Methicillin-resistant Staphylococcus aureus colonization among healthcare workers in Oman.

Introduction: Methicillin-Resistant Staphylococcus aureus (MRSA) is a S. aureus strain characterized by resistance to cloxacillin. Healthcare workers (HCWs), are recognized for their heightened risk for MRSA acquisition and possibly for MRSA nosocomial transmission.

Overexpression of EGFR protein in Bruneian lung cancer patients.

Background: Lung cancer is the leading cause of cancer death in Brunei Darussalam, accounting for almost 20% of the total. The epidermal growth factor receptor (EGFR) is a member of the erbB family of tyrosine kinase receptor proteins, which includes c-erbb2(HER2/neu), erb-B3, and erb-B4. EGFR overexpression is found in a third of all epithelial cancers, often associated with a poor prognosis.

The prevalence of dengue virus in Brunei Darussalam during January-November 2010.

The aim of this study was to retrospectively determine the prevalence of dengue virus from April 2010 to November 2010 in Brunei Darussalam. A total of 250 serum samples from dengue diagnosed patients were examined. All serum samples were tested for dengue IgM and IgG antibodies and dengue NS1 antigen using the PanBio dengue ELISA commercial kit.

Lack of increased P15INK4B protein expression in basal cell carcinomas.

Background: The basal cell carcinoma (BCC) is the most common non-melanoma skin cancer (NMSK). BCC might develop because of the faulty cell cycle arrest. P15INK4b is a tumor suppressor gene, involved in cell cycle arrest and inactivated in most human cancers.

Analysis of APC allelic imbalance/loss of heterozygosity and APC protein expression in cutaneous squamous cell carcinomas.

Background: The adenomatous polyposis coli (APC) gene is a tumor suppressor gene which is mutated in the hereditary disease, familial adenomatous polyposis (FAP). Somatic mutations of the APC gene have also been identified in the majority of sporadic colorectal carcinomas, and mutation of the APC gene appears to be an early step in the initiation of colon cancer. Loss of heterozygosity (LOH) of APC has been described in a variety of other cancer types, including renal cell carcinoma, gastric cancer, non-small cell lung cancer, endometrial cancer and oral squamous cell carcinomas (SCC).

Investigation of the effect of UV irradiation on DNA damage: comparison between skin cancer patients and normal volunteers.

Background: Susceptibility to environmental carcinogenesis is the consequence of a complex interplay between intrinsic hereditary factors and actual exposure to potential carcinogenic agents. Exposure to sunlight is the primary etiological agent for basal cell carcinoma (BCC).

Aim: The aim of this study was to determine the effects of different ultraviolet (UV) doses on DNA damage in epidermal keratinocytes in vivo and to elucidate if patients with BCC are more susceptible to UV-induced DNA damage in comparison with normal healthy volunteers in response to solar simulator radiation (SSR).

Methylthioadenosine phosphorylase expression in cutaneous squamous cell carcinoma.

The methylthioadenosine phosphorylase (MTAP) gene is a tumour suppressor gene, located on chromosome 9p21, 100 kb telomeric of the p15 and p16 genes, which are often deleted in tumor cells. The role of MTAP protein expression in the genesis of cutaneous squamous cell carcinoma (SCC) is currently not known. In a previous study we have shown the frequent occurrence of allelic imbalance/loss of heterozygosity (AI/LOH) in cutaneous SCCs using AI/LOH markers flanking the p15, p16, and MTAP genes and demonstrated reduction in p15 and p16 protein expression in comparison to normal human skin.

hTR RNA component as a marker of cellular proliferation in oral lichen planus.

Previously, we have shown that the telomerase RNA component hTR is highly expressed in the epithelium of non-dysplastic Oral Lichen Planus (OLP) lesions (11). We concluded that it is possible that this high expression might be related to the increased cellular proliferation seen in OLP rather than being an indicator of potential malignant transformation. In the present study, and in order to confirm our finding in the previous study that hTR might be a marker for cellular proliferation in OLP, we analysed OLP biopsies known to be positive for RNA component of Telomerase (hTR) for the expression of Ki-67 as a marker for cellular proliferation.

Immunohistochemical determination of the P15 protein expression in cutaneous squamous cell carcinoma.

The tumor suppressor gene p15(INK4b) is a cyclin-dependent kinase inhibitor, in which its inactivation has been determined in primary tumors and in several tumor-derived cell lines. The precise role of p15(INK4b) protein expression in cutaneous squamous cell carcinoma (SCC) is currently not known. In a previous study, we have shown the frequent occurrence of allelic imbalance/loss of heterozygosity in cutaneous SCC using two microsatellite markers flanking the p15(INK4b) gene.

Analysis of FHIT allelic imbalance/loss of heterozygosity and FHIT expression in cutaneous squamous cell carcinomas.

Aberrations of the tumor suppressor gene, the fragile histidine triad gene (FHIT), have been reported in a wide variety of human cancers including cervical carcinoma, oral squamous cell carcinoma (SCC) and oesophageal SCC. This study aimed to examine the integrity of the FHIT gene in cutaneous SCC. Allelic imbalance/loss of heterozygosity (AI/LOH) was examined in 21 histologically confirmed cutaneous SCC at two microsatellite markers, D3S1300 and D3S4103, both of which are located within intron 5 of the FHIT gene.

Molecular genetic analysis of the BRCA2 tumor suppressor gene region in cutaneous squamous cell carcinomas.

Background: Germ line mutations of the BRCA2 tumor suppressor gene with subsequent loss of the remaining wild-type BRCA2 allele have been identified in up to 35% of familial breast cancer cases. A high frequency of allelic loss at the BRCA2 gene locus has also been reported in a variety of sporadic epithelial tumors including oesophageal squamous cell carcinomas (SCC), and sporadic head and neck SCC.

Aim: The present study aimed to examine the integrity of the BRCA2 gene in cutaneous SCC.

Enhanced detection of microsatellite instability and mismatch repair gene expression in cutaneous squamous cell carcinomas.

Background: Microsatellite instability (MSI) is a phenotypic characteristic of tumors with biallelic inactivation of mismatch repair genes, such as MSH2 or MLH1, and contributes to malignant transformation.

Aims: The aim of this study was to examine the prevalence of MSI in cutaneous squamous cell carcinoma (SCC) using a PCR and fluorescent-based detection system. These methods of analysis offer several advantages over the use of silver staining and autoradiographic techniques.

Analysis of p16 expression and allelic imbalance / loss of heterozygosity of 9p21 in cutaneous squamous cell carcinomas.

Deletions of the short arm of chromosome 9 have been reported in different types of malignancies. This chromosomal region contains a number of known tumour suppressor genes, including the p16INK4A (CDKN2A), p15INK4B and MTAP tumour suppressor genes located at 9p21. In this study twenty-two paraffin embedded invasive cutaneous SCC were examined for allelic imbalance/ loss of heterozygosity (AI/LOH) of the 9p region (in particular 9p21), and for p16 protein expression.

The effect of infection of hatched blastocyst bovine embryos with border disease and bovine viral diarrhea viruses.

The effect of infection with teratogenic viruses at early stages of pregnancy is not fully understood. This study aimed to look at the effect of infection with teratogenic viruses such as bovine viral diarrhea virus (BVDV) and border disease virus (BDV), on early stage embryos at the hatched blastocyst stage. BVDV and BDV are known to cross the placenta of infected mothers and lead to congenital defects and death of developing fetuses.

RNA in situ hybridization for the detection of Feline Immunodeficiency Virus in infected cells.

In the present study, we have applied a novel approach to generate specific digoxigenin- and biotin-labeled RNA probes to detect Feline Immunodeficiency Virus (FIV) gag gene in the FIV-infected feline T-lymphoblastoid cell line (MYA-1). This involved cloning of the FIV gag gene into a PCR Script vector containing both T3 and T7 promoters, followed by amplification of the insert and the two promoter sequences, using specific primer sequences. The FIV RNA probes were more sensitive than FIV DNA probes.

Telomerase: is it the future diagnostic and prognostic tool in human cancer?

A number of methods exist to detect levels of telomerase activity and the presence of telomerase subunits in a variety of tissues. As telomerase activation seems to be an important step in tumorigenesis, accurate detection of the presence and activity of the enzyme and its subunits is vital. The original method of detecting telomerase activity was developed by Kim and coworkers in 1994, and was termed the telomeric repeat amplification protocol.

Neuropathology associated with feline immunodeficiency virus infection highlights prominent lymphocyte trafficking through both the blood-brain and blood-choroid plexus barriers.

Feline immunodeficiency virus (FIV) infection in the cat is a well-evaluated model of human immunodeficiency virus (HIV)-1 infection in man with both viruses associated with significant neuropathology. Although studies in both HIV and FIV infections have shown that virus enters the brain in the acute stages of disease, little is known of the mechanisms of viral entry. The dissection of this stage is fundamental to the development of therapies that may prevent or modulate central nervous system (CNS) infection.

In situ hybridization: detecting viral nucleic acid in formalin-fixed, paraffin-embedded tissue samples.

In situ hybridization is a method for detecting specific nucleic acid sequences within individual cells. This technique permits visualization of viral nucleic acid or gene expression in individual cells within their histologic context. In situ hybridization is based on the complementary binding of a labeled nucleic acid probe to complementary sequences in cells or tissue sections, followed by visualization of target sequences within the cells.

Investigation into a possible association between oral lichen planus, the human herpesviruses, and the human papillomaviruses.

Background: Oral lichen planus (OLP) is a chronic relapsing cell-mediated condition of unknown etiology. The purpose of this study was to ascertain if the human herpesviruses (HHVs) or human papillomaviruses (HPVs) act as possible factors or co-factors in the pathogenesis of OLP.

Methods: Thirty-eight histologically confirmed OLP and 20 normal control buccal mucosa tissue samples were analyzed.

Dynamics of viral and proviral loads of feline immunodeficiency virus within the feline central nervous system during the acute phase following intravenous infection.

Animal models of human immunodeficiency virus 1, such as feline immunodeficiency virus (FIV), provide the opportunities to dissect the mechanisms of early interactions of the virus with the central nervous system (CNS). The aims of the present study were to evaluate viral loads within CNS, cerebrospinal fluid (CSF), ocular fluid, and the plasma of cats in the first 23 weeks after intravenous inoculation with FIV(GL8). Proviral loads were also determined within peripheral blood mononuclear cells (PBMCs) and brain tissue.

Comparison of the expression of p53, p21, Bax and the induction of apoptosis between patients with basal cell carcinoma and normal controls in response to ultraviolet irradiation.

Aim: Ultraviolet light (UV) is known to cause DNA damage in the epidermis. The damaged DNA is repaired or deleted by apoptosis to prevent the generation of cancer. It has been suggested that a deficient apoptotic mechanism may predispose individuals to skin cancer.

Telomerase activity detected in oral lichen planus by RNA in situ hybridisation: not a marker for malignant transformation.

Background: Oral lichen planus (OLP) is a chronic inflammatory condition. Clinically, it is characterised by the presence of a white lace-like lesion on the buccal mucosa, tongue, and gingivae, with erosions and ulceration. The World Health Organisation considers OLP to be a premalignant condition.

Loss of Fhit expression as a potential marker of malignant progression in preinvasive squamous cervical cancer.

Objective: In a previous study using the same cases of squamous cervical neoplasia and microinvasive carcinoma (MICA) we found an association between FHIT gene deletion and infection with high-risk HPV (HR HPV). The purpose of this study was to evaluate Fhit protein expression by immunohistochemistry in order to determine whether FHIT gene deletion or infection with HR HPV correlated with aberrant protein expression and grade of lesion.

Methods: A total of 74 archival LLETZ biopsy cases consisting of 23 cervical intraepithelial neoplasia grade 1 (CIN1), 28 CIN3, and 23 MICA cases were selected for Fhit immunostaining.