The impact of metformin on survival in diabetes patients with operable colorectal cancer: A nationwide retrospective cohort study

OBJECTIVE

To investigate the impact of metformin on survival of diabetic patients following surgery for colorectal cancer (CRC).

METHODS

This was a retrospective cohort study. From Taiwan's population-based National Health Insurance Research Database (NHIRD) we identified 12,512 patients with CRC and type II diabetes who underwent curative surgery between 2000 and 2012. Of these, 6222 patients were included in a matched cohort. Using Cox regression models with time-dependent covariates we examined the impact of metformin on survival.

RESULTS

Average duration of follow-up was 49 and 54 months for metformin users and non-users, respectively. Cox proportional hazard model showed that metformin was associated with 5-year overall survival benefit (Hazard ratio, 0.23 [95% CI, 0.20-0.26]) and inverse association with risk of liver metastasis (Hazard ratio, 0.79 [95% CI, 0.68-0.93]).

CONCLUSIONS

Metformin was associated with a survival benefit in diabetic patients with CRC following surgery, and an inverse association with risk of liver metastases suggesting a potential anti-tumorigenic effect.

Cerebrospinal fluid predictors of shunt-dependent hydrocephalus after hemorrhagic stroke: a systematic review and meta-analysis

Hydrocephalus is a common complication of hemorrhagic stroke and has been reported to contribute to poor neurological outcomes. Herein, we aimed to investigate the validity of cerebrospinal fluid (CSF) data in predicting shunt-dependent hydrocephalus (SDHC) in patients with hemorrhagic stroke. PubMed, CENTRAL, and Embase databases were searched for relevant studies published through July 31, 2021. The 16 studies with 1505 patient included those in which CSF data predicted risk for SDHC and reports on CSF parameters in patients in whom SDHC or hydrocephalus that was not shunt-dependent developed following hemorrhagic stroke. We appraised the study quality using Newcastle-Ottawa Scale and conducted a meta-analysis of the pooled estimates of the CSF predictors. The meta-analysis revealed three significant CSF predictors for shunt dependency, i.e., higher protein levels (mean difference [MD] = 32.09 mg/dL, 95% confidence interval [CI] = 25.48-38.70, I² = 0%), higher levels of transforming growth factor β1 (TGF-β1; MD = 0.52 ng/mL, 95% CI = 0.42-0.62, I² = 0%), and higher ferritin levels (MD = 108.87 µg/dL, 95% CI = 56.68-161.16, I² = 36%). The red blood cell count, lactate level, and glucose level in CSF were not significant in predicting SDHC in patients with hemorrhagic stroke. Therefore, higher protein, TGF-β1, and ferritin levels in CSF are significant predictors for SDHC in patients with hemorrhagic stroke. Measuring these CSF parameters would help in the early recognition of SDHC risk in clinical care.

Portal endotoxemia stimulates the release of an immunosuppressive factor from alveolar and splenic macrophages

Impairment of cell-mediated immunity is both a common manifestation of critical illness and a potential cause of increased infectious morbidity and mortality. The mechanisms responsible for alterations in systemic immune regulation are incompletely understood; however, monocytes and fixed tissue macrophages appear to play a central role. We have previously shown that infusion of gram-negative organisms into the portal vein, but not into the systemic circulation, induces suppression of delayed hypersensitivity responsiveness in vivo and of mitogen-stimulated lymphocyte proliferation in vitro. The present studies were undertaken to probe the mechanisms of this suppression. Rats received 3 x 10(8) killed Pseudomonas aeruginosa via the inferior vena cava or the portal vein; they were sacrificed 24 hr later and the mitogen-driven proliferative responses of isolated splenocytes were assayed. Portal infusion resulted in significant suppression of Con A-induced proliferative responses (15.5 +/- 2.7 cpm x 10(-3) compared to 68.6 +/- 9.8 cpm x 10(-3) for infrahepatic vena cava-infused animals and 48.0 +/- 5.4 cpm x 10(-3) for nonoperated controls). Suppression was shown to be a consequence of the release of a soluble suppressive factor from splenic adherent cells. Suppression of the proliferative responses of control lymphocytes could also be induced by a soluble factor present in culture supernatants of alveolar macrophages harvested from portally infused animals (4.7 +/- 0.4 cpm x 10(-3) vs 88.6 +/- 27 cpm x 10(-3) for systemically infused animals and 60.1 +/- 8.4 cpm x 10(-3) for nonoperated controls). The stimulus for the release of this factor was not endotoxin, but a second factor released from the liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Nosocomial infection in the surgical intensive care unit

The critically ill surgical patient is at high risk for the development of ICU-acquired infection. Normal mucosal defenses are breached by surgical incisions or by intravascular devices, urinary catheters, and endotracheal tubes. The integrity of the gastrointestinal epithelium is compromised by the lack of enteral nutrition and episodes of hypoperfusion, resulting in translocation of normal or disturbed enteric flora. The indigenous microbial flora, an important component of normal host defenses against invasive infection, is disrupted through the use of broad-spectrum antibiotics or by poorly understood influences associated with critical illness. Systemic immunity is altered, and multiple abnormalities of specific and nonspecific immune function can be documented. Infections acquired within the ICU are commonly caused by endogenous organisms of low intrinsic pathogenicity, and the contribution of these infections to ICU outcome is controversial. Diagnosis is established by directed investigations, focusing on surgical sites and invasive devices. Therapy is primarily physical (drainage of infected collections or removal of contaminated devices), and antimicrobial therapy should employ narrow-spectrum agents guided by the results of Gram stain and culture. The prevention of ICU-acquired infection is based on timely and definitive surgical therapy, judicious use of invasive devices and antibiotics, and early enteral feeding. Infection-control measures aimed at endogenous reservoirs show some preliminary promise for certain subsets of patients, but remain, at present, experimental.