ABSTRACT

Background and aims. Paracetamol (AAP) is the most common drug used as an analgesic and antipyretic. It can induce oxidative stress which can cause cell death. The aim of this study was to assess the effect of paracetamol on the submandibular salivary gland (SMG)of Albino rats. Methods. Twelve adult male albino rats were used, divided into control and experimental groups. The experimental group received orally 350mg/kg (paracetamol) once daily for 4 weeks and control groups received 2ml physiologic saline, and methyl cellos once orally daily during whole experimental period. Results. Histological examination of the experimental group showed that acinar cells demonstrated pyknotic and deeply stained nuclei with many cytoplasmic vacuolations. The ducts showed some signs of degeneration with loss of their normal cellular outlines. However, showed degenerative changes. Apoptotic changes expressed by anti-active caspase 3 were more obvious in acinar cells than in ductal cells. Statistical results showed a significant (P<0.05) statistical difference between the two groups. Conclusion. Long use of paracetamol leads to a degenerative and apoptotic change in acinar and ductal cells (SMG).

Penicillin is a drug commonly used as an antibiotic agent. It is among the earliest discoveries made. It is a natural compound released to the environment by fungi (Penicillium notatum). Penicillin was discovered by Alexander Fleming in 1928 (Davies and Davies, 2010).

 Penicillin is found in various diverse forms and mostly obtained from Penicillium. The basic structures of penicillin and its derivatives are generally very similar and closely related. Penicillin and its derivatives generally have the similar basic ring β-lactam structure, which is formed by valine and cysteine amino acids through an intermediate tripeptide. The tripeptide third amino acid is substituted by an acyl group and this acyl group has specific functions and properties on penicillin and its derivatives

Penicillin G is one of the most used penicillin against microbes and it is not stable in gastric hydrochloric acid (Barker CI,2017). Oral intake of penicillin G is destroyed by stomach gastric acid before its absorbed in the blood and before it acts at the microbial infection site. Hence its route of administration is intra-muscular injection

penicillin is the most effective drug on Gram-positive bacteria. It is also known not to be effective on Gram-negative bacteria and fungi., penicillin act on the bacterial cell wall by breaking it down. Hence this leads to the death of the bacteria.Penicillin is a drug commonly used as an antibiotic agent. It is among the earliest discoveries made. It is a natural compound released to the environment by fungi (Penicillium notatum). Penicillin was discovered by Alexander Fleming in 1928 (Davies and Davies, 2010).

 Penicillin is found in various diverse forms and mostly obtained from Penicillium. The basic structures of penicillin and its derivatives are generally very similar and closely related. Penicillin and its derivatives generally have the similar basic ring β-lactam structure, which is formed by valine and cysteine amino acids through an intermediate tripeptide. The tripeptide third amino acid is substituted by an acyl group and this acyl group has specific functions and properties on penicillin and its derivatives

Penicillin G is one of the most used penicillin against microbes and it is not stable in gastric hydrochloric acid (Barker CI,2017). Oral intake of penicillin G is destroyed by stomach gastric acid before its absorbed in the blood and before it acts at the microbial infection site. Hence its route of administration is intra-muscular injection

penicillin is the most effective drug on Gram-positive bacteria. It is also known not to be effective on Gram-negative bacteria and fungi., penicillin act on the bacterial cell wall by breaking it down. Hence this leads to the death of the bacteria.

The most common antibiotics prescribed by dentists for dental infections in Gharyan city and neighbour regions

The type VI secretion system (T6SS) is a multi-protein complex that injects bacterial effector proteins into target cells. It is composed of a cell membrane complex anchored to a contractile bacteriophage tail-like apparatus consisting of a sharpened tube that is ejected by the contraction of a sheath against a baseplate. We present structural and biochemical studies on TssA subunits from two different T6SSs that reveal radically different quaternary structures in comparison to the dodecameric E. coli TssA that arise from differences in their C-terminal sequences. Despite this, the different TssAs retain equivalent interactions with other components of the complex and position their highly conserved N-terminal ImpA_N domain at the same radius from the centre of the sheath as a result of their distinct domain architectures, which includes additional spacer domains and highly mobile interdomain linkers. Together, these variations allow these distinct TssAs to perform a similar function in the complex.

TssA is a core component of the type VI secretion system, and phylogenetic analysis of TssA subunits from different species has suggested that these proteins fall into three distinct clades. Whilst representatives of two clades, TssA1 and TssA2, have been the subjects of investigation, no members of the third clade (TssA3) have been studied. Constructs of TssA from Burkholderia cenocepacia, a representative of clade 3, were expressed, purified and subjected to crystallization trials. Data were collected from crystals of constructs of the N-terminal and C-terminal domains. Analysis of the data from the crystals of these constructs and preliminary structure determination indicates that the C-terminal domain forms an assembly of 32 subunits in D16 symmetry, whereas the N-terminal domain is not involved in subunit assocation.

The effect of the duration of cigarette smoking on liver function

Study was to identify DNA repair gene (HexB) from S. pneumoniae in

the public databases, and using available programs to analyse and

compare the sequences between different strains. In this study, we

observe interesting polymorphisms in the sequences of HexB enzyme.

The amino acid sequences of HexB were identified from 16 strains

and differ by 1% from R6 HexB. At nucleotide level of HexB the

region 801-1000 may represent mosaic gene, as it differ by 10%. This

result suggests that the HexB proteins are highly conserved which

may indicates that these proteins perform a common essential role in repair process

ABSTRACT Computers are increasingly present in operating rooms, dental examination rooms, Intensive care unit and wards for bedside documentation. Recently they have been suspected as possible reservoirs for mi- croorganisms and provide opportunities for the transfer of pathogens to patients and ultimately leading to cause no- socomial infections. A number of studies indicate that healthcare workers may contaminate their hands by touching contaminated environmental surfaces and that contaminated hands participate to transmit the pathogen to patients. Pathogens may also be transferred directly from contaminated environmental surfaces to susceptible host in health care setting. The purpose of this study was to examine the microbial contamination of computer keyboards with potentially patho- genic microorganisms in clinical area and to postulate that computer keyboards are significant reservoirs of nosocomial pathogen. Sterile swab samples were received from 20 computer keyboards randomly from fifth year medical and fourth year dental students at AlJabal AlGharbi University and Gharian teaching hospital during a period of one month. These computer keyboards were used in clinical areas (in hospital sitting or dental practice unit). Microbes obtained from the specimens were identified to the species level on the basis of colony morphology, gram stain, biochemical test and API. Organisms isolated from the keyboards included Micrococci, Bacillus spp, Coagulase-negative staphylococci and less common isolates were Staph. aureus, Bacteroides, Flavobacterium spp, Listeria grayi, and Pseudomonas spp. Some keyboards were also contaminated with anaerobic environmental organisms. The findings of this study add evidence to support the hypothesis that these particular surfaces may serve as reservoirs of nosocomial pathogens and vector for cross transmission of infection in universities and hospital setting.

. Comparative analyses of the sequencesof DNA repair gene (Hex A) between different strains of Streptococcus pneumoniae