The positive control of ilvC expression in E. coli K-12

The mechanism of ilvC expression in Escherichia coli was investigated. To carry out this work several different approaches were used. Firstly, sequencing of the ilvY2143 allele which carries a mutation that makes ilvC expression constitutive was completed. The location of the mutation was determined to be at the 5 end of the gene. It is a single base substitution (G to A) at position 87 (counted from the transcription startpoint of ilvY). This results in a change of the codon for one amino acid. Glutamine in wild-type ilvY protein is replaced by lysine in the constitutive one. This substitution in the polypeptide of the upsilon protein (product of the ilvY gene) was found to be solely responsible for making the up silon protein independent of the ilvC gene substrates (a-acetohydroxybutyrate or acetolactate) needed for ilvC induction. Two approaches were used to determine the direction of ilvY trancription. One of these employed a gene fusion technique which involves two DNA fragments of ilvY being fused separately to a promoterless lacZ gene, then monitoring the expression of lacZ. The other approach involved the labeling of the upsilon protein withes -methionine after expression of ilvY in a T7 RNA polymerase dependent promoter system. DNA-binding activity of upsilon protein was investigated. This was carried out in two assays, filter binding and gel retardation assays. These assays were employed to monitor purification of upsilon protein to near homogeneity. Upsilon protein has a subunit size of 35 kd and a native molecular weight of approximately 211 kd, suggesting upsilon exists as a hexamer. Finally, in vitro activities of the upsilon protein were tested using transcriptional and coupled transcription-translation assays. Upsilon protein was shown to cause elevation of ilvC transcription. Two models for the action of the upsilon protein in regulating the transcription of the ilvYC are proposed

Thymic Carcinoid Responds to Neoadjuvant Therapy with Sunitinib and Octreotide: A Case Report

Carcinoids are malignant neuroendocrine tumors consisting of a spectrum of neoplasms from low-grade typical carcinoid to high-grade small cell carcinoma. We report a case of atypical thymic carcinoid that responded to neoadjuvant therapy with octreotide and sunitinib, an oral multikinase inhibitor. After 3 weeks of treatment, tumor size significantly decreased to allow for a safe surgical resection with clear margins. We believe that further study of sunitinib and octreotide with the neoadjuvant intent of preparing tumors for resection is warranted as a strategy to improve curative management of neuroendocrine tumors

Rydberg-London Potential for Diatomic Molecules and Unbonded Atom Pairs

We propose and test a pair potential that is accurate at all relevant distances and simple enough for use in large-scale computer simulations. A combination of the Rydberg potential from spectroscopy and the London inverse-sixth-power energy, the proposed form fits spectroscopically determined potentials better than the Morse, Varnshi, and Hulburt-Hirschfelder potentials and much better than the Lennard-Jones and harmonic potentials. At long distances, it goes smoothly to the correct London force appropriate for gases and preserves van der Waals's "continuity of the gas and liquid states," which is routinely violated by coefficients assigned to the Lennard-Jones 6-12 form.Comment: Five pages, 10 figure

Parametrization of the Hybrid Potential for Pairs of Neutral Atoms

The hybrid form is a combination of the Rydberg potential and the London inverse-sixth-power energy. It is accurate at all relevant distance scales and simple enough for use in all-atom simulations of biomolecules. One may compute the parameters of the hybrid potential for the ground state of a pair of neutral atoms from their internuclear separation, the depth and curvature of their potential at its minimum, and from their van der Waals coefficient of dispersion.Comment: 7 pages, 11 figures, includes lithium, sodium, & potassium dimers, minor correction

The Determination of Bound Water in Waste Phosphatic Clay

Phosphatic clay is a by-product of phosphate strip mining, particularly in Florida, USA. This waste material occupies about 100 000 acres of land which could be utilized for other causes. Thus, its use as an alternating cementing material for the addition into the mixing matrix of cement paste and concrete to yield higher strength would be profitable for both materials involved. But the biggest drawback faced is that the phosphatic clay possesses high water holding capacity. The water is thus not available for mixing purposes when added to cement paste and concrete and is thus known as bound water. It is therefore essential to determine the amount of bound water to phosphatic clay which shall not be available for the hydration reaction of cement in cement paste and concrete

Recreational use of naturally occurring dimethyltryptamine - contributing to psychosis?

Johanna M Warren, Pallavi Dham-Nayyar, and Jacob Alexande

Association of the level of cognition and obesity among middle-aged adults in Sri Lanka

Background: Cognition is the collection of an intellectual process, such as perception, thinking, and reasoning for goal-directed behaviours. The obesity-associated cognitive functions (CFs) was varied due to inconsistency of the findings and it is also context bounded. The objective was to assess the association between cognitive function and obesity among middle-aged adults in Sri Lanka.Methods: A descriptive study was conducted among middle-aged adults aged between 50-60 years in Colombo District, Sri Lanka. While Generalized obesity was estimated by the WHO cutoff of body mass index (BMI) while the central obesity was determined using and waist hip ratio (WHR). CFs was assessed using a validated Montreal cognitive assessment (MoCA) and the Mini-mental state examination (MMSE) tools.Results: The study sample consisted of 83 subjects of each obese and normal weight categories, while 50% were females. Middle-aged adults with obesity showed significantly lower CF scores in both MoCA and MMSE compared to the normal-weight adults (p<0.01). In addition, lower MMSE scores were significantly associated with high WHR values (p<0.05). The level of education of adults was a significant predictor of cognitive functions among middle-aged adults (p<0.05).Conclusions: Therefore, the results further confirmed that obesity-associated cognitive impairment among middle-aged adults and further research is warranted to clarify the cause and effect relationship between obesity and body composition.

Fluorodeoxyglucose-positron emission tomography/computed tomography in the staging and evaluation of treatment response in a patient with Castleman's disease: a case report

<p>Abstract</p> <p>Introduction</p> <p>Castleman's disease is a rare lymphatic polyclonal disorder that is characterised by unicentric or multicentric lymph node hyperplasia and non-specific symptoms and signs including fever, asthenia, weight loss, enlarged liver and abnormally high blood levels of antibodies.</p> <p>Case presentation</p> <p>We present the case of a 74-year-old man with Castleman's disease. The disease was detected with a contrast-enhanced computed tomography (CT) scan and a fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT study; diagnosis was made with histopathology. After treatment with surgical excision followed by chemotherapy, the disease response was evaluated using both diagnostic techniques. However, only the PET study was able to identify the spread of the disease to the abdominal lymph nodes, which were both enlarged and normal size, and, after treatment, to evaluate the disease response.</p> <p>Conclusion</p> <p>Based on the results of previous case reports and on those of the present study, it seems that Castleman's disease has a high glucose metabolic activity. Therefore, the use of PET can be considered appropriate in order to stage or restage the disease and to evaluate the response of the disease to treatment.</p