A Critical Review on Detection of Foodborne Pathogens Using Electrochemical Biosensors.

An outbreak of foodborne pathogens would cause severe consequences. Detecting and diagnosing foodborne diseases is crucial for food safety, and it is increasingly important to develop fast, sensitive, and cost-effective methods for detecting foodborne pathogens. In contrast to traditional methods, such as medium-based culture, nucleic acid amplification test, and enzyme-linked immunosorbent assay, electrochemical biosensors possess the advantages of simplicity, rapidity, high sensitivity, miniaturization, and low cost, making them ideal for developing pathogen-sensing devices. The biorecognition layer, consisting of recognition elements, such as aptamers, antibodies and bacteriophages, and other biomolecules or polymers, is the most critical component to determine the selectivity, specificity, reproducibility, and lifetime of a biosensor when detecting pathogens in a biosample. Furthermore, nanomaterials have been frequently used to improve electrochemical biosensors for sensitively detecting foodborne pathogens due to their high conductivity, surface-to-volume ratio, and electrocatalytic activity. In this review, we survey the characteristics of biorecognition elements and nanomaterials in constructing electrochemical biosensors applicable for detecting foodborne pathogens during the past five years. As well as the challenges and opportunities of electrochemical biosensors in the application of foodborne pathogen detection are discussed.

Clinicopathological Profile and Survival Outcomes in Patients with Localised Extremity Synovial Sarcomas.

AIMS: Synovial sarcoma is a rare but aggressive variant of soft-tissue sarcoma. Literature is sparse and reported mostly from the West. We analysed the clinical profiles and prognostic factors of extremity synovial sarcoma patients in order to study their clinical journey. MATERIALS AND METHODS: This was a retrospective analysis. All patients with extremity synovial sarcoma treated between 1992 and 2020 were included. Patients with metastases at presentation were excluded. A descriptive analysis of demographic and clinicopathological features of patients undergoing limb salvage surgery (LSS) or amputation was carried out. Overall survival and disease-free survival were calculated for the entire cohort as well as for the LSS and amputation groups. Factors prognostic for survival were identified. RESULTS: In total, 157 patients had localised extremity synovial sarcoma. Predominantly, young adults (median 31 years) and males (61%) were affected. Over 70% of patients presented after recurrence or unplanned surgeries. Sixty-seven per cent of tumours were >5 cm, 69% were deep and 23% involved bone. The limb salvage rate was 64%. In the LSS group, adjuvant radiotherapy and chemotherapy were given to 72% and 68% of patients, respectively. In the amputation group, 72% of patients received adjuvant chemotherapy. In a median follow-up of 59 months, 39.4% of patients had recurrences, the majority (61.2%) were systemic. Five-year overall survival and disease-free survival were 53.4% and 49.8%, respectively. Overall survival was 63.9% and 29.7% in the LSS and amputation groups, respectively. On multivariate analysis, tumour size, depth, omission of radiotherapy and bone invasion were found to be the adverse prognostic factors. CONCLUSION: This is one of the largest studies on extremity synovial sarcoma. Mostly males and young adults were affected. The limb salvage rate was 64%, despite most being referred after unplanned surgery. Almost 70% of patients received radiotherapy and chemotherapy. Overall survival was inferior in the amputation group. Tumour size >5 cm, depth and bone invasion were negative, whereas adjuvant radiotherapy was a positive prognostic factor for survival. Chemotherapy had no impact on survival.

Sustainability assessment of hybrid active greenhouse solar dryer integrated with evacuated solar collector.

Environment and Economy are the two important pillars of sustainability. In this paper, the economic viability and environmental impact of the novel greenhouse dryer with an evacuated solar collector are calculated. For this analysis, tomato is dried inside the dryer as it is a high moisture crop that requires a faster drying rate otherwise it starts giving a bad odor and gets contaminated. The hybrid active greenhouse dryer is developed especially for drying high moisture agro and non-agro-based produce. Evacuated tube solar collector is integrated with the dryer that supplies the hot water to the heat exchanger kept inside the dryer. The hot water flowing inside the copper tubes of the heat exchanger transfers its heat to room air through convection and to crop through conduction. Hence the higher room temperature and faster moisture removal rate are obtained. Tomato slices have been dried from 94.6% (wb) to 10% (wb) moisture content in 10 h. The developed dryer can produce 261 kg of dried tomato annually and its payback time is only 1.73 years which is very less as compared to its life of 30 years. In its entire lifetime, the dryer will mitigate 169.10 tonnes of CO2 that prove its suitability from a sustainable point of view.

The biochemical womb of schizophrenia: A review.

The conclusive identification of specific etiological factors or pathogenic processes in the illness of schizophrenia has remained elusive despite great technological progress. The convergence of state-of-art scientific studies in molecular genetics, molecular neuropathophysiology, in vivo brain imaging and psychopharmacology, however, indicates that we may be coming much closer to understanding the genesis of schizophrenia. In near future, the diagnosis and assessment of schizophrenia using biochemical markers may become a "dream come true" for the medical community as well as for the general population. An understanding of the biochemistry/ visa vis pathophysiology of schizophrenia is essential to the discovery of preventive measures and therapeutic intervention.

Efflux pumps in drug resistance of Candida.

The incidences of human pathogenic yeast Candida albicans and its related species acquiring resistance to antifungals have increased considerably, which poses serious problems towards its successful chemotherapy. The resistance of these pathogenic fungi is not restricted to the commonly used triazole compounds but is even encountered, though not often, with polyene derivatives as well. The efflux pump proteins belonging to ABC (ATP Binding Cassette) and MFS (Major Facilitators) super family are the most prominent contributors of multidrug resistance (MDR) in yeasts. The abundance of the drug transporters and their wider specificity suggest that these transporters may not be exclusively drug exporters in yeasts and may have other cellular functions. In this article we focus on some of the recent advances on the structure and function, evolution and transcriptional control of drug efflux proteins of Candida. A short discussion on the physiological relevance of drug transporters is also included.

Megakaryocytes derived from human embryonic stem cells: a genetically tractable system to study megakaryocytopoiesis and integrin function.

BACKGROUND: The platelet fibrinogen receptor, a heterodimer consisting of integrin subunits alpha(IIb) and beta(3), is required for platelet aggregation, spreading, and hemostasis. Platelet agonists such as thrombin and adenosine diphosphate (ADP) lead to the activation of alpha(IIb)beta(3), thereby enhancing its affinity and avidity for binding fibrinogen (inside-out signaling). Furthermore, fibrinogen binding to alpha(IIb)beta(3) triggers cytoskeletal changes and granule release (outside-in signaling). AIM: Genetic approaches to characterize the molecular pathways involved in alpha(IIb)beta(3) signaling are not possible with anucleate blood platelets. Therefore, we have established an OP9 stromal cell co-culture system to generate megakaryocytes from human embryonic stem cells (hESCs). RESULTS: alpha(IIb)beta(3) activation, measured by soluble fibrinogen binding to hESC-derived megakaryocytes, /GPIbalpha(+) cells, is readily detectable following stimulation with known platelet agonists. Dose-response curves for peptide agonists specific for the two platelet thrombin receptors, protease-activated receptor 1 (PAR1) and PAR4, show a relative responsiveness that mirrors that of human platelets, and sub-maximal ADP responses are augmented by epinephrine. Moreover, hESC-derived megakaryocytes undergo lamellipodia formation, actin filament assembly, and vinculin localization at focal adhesions when plated on a fibrinogen-coated surface, characteristic of alpha(IIb)beta(3) outside-in signaling. Undifferentiated hESCs genetically modified by lentiviral infection can be cloned and maintained in an undifferentiated state and then differentiated into megakaryocytes capable of alpha(IIb)beta(3) activation. CONCLUSION: Using hESCs, we have developed a renewable source of human megakaryocytes, and a genetically tractable system for studying megakaryocytopoiesis and alpha(IIb)beta(3) signaling in the native cellular environment.

Characterization of Mpl mutants using primary megakaryocyte-lineage cells from mpl(-/-) mice: a new system for Mpl structure-function studies.

Mpl is the thrombopoietin (TPO) receptor. The current molecular understanding of how Mpl activation stimulates proliferation of megakaryocyte-lineage cells is based largely on the engineered expression of Mpl in nonmegakaryocyte-lineage cell lines. However, the relevance of these findings to Mpl signaling in primary megakaryocyte-lineage cells remains largely unknown. Therefore, a system was developed to study Mpl function in primary mpl(-/-) megakaryocyte-lineage cells. Expressing avian retroviral receptors on the surfaces of mammalian cells overcomes their natural block to avian retroviral infection; 815 bp of human GPIIb regulatory sequence was used to generate transgenic mice with megakaryocyte-lineage expression of the subgroup A avian leukosis virus receptor, TVA. Avian retroviral infection of unfractionated bone marrow from these mice is restricted to megakaryocyte-lineage cells. The transgenic mice were crossed to an mpl(-/-) background generating GPIIb-tva+mpl(-/-) mice. By using avian retroviruses to express wild-type or mutant Mpl on the surfaces of primary megakaryocyte-lineage cells, it was demonstrated that (1) the 10 membrane-proximal, cytoplasmic amino acids of Mpl are required for TPO-induced proliferation; (2) Y582F mutation confers a proliferative advantage over wild-type Mpl and imparts a constitutive anti-apoptotic signal; (3) truncating the 50 C-terminal Mpl amino acids reduces but does not eliminate TPO-induced mitogen-activated protein kinase activation, yet it does not alter the synergistic effect of stem cell factor on TPO-induced proliferation; and (4) TPO-induced proliferation of early, primary megakaryocyte-lineage cells does not require Stat-5 phosphorylation. The system reported provides an improved approach for Mpl structure-function studies, and the method can be applied to any hematopoietic lineage.

Inductively coupled plasma emission spectroscopic and flame photometric analysis of goat epididymal fluid.

AIM: The elemental composition of the epididymal luminal fluid (ELF) in adult goat (Capra indica) was investigated. METHODS: ELF was collected by micropuncture from twelve sites along the epididymal duct. The elemental contents was analyzed with inductively coupled plasma (ICP) emission spectroscopy, a microanalytical technique that can simultaneously measure many elements in minute volumes of sample. The Na and K concentrations were determined by flame photometry. RESULTS: ICP spectroscopy showed the presence of copper, calcium, nickel, iron, magnesium, chromium, titanium and zinc in ELF, with fluctuating levels at different sites along the length of the epididymis. Cadmium, cobalt, lead and manganese were not found. The Na+/K+ ratio was seen to be higher at the initial segments of the epididymis and lower at the distal. CONCLUSION: It is proposed that the observed characteristic distribution of elements in ELF may have far reaching implications in sperm maturation and storage known to occur in the epididymis.

Mutations in the human immunodeficiency virus type 1 integrase D,D(35)E motif do not eliminate provirus formation.

The core domain of human immunodeficiency virus type 1 (HIV-1) integrase (IN) contains a D,D(35)E motif, named for the phylogenetically conserved glutamic acid and aspartic acid residues and the invariant 35 amino acid spacing between the second and third acidic residues. Each acidic residue of the D,D(35)E motif is independently essential for the 3'-processing and strand transfer activities of purified HIV-1 IN protein. Using a replication-defective viral genome with a hygromycin selectable marker, we recently reported that a mutation at any of the three residues of the D,D(35)E motif produces a 10(3)- to 10(4)-fold reduction in infectious titer compared with virus encoding wild-type IN (A. D. Leavitt et al., J. Virol. 70:721-728. 1996). The infectious titer, as measured by the number of hygromycin-resistant colonies formed following infection of cells in culture, was less than a few hundred colonies per microg of p24. To understand the mechanism by which the mutant virions conferred hygromycin resistance, we characterized the integrated viral DNA in cells infected with virus encoding mutations at each of the three residues of the D,D(35)E motif. We found the integrated viral DNA to be colinear with the incoming viral genome. DNA sequencing of the junctions between integrated viral DNA and host DNA showed that (i) the characteristic 5-bp direct repeat of host DNA flanking the HIV-1 provirus was not maintained, (ii) integration often produced a deletion of host DNA, (iii) integration sometimes occurred without the viral DNA first undergoing 3'-processing, (iv) integration sites showed a strong bias for a G residue immediately adjacent to the conserved viral CA dinucleotide, and (v) mutations at each of the residues of the D,D(35)E motif produced essentially identical phenotypes. We conclude that mutations at any of the three acidic residues of the conserved D,D(35)E motif so severely impair IN activity that most, if not all, integration events by virus encoding such mutations are not IN mediated. IN-independent provirus formation may have implications for anti-IN therapeutic agents that target the IN active site.

Rejuvenation of epididymal principal cells by prolactin under androgen deficiency.

Influence of prolactin on the ultrastructure of principal cells lining the epididymal epithelium was investigated in Wistar rats. Orchidectomy produced degenerative changes suggesting that structural integrity of principal cell is maintained by factors originating in the testis. The atrophic changes in the principal cell of ordhidectomised rats were significantly reversed when prolactin was administered to these animals. The number of cells that responded were found to increase with the dose of prolactin injected. On the otherhand, bromocryptine treatment did not appreciably change the ultrastructure of principal cells in orchidectomised rats. Results suggest that prolactin may have a rejuvenating epididymal principal cells in androgen deficient states.

Impact of prolactin on epididymal lipid profile in castrated rats.

Prolactin treatment to castrated rats led to accumulation of triacylglycerol and esterified cholesterol. There was no appreciable drift in epididymal cholesterol: phospholipid ratio between the prolactin treated and control animals. However, further analysis of phospholipids showed a build up of phosphatidyl inositol, phosphatidyl choline and phosphatidyl ethanolamine but a drop in the levels of phosphatidyl serine and sphingomyelin in prolactin treated castrated rats as compared to those castrated animals injected with vehicle alone. Changes in phospholipids reported above were prominently seen in the group of castrated rats that received 100 micrograms oPRL/100 g body weight but not in those animals which received either lower or higher doses of the hormone. Interestingly, bromocryptine treatment in castrated rats produced a general depletion in the levels of all lipid classes studied in the epididymis. It is suggested that this may be due to impaired synthesis and/or increased breakdown of lipids in this organ.

Serum and urinary zinc levels in urolithiasis.

Zinc has an important place amongst inhibitors of crystallisation and crystal growth. These views are supported by in vivo and in vitro studies which suggest that the urinary zinc level is a significant factor in urolithiasis. Some recent studies have given contradictory results. Blood serum and urinary zinc levels were measured in 30 normal healthy controls and 42 stone forming patients (renal, ureteric and vesical). Statistically significant levels were found in all groups, varying according to the number of calculi. Increased urinary zinc levels and decreased serum zinc levels appear to be secondary to the process of stone formation. The role of zinc as an inhibitor of urolithiasis is questionable.

[Small disturbance in arterial blood flow]. / Maloe vozmushchenie v potoke arterial'noi krovi.

The behaviour of a small disturbance in an arterial blood flow has been studied analytically. The growth equation governing growth or decay of a disturbance has been obtained and solved. The behaviour of wave amplitude has been investigated as the wave propagates in time. The application of results to the human arterial system shows that the shock waves are not expected under normal physiological conditions. In the case of a pathologically increased pressure rise at the root of aorta, shock-like transitions may develop in the periphery. It is observed that the friction effects are to resist the tendency of shock formation in arteries.