Stable azole drug resistance associated with a substrain of Candida albicans from an HIV-infected patient

Oral candidiasis is one of the earliest and most frequent complications of a failing immune system in HIV-infected individuals. For several years, oral candidiasis has been treated effectively with azole drugs, the one most frequently used is fluconazole. Unfortunately, extensive use of the drug for treatment and prophylaxis has led to treatment failure in an increasing number of patients. In most of these cases, strains of C. albicans isolated from the infection are less susceptible to fluconazole. The development of azole resistance in strains of C. albicans has been studied biochemically and more recently with molecular techniques. One excellent example of the development of azole resistance in C. albicans has been documented in a series of 17 C. albicans isolates from a single patient over a 2-year period. During this time, the patient experienced 14 episodes of oral candidiasis and was treated with increasing doses of fluconazole. Molecular and biochemical analyses confirms that the isolates are the same strain of C. albicans and that the resistance in these isolates is stable over 600 generations, suggesting that the changes in this strain are genetic in nature. In addition, the development of resistance is correlated with the identification of a substrain or variant of the original strain, as identified by restriction fragment length polymorphism (RFLP) analysis with the moderately repetitive probe, Ca3. The analysis of this series of isolates demonstrates that azole drug resistance is associated with several small genetic changes, each of which contributes to the overall resistance of the strain. Clearly, continual use of azole drugs by a patient can select for genetic changes that render oral candidiasis refractory to treatment.     

Photodynamic therapy of viral contaminants with potential for blood banking applications

A photodynamic method has been evaluated as a means of eradicating viral contaminants with the potential for rendering blood safe for transfusion. Herpes simplex virus type 1 (HSV-1) was tested under flowing conditions in culture media or in blood supplemented with the virus. Hematoporphyrin derivative was used as the sensitizer and was photoactivated with visible light at 630 nm and 5 J/cm2. HSV-1 in suspension both in culture medium as well as in blood was shown to be killed. The human immunodeficiency virus was also found to be photoinactivated in flowing cell culture medium and, thus, potentially may be inactivated in blood. These findings extend our previous studies which demonstrated that enveloped viruses can be photoinactivated with hematoporphyrin derivative in a static fluid system. Analysis of blood cell number, red cell lysis, plasma proteins, and other standard hematological tests showed no significant change. The possibility that transfusion-associated acquired immunodeficiency syndrome (AIDS) may result from a blood unit infected with human immunodeficiency virus that tested negative makes it imperative that a safe and effective means of viral killing be developed. The system reported here offers promise as an effective approach to this problem.     

A novel system for providing compatible blood to patients during surgery: "self-service" electronic blood banking by nursing staff

BACKGROUND: A good blood bank must be able to provide compatible blood units promptly to operating room patients with minimal wastage. A "self- service" by nursing staff blood banking system that is safe, efficient, and well-accepted has been developed. STUDY DESIGN AND METHODS: Specific blood units are no longer assigned to surgical patients who have a negative pretransfusion antibody screen, irrespective of the type of surgery. A computer-generated list of the serial numbers of all group-identical blood units currently in the blood bank inventory is provided for each patient. The units themselves are not labeled with a patient's name. The group O list will be provided for group O patients, the group A list for group A patients, and so forth. Should the patient require transfusion during surgery, the operating room nurses go to the refrigerator, remove any group-identical unit, and check the serial number of the unit against the serial numbers on the patient's list. If the serial number is on that list, the blood bank will accept responsibility for compatibility. The system was implemented in 1995. RESULTS: Since implementation, a total of 2154 patients have undergone operations at this hospital. Thirty-two patients received more than 10 units of red cells each. There were no transfusion errors. The crossmatch-to-transfusion ratio was reduced from 1.67 to 1.12. Turnaround time for supplying additional or urgent units to patients in operating room was shortened from 33 to 2.5 minutes. There was no incidence of a blood unit's serial number not being on the list. Work by nurses and technical staff was reduced by nearly 50 percent. CONCLUSION: The "self-service" (by nursing staff) blood banking system described is safe and efficient. It saves staff time and can be easily set up.     

Silencing of hypoxia-inducible tumor suppressor lysyl oxidase gene by promoter methylation activates carbonic anhydrase IX in nasopharyngeal carcinoma

Lysyl oxidase (LOX) is an oxidative enzyme known to initiate the cross-linking of collagens and elastin, and suggested recently as a tumor suppressor for several tumor types including lung, pancreatic and gastric cancers. Previously we showed that LOX is strongly induced upon hypoxia in nasopharyngeal carcinoma (NPC) cell lines CNE2 and HONE1 but only slightly in HK1 and not in C666-1. Here, we further studied the regulatory mechanism and functions of LOX in NPC. LOX is widely expressed in human normal tissues with variations in expression levels. LOX was expressed in most NPC cell lines except for C666-1, while HK1 and FaDu (laryngeal cancer) only expressed low level of LOX. Methylation analysis showed that the LOX promoter was methylated in C666-1 and partially methylated in HK1. After demethylation with 5-aza-2’-deoxycytidine, LOX expression was reactivated along with increased unmethylated alleles. LOX promoter methylation was detected in 42/49 (85.7%) of NPC primary tumors but only 3/16 (18.75%) of nose swab samples from NPC patients. LOX overexpression reduced the clonogenicity and cell growth of NPC cells, and also inhibited the migration and invasion of the NPC cells. Carbonic anhydrase IX (CA9) mRNA level was obviously decreased in HK1 cells after transfection with LOX. The elevation of CA9 protein upon hypoxia was inhibited in LOX-transfected HK1 cells. The protein levels of an apoptosis marker cPARP were increased in LOX-transfected HK1 cells upon hypoxia treatment. Our data showed that silencing or down-regulation of LOX in NPC was due to its promoter methylation and LOX acts as a tumor suppressor in NPC. LOX silencing would facilitate NPC cells to escape from hypoxia-induced apoptosis and maintains a malignant and metastatic phenotype.     

Blood transfusions increase circulating plasma free hemoglobin levels and plasma nitric oxide consumption: a prospective observational pilot study

ABSTRACT: INTRODUCTION: The increasing number of reports on the relation between transfusion of stored red blood cells (RBCs) and adverse patient outcome has sparked an intense debate on the benefits and risks of blood transfusions. Meanwhile, the pathophysiological mechanisms underlying this postulated relation remain unclear. The development of hemolysis during storage might contribute to this mechanism by release of free hemoglobin (fHb), a potent nitric oxide (NO) scavenger, which may impair vasodilation and microcirculatory perfusion after transfusion. The objective of this prospective observational pilot study was to establish whether RBC transfusion results in increased circulating fHb levels and plasma NO consumption. In addition, the relation between increased fHb values and circulating haptoglobin, its natural scavenger, was studied. METHODS: Thirty patients electively received 1 stored packed RBC unit (n = 8) or 2 stored packed RBC units (n = 22). Blood samples were drawn to analyze plasma levels of fHb, haptoglobin, and NO consumption prior to transfusion, and 15, 30, 60 and 120 minutes and 24 hours after transfusion. Differences were compared using Pearson's chi-square test or Fisher's exact test for dichotomous variables, or an independent-sample t test or Mann-Whitney U test for continuous data. Continuous, multiple-timepoint data were analyzed using repeated one-way analysis of variance or the Kruskall-Wallis test. Correlations were analyzed using Spearman or Pearson correlation. RESULTS: Storage duration correlated significantly with fHb concentrations and NO consumption within the storage medium (r = 0.51, P < 0.001 and r = 0.62, P = 0.002). fHb also significantly correlated with NO consumption directly (r = 0.61, P = 0.002). Transfusion of 2 RBC units significantly increased circulating fHb and NO consumption in the recipient (P < 0.001 and P < 0.05, respectively), in contrast to transfusion of 1 stored RBC unit. Storage duration of the blood products did not correlate with changes in fHb and NO consumption in the recipient. In contrast, pre-transfusion recipient plasma haptoglobin levels inversely influenced post-transfusion fHb concentrations. CONCLUSION: These data suggest that RBC transfusion can significantly increase post-transfusion plasma fHb levels and plasma NO consumption in the recipient. This finding may contribute to the potential pathophysiological mechanism underlying the much-discussed adverse relation between blood transfusions and patient outcome. This observation may be of particular importance for patients with substantial transfusion requirements.     

Risk perception among Brazilian individuals with high risk for colorectal cancer and colonoscopy

Background

Risk perception is considered a motivating factor for adopting preventive behaviors. This study aimed to verify the demographic characteristics and cancer family history that are predictors of risk perception and to verify if risk perception is a predictor of colonoscopy adherence.

Methods

Individuals with a family colorectal cancer history as indicated by a proband with cancer were interviewed by telephone. They responded to a questionnaire covering demographic characteristics, colonoscopy history and four questions on risk perception. Tests of multiple linear regression and logistic regression were used to identify associations between dependent and independent variables.

Results

The 117 participants belonged to 62 families and had a mean age of 45.2 years. The majority of these individuals were female (74.4%) and from families who met the Amsterdam Criteria (54.7%). The average risk perception was 47.6%, with a median of 50%. The average population perception of individual risk was 55.4%, with a median of 50%. Variables associated with a higher risk perception were age, gender, religion, school level, income, and death of a family member. The variable predicting colonoscopy was receiving medical information regarding risk (odds ratio OR 8.40).

Conclusions

We found that family cancer history characteristics (number of relatives with cancer, risk classification) are associated with adequate risk perception. Risk perception does not predict colonoscopy in this sample. The only variable that predicted colonoscopy was receiving medical information recommending screening.     

Should endometrial polyps be removed in patients with postmenopausal bleeding?—an assessment of study designs and report of a failed randomised controlled trial (ISRCTN73825127)

We describe the design of a randomised controlled trial to evaluate the efficacy of endometrial polyp removal in women with postmenopausal bleeding. We designed a trial in which patients with postmenopausal bleeding and endometrial thickness >4 mm undergo hysteroscopy. If during hysteroscopy an endometrial polyp was diagnosed, patients were asked to participate in this trial and after informed consent allocated to immediate removal of the polyp or expectant management. This trial suffered from lack of recruitment related both to doctors seeking for informed consent as well as to patients' unwillingness to participate in this trial. However, a randomised controlled trial on this subject is still necessary to evaluate the efficacy of uterine cavity evaluation in the diagnostic work-up of women with postmenopausal bleeding, focussing on benign pathology. Therefore, we propose an alternative design, which might be more feasible.