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Aeromonas veronii is an important aquatic zoonotic pathogen in humans and animals. In recent years, extracellular proteins from bacteria have been found to be the major pathogenic factors for aquatic animals. The aim of this study was to systematically analyze the extracellular proteins of nine sources of A. veronii and the effects of hisJ on virulence. We screened only the common proteins from nine different sources of A. veronii by liquid chromatography-tandem mass spectrometry and identified the gene hisJ. We then constructed ΔhisJ (deleted) and C-hisJ (complemented) variants of A. veronii TH0426 to assess the biological function of hisJ. While the ΔhisJ strain did not show altered growth (P > 0.05), we observed that it had reduced colony formation and biofilm formation and reduced adhesion to and invasion of epithelioma papulosum cyprini cells by 2.0-, 1.9-, and 10.8-fold, respectively. Additionally, infection experiments on zebrafish and mouse infection experiments showed that the virulence of the ΔhisJ strain was decreased by 865-fold (P < 0.001) compared with the wild-type strain; virulence of the complemented C-hisJ strain was reduced only 2.8-fold. Furthermore, in the context of hisJ deletion, flagella of A. veronii TH0426 were easily detached and the expression of virulence genes was downregulated. A persistence test (of bacterial colonies in crucian carp) showed that the number of bacteria in the immune organs of the ΔhisJ-infected group was lower than that in the wild-type-infected group. Overall, these results show that hisJ affects flagellar shedding, virulence, biofilm formation, adhesion, and invasion of A. veronii TH0426, and that hisJ is closely associated with virulence and plays a crucial role in its pathogenicity of A. veronii TH0426.

Antimicrobial peptides (AMPs) have a unique action mechanism that can help to solve global problems in antibiotic resistance. However, their low therapeutic index and poor stability seriously hamper their development as therapeutic agents. In order to overcome these problems, we designed peptides based on the sequence template XXRXXRRzzRRXXRXX-NH2, where X represents a hydrophobic amino acid like Phe (F), Ile (I), and Leu (L), while zz represents Gly&ndash, Gly (GG) or d-Pro&ndash, Gly (pG). Showing effective antimicrobial activity against Gram-negative bacteria and low toxicity, designed peptides had a tendency to form an &alpha, helical structure in membrane-mimetic environments. Among them, peptide LRpG (X: L, zz: pG) showed the highest geometric mean average treatment index (GMTI = 73.1), better salt, temperature and pH stability, and an additive effect with conventional antibiotics. Peptide LRpG played the role of anti-Gram-negative bacteria through destroying the cell membrane. In addition, peptide LRpG also exhibited an anti-inflammatory activity by effectively neutralizing endotoxin. Briefly, peptide LRpG has the potential to serve as a therapeutic agent to reduce antibiotic resistance owing to its high therapeutic index and great stability.

Peer-marked assessment of professional behaviour among medical students has currently been established in most of the developed world. It is one of the standard components of overall summative assessment systems in undergraduate medical education. However, in many places globally, it has not been introduced in final examinations. This paper reviews the recent local studies on professional behaviour in some medical schools of Pakistan and analyses the need of an assessment process. It also examines various studies done throughout the world validating the peer assessment method. Developing on the findings of the local studies and the authentic evidence showing effectiveness of the system internationally, we are proposing a model of peer -marked assessment among medical students in Pakistan. An instrument already found reliable and valid has been adapted in this proposal while at the same time considering local factors in its implementation.

The oxygen-methane diffusion flame taking place in a gas turbine reactor was investigated experimentally with emphasis on flame stability. The oxidizer is a mixture of O2 and CO2 and the oxy-combustion process was studied at different equivalence ratios ranging from Φ = 0.5 to 1.0 and different O2/CO2 mixture composition (100/0, 80/20, 60/40, 50/50, 40/60, 30/70 and 25/75). The flame blowout condition was achieved through the reduction of oxygen percentage in the oxidizer mixture. Measurements were obtained for the flue gas temperature and concentration as well as flame visualization. It was found that the flame is very stable at the equivalence ratio of 0.65. At this ratio, the flame blows out at an O2/CO2 blending ratio of 22/78 for the case of fuel flow rate of 6 L/min and at a blending ratio of 21/79 for the case of fuel flow rate of 9 L/min. Attempts for operating the burner with less than 21% O2 were unsuccessful at all ranges of the operating parameters and resulted in unstable operation and blowout. Moreover, it was observed that the stabilization behavior did not change significantly with the variation of the fuel volume flow rate. It was also found that both flame and flue gas temperatures are reduced with the increase of the equivalence ratio.

Wet grinding process is an interesting means of producing fine and nano particles. The particle sizing plays an important role in interpretation, control and optimization of various aspects of the wet grinding process. There is a lack of knowledge in understanding different aspects of particle sizing during a wet grinding process. The particle sizing in a wet grinding process is typical in the sense: (i) The dispersions in a wet grinding process, often, involve additives and (or) impurities. It is less known how impurities and additives influence the particle size of the dispersions in the wet grinding process. (ii) In a wet grinding process, dispersions of different concentrations may be used. It is less known how dispersions of different concentration may influence the particle sizing in a wet grinding process. (iii) In a wet grinding process, the change in average particle size of the product is rapid due to relatively fast breakage of the particles. (iv) The degree of poly dispersity in product changes with grinding time. (v) The nature of interaction between particles is non-colloidal before grinding process; this interaction becomes colloidal after a certain grinding time. Similarly, there is a lack of knowledge to understand how quality of final ground product is influenced in a wet grinding process. This study investigates the different aspects of particle sizing and product quality of aqueous dispersions of CaCO3 in a wet grinding process carried out in a stirred media mill. Acoustic attenuation spectroscopy that is known for measuring particle size of dispersions on line, under real process conditions and without diluting the sample has been employed in the study in addition to the technique of dynamic light scattering. The study brings out the conditions in which the effects of impurities and additives etc. on particle size of the dispersions may be determined using acoustic attenuation spectroscopy. Furthermore, the study compares and analyze the particle sizing results obtained though acoustic attenuation spectroscopy and dynamic light scattering. The causes of differences in the results of two techniques have been investigated. We report presence of multiple scattering at high concentration of the dispersions during wet grinding process that result in misleading results of the particles sizes. Quality is an intangible concept. In order to understand how different operating parameters influence product quality, we propose a method based upon the definition of quality as defined in ISO 9000:2005. The method takes into consideration the important operating parameters of wet grinding process (such as the operating condition of the mill, the measurement of particle size and the material) and important product characteristics ( such as average particle size, range of width of particle size distribution, stability of dispersion, degree of impurities, specific energy input and physical appearance). We bring out how a relationship between operating parameters and products of different grades may be established in a wet grinding process.

In our clinical set up transbonchial needle aspiration of lymph node and parenchymal lesions is an underutilized technique. This study was done to highlight the usefulness of this technique in the pulmonologists armamentarium.Thirty procedures were performed on patients with intrathoracic lymphadenopathy or parenchymal lung lesions in this study from October, 2006 to April, 2007. Patients with an easily accessible peripheral lymph node, bleeding diathesis and an already confirmed diagnosis were excluded from the study as were patients with a well visualized biopsiable endobronchial lesion.Nineteen patients (63.3%) on whom transbonchial needle aspirations were performed had intrathoracic lymphadenopathy while 11 (36.6%) had parenchymal lesions without endobronchial lesions which could be biopsied. Adequate samples were obtained in 23 patients (76.6%) chronic granulomatous inflammations which was diagnosed as tuberculosis in corroboration with other clinical and laboratory evidence was seen in 3 cases (10%). Carcinoma was diagnosed in 6 cases (20%). Thirteen cases (43%) were reported as normal and inadequate samples were obtained in 7 cases (23%).Transbronchial Needle Aspiration (TBNA) is an effective method of obtaining cytological material from intrathoracic lymph nodes and parenchymal lesions and can provide a safe alternative to invasive mediastinotomy/mediastinoscopy and open lung biopsy.

To determine the frequency of chronic obstructive pulmonary disease (COPD) as a sequel of treated pulmonary tuberculosis.A case series.Department of Pulmonology, Military Hospital, Rawalpindi, from April to November 2007.Forty seven adults, previously treated for pulmonary tuberculosis and presenting subsequently with chronic exertional dyspnoea for which no other alternate cause was found were included. Those having a probability of re-activated TB, having history of current or previous smoking or occupational exposure, asthmatics and cases of interstitial lung disease and ischemic heart disease were excluded. Pre- and post-dilator FVC, FEV1 and FEV1/FVC were recorded in each case through simple spirometry on Spirolab-II-MIR S/N 507213. Stage and pattern of COPD was recorded.There were 76.5% (n=36) males. Mean age was 56.4 and 44.2 years in males and females respectively. Twenty six (55.3%) were found to have an obstructive ventilatory defect of different degrees: severe/stage III in 69.2% (n=18), moderate/stage II in 23.0 % (n=6) and mild/stage I in 5.9% (n=2). Fourteen (29.7%) were found to have a restrictive pattern and 7 (14.8%) revealed a mixed obstructive and restrictive pattern.Chronic obstructive pulmonary disease can occur as one of the chronic complications of pulmonary tuberculosis and the obstructive ventilatory defect appears more common among various pulmonary function derangements.