Microdialysis is a technique used to measure the unbound antibiotic concentration in the interstitial spaces, the target site of action. In vitro recovery studies are essential to calibrating the microdialysis system for in vivo studies. The effect of a combination of antibiotics on recovery into microdialysate requires investigation. In vitro microdialysis recovery studies were conducted on a combination of vancomycin and tobramycin, in a simulated in vivo model. Comparison was made between recoveries for three different concentrations and three different perfusate flow rates. The overall relative recovery for vancomycinwas lower than that of tobramycin. For tobramycin, a concentration of 20μg/mL and flow rate of 1.0μL/min had the best recovery. A concentration of 5.0μg/mL and flow rate of 1.0μL/min yielded maximal recovery for vancomycin. Large molecular size and higher protein binding resulted in lower relative recoveries for vancomycin. Perfusate flow rates and drug concentrations affected the relative recovery when a combination of vancomycin and tobramycin was tested. Low perfusate flow rates were associated with higher recovery rates. For combination antibiotic measurement which includes agents that are highly protein bound, in vitro studies performed prior to in vivo studies may ensure the reliable measurement of unbound concentrations.

BACKGROUND: Peanut allergy is an increasing problem in Singapore and strict avoidance is difficult as peanut is ubiquitous in Asian cuisine. OBJECTIVE: We aimed to assess the efficacy and safety of peanut oral immunotherapy (OIT) in children with obvious peanut allergy in Singapore. METHODS: This was an open-label study of peanut OIT in children living in Singapore, with 2 weekly dose escalation until final maintenance dose of 3,000 mg of peanut protein and a maintenance phase of 12 months. An oral food challenge was performed at 6 months to assess for desensitisation and at 4 weeks after discontinuation of OIT having completed 12 months of maintenance therapy to assess for possible sustained unresponsiveness. The adverse events were monitored using the symptom diaries. RESULTS: Nine subjects were started on OIT, with 7 managing to complete maintenance phase of therapy. Of these 7, all were able to tolerate at least 3,000 mg of peanut protein by 6 months of maintenance therapy, showing that the OIT was effective. Of these 7, 3 patients complied with the 4-week abstinence period after completion of OIT before another peanut challenge; 2 of the 3 subjects showed a significant decrease from the initial ability to tolerate 3,000 mg of peanut protein. Side effects were mainly gastrointestinal in nature and were more common during the updosing phase than the maintenance phase. No episodes of anaphylaxis were observed in this study. CONCLUSION: Peanut OIT seemed to be effective and safe in our cohort of Singaporean children.
Anaphylaxis ; Arachis ; Asian Continental Ancestry Group ; Child ; Cohort Studies ; Humans ; Hypersensitivity ; Immunotherapy ; Peanut Hypersensitivity ; Pilot Projects ; Probiotics ; Singapore

Background/Aims: The American Society for Gastrointestinal Endoscopy (ASGE) revised its guidelines for risk stratification of patients with suspected choledocholithiasis. This study aimed to assess the diagnostic performance of the revision and to compare it to the previous guidelines. Methods: We conducted a retrospective cohort study of 267 patients with suspected choledocholithiasis. We identified high-risk patients according to the original and revised guidelines and examined the diagnostic accuracy of both guidelines. We measured the association between individual criteria and choledocholithiasis. Results: Under the original guidelines, 165 (62%) patients met the criteria for high risk, of whom 79% had confirmed choledocholithiasis. The categorization had a sensitivity and specificity of 68% and 55%, respectively, for the detection of choledocholithiasis. Under the revised guidelines, 86 (32%) patients met the criteria for high risk, of whom 83% had choledocholithiasis. The revised categorization had a lower sensitivity and higher specificity of 37% and 80%, respectively. The positive predictive value of the high-risk categorization increased with the revision, reflecting a potential decrease in diagnostic endoscopic retrograde cholangiopancreatograpies (ERCPs). Stone visualized on imaging had the greatest specificity for choledocholithiasis. Gallstone pancreatitis was not associated with the risk for choledocholithiasis. Conclusions The 2019 revision of the ASGE guidelines decreases the utilization of ERCP as a diagnostic modality and offers an improved risk stratification tool.

Background/Aims: The American Society for Gastrointestinal Endoscopy (ASGE) revised its guidelines for risk stratification of patients with suspected choledocholithiasis. This study aimed to assess the diagnostic performance of the revision and to compare it to the previous guidelines. Methods: We conducted a retrospective cohort study of 267 patients with suspected choledocholithiasis. We identified high-risk patients according to the original and revised guidelines and examined the diagnostic accuracy of both guidelines. We measured the association between individual criteria and choledocholithiasis. Results: Under the original guidelines, 165 (62%) patients met the criteria for high risk, of whom 79% had confirmed choledocholithiasis. The categorization had a sensitivity and specificity of 68% and 55%, respectively, for the detection of choledocholithiasis. Under the revised guidelines, 86 (32%) patients met the criteria for high risk, of whom 83% had choledocholithiasis. The revised categorization had a lower sensitivity and higher specificity of 37% and 80%, respectively. The positive predictive value of the high-risk categorization increased with the revision, reflecting a potential decrease in diagnostic endoscopic retrograde cholangiopancreatograpies (ERCPs). Stone visualized on imaging had the greatest specificity for choledocholithiasis. Gallstone pancreatitis was not associated with the risk for choledocholithiasis. Conclusions The 2019 revision of the ASGE guidelines decreases the utilization of ERCP as a diagnostic modality and offers an improved risk stratification tool.

Yolk Sac tumour (YST) of the nasal cavity is extremely rare with only less than five previously reported cases in the English literature. Due to its rarity, the diagnosis is not one that is considered at initial presentation until tissue biopsies are sent for histopathological examination. Serum α-fetoprotein levels aid in diagnosis and in monitoring progression of the tumour. Being a very uncommon tumour of germ cell origin presenting as localized disease in the nasal cavity, prognosis and survival rates are difficult to determine. We are reporting a rare yolk sac tumour case in an infant and the challenges encountered in its management.