Use of the Ramsay Assay to Measure Fluid Secretion and Ion Flux Rates in the Drosophila melanogaster Malpighian Tubule

Modulation of renal epithelial ion transport allows organisms to maintain ionic and osmotic homeostasis in the face of varying external conditions. The Drosophila melanogaster Malpighian (renal) tubule offers an unparalleled opportunity to study the molecular mechanisms of epithelial ion transport, due to the powerful genetics of this organism and the accessibility of its renal tubules to physiological study. Here, we describe the use of the Ramsay assay to measure fluid secretion rates from isolated fly renal tubules, with the use of ion-specific electrodes to measure sodium and potassium concentrations in the secreted fluid. This assay allows study of transepithelial fluid and ion fluxes of ~20 tubules at a time, without the need to transfer the secreted fluid to a separate apparatus to measure ion concentrations. Genetically distinct tubules can be analyzed to assess the role of specific genes in transport processes. Additionally, the bathing saline can be modified to examine the effects of its chemical characteristics, or drugs or hormones added. In summary, this technique allows the molecular characterization of basic mechanisms of epithelial ion transport in the Drosophila tubule, as well as regulation of these transport mechanisms.     

Multi-Morbidity in Hospitalised Older Patients: Who Are the Complex Elderly?

Background

No formal definition for the “complex elderly” exists; moreover, these older patients with high levels of multi-morbidity are not readily identified as such at point of hospitalisation, thus missing a valuable opportunity to manage the older patient appropriately within the hospital setting.

Objectives

To empirically identify the complex elderly patient based on degree of multi-morbidity.

Design

Retrospective observational study using administrative data.

Setting

English hospitals during the financial year 2012–13.

Subjects

All admitted patients aged 65 years and over.

Methods

By using exploratory analysis (correspondence analysis) we identify multi-morbidity groups based on 20 target conditions whose hospital prevalence was ≥ 1%.

Results

We examined a total of 2788900 hospital admissions. Multi-morbidity was highly prevalent, 62.8% had 2 or more of the targeted conditions while 4.7% had six or more. Multi-morbidity increased with age from 56% (65-69yr age-groups) up to 67% (80-84yr age-group). The average multi-morbidity was 3.2±1.2 (SD). Correspondence analysis revealed 3 distinct groups of older patients. Group 1 (multi-morbidity ≤2), associated with cancer and/or metastasis; Group 2 (multi-morbidity of 3, 4 or 5), associated with chronic pulmonary disease, lung disease, rheumatism and osteoporosis; finally Group 3 with the highest level of multi-morbidity (≥6) and associated with heart failure, cerebrovascular accident, diabetes, hypertension and myocardial infarction.

Conclusions

By using widely available hospital administrative data, we propose patients in Groups 2 and 3 to be identified as the complex elderly. Identification of multi-morbidity patterns can help to predict the needs of the older patient and improve resource provision.     

Evaluation of Commercially Available Real-Time Polymerase Chain Reaction Assays for the Diagnosis of Invasive Aspergillosis in Patients with Haematological Malignancies

Mycopathologia - Early diagnosis of invasive aspergillosis (IA) is a challenge. Non-specific clinical and radiologic findings, as well as difficulties in conventional diagnostic method application,...     

Early In-Hospital Mortality following Trainee Doctors' First Day at Work

Background

There is a commonly held assumption that early August is an unsafe period to be admitted to hospital in England, as newly qualified doctors start work in NHS hospitals on the first Wednesday of August. We investigate whether in-hospital mortality is higher in the week following the first Wednesday in August than in the previous week.

Methodology

A retrospective study in England using administrative hospital admissions data. Two retrospective cohorts of all emergency patients admitted on the last Wednesday in July and the first Wednesday in August for 2000 to 2008, each followed up for one week.

Principal Findings

The odds of death for patients admitted on the first Wednesday in August was 6% higher (OR 1.06, 95% CI 1.00 to 1.15, p = 0.05) after controlling for year, gender, age, socio-economic deprivation and co-morbidity. When subdivided into medical, surgical and neoplasm admissions, medical admissions admitted on the first Wednesday in August had an 8% (OR 1.08, 95% CI 1.01 to 1.16, p = 0.03) higher odds of death. In 2007 and 2008, when the system for junior doctors'' job applications changed, patients admitted on Wednesday August 1^st had 8% higher adjusted odds of death than those admitted the previous Wednesday, but this was not statistically significant (OR 1.08, 95% CI 0.95 to 1.23, p = 0.24).

Conclusions

We found evidence that patients admitted on the first Wednesday in August have a higher early death rate in English hospitals compared with patients admitted on the previous Wednesday. This was higher for patients admitted with a medical primary diagnosis.     

The investigation of structural and thermosensitive properties of new phosphazene derivative bearing glycol and aminoalcohol

Three isomers (nongeminal cis-2,4,6 (2); nongeminal trans-2,4,6 (3); geminal 2,2,4 (4)) were isolated from the reaction of hexachlorocyclotriphosphazatriene (trimer) (1) with diethylene glycol monobutyl ether (DEGBE). The substitution reactions of cis-tris isomer (2) with 3-amino-1-propanol were investigated under different solutions conditions to provide amphiphilic phosphazene (5). All of compounds were characterized by using elemental analysis, ³¹P NMR and mass spectroscopies. Thermosensitive properties of compound 5 were studied. The compound 5 is soluble in both water and organic media. This indicates that compound 5 is an amphiphilic molecule. Concentration-dependent LCST (Lower Critical Solution Temperature) behavior of 5 was measured in water. Compound 5 exhibited a reversible and thermosensitive phase transition in aqueous medium, from soluble to insoluble states. Compound 5 showed LCST at 37 °C (for 7 wt.% concentration) which is near to body temperature.     

Do we think dreams are in black and white due to memory problems?

The present study was designed to investigate whether memory processes play a role in why some persons say their dreams are black and white. The findings indicate that the percentages of black and white dreams are related negatively to color memory and dream recall frequency. When colors were recorded immediately after the dream was recorded, the percentage of black and white dream elements dropped to 2.7%. When participants were presented the option that dream colors might not be remembered, the percentage of explicit black and white dreams became very small, and the findings are thus in line with the continuity hypothesis of dreaming. Future studies might use extensive training of color memory and dream recall in order to investigate whether highly trained persons still have some dreams or dream elements that are in black and white. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of silver nitrate on multiple shoot formation of Virginia-type peanut through shoot tip culture

Summary A protocol for micropropagation of Virginia-type peanut plants, an ancient crop of the New World, is reported. This study was conducted to explore the effect of silver nitrate (AgNO₃), alone or in combination with growth regulators, on multiple shoot formation from shoot tip culture. Incorporation of AgNO₃ into the medium, without growth regulators, induced regeneration of the explants (which did not develop at all in the AgNO₃-free medium), and stimulated the emergence of axillary shoots. When AgNO₃ was added in combination with cytokinins and α-naphthaleneacetic acid (NAA), maximum average shoot number per regenerating explant was recorded (6.3) in Murashige and Skoog (MS) medium containing 33 μM 6-benzyladenine, 5.3 μM NAA, and 23.54 μM AgNO₃. Moreover, AgNO₃ showed a positive and marked effect on both shoot elongation and the reduction of callus proliferation from the basal ends of shoot tips. Following a period of elongation, the shoots were rooted in hormone-free Ms medium, showing no residual effects due to the long-term culture in AgNO₃-containing media. Acclimatization was easily obtained after plantlets were transferred to pots under greenhouse conditions, with 90% survival.     

Evaluation of increased proportion of cells with unusually high sister chromatid exchange counts as a cytogenetic biomarker for lead exposure

Sister chromatid exchange (SCE) frequency and high-frequency cells (HFCs) were analyzed in 50 storage battery plant workers with mean blood lead level (BLL) of 40.14±9.99 μg/dL. The mean BLL in the control group (n=30) was 9.77±1.67 μg/dL. This difference in mean BLLs between control and exposed group was statistically significant (p<0.05) and reflects clearly the lead exposure in the workers. Urinary aminolevulinic acid (U-ALA) was also determined in both control (3.37±0.89 mg ALA/g creatinine) and exposed groups (12.39±6.18 mg ALA/g creatinine) and U-ALA excretion was statistically higher (p<0.05) in lead-exposed workers. The relationship between biomarkers of lead exposure/effect and HFC percentage was higher than the relationship between biomarkers of lead exposure/effect and SCE frequency. Accordingly, HFC analysis seemed to be more sensitive than the SCE analysis as a cytogenetic biomarker for lead exposure. Additionally, the statistically significant correlation (r ²=0.880, p<0.01) between U-ALA excretion and HFC percentage in lead-exposed workers supported the probability of ALA mediated indirect mechanism for lead genotoxicity.