Selection of ACC deaminase positive, thermohalotolerant and drought tolerance enhancing plant growth-promoting bacteria from rhizospheres of Cyamopsis tetragonoloba grown in arid regions

Plant growth-promoting bacteria (PGPB) expressing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity are widely acknowledged to have a role in mitigation of abiotic stress caused by extreme environmental conditions. Consequently, several studies have focused on the isolation of ACC deaminase positive PGPBs. However, the application of such strains in drought-prone arid regions has remained grossly under-exploited. In order to be used in arid agroecosystems, PGPBs need to have the dual capability: to express ACC deaminase and to have the ability to tolerate increased temperature and salt concentration. Conspicuously, to date, very few studies have reported about isolation and characterization of PGPBs with this kind of dual capability. Here we report the isolation of bacterial strains from rhizosphere(s) of Cyamopsis tetragonoloba, a commercial crop from arid regions of Rajasthan, India, and their characterization for ACC deaminase activity and thermohalotolerance. Isolates found positive for desired traits were subsequently assessed for plant growth promotion under simulated drought conditions. Our finding showed that although the bacterial diversity within the rhizosphere of C. tetragonoloba grown in the arid region is quite poor, multiple isolates are ACC deaminase positive. Four isolates were found to be ACC deaminase positive, thermohalotolerant, and successfully enhanced drought tolerance. These isolates were identified as strains belonging to genera Pseudomonas, Enterobacter, and Stenotrophomonas based on 16S rRNA sequence homology.

Improving the early identification of COVID-19 pneumonia: a narrative review

Delayed presentation of COVID-19 pneumonia increases the risk of mortality and need for high-intensity healthcare. Conversely, early identification of COVID-19 pneumonia grants an opportunity to intervene early and thus prevent more complicated, protracted and less successful hospital admissions. To improve the earlier detection of COVID-19 pneumonia in the community we provide a narrative review of current evidence examining the clinical parameters associated with early disease progression. Through an evolving literature review, we examined: the symptoms that may suggest COVID-19 progression; the timing of deterioration; the utility of basic observations, clinical examination and chest X-ray; the value of postexertion oxygen saturations; and the use of CRP to monitor disease progression. We go on to discuss the challenges in monitoring the COVID-19 patient in the community and discuss thresholds for further assessment. Confusion, persistent fever and shortness of breath were identified as worrying symptoms suggestive of COVID-19 disease progression necessitating urgent clinical contact. Importantly, a significant proportion of COVID-19 pneumonia patients appear not to suffer dyspnoea despite severe disease. Patients with this asymptomatic hypoxia seem to have a poorer prognosis. Such patients may present with other signs of hypoxia: severe fatigue, exertional fatigue and/or altered mental status. We found duration of symptoms to be largely unhelpful in determining risk, with evidence of deterioration at any point in the disease. Basic clinical parameters (pulse, respiratory rate, blood pressure, temperature and oxygen saturations (SpO₂)) are likely of high value in detecting the deteriorating community COVID-19 patient and/or COVID-19 mimickers/complications (eg, sepsis, bacterial pneumonia and pulmonary embolism). Of these, SpO₂ carried the greatest utility in detecting COVID-19 progression. CRP is an early biochemical parameter predictive of disease progression and used appropriately is likely to contribute to the early identification of COVID-19 pneumonia. Identifying progressive COVID-19 in the community is feasible using basic clinical questions and measurements. As such, if we are to limit the mortality, morbidity and the need for complicated, protracted admissions, monitoring community COVID-19 cases for signs of deterioration to facilitate early intervention is a viable strategy.

Reliability of COVID-19 symptom checkers as national triage tools: an international case comparison study

Objectives

Triage is a critical component of the pandemic response. It affects morbidity, mortality and how effectively the available healthcare resources are used. In a number of nations the pandemic has sponsored the adoption of novel, online, patient-led triage systems—often referred to as COVID-19 symptom checkers. The current safety and reliability of these new automated triage systems remain unknown.

Methods

We tested six symptom checkers currently in use as triage tools at a national level against 52 cases simulating COVID-19 of various severities to determine if the symptom checkers appropriately triage time-critical cases onward to healthcare contact. We further analysed and compared each symptom checker to determine the discretionary aspects of triage decision-making that govern the automated advice generated.

Results

Of the 52 clinical presentations, the absolute rate of onward referral to any form of healthcare contact was: Singapore 100%, the USA 67%, Wales 65%, England 62%, Scotland 54% and Northern Ireland 46%. Triage decisions were broadly based on either estimates of ‘risk’ or ‘disease severity’. Risk-based symptom checkers were more reliable, with severity-based symptom checkers often triaging time-critical cases to stay home without clinical contact or follow-up.

Conclusion

The COVID-19 symptom checkers analysed here were unable to reliably discriminate between mild and severe COVID-19. Risk-based symptom checkers may hold some promise of contributing to pandemic case management, while severity-based symptom checkers—the CDC and NHS 111 versions—confer too much risk to both public and healthcare services to be deemed a viable option for COVID-19 triage.

Performance of national COVID-19 'symptom checkers': a comparative case simulation study

OBJECTIVES

Identifying those individuals requiring medical care is a basic tenet of the pandemic response. Here, we examine the COVID-19 community triage pathways employed by four nations, specifically comparing the safety and efficacy of national online 'symptom checkers' used within the triage pathway.

METHODS

A simulation study was conducted on current, nationwide, patient-led symptom checkers from four countries (Singapore, Japan, USA and UK). 52 cases were simulated to approximate typical COVID-19 presentations (mild, moderate, severe and critical) and COVID-19 mimickers (eg, sepsis and bacterial pneumonia). The same simulations were applied to each of the four country's symptom checkers, and the recommendations to refer on for medical care or to stay home were recorded and compared.

RESULTS

The symptom checkers from Singapore and Japan advised onward healthcare contact for the majority of simulations (88% and 77%, respectively). The USA and UK symptom checkers triaged 38% and 44% of cases to healthcare contact, respectively. Both the US and UK symptom checkers consistently failed to identify severe COVID-19, bacterial pneumonia and sepsis, triaging such cases to stay home.

CONCLUSION

Our results suggest that whilst 'symptom checkers' may be of use to the healthcare COVID-19 response, there is the potential for such patient-led assessment tools to worsen outcomes by delaying appropriate clinical assessment. The key features of the well-performing symptom checkers are discussed.

Ameloblastoma in children: should we be radical?

Ameloblastoma is the most common aggressive benign odontogenic tumor of the jaws. The tumor is often asymptomatic, presenting as a slowly enlarging facial swelling. The physical presence of the tumor may cause symptoms such as pain, ulceration, loosening of teeth, or malocclusion. Ameloblastoma is a locally destructive tumor with a propensity for recurrence if not entirely excised. It is seen in all age groups, but the lesion is most commonly diagnosed in the third and fourth decades. The tumor is considered a rarity in the young age group. The treatment of ameloblastoma is still controversial and presents some special problems in children like the growth of the jaw, the different incidence, behavior and prognosis of the tumor in children, which make the surgical considerations different from adults. Some reports have encouraged conservative treatment for ameloblastoma in children.

Parotid secretory protein binds phosphatidylinositol (3,4) bisphosphate

Molecular interactions that direct trafficking of secreted proteins are not well-described in salivary glands. Here, we report that the soluble cargo protein Parotid Secretory Protein (PSP) is bound to the membranes of secretory granules isolated from rat parotids. This is apparently due to specific interaction with phosphatidylinositol phosphates (PtdInsP). PSP binds PtdIns(3,4)P(2), 10-fold greater than PtdIns(3,5)P(2) or PtdIns(4)P, and does not bind PtdIns(3)P or PtdIns(5)P. Human PSP synthesized in vitro also binds PtdIns(3,4)P(2). Bacterially expressed rat PSP binds PtdIns(3,4)P(2) with a K(d) of 2.4 x 10(-11) M. Other major secretory proteins (amylase, proline-rich protein) are not bound to isolated granule membranes and do not bind phosphatidylinositol phosphates. Immunofluorescence shows PtdIns(3,4)P(2) at the secretory granules, and fluorescent PtdIns(3,4)P(2) can flip from the outer leaflet to the inner leaflet of the membrane. Binding of PSP to PtdInsPs may contribute to sorting during the formation of the secretory granules, or sorting by retention during maturation of the granules.

Microstructure Development in Thin Films During Deposition from the Vapor Phase

Transmission electron microscope observations of the structures of single-phase metallic thin films have been made. Films prepared by sputtering and by thermal evaporation have been used and the structures have been evaluated quantitatively as a function of film thickness. It is found that the grain size in all films increases linearly with the film thickness, indicating that grain growth occurs during film deposition.

Antenatal maternal hypoxic stress: adaptations of the placental renin-angiotensin system in the mouse

The stress of Antenatal Maternal Hypoxia (AMH) can lead to a number of physiological and pathological changes in both mother and fetus, changes which can be linked to alterations in placental morphology and gene regulation. Recently, in the Brown Norway rat "model" of placental insufficiency, we reported alterations in placental renin-angiotensin system (RAS) genes. Moreover, AMH can lead to reduced oxygen availability to the fetus, similar to a state of placental insufficiency. Thus, in pregnant mice dams we tested the hypothesis that antenatal maternal hypoxic stress leads to alterations in the placental RAS. These alterations may, in part, account for the phenotypic changes in both pregnant mice dams as well as fetus and adult offspring.

METHODS

Pregnant FVB/NJ mice dams were either maintained as controls, or exposed to 10.5% O(2) for 48 h from 15.5 to 17.5 day post coitum. We then measured placental mRNA and protein expression of several RAS genes (n = 4 to 5; P < 0.05 was considered significant).

RESULT

In murine placenta: (1) angiotensinogen (AGT) mRNA was undetectable; however, AGT protein was detectable and increased significantly with AMH. (2) In AMH, although renin mRNA was reduced protein expression increased, in association with decreased microRNA (miRNA) 199b, which can lead to increased renin translation. (3) Also in AMH placenta, angiotensin converting enzyme (ACE) -1 mRNA was unaltered; however, protein expression increased significantly, in association with decreased miRNA 27a, which can result in increased ACE-1 translation. (4) In AMH placenta, ACE-2 mRNA was reduced significantly, whereas protein expression was significantly greater, in association with reduced miRNA 429. (5) In AMH placenta, angiotensin II type (AT) -1a receptor mRNA expression was unaltered while AT-1b receptor mRNA was undetectable in both groups. Moreover, AT-1 receptor protein expression was unchanged in response to AMH. (6) AT-2 receptor mRNA and proteins were undetectable in both groups.

CONCLUSION

The normal murine placenta possesses several components of RAS, and in response to AMH several of these elements undergo important changes. In addition, differential expression of RAS mRNA, miRNA and protein, indicate post-transcriptional regulatory mechanisms involved with hypoxic stress, and necessitate further investigation.

Do heart failure patients understand their diagnosis or want to know their prognosis? Heart failure from a patient's perspective

The management of heart failure has evolved to become a multidisciplinary affair. Constraints of time and resources limit the amount of counselling that is given to heart failure patients in hospital and, with the advent of community heart failure specialist nurses, there is a trend to move more of these services into the community. Most heart failure patients are elderly and may find the information given to them, at the time of diagnosis and later on at home by heart failure nurses, difficult to grasp. In this study, patients' perspectives of a diagnosis of heart failure, their understanding of the diagnosis as well as what being diagnosed with heart failure means to them were recorded. Patients were questioned on whether the news of the heart failure diagnosis was broken to them in a sympathetic manner and how they felt about the information provided at diagnosis.

The effects of maximal treadmill graded exercise testing on haemorheological, haemodynamic and flow cytometry platelet markers in patients with systolic or diastolic heart failure

BACKGROUND

Acute exercise has been associated with activation of thrombosis, and this risk may be accentuated in patients with heart failure. Given the relation of platelets to atherothrombosis, we tested the hypothesis that acute exercise would adversely affect platelet indices and platelet activation markers in patients with systolic and diastolic heart failure.

MATERIALS AND METHODS

We studied 20 patients with systolic heart failure (17 men, 3 women; mean age 64 +/- 10 years, all with ejection fraction (EF) < or = 40%) and 20 patients with diastolic heart failure (14 men, 6 women; mean age 64 +/- 8 years, mean EF = 66%) who were exercised to maximal intensity, who were compared to 13 healthy controls (6 men, 7 women; mean age 60 +/- 4 years, mean EF = 73%). We measured platelet indices (platelet volume, mass and component) and platelet activation markers (platelet-bound CD62P%G, CD63%G and CD40L%G using flow cytometry, as well as plasma sCD40L and soluble P-selectin (sP-sel) levels).

RESULTS

Baseline Mean Platelet Volume (MPV), sP-sel, CD40L%G and CD63%G levels were significantly higher in patients with systolic and diastolic heart failure, when compared with controls. The mean exercise duration and VO(2 )peak in patients with systolic and diastolic heart failure were not significantly different, but lower than that seen in healthy controls. Following exercise, mean haematocrit, CD62P%G, and CD63%G significantly increased in all three subject groups (all P < 0.05). The proportional change in CD62P%G and CD63%G were not significantly different between healthy controls and heart failure patients (P > 0.05).

CONCLUSION

Acute maximal graded exercise increases platelet activation markers, with no disproportionate differences between heart failure patients and healthy controls, despite the former group having a lower exercise tolerance and VO2 peak.

Assessment of single versus twice daily dosing of ramipril by ambulatory blood pressure monitoring in patients similar to those included in the HOPE study

Ramipril has been used in twice daily dose of 5 mg in most heart failure trials, whereas the dose used in Heart Outcomes Prevention Evaluation (HOPE) study was 10 mg once at bedtime. The HOPE investigators in an ambulatory blood pressure (ABP) substudy observed a fall of nighttime but not daytime blood pressure (BP). We examined the effects of once daily ramipril 10 mg versus 5 mg twice a day. Twenty-nine patients were recruited based on the original criteria for the HOPE study and were given ramipril either in twice-daily dose (5 mg b.d.) or once daily (10 mg o.d.) each morning in randomized, prospective crossover trial. Twenty-four hour ABP recordings were taken just before commencement of ramipril therapy and after treatment with twice-daily and once-daily ramipril. Our results show that ramipril causes a significant reduction of BP over 24-h period as compared with baseline. The mean baseline ABP was 124/73 mm Hg, which reduced to 117/69 mm Hg for the twice-a-day regimen (P<0.001) and 115/68 mm Hg for the once a day regimen (P<0.001). Both regimes effectively lower BP to a similar extent. Ramipril causes significant BP reduction in both once- and twice-daily dosing. The fall in BP after daytime dosing is greater than that observed in the HOPE study (including ABP substudy). Once-daily dosing in the morning seems to be effective in causing a significant reduction in the ABP profile of patients at high-risk of a future vascular event.

Lung and blood mononuclear cell responses of tuberculosis patients to mycobacterial proteins

The differences in specificity of human lung and peripheral lymphocytes for mycobacterial antigens (Ag) need to be evaluated in order to identify vaccine candidates against pulmonary tuberculosis (TB). Therefore, the present study examined the response to low molecular weight secretory proteins of Mycobacterium tuberculosis in bronchoalveolar lavage (BAL) and peripheral blood mononuclear cells (PBMCs) from minimal pulmonary TB and non-TB patients. Ag85A, Ag85B, culture filtrate protein (CFP)-31, CFP-22.5, CFP-21, M. tuberculosis protein-64 and an as yet uncharacterised 19 kDa protein were found to be predominantly recognised by BAL cells of TB patients on the basis of lymphocyte proliferation and significant interferon-gamma release. However, recognition of CFP-8, 6-kDa early secreted antigenic target, CFP-10, CFP-14.5, M. tuberculosis secretory protein-17 and five other as yet uncharacterised low molecular weight polypeptides was found to be high on the basis of lymphocyte proliferation at the level of PBMCs. Furthermore, BAL macrophages, and not blood monocytes, were found to produce nitric oxide (NO) in response to mycobacterial Ags. Among polypeptides predominantly recognised by BAL lymphocytes, only Ag85A and Ag85B were found to induce both NO and interleukin-12 (p40) by alveolar macrophages. In conclusion, the present results indicate heterogeneity in antigen recognition by bronchoalveolar lavage cells and peripheral mononuclear blood cells of minimal tuberculosis patients, and also suggest the utility of antigen 85 complex polypeptides for the development of a future mucosal antituberculous vaccine.

Spotted dermopathy in a diabetic patient due to insulin allergy

A rare case of diabetic patient who developed multiple cutaneous hyperpigmented spots following bovine isophane (NPH) insulin injection is described here.

Transnasal access for sampling a skull base lesion

SUMMARY

Transnasal needle access for sampling was used in two patients with posterior nasopharyngeal lesions. The procedure was performed under CT guidance. This new technique is simple and appears suitable for selected cases. The two cases and the details of the procedure are described.

A classification system for characterization of physical and non-physical work factors

A comprehensive evaluation of work-related performance factors is a prerequisite to developing integrated and long-term solutions to workplace performance improvement. This paper describes a work-factor classification system that categorizes the entire domain of workplace factors impacting performance. A questionnaire-based instrument was developed to implement this classification system in industry. Fifty jobs were evaluated in 4 different service and manufacturing companies using the proposed questionnaire-based instrument. The reliability coefficients obtained from the analyzed jobs were considered good (0.589 to 0.862). In general, the physical work factors resulted in higher reliability coefficients (0.847 to 0.862) than non-physical work factors (0.589 to 0.768).

Japanese encephalitis with movement disorder and atypical magnetic resonance imaging

With the advent of magnetic resonance imaging, brain lesions associated with Japanese encephalitis are increasingly being recognized and correlated with movement disorder. Bilateral haemorrhagic thalamic infarcts on MRI, suggested as a characteristic finding in Japanese encephalitis were conspicuous by their absence in this case report of Japanese encephalitis.

Low dose poly I:C prevents diabetes in the diabetes prone BB rat

Poly I:C, an inducer of IFN-alpha and other cytokines, has been used to study the development of diabetes in both the BioBreeding (BB) diabetes prone rat and non-obese diabetic (NOD) mouse animal models of insulin-dependent diabetes mellitus (IDDM). Surprisingly, poly I:C accelerates the disease in the BB rat while inhibiting it in the NOD mouse. Since cytokines can have dose related opposing effects on immune responses, we hypothesized that the paradoxical effect of polyinosinic polycytidylic acid (poly I:C) on diabetes in the two animal models is dose related. Accordingly, we compared the incidence of diabetes and degree of insulitis in diabetes prone BB rats administered saline and poly I:C at doses (0.05 microg/g body weight and 0.1 microg/g body weight) up to 100-fold lower than doses (poly-5 microg/g) previously found to accelerate diabetes. In addition, the non-specific suppressor activity of mononuclear splenocytes from BB rats administered low dose (poly-0.05 microg/g body weight), high dose (poly-5 microg/g body weight), and saline were compared. The development of diabetes was inhibited in rats treated with each dose of poly I:C. The degree of insulitis in poly-I:C treated animals was also less severe. The total white blood cell count and proportion of RT6+ T-cells and each T-cell subset were unaltered by poly I:C. When compared to splenocytes of control animals, splenocytes from poly I:C (0.05 microg/g body weight) treated rats suppressed responder cell proliferation to concanavalin A and alloantigen. However, spleen cells from high dose poly-I:C did not suppress responder cell proliferation to alloantigen. In adoptive transfer studies, the administration of spleen cells from poly-0.05 treated rats decreased the development of diabetes in recipient BB rats. In vitro studies also demonstrated that poly-I:C inhibits the proliferative response of BB rat spleen cells to concanavalin A. The administration of poly-0.05, but not poly-5.0, decreased TNF-alpha mRNA and IL-10 mRNA content in spleen cells. We conclude that poly I:C, at a dose 100 times lower than that required to accelerate diabetes prevents the development of diabetes in BB rates by interfering with the development of insulitis. The induction of suppressor cell activity induced by low dose poly-I:C in vivo and the inhibition of T-cell responses by poly-I:C in vitro suggests that the diabetes sparing activity of poly I:C is mediated by augmented immunoregulatory cell activity. Further studies with poly I:C may be important in increasing our understanding of the pathogenesis of IDDM and provide a means to prevent it.

The B-subunit of cholera toxin induces immunoregulatory cells and prevents diabetes in the NOD mouse

The B-subunit of the cholera toxin molecule (CT-B) has T-cell immunomodulatory properties. Because the pathogenesis of diabetes in the nonobese diabetic (NOD) mouse model of IDDM is thought to be a T-cell-mediated process due to an imbalance of immunoregulatory and anti-islet effector cells, we examined the effect of CT-B administration on the development of diabetes in the NOD mouse and assessed whether this potential diabetes-sparing effect of CT-B is mediated by changes in immunoregulatory and/or anti-islet cytotoxic effector cell activity. The administration of either intravenous or intraperitoneal CT-B decreased the development of diabetes with no apparent drug toxicity. At 6 months of age, only 18% of CT-B vs. 75% of saline-treated animals had diabetes. Histopathological examination revealed less islet atrophy in CT-B-treated animals. The in vitro proliferative responses of mononuclear splenocytes and thymocytes to concanavalin A and lipolysaccharide and the proportion of B-cells and T-cell subsets were not altered by CT-B treatment. CT-B administration did not inhibit the primary immunization of mice to tetanus toxoid. The development of diabetes in irradiated NOD mice was slower in the animals injected with spleen cells (SC) from CT-B-treated than from saline-treated NOD mice, suggesting that CT-B decreases anti-islet effector cell activity. The injection of SC from CT-B-treated mice inhibited the adoptive transfer of diabetes by SC from diabetic mice into irradiated NOD mice, documenting that CT-B administration induces regulatory cell activity. In conclusion, CT-B administration prevents the development of diabetes in NOD mice by inhibiting the immune destruction of islets. This islet-sparing activity appears mediated, at least in part, by the induction of regulatory cells and, in turn, suppression of anti-islet effector cells, which is not associated with generalized immunosuppression or T- or B-cell depletion.

A cryptic plasmid pBL1 from Brevibacterium lactofermentum causes growth inhibition and filamentation in Escherichia coli

A shuttle vector composed of pBL1, a 4.46-kb cryptic plasmid from coryneform bacterium Brevibacterium lactofermentum, and Escherichia coli vector pHSG298 was found to inhibit growth and cause cell filamentation in E coli. After construction of several deletions of pBL1, a 1.23-kb AccI-HindIII fragment was found responsible. DNA sequence analysis showed that this fragment contained a 726-bp-long open reading frame (ORF3), encoding a protein with 242 amino acid residues. Corresponding to ORF3, a 28-kDa protein was detected in an in vitro protein synthesis system. ORF3 was dispensable for the stable maintenance of pBL1 in coryneform bacteria.