Use of oxygen therapy for pneumocephalus: a systematic review

Pneumocephalus is the pathologic collection of air in the intracranial cavity. In sufficient volumes, it can contribute to symptoms ranging from headaches to death. For conservative treatment, oxygen use is commonplace. Although this is an accepted tenet of clinical practice, it is not necessarily founded on robust trials. An electronic search of databases EMBASE and MEDLINE and the Cochrane Library was undertaken as per the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. Three articles were included. Although the modes of oxygen delivery were heterogenous (non-rebreather versus endotracheal versus hyperbaric chamber), all studies concluded favorably on the use of oxygen therapy for increased reabsorption of pneumocephalus.

MRI for Cushing Disease: A Systematic Review

BACKGROUND

MR imaging is key in the diagnostic work-up of Cushing disease. The sensitivity of MR imaging in Cushing disease is not known nor is the prognostic significance of "MR imaging-negative" disease.

PURPOSE

Our aim was to determine the overall sensitivity and prognostic significance of MR imaging localization of Cushing disease.

DATA SOURCES

We performed a systematic review of the MEDLINE and PubMed databases for cohort studies reporting the sensitivity of MR imaging for the detection of adenomas in Cushing disease.

STUDY SELECTION

This study included 57 studies, comprising 5651 patients.

DATA ANALYSIS

Risk of bias was assessed using the methodological index for non-randomized studies criteria. Meta-analysis of proportions and pooled subgroup analysis were performed.

DATA SYNTHESIS

Overall sensitivity was 73.4% (95% CI, 68.8%-77.7%), and the sensitivity for microadenomas was 70.6% (66.2%-74.6%). There was a trend toward greater sensitivity in more recent studies and with the use of higher-field-strength scanners. Thinner-section acquisitions and gadolinium-enhanced imaging, particularly dynamic sequences, also increased the sensitivity. The use of FLAIR and newer 3D spoiled gradient-echo and FSE sequences, such as spoiled gradient-echo sequences and sampling perfection with application-optimized contrasts by using different flip angle evolutions, may further increase the sensitivity but appear complementary to standard 2D spin-echo sequences. MR imaging detection conferred a 2.63-fold (95% CI, 2.06-3.35-fold) increase in remission for microadenomas compared with MR imaging-negative Cushing disease.

LIMITATIONS

Pooled analysis is limited by heterogeneity among studies. We could not account for variation in image interpretation and tumor characteristics.

CONCLUSIONS

Detection on MR imaging improves the chances of curative resection of adenomas in Cushing disease. The evolution of MR imaging technology has improved the sensitivity for adenoma detection. Given the prognostic importance of MR imaging localization, further effort should be made to improve MR imaging protocols for Cushing disease.

Detection of dengue viruses in field caught male Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Singapore by type-specific PCR

Field male Aedes aegypti (L.) and Aedes albopictus (Skuse) adults caught from fixed monitoring stations weekly for 1 yr were screened for dengue viruses (DEN-1, DEN-2, DEN-3, and DEN-4). The assay was carried out using a single-step reverse transcription (or transcriptase)-polymerase chain reaction (PCR) (RT-PCR) followed by a semi-nested PCR using an upstream consensus primer and four type-specific primers within the nonstructural protein three gene (NS3) of dengue viruses. The diagnostic fragments for DEN-1, DEN-2, DEN-3, and DEN-4 serotypes were of sizes 169, 362, 265, and 426 bp, respectively. Results showed that in Singapore 1.33% and 2.15% of Aedes aegypti and Aedes albopictus adult male mosquitoes, respectively, were positive for dengue viruses. The serotypes detected in male Ae. aegypti was DEN-1 (44%), followed by DEN-2 (22.2%) and DEN-3 (22.2%), and DEN-4 (11.1%). For Aedes albopictus males, the serotype was DEN-4 (38.9%), followed by DEN-2 (33.3%), DEN-3 (16.7%), and DEN-1 (11.1%).