Biologie moléculaire : accès libre

Ultrasonic technologies pervade the medical field as a long established imaging modality in clinical diagnostics and, with the emergence of targeted high-intensity focused ultrasound, as a means of thermally ablating tumors. Ultrasound (US) causes multiple thermal and non-thermal effects, such as mechanical and chemical stresses, that can result in damage to the cellular membrane and nucleus, leading to transient membrane pores, alterations in gene expression, and cell death, including apoptosis. On the basis of its biological effects US has been proposed as a new drug delivery and molecular targeting tool for cancer therapy. However, the molecular mechanisms involved in USinduced cell killing are not yet fully understood. Recently, we have reported that the mechanical effects of US elicit DNA single strand as well as double strand breaking- the most cytotoxic form of DNA damage, which initiates subsequent DNA damage response associated with DNA repair, cell cycle arrest, and cell death. Here in the present study we have focused on one of the most significant biological effects of US, i.e., DNA damage and discussed the underlying mechanisms and a unique cellular response. In addition, we have described the characteristic DNA damage response induced by heat stress, which could have caused by the thermal effects of US. Moreover, the study will enrich the literature relevant to furthering our understanding of US for future applications in cancer therapy.

Objective: We sought to determine the importance of histopathological assessment in patients with chronic diarrhoea who had macroscopically normal colonic endoscopies.

Methods: Of 300 consecutive patients undergoing colonoscopy by one endoscopist during a five year period, biopsies were taken in 200 cases of unexplained diarrhoea of at least 6 weeks and their colorectal mucosa appeared macroscopically normal. All biopsies were reviewed by one pathologist.

Results: Of the 200 patients enrolled, 36 (18%) cases were classified as unremarkable histopathological diagnosis and 164 (82%) cases showed histopathological changes: 121 (73.78%) non-specific inflammation, 19 (11.58%) ulcerative colitis, 11 (6.7%) collagenous colitis, 7 (4.26%) lymphocytic colitis, and 6 (3.65%) bilharzial colitis.

Conclusion: We conclude that the role of biopsies in chronic diarrhoea patients with grossly normal colon at endoscopy is high as yielding a histological diagnosis in 21.5% of patients is so benefit to them as they may had modified the therapy received after identification of a specific cause as collagenous colitis, lymphocytic colitis, ulcerative colitis and bilharzial colitis. So Patients should be subject to colonoscopy and biopsy to aid specific diagnoses.

Background: The gene associated with the CAD disease was found out to be the HFE (High Iron Fe) gene and the disease is described with the two, missense mutations of the gene– C282Y and H63D. The focus of this study was to assess the C282Y mutation in CAD patients that results from transition of guanine to adenine (G-A) at the nucleotide position 845, which in turn changes cysteine to tyrosine at the 282^nd position.

Material and methods: C282Y mutation was analyzed by allele specific PCR (AS-PCR) in 100 samples which includes 96 males and 4 females. Data was collected from each patient. The blood from each patient was collected and analyzed for their cholesterol level, diabetes, RBS (Random blood sugar), LDL (low-density lipoprotein), HDL (high-density lipoproteins), TGL (Triglycerides), smoking, etc.

Results: Out of 100 patients, 12 were found to be C282 and 88 were found to be C282Y. The frequency of C282Y in CAD patients with respect to age was found to be 84 in males. Out of 88 C282Y patients 49 was found to have ≤ 140 mg RBS level and 39 patients was found to have >140 mg RBS level. The frequency of C282Y with respect to cholesterol level was found to be ≤ 200 mg in 82 patients and >200 mg in 6 patients. The frequency of C282Y with respect to HDL was found to be ≤ 40 mg in 79 patients and >40 mg in 9 patients. The frequency of C282Y with respect to LDL was found to be ≤ 100 mg in 70 patients and >100 mg in 18 patients. The frequency of C282Y with respect to TGL was found to be ≤ 150 mg in 45 patients and >150 mg in 43 patients. Out of C282Y patients 4 patients had CHD, 13 were hypertensive, 21 were diabetic, 55 were smokers and 40 were alcoholic.

Conclusion: There association between the C282Y mutation in the haemochromatosis gene and prevalence of CAD was not evident. Besides this mutation is not a threat for advanced disease or depressed ejection fraction in CAD.

Ex vitro propagation of micropropagated sugarcane plantlets of three selected sugarcane genotypes was carried out with the objective of evaluating their propagation responses to the interaction effects of BAP and IBA. Accordingly, six levels of IBA (0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 mg L^-1) and eight levels of BAP (0.0, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 and 2.25 mg L^-1) with three sugarcane genotypes, each replicated three times were tested. The treatments were arranged in a factorial completely randomized design. Data on the number of tillers per shoot, average shoot length (cm) and number of active leaves per shoot were collected twice every 30th day after 30 days of treatment application. Analysis of variance revealed that the interaction effects of BAP, IBA and the sugarcane genotypes was very highly significant (P<0.0001) on the number of tillers per shoot, average shoot length and number of active leaves per shoot. The optimum number of tillers per shoot (5.67), average shoot length (40.77 cm) and number of active leaves per shoot (6.97) were obtained at 0.1 mg/l IBA+0.75 mg/l BAP in C132-81. In C86-56, the optimum number of tillers per shoot (4.50) was obtained at 0.1 mg/l IBA+1.5 mg/l BAP while the maximum average shoot length (48.33 cm) and maximum number of active leaves per shoot (7.67) were obtained at 0.2 mg/l IBA+0.75 mg/l BAP. In SP70-1284, the optimum number of tillers per shoot (6.43) was obtained at 0.3 mg/l+1 mg/l BAP with 16.05 cm average shoot length and 4.87 active leaves per shoot. Thus, it can be deduced that production of an average of 5.5 plantlets per shoot within a month can be possible.

Background: Since hepatitis B virus (HBV) and human immunodeficiency virus (HIV) have the same modes of transmission, it is usual for them to infect the same host. This study was conducted at Bashair University Hospital during the period from April to July 2013, to detect HBV among HIV-infected individuals using polymerase chain reaction (PCR).

Methodology: A total of 87 subjects (n=87) were included in this observational, descriptive, case-study. The subjects were confirmed as HIV-positive by an ELISA assay, from ages ranged from 16 to 60 years, and from both sexes. From the study participants, serum samples were collected and tested for HBsAg by a capture ELISA assay and for HBV DNA by PCR.

Results: Out of the 87 people who took part in the study, 13 (14.9%) were positive for HBV DNA, while 14 (16.1%) were positive for HBsAg. Six people (6.9%) tested positive for both HBV DNA and HBsAg and 7 people (8.0%) were found to have occult hepatitis B infection (OBI) (i.e., positive for HBV DNA, negative for HBsAg).

Conclusion: From the above findings we concluded that, there is a high percentage of HBV/HIV coinfection in the Sudan. Also, there is an increasing percentage of OBI in HIV patients. Hence, we recommend the screening of HIVpositive subjects for HBV markers and the use of HBV DNA as a marker of OBI in the same population.