaline protease 0.4 % (v/w)) on degrading the baker's yeast Saccharomyces cerevisiae.

MATERIALS AND METHODS

The efficiency of processes was evaluated according to the recovered solid and protein contents, release of intracellular materials, cell viability, microscopy imaging, degree of hydrolysis and electrophoresis studies.

RESULTS

Results showed that the increased recovered solids and proteins, as well as a higher degree of hydrolysis (DH) were obtained for the enzymatic hydrolyzed cells using alkaline protease. SDS-PAGE analysis also confirmed the results. Further, functionality of the final products by agglutination test showed that the hydrolyzed cells could effectively bind pathogenic bacteria compared to the other cell lysates.

CONCLUSIONS

In conclusion, this work provides adequate evidence for efficiency of alkaline protease for producing the nutritional cell lysates from baker's S. cerevisiae used in food, feed, cosmetic, and pharmaceutical applications. Moreover, this was the first report on using coconut fatty acids and alkaline protease in lysis of baker's yeast.

Human study on cancer diagnostic probe (CDP) for real-time excising of breast positive cavity side margins based on tracing hypoxia glycolysis; checking diagnostic accuracy in non-neoadjuvant cases

BACKGROUND

Cancer diagnostic probe (CDP) had been developed to detect involved breast cavity side margins in real-time (Miripour et al. Bioeng Transl Med. e10236.). Here, we presented the results of the in vivo human model CDP studies on non-neoadjuvant cases.

METHODS

This study is a prospective, blind comparison to a gold standard, and the medical group recruited patients. CDP and frozen data were achieved before the permanent pathology experiment. The main outcome of the study is surgical margin status. From November 2018 to April 2020, 202 patients were registered, and 188 were assigned for the study. Breast-conserving surgery at any age or gender, re-surgery due to re-currency, or involved margins are acceptable. Patients must be non-neoadjuvant. The reliability of CDP scoring had been evaluated by the pathology of the scored IMs. Then, three models of the study were designed to compare CDP with the frozen sections. Receiver operating characteristic (ROC) curves and AUC were measured based on the permanent postoperative pathology gold standard.

RESULTS

A matched clinical diagnostic categorization between the pathological results of the tested IMs and response peaks of CDP on 113 cases, was reported (sensitivity = 97%, specificity = 89.3%, accuracy = 92%, positive predictive value (PPV) = 84.2%, and negative predictive value (NPV) = 98%). Study A showed the independent ability of CDP for IM scoring (sensitivity = 80%, specificity = 90%, accuracy = 90%, PPV = 22.2%, and NPV = 99.2%). Study B showed the complementary role of CDP to cover the missed lesions of frozen sections (sensitivity = 93.8%, specificity = 91%, accuracy = 91%, PPV = 55.6%, and NPV = 99.2%). Study C showed the ability of CDP in helping the pathologist to reduce his/her frozen miss judgment (specificity = 92%, accuracy = 93%, PPV = 42.1%, and NPV = 100%). Results were reported based on the post-surgical permanent pathology gold standard.

CONCLUSION

CDP scoring ability in intra-operative margin detection was verified on non-neoadjuvant breast cancer patients. Non-invasive real-time diagnosis of IMs with pathological values may make CDP a distinct tool with handheld equipment to increase the prognosis of breast cancer patients.

Intra-radiological pathology-calibrated Electrical Impedance Spectroscopy in the evaluation of excision-required breast lesions

PURPOSE

Evaluating a real-time complementary bioelectrical diagnostic device based on Electrical Impedance Spectroscopy(EIS) for improving breast imaging-reporting and data system (BIRADS) scoring accuracy, especially in high-risk or borderline breast diseases. The primary purpose is to characterize breast tumors based on their dielectric properties. Early detection of high-risk lesions and increasing the accuracy of tumor sampling and pathological diagnosis are secondary objectives of the study.

METHODS

The tumor detection probe (TDP) was first applied to the mouse model for electrical safety evaluations by electrical current measurement, then to 138 human palpable breast lesions undergo CNB, VAB, or FNA with the surgeon's requests. Impedance phase slope(IPS) in frequency ranges of 100 kHz to 500 kHz and impedance magnitude in f = 1kHz were extracted as the classification parameters. Consistency of radiological and pathological declarations for the excisional recommendation was then compared with the IPS values.

RESULTS

Considering pathological results as the gold standard, meaningful correlations between IPS and pathophysiological status of lesions recommended for excision (such as atypical ductal hyperplasia, papillary lesions, complex sclerosing adenosis, and fibroadenoma, etc.) were observed (p<0.0001). These pathophysiological properties may include cells size, membrane permeability, packing density, adenosis, cytoplasm structure, etc. Benign breast lesions showed IPS values greater than zero, while high-risk proliferative, precancerous, or cancerous lesions had negative IPS values. Statistical analysis showed 95% sensitivity with Area Under the Curve(AUC) equal to 0.92.

CONCLUSION

Borderline breast diseases and high-risk lesions that should be excised according to standard guidelines can be diagnosed with TDP before any sampling process. It is a precious outcome for high-risk lesions that are radiologically underestimated to BI-RADS3, specifically in younger patients with dense breast masses, challenging in mammographic and sonographic evaluations. Also, the lowest IPS value detects the most pathologic portions of the tumor for increasing sampling accuracy in large tumors.

SIGNIFICANCE

Precise detection of high-risk breast masses, which may be declared BI-RADS3 instead of BI-RADS4a. This article is protected by copyright. All rights reserved.

Electrochemical tracing of hypoxia glycolysis by carbon nanotube sensors, a new hallmark for intraoperative detection of suspicious margins to breast neoplasia

For most people, the first step in treatment is to take out the tumor (surgery), so precise and fast diagnosis of any sign of high-risk and neoplastic cells, especially in surgical cavity margins, is significant. The frozen pathology method is the conventional standard of intraoperative diagnosis, but the low number of slides prepared from non-fixed tissues prevents us from achieving a perfect diagnosis. Although many improvements in intraoperative margin detection were achieved, still real-time detection of neoplastic lesions is crucial to improving diagnostic quality. Functionalized carbon nanotubes grown on the electrode needles lively and selectively determine the H2O2 released from cancer/atypical cells through reverse Warburg effect and hypoxia assisted glycolysis pathways in a quantitative electrochemical manner. The study was carried out on cell lines, 57 in vivo mice models with breast cancer, and 258 fresh in vitro samples of breast cancer tumors. A real-time electrotechnical system, named cancer diagnostic probe (CDP) (US Patent Pub. No.: US 2018/02991 A1, US 2021/0007638 A1, and US 2021/0022650 A1 [publications], and US 10,786,188 B1 [granted]), has been developed to find pre-neoplastic/neoplastic cells in vivo in a quantitative electrochemical manner by tracing hypoxia glycolysis byproducts. Matched pathological evaluations with response peaks of CDP were found based on the presence of neoplasia (from atypia to invasive carcinoma) in live breast tissues. The ability of CDP to find neoplastic lesions in mice models in vivo and fresh breast tumors in vitro was verified with sensitivity and specificity of 95% and 97%, respectively. The system may help a surgeon assistant system for usage in the operating room after passing many trials and standard examinations in the future.

Nanoporous platinum needle for cancer tumor destruction by EChT and impedance-based intra-therapeutic monitoring

Herein, we present a new design on the Single Needle Electrochemical Therapy (SNEChT) method by introducing some major improvements, including a nanoporous platinum electrode, tunable in situ anode size that depends on the width and location of the tumor, and the capability of measuring the efficacy of therapy based in intra-therapeutic impedance recording by the same EChT needle. It could have significant implications in optimizing EChT operative conditions. The nanoporous Pt electrode increased the interactive surface with a tumor, and produced a higher amount of current with lower stimulating DC voltage. The tunable anode size prevents the over-acidification of treated or non-desired lesions. Hence, this feature reduced the over distribution of tissue. Monitoring the impedance during the therapy clearly informs us about the local destruction of the tumor in each location. Thus, we can be informed about the threshold of tissue acidosis with the lowest electrical stimulation. The insertion of one needle with a tunable anode length for both precise therapy and impedance-based intra-therapeutic monitoring will shed new light on the applications of EChT.

Bioelectrical pathology of the breast; real-time diagnosis of malignancy by clinically calibrated impedance spectroscopy of freshly dissected tissue

In this paper, freshly (non-fixed) dissected tissues obtained from breast cancer surgery were impedimetrically and pathologically scanned, analyzed, and probable electro-pathological mutual matching was investigated. A new electrical model was proposed for pathological scores of breast lesions based on the theory of electric current dispersion by different types of biological tissues. This integrated handheld bioimpedance sensor named EPA would score the clearance or malignancy involvement of dissected tumor margins by introducing two crucial classification parameters named Z_1kHz and IPS (impedance phase slope in the frequency ranges of 100-500 kHz). EPA benefits from a precise signal recording and analysis method which leads to the detection of the presence of even about 5% distribution of premalignant cells among healthy breast tissue. EPA can be clinically used by pathologists, as a complementary device, for real-time diagnosis of suspicious margins of dissected tumors to declare more precise intraoperative diagnosis by scanning all around the dissected tissues. Each data sampling and analysis covers 2 mm of the surface in less than 5 s. Measurements on about 313 human breast tumor margins showed more than 90% accuracy and near 93% specificity for EPA as an independent diagnostic tool.

Real-time diagnosis of reactive oxygen species (ROS) in fresh sputum by electrochemical tracing; correlation between COVID-19 and viral-induced ROS in lung/respiratory epithelium during this pandemic

COVID-19 is the shocking viral pandemics of this year which affected the health, economy, communications, and all aspects of social activities all over the world. Early diagnosis of this viral disease is very important since it can prevent lots of mortalities and care consumption. The functional similarities between COVID-19 and COVID-2 in inducing acute respiratory syndrome lightened our mind to find a diagnostic mechanism based on early traces of mitochondrial ROS overproduction as lung cells' dysfunctions induced by the virus. We designed a simple electrochemical sensor to selectively detect the intensity of ROS in the sputum sample (with a volume of less than 500 μl). Comparing the results of the sensor with clinical diagnostics of more than 140 normal and involved cases resulted in a response calibration with accuracy and sensitivity both 97%. Testing the sensor in more than 4 hospitals shed promising lights in ROS based real-time tracing of COVID-19 from the sputum sample.

Low frequency stimulation induces polarization-based capturing of normal, cancerous and white blood cells: a new separation method for circulating tumor cell enrichment or phenotypic cell sorting

Separation of cancerous cells from normal cells is of broad importance in a large number of cancer diagnosis and treatment methods.

Protection by Ziziphora clinopoides of acetic acid-induced toxic bowel inflammation through reduction of cellular lipid peroxidation and myeloperoxidase activity

Inflammatory bowel disease (IBD) is a chronic condition of the intestine with unknown etiology involving multiple immune, genetic and environmental factors. We were interested in examining the effect of a total extract from Ziziphora clinopoides, an Iranian folk herbal medicine, in the prevention and control of experimental mouse IBD. Z. clinopoides was administered (75, 150, 300 mg/kg) through drinking water to mice, which dispensed a toxic dose of acetic acid intrarectally. Prednisolone was used as the standard drug for comparison. Biochemical, macroscopic and microscopic examinations of the colon were performed. Biochemical evaluation of the inflamed colon was carried out using assays of myeloperoxidase (MPO) activity and thiobarbituric acid reacting substances (TBARS) as indicators of free radical activity and cellular lipid peroxidation. Results indicated that the activity of MPO and lipid peroxidation products (TBARS) increased in acetic acid-treated groups, while recovered by pretreatment of animals with Z. clinopoides (75-300 mg/kg) and prednisolone. All doses of Z. clinopoides and prednisolone-treated groups showed significant lower score values of macroscopic and microscopic characters when compared to the acetic acid-treated group. The beneficial effect of Z. clinopoides (300 mg/kg) was comparable to that of prednisolone. It is concluded that Z. clinopoides inhibits acetic acid toxic reactions in the mouse bowel through inhibition of cellular oxidative stress. Proper clinical investigation should be carried out to confirm the same activity in human.

Relationship between rate of digestion of foods and post-prandial glycaemia

The amount of carbohydrate released at 1 and 5 h by digestion in vitro of 2 g carbohydrate portions of 14 foods by human digestive juices was compared with the area under the 2-h blood glucose response curve when 50 g carbohydrate portions were fed to groups of five to ten healthy volunteers. A significant relationship was found between the amounts of sugars and oligosaccharides liberated at 1 and 5 h and the food blood glucose area expressed as a percentage of the blood glucose area for 50 g glucose (r = 0.8627 and 0.8618, p less than 0.001). A significant relationship was also found between the glycaemic index and the food fibre content (p less than 0.02) and between the glycaemic index and the glucose trapping capacity of the foods (p less than 0.05). Legumes as a group liberated 56% less sugars and oligosaccharides (p less than 0.01) than the eight cereal foods over 5 h. It is suggested that such studies in vitro may help to identify food of use for diabetic patients, and at the same time throw further light on factors which affect post-prandial glycaemia.

Rate of digestion of foods and postprandial glycaemia in normal and diabetic subjects

Carbohydrate portions (2 g) of lentils, soya beans, and wholemeal bread were incubated for three hours with human digestive juices and the effect of digestibility on blood glucose examined. Lentils and soya beans released only 39% and 8% respectively of the sugars and oligosaccharides liberated from bread. In healthy volunteers 50 g carbohydrate portions of cooked lentils and soya beans raised blood glucose concentrations by only 42% (p < 0.001) and 14% (p < 0.001) of the bread value. There was a similar response in diabetics. These results suggest that rate of digestion might be a important factor determining the rise in blood glucose concentration after a meal and that supplementing chemical analysis with in-vitro and in-vivo food testing might permit identification of especially useful foods for diabetics.