Structural characterization of the tobramycin-piperacillin reaction product formed at pH 6.0

Tobramycin is an aminoglycoside antibiotic that loses a significant amount of activity in the presence of Zosyn at pH 6. As part of our investigation into ways to improve the compatibility of tobramycin with Zosyn (which contains piperacillin and tazobactam in an 8:1 ratio buffered at pH 6 by sodium citrate) by lowering the pH, we identified the reaction product of tobramycin and piperacillin at pH 6.0 and the order of the pK(a) values of tobramycin. The structure of the main reaction product of tobramycin and piperacillin at pH 6.0 was determined by 2D NMR to be the product of 3″-NH(2) reacting with the β-lactam of piperacillin. The order of the pK(a) values of the nitrogens of tobramycin was determined by (1)H and (15)N NMR titrations to be 6'-NH(2)>2'-NH(2)>1-NH(2)≈3″-NH(2)>3-NH(2). At pH 4.0, the reaction between tobramycin and Zosyn was almost negligible for a period of up to 2?h. The pH can be lowered by adding an acid such as HCl or citric acid to Zosyn to make a pH 4.0 buffer.     

Validity and reliability of the multidimensional health locus of control scale for college students

Background  

The purpose of the present study was to assess the validity and reliability of Form A of Multidimensional Health Locus of Control scales in Iran. Health locus of control is one of the most widely measured parameters of health belief for the planning of health education programs.     

The role of neighborhood level socioeconomic characteristics in <Emphasis Type="Italic">Salmonella</Emphasis> infections in Michigan (1997–2007): Assessment using geographic information system

Background:  

The majority of U.S. disease surveillance systems contain incomplete information regarding socioeconomic status (SES) indicators like household or family income and educational attainment in case reports, which reduces the usefulness of surveillance data for these parameters. We investigated the association between select SES attributes at the neighborhood level and Salmonella infections in the three most populated counties in Michigan using a geographic information system.     

Prognostic value of chromosome 1 and 8 copy number in invasive ductal breast carcinoma among iranian women: An interphase FISH analysis

Breast cancer is amongst the leading causes of death in women worldwide and the most common cancer amongst Iranian women. Unfortunately, the current clinical and histological criteria can only help 60 percent of women with breast cancer in diagnosis and long-term treatment. Therefore, genetic markers both at single gene and chromosomal level can play an important role in improving the diagnosis and prognosis of breast cancer patients. The aim of this retrospective study was to investigate the role of chromosome 1 and 8 copy number assessed by interphase fluorescence in situ hybridization (FISH), as prognostic parameters in 50 Iranian women, aged 35 to 64 years, with sporadic invasive ductal breast carcinoma. Chromosome 1 and 8 copy numbers were evaluated in relation to established clinicopathological parameters, the immunohistochemical markers ER, PR, P53 and cathepsin D, DNA index by flow cytometry, age and survival status of the patients. FISH using centromeric probes for chromosomes 1 and 8 was applied to interphase cell suspensions prepared from archived, Carnoyfixed tumor cells and selected paraffin-embedded tumor sections. Aneusomy for chromosomes 1 and 8 was present in all 50 patients to different levels. The total abnormality rate for chromosome 1 was 33.92 percent (4.24 percent monosomy and 29.68 percent polysomy), whereas for chromosome 8 this rate was 28.30 percent (6.48 percent monosomy and 21.82 percent polysomy). Statistically significant association (p<0.05) was demonstrated between monosomy 1 and patients’ age below 50 years, and between monosomy 1 and poor survival, respectively. Disomy 8 was significantly associated with P53 expression. A borderline significant correlation was demonstrated between polysomy 8 and diploid DNA content, as well as between disomy 1 and disease-free status of the patients. Chromosome 1 and 8 copy numbers may be considered as useful prognostic markers in invasive ductal carcinoma of the breast.     

Modelling and multivariable control in anaesthesia using neural-fuzzy paradigms. Part I. Classification of depth of anaesthesia and development of a patient model

OBJECTIVE: The first part of this research relates to two strands: classification of depth of anaesthesia (DOA) and the modelling of patient's vital signs. METHODS AND MATERIAL: First, a fuzzy relational classifier was developed to classify a set of wavelet-extracted features from the auditory evoked potential (AEP) into different levels of DOA. Second, a hybrid patient model using Takagi-Sugeno Kang fuzzy models was developed. This model relates the heart rate, the systolic arterial pressure and the AEP features with the effect concentrations of the anaesthetic drug propofol and the analgesic drug remifentanil. The surgical stimulus effect was incorporated into the patient model using Mamdani fuzzy models. RESULTS: The result of this study is a comprehensive patient model which predicts the effects of the above two drugs on DOA while monitoring several vital patient's signs. CONCLUSION: This model will form the basis for the development of a multivariable closed-loop control algorithm which administers "optimally" the above two drugs simultaneously in the operating theatre during surgery.     

Low Level Laser Therapy--a conservative approach to the burn scar?

Burn scars are known to be difficult to treat because of their tendency to worsen with hypertrophy and contracture. Various experimental and clinical efforts have been made to alleviate their effects but the problem has not been solved. Since patients keep asking for Low Level Laser Therapy (LLLT) and believe in its effectiveness on burn scars, and since former studies show contradictory results of the influence of LLLT on wound healing, this prospective study was designed to objectify the effects of LLLT on burn scars. Nineteen patients with 19 burn scars were treated with a 400 mW 670 nm Softlaser twice a week over 8 weeks. In each patient a control area was defined, that was not irradiated. Parameters assessed were the Vancouver Scar Scale (VSS) for macroscopic evaluation and the Visual Analogue Scale (VAS) for pruritus and pain. Photographical and clinical assessments were recorded in all the patients. Seventeen out of 19 scars exhibited an improvement after treatment. The average rating on the VSS decreased from 7.10+/-2.13 to 4.68+/-2.05 points in the treated areas, whereas the VSS in the control areas decreased from 6.10+/-2.86 to 5.88+/-2.72. A correlation between scar duration and improvement through LLLT could be found. No negative effects of LLLT were reported. The present study shows that the 400 mW 670 nm softlaser has a positive, yet sometimes limited effect on burn scars concerning macroscopic appearance, pruritus, and pain.     

Successful percutaneous coil occlusion of a large pulmonary arteriovenous malformation

Pulmonary arteriovenous malformation is one of the rarest congenital anomalies of cardiovascular system. We present a case of 30-year-old female with a large pulmonary arteriovenous malformation (PAVM) arising from the right lower pulmonary artery and draining to the left atrium. She underwent successful embolization using three detachable Cook coils.