MicroRNA-7 functions as an anti-metastatic microRNA in gastric cancer by targeting insulin-like growth factor-1 receptor

Metastasis is a major clinical obstacle in the treatment of gastric cancer (GC) and it accounts for the majority of cancer-related mortality. MicroRNAs have recently emerged as regulators of metastasis by acting on multiple signaling pathways. In this study, we found that miR-7 is significantly downregulated in highly metastatic GC cell lines and metastatic tissues. Both gain-of-function and loss-of-function experiments showed that increased miR-7 expression significantly reduced GC cell migration and invasion, whereas decreased miR-7 expression dramatically enhanced cell migration and invasion. In vivo metastasis assays also demonstrated that overexpression of miR-7 markedly inhibited GC metastasis. Moreover, the insulin-like growth factor-1 receptor (IGF1R) oncogene, which is often mutated or amplified in human cancers and functions as an important regulator of cell growth and tumor invasion, was identified as a direct target of miR-7. Silencing of IGF1R using small interefering RNA (siRNA) recapitulated the anti-metastatic function of miR-7, whereas restoring the IGF1R expression attenuated the function of miR-7 in GC cells. Furthermore, we found that suppression of Snail by miR-7, through targeting IGF1R, increased E-cadherin expression and partially reversed the epithelial-mesenchymal transition (EMT). Finally, analyses of miR-7 and IGF1R levels in human primary GC with matched lymph node metastasis tissue arrays revealed that miR-7 is inversely correlated with IGF1R expression. The present study provides insight into the specific biological behavior of miR-7 in EMT and tumor metastasis. Targeting this novel miR-7/IGF1R/Snail axis would be helpful as a therapeutic approach to block GC metastasis.

How effective are physical activity interventions for alleviating depressive symptoms in older people? A systematic review

BACKGROUND

The benefits of physical exercise in reducing clinically defined depression in the general population have been established, although a review of the evidence for older adults is needed.

OBJECTIVES

To assess the efficacy of physical exercise for the treatment of depressive symptoms in older adults (>60 years).

DATA SOURCES

We searched: MEDLINE (1966-May 2008); EMBASE (1980-May 2008); Cumulative Index to Nursing & Allied Health Literature (CINAHL; 1982-May 2008); PsycINFO (1966-May 2008), The Cochrane Library (Issue 2, 2008), and National Research Register (NRR; Issue 2, 2008).

REVIEW METHODS

Randomized controlled trials and quasi-experimental studies of physical exercise interventions for depression were included where 80% or more of participants were >60 years. Abstracts were assessed to determine whether they met specified inclusion criteria. Primary analysis focused on the prevalence of diagnosable depressive disorder following intervention. Secondary outcome was depression or mood scores on standardized scales.

RESULTS

Eleven randomized controlled trials with a total of 641 participants were included in the review. Short-term positive outcome for depression or depressive symptoms was found in nine studies, although the mode, intensity and duration of intervention varied across studies. Medium- to long-term effects of intervention were less clear.

CONCLUSION

Physical exercise programmes obtain clinically relevant outcomes in the treatment of depressive symptoms in depressed older people. Exercise, though not appropriate for all in this population, may improve mood in this group. Further research is needed to establish medium- to long-term effects and cost-effectiveness.

A randomized, double-blind comparison of ampicillin/sulbactam and ceftriaxone in the prevention of surgical-site infections after neurosurgery

BACKGROUND

The use of prophylactic antibiotics has been shown to decrease the rate of surgical-site infections after clean neurosurgical operations, although previous clinical trials have provided no evidence that one antibiotic is superior to another for this purpose.

OBJECTIVE

This study was undertaken to compare the rates of postoperative infectious complications of neurosurgery with prophylactic ceftriaxone and ampicillin/sulbactam, a less-expensive antibiotic.

METHODS

Consecutive patients undergoing neurosurgery between January and December 1998 were recruited for the study. Those who had an infectious disease for which antibiotics were required, who received antibiotics within 48 hours before surgery, were aged <12 or >85 years, had an indwelling catheter for the monitoring of intracranial pressure, or had a history of allergy to the study drugs were excluded. Before the operation, eligible patients were randomized to either ampicillin/sulbactam 3 g or ceftriaxone 2 g. Surgeons and patients were blinded to treatment assignment. The study drugs were administered by the anesthesiologist as an IV bolus after induction of general anesthesia. All patients were followed for 6 weeks postoperatively. If reoperation was required within 6 weeks of the original operation, the patient received the same antibiotic as during the first surgery, without further randomization.

RESULTS

Over the 1-year study period, 180 consecutive patients undergoing neurosurgical operations were recruited. Surgical-site infection occurred in 2 (2.3%) patients in the ampicillin/sulbactam group and 3 (3.3%) in the ceftriaxone group; nonsurgical-site infection occurred in 25 (28.4%) patients in the ampicillin/sulbactam group and 15 (16.3%) in the ceftriaxone group. The between-group differences were not statistically significant, with the exception of surgical implantation of foreign material, which was performed sig- nificantly more frequently in the ceftriaxone group (P = 0.045). In addition, 2 of 3 surgical-site infections in the ceftriaxone group involved foreign-material implantation; however, if these operations are omitted from the analysis, the difference between treatments remains nonsignificant.

CONCLUSIONS

The results suggest that ampicillin/sulbactam and ceftriaxone are of similar prophylactic efficacy in clean neurosurgical operations. Because the acquisition cost of 2 g ceftriaxone is approximately 3 times greater than that of 3 g ampicillin/sulbactam, the latter may be more cost-effective than the former for neurosurgical prophylaxis; however, other relevant hospital-related costs were not assessed in this study.

Atypical cellular chorangioma

We describe an unusual, large atypical cellular chorangioma with abundant mitoses and focal necrosis. Other than premature birth, the prenatal and postpartum clinical course was unremarkable for both the mother and baby. Our case and a few similar cases reported in literature suggest that atypical cellular chorangioma is a benign tumor, despite its worrisome histopathologic features.

Hong Kong strains of methicillin-resistant and methicillin-sensitive Staphylococcus aureus have similar virulence

While most authorities agree that methicillin-resistant Staphylococcus aureus (MRSA) are as pathogenic as methicillin-sensitive strains (MSSA), some believe that MRSA are relatively avirulent opportunists, and that their importance has been exaggerated. We present evidence that Hong Kong strains of MRSA and MSSA are equally pathogenic: they have similar virulence in animal models; they are isolated in similar proportions from both deep and superficial clinical sites including blood; in patients with hospital-acquired bacteraemias mortality rates are similar when adjusted for clinical factors; and in both animals and patients with systemic MRSA infection, mortality rates are significantly reduced by vancomycin therapy. Efforts to control the spread of MRSA are justified, and in invasive sepsis early treatment with vancomycin may be life-saving.