Changes in the epidemiology of meticillin-resistant Staphylococcus aureus associated with the emergence of EMRSA-16 at a university hospital

This study investigated the molecular epidemiology of meticillin-resistant Staphylococcus aureus (MRSA) in the University Hospital of the Canary Islands (HUC) in order to evaluate epidemiological changes over a six-year period. Clinical and epidemiological data were collected between May 2000 and December 2003, and isolates were subjected to pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), SCCmec typing and spa typing. Since 2000, the rate of MRSA infections has increased at the HUC, coinciding with the emergence and spread of the EMRSA-16 clone (ST36-MRSA-II) and replacement of the Iberian clone (ST247-MRSA-I). Genotypic changes were associated with changes in the epidemiological profile. The mean age and proportion of patients over 60 years old (P=0.01) and the proportion of respiratory infections (P=0.001) increased significantly. Gentamicin and tetracycline susceptibility of MRSA isolates increased (P<0.001) following the emergence of EMRSA-16. Combining PFGE, SCCmec and MLST has been instrumental in understanding these changes and defining the clones circulating in the HUC patient population.

Biocompatibility of Supercritical CO2-Treated Titanium Implants in a Rat Model

Supercritical phase CO2 is a promising method for sterilizing implantable devices and tissue grafts. The goal of this study is to evaluate the biocompatibility of titanium implants sterilized by supercritical phase CO2 in a rat subcutaneous implantation model. At 5 weeks post implantation titanium implants sterilized by supercritical phase CO2 produce a soft tissue reaction that is comparable to other methods of sterilization (steam autoclave, ultraviolet light radiation, ethylene oxide gas, and radio-frequency glow-discharge), as indicated by the thickness and density of the foreign body capsule, although there were some differences on the capillary density. Overall the soft tissue response to the implants was similar among all methods of sterilization, indicating supercritical phase CO2 treatment did not compromise the biocompatibility of the titanium implant.

Osteomalacia after Roux-en-Y gastric bypass

OBJECTIVE

To emphasize the potential for Roux-en-Y gastric bypass treatment of morbid obesity to result in late development of metabolic bone disease and to illustrate the error of treating a low bone mineral density with bisphosphonates in the presence of unrecognized osteomalacia.

METHODS

We conducted a retrospective case review of clinical, laboratory, and radiologic details in a patient who underwent Roux-en-Y gastric bypass as well as a review of the literature relative to metabolic bone disease associated with bariatric surgical procedures.

RESULTS

A 42-year-old woman was diagnosed with high bone turnover osteoporosis and failed to respond to bisphosphonate (alendronate) therapy. Her past medical history included corticosteroid-dependent asthma and a Roux-en-Y gastric bypass surgical procedure for obesity approximately 6 1/2 years before the current assessment. Evaluation revealed vitamin D deficiency in conjunction with pronounced secondary hyperparathyroidism and biochemical evidence of osteomalacia. Aggressive calcium and vitamin D supplementation corrected the vitamin D-deficient state and was accompanied by rapid improvement in clinical symptoms, biochemical variables, and bone mineral density.

CONCLUSION

This case exemplifies two principles: (1) the potential for a Roux-en-Y gastric bypass surgical procedure to lead to the development of metabolic bone disease and (2) the importance of recognizing mineralization defects as a cause for low bone mineral density, before initiation of therapy with bisphosphonates.

The AeAct-4 gene is expressed in the developing flight muscles of female Aedes aegypti

Population reduction of mosquitoes is an effective method for controlling dengue fever and malaria transmission. Recent developments in control techniques include proposals to construct transgenic strains of mosquitoes carrying dominant, conditional-lethal genes under the control of sex- and stage-specific promoters. In order to identify such promoters, subtractive cDNA libraries derived from male and female pupal mRNA of the yellow fever mosquito, Aedes aegypti, were constructed and screened. A cDNA clone, F49, corresponds to a gene expressed specifically in female pupae. Sequence analyses revealed that this gene belongs to the actin gene family, and therefore was designated Aedes Actin-4 (AeAct-4). Transcription analyses demonstrated that this gene is expressed predominantly in the indirect flight muscles and, to a lesser extent, the legs of developing female mosquitoes. The promoter of this gene may be a useful tool for developing conditional lethal strains of mosquitoes.

Activity of some Mexican medicinal plant extracts on carrageenan-induced rat paw edema

The extracts obtained from 14 plants of the Mexican medicinal flora were assessed for anti-inflammatory activity by carrageenan-induced rat paw edema model. The i.p. administration of the extracts at a dose of 400 mg/kg produced a high reduction of edema with 70% of the plant extracts. Oenothera rosea methanol extract, Sphaeralcea angustifolia chloroform extract, Acaciafarnesiana, Larrea tridentata and Rubus coriifolius methanol extracts as well as the aqueous extract of Chamaedora tepejilote were demonstrated to be particularly active against the induced hind-paw edema. Moderate inhibition of edema formation was also demonstrated with the methanol extracts of Astianthus viminalis, Brickellia paniculata, C. tepejilote and Justicia spicigera.

Congenital self-healing reticulohistiocytosis: report of a case and review of the literature

Congenital self-healing reticulohistiocytosis (CSHRH), a rare disorder initially seen at birth or in the newborn period, is characterized by spontaneously involuting skin lesions. We present the case of a 12-d-old female who was born with many red-brownish nodules scattered over her entire body, and which regressed spontaneously.

CONCLUSION

Although there are no clues to differentiate CSHRH from Letterer-Siwe disease, some signs and symptoms might enable us to reach an accurate diagnosis. A long-term follow-up to detect evidence of relapse or progression of the disease would be well advised.

Location and effects of long-term NaCl stress on superoxide dismutase and ascorbate peroxidase isoenzymes of pea (Pisum sativum cv. Puget) chloroplasts

The present work describes the intrachloroplast localization and the changes that took place in the thylakoid and stroma-located superoxide dismutases (SOD, EC 1.15.1.1) and ascorbate peroxidases (APX, EC 1.11.1.11), in response to long-term NaCl stress in Pisum sativum L. cv. Puget plants. Native PAGE using high chloroplast protein concentrations pointed to the presence of the two main Fe-SODs, together with CuZn-SODs, both in thylakoids and in the stroma. Western blot and immunogold labelling using the antibodies against chloroplastic Fe-SOD from Nuphar luteum also confirmed the chloroplastic localization of a Fe-SOD. Thylakoidal Fe-SOD activity was induced by a NaCl concentration as low as 70 mM, while CuZn-SOD was induced at 90 mM, although in severe stress conditions (110 mM) both activities were similar to the levels at 90 mM NaCl. NaCl stress also induced stromatic Fe-SOD and CuZn-SOD activities, although these inductions only started at higher NaCl concentration (90 mM) and were significant at 110 mM NaCl. The increase in activity of both Fe-SODs was matched by an increase in Fe-SOD protein. Chloroplastic APX isoenzymes behaved differently in thylakoids and stroma in response to NaCl. A significant increase of stromal APX occurred at 70 mM, whereas the thylakoidal APX activity was significantly and progressively lost in response to NaCl stress (70-110 mM). A significant increase in the H2O2 content of chloroplasts during stress and a reduction in the ascorbate level at 90 mM NaCl also took place, although the oxidized ascorbate pool at the highest NaCl concentration did not show significant changes. These results suggest that the loss of thylakoidal APX may be an important factor in the increase in chloroplastic H2O2, which also results from the increased thylakoid and stroma-located Fe-SOD and CuZn-SOD activities. This H2O2 may be involved in the induction of stromal APX. The up-regulation of the above enzymes in the described stress conditions would contribute to the adaptation of cv. Puget plants to moderate NaCl stress.

Disseminated varicella infection in adult renal allograft recipients: role of mycophenolate mofetil

Disseminated varicella zoster virus (VZV) infection is a rare complication after renal transplantation in adults. We report 4 cases diagnosed in our transplant patients. One of which was a primary infection (chicken pox) with multivisceral involvement (hepatitis, pneumonitis, myocarditis, and disseminated intravascular coagulation). The other 3 patients VZV-seropositive before transplantation suffered from disseminated zoster. No immunosuppressive drug was significantly associated with a higher risk of disseminated VZV infection. However, from our experience, we believe that mycophenolate mofetil (MMF), plays a part in the clinical presentation of the disease. Early treatment with high doses of acyclovir is fundamental in infection control. It is essential to perform a pretransplantation serological VZV study on all patients.

Cadherin-13, a mediator of calcium-dependent cell-cell adhesion, is silenced by methylation in chronic myeloid leukemia and correlates with pretreatment risk profile and cytogenetic response to interferon alfa

PURPOSE

Cadherin-13 (CDH13) is a newly characterized cadherin molecule responsible for selective cell recognition and adhesion, the expression of which is decreased by methylation in a variety of human cancers, indicating that the CDH13 gene functions as a tumor suppressor gene. Although defective progenitor-stromal adhesion is a well-recognized feature of chronic myeloid leukemia (CML), the role of CDH13 abnormalities has not been evaluated in this disease.

PATIENTS AND METHODS

We examined the methylation status of the CDH13 promoter in 179 chronic phase (CP)-CML patients and in 52 advanced-phase samples and correlated it with mRNA expression using methylation-specific polymerase chain reaction (PCR) and reverse transcriptase PCR.

RESULTS

Aberrant de novo methylation of the CDH13 promoter region was observed in 99 (55%) of 179 of CP-CML patients, and 90 of the patients failed to express CDH13 mRNA (P <.0001). Advanced-stage samples (n = 52) showed concordant methylation results with their corresponding CP tumors, indicating that CDH13 methylation was not acquired during the course of the disease. Nevertheless, absence of CDH13 expression was more frequently observed among Sokal high-risk patients (P =.01) and was also independently associated with a shorter median progression-free survival time (P =.03) and poor cytogenetic response to interferon alfa treatment (P =.0001).

CONCLUSION

Our data indicate that the silencing of CDH13 expression by aberrant promoter methylation occurs at an early stage in CML pathogenesis and probably influences the clinical behavior of the disease.

Patient surface radiation doses at two PET imaging facilities

To develop a practical means of auditing the procedures and to optimize the administered radionuclide activity, patient surface radiation doses following the administration of 18FDG for PET imaging have been measured at breast and gonad locations at two PET facilities. Patient dosimetry was performed using LiF TLD-100 chips placed near the breasts and gonads for 2 h following tracer injection. Standard uptake values from the image-reconstruction algorithms of one PET camera were investigated in regions of interest in tomograms of the myocardium and liver with the aim of validating dosimetry at breasts. Mean doses measured on the patient's skin ranged between 3.3 and 6.1 microGy MBq(-1) at the gonads and between 3.9 and 6.4 microGy MBq(-1) at the breasts, noticeably lower than the calculations reported in the literature. These values show good concordance with the injected activities, although they are not proportional. The proportion of injected activity actually contributing to image production seems to decrease gradually as the injected activity increases. Conversely, for a given injected activity, breast and gonadal doses were found to be lower than the values expected from the numerical calculations reported in the literature, showing increasing discrepancies when the injected activity increased. Doses measured at the right breast were consistently higher than for the left, which is indicative of greater radiotracer absorption by the liver compared to the average absorption in the body.

5' CpG island hypermethylation is associated with transcriptional silencing of the p21(CIP1/WAF1/SDI1) gene and confers poor prognosis in acute lymphoblastic leukemia

The p21 is a downstream effector of p53/p73 and belongs to the CIP/KIP family of cyclin-dependent kinase inhibitors (CDKIs). It is, therefore, a potential tumor suppressor gene and probably plays an important role in tumor development. Moreover, reduced expression of p21 has been reported to have prognostic value in several human malignancies. In contrast with other CDKIs, mutational inactivation of p21 is infrequent, but gene inactivation by an alternative mechanism seems to be the general pathway. In this study, we analyzed the methylation status of the p21 promoter region using semiquantitative polymerase chain reaction in 124 patients with acute lymphoblastic leukemia (ALL). We observed p21 hypermethylation in bone marrow cells from 41% (51 of 124) of ALL patients. Hypermethylation within promoter strongly correlated with decreased p21 messenger RNA expression in tumoral cells. Clinical, molecular, and laboratory features and complete remission rate did not differ significantly between hypermethylated and normally methylated patients. Estimated disease-free survival (DFS) and overall survival at 7 and 9 years, respectively, were 59% and 65% for healthy patients and 6% and 8% for hypermethylated patients (P =.00001 and P =.006). Multivariate analysis of potential prognostic factors demonstrated that p21 methylation status was an independent prognostic factor in predicting DFS (P =.0001). Our results indicate that the p21 gene is subject to methylation regulation at the transcription level in ALL and seems to be an important factor in predicting the clinical outcome of these patients.

EMA: a differentiation antigen related to node metastatic capacity of breast carcinomas

Epithelial membrane antigen (EMA), also known as MUC1, is a mucinous glycoprotein fixed to the luminal domain of the epithelial cell membrane of normal breast ducts. However, in breast cancer cells, it is usually dispersed in the cytoplasm. EMA staining patterns of 330 breast carcinomas were examined, and three groups formed: lineal (16%), cytoplasmic (75%), and negative (9%). Although these patterns were somewhat related to histological cancer types, this was not statistically significant. However, EMA showed statistically significant univariate relationships to tumor grade, tumor size, estrogen and progesterone receptors, and nodal stage. Logistic regression analysis showed that among these variables, all of which were univariately related to node metastasis, only tumor size and EMA were independent nodal stage predictors. A combined analysis of these two factors revealed that the statistical probability of a tumor metastasizing to four or more nodes increased in each tumor size group from 0.9% to 12% for pT1, from 2% to 29% for pT2 and from 10% to 63% for pT3, depending on the EMA staining. The tumors showing a lineal pattern were the least metastasizing, while the EMA-negative tumors were the most. After recognizing these relationships between EMA staining patterns and other well-known differentiation markers and the lymph node metastatic capacity of carcinomas, and considering the results obtained by others on survival, one might conclude that EMA is both a differentiation marker and a histological prognostic factor.

Reverse microdialysis of N-methyl-D-aspartic acid into the lateral hypothalamus of rats: effects on feeding and other behaviors

The effects of reverse microdialysis of N-methyl-D-aspartic acid (NMDA) into the lateral hypothalamus (LH) on feeding and other behaviors were examined. Consistent with similar studies utilizing central microinjections, NMDA reverse microdialysed into the rat LH rapidly elicited a strong concentration-dependent stimulation of feeding. The minimum perfusate concentration of NMDA needed to elicit feeding with reverse microdialysis was 660 microM, a concentration 1/50 of that needed with pressure injections. Further, eating responses could be consistently elicited in sequential tests separated by 2-4 h in the same subject, and the magnitude of the eating in the first and second tests was highly correlated (r=0.87). Behavioral analysis revealed that the main response to NMDA consisted of eating without the concomitant hyperactivity produced by central microinjections of this agonist. The other behaviors exhibited during NMDA administration were those that normally occur during spontaneous feeding in rats. Also, rats precisely compensated for the increased food intake elicited by NMDA by reducing spontaneous feeding during the subsequent nocturnal phase, so as to maintain normal daily intakes. In contrast, N-methyl-L-aspartate (NMLA) reverse microdialysed in to the LH (660 microM) did not elicit feeding nor affect any other behaviors we examined. These data support a role for LH glutamate and NMDA receptors in the control of feeding.

E1A3 as a unique, naturally occurring BCR-ABL transcript in an indolent case of chronic myeloid leukaemia

A woman with Ph-positive chronic myeloid leukaemia (CML) with an atypical e1a3 BCR-ABL hybrid gene is described. To our knowledge, this is the first report of this transcript type as a unique naturally occurring BCR-ABL fusion in a CML patient. This case was characterized by a low leucocyte count and a very indolent course without treatment. Because the deletion of ABL exon 2 sequences results in deletion of an essential part of the ABL SH3 domain, our case suggests that this ABL SH3 domain is not absolutely necessary for efficient induction of a myeloproliferative disease in the context of BCR-ABL/p190.

Hypermethylation of the calcitonin gene in acute lymphoblastic leukaemia is associated with unfavourable clinical outcome

We analysed calcitonin (CALC1) gene hypermethylation using semiquantitative differential polymerase chain reaction in 105 patients with adult (n = 49) and childhood (n = 56) acute lymphoblastic leukaemia (ALL), and studied the association of CALC1 hypermethylation with clinical presentation features and disease outcome. We also investigated the possible relationship between CALC1 methylation status and expression of the cell cycle inhibitor gene p57KIP2. We observed CALC1 hypermethylation in bone marrow cells from 43% (45 out of 105) of ALL patients. Clinical, molecular and laboratory features did not differ significantly between hypermethylated and hypomethylated patients, only T-cell lineage was associated with hypermethylation (14% vs. 47%, P = 0025). Complete remission rate was similar in both groups although hypermethylated patients had a higher relapse rate (68% vs. 19%, P < 0.00001) and mortality rate (55% vs. 36%, P = 0.06) than hypomethylated patients. Estimated disease-free survival (DFS) at 6 years was 66.1% for hypomethylated patients and 5.3% for hypermethylated patients (P < 0,00001). Multivariate analysis from potential prognostic factors demonstrated that CALC1 methylation status was an independent prognostic factor in predicting DFS (P = 0.0001). Separate analysis of adult and childhood ALL patients showed similar results to the whole series. In addition, hypermethylated patients showed downregulation of p57KIP2 expression. Our results suggest that CALC1 gene hypermethylation is associated with an enhanced risk of relapse independently of known poor-prognostic factors and we describe, for the first time, a possible implication of the p57KIP2 gene in the genesis and prognosis of ALL.