Routine analysis of plasma busulfan by gas chromatography–mass fragmentography

Abstract Busulfan (BU) is a widely used alkylating agent for antineoplastic therapy and marrow ablation in preparation for bone marrow transplantation (BMT). High-dose BU often leads to successful preparation and low relapse but is associated with veno-occlusive disease of liver. We established a protocol to determine postdosage plasma BU concentrations by gas chromatography–mass fragmentography in an attempt to relate clinical outcome to plasma BU concentrations. We used nonisotopic pusulfan as the internal standard. After extraction into ethyl acetate, BU and pusulfan were iodinated into 1,4-diiodobutane and 1,5-diiodopentane, respectively. Gas chromatography–mass spectrometry (GC–MS) analysis was carried out on an Hewlett–Packard (HP) 5890II gas chromatograph with a 30-m 100% methyl silicon narrow bore, fused-silica capillary column interfaced with an HP 5970A mass spectrometer. Helium was the carrier gas. The sample molecules were identified by total ion monitoring and quantified by selective ion monitoring of m/z 183 and 197. The calibration curve was linear to 4 mg/L. The limit of quantification was 0.04 mg/L, and the analytical recovery was ∼97%. The within-day and between-day imprecision (CV) was &amp;lt;6% and 9%, respectively. In a preliminary study of 12 children, the BU areas under the BU-time curve were 616–949 μmol · min/L after the first dose and 793-1143 μmol · min/L after the fifth dose. We conclude that the GC–MS procedure is suitable for routine analysis of plasma BU.</jats:p

Mimicking multiple sclerosis - Ghost tumor that comes and goes in different parts of the brain without any treatment

Lesions that spontaneously come and go in central nervous system without any treatment at different time points and at different locations (CNS) usually lead ones to think of the possibilities of multiple sclerosis. However, sometimes there are exceptions. Surgical biopsy remains an important tool for definitive diagnosis in difficult cases. We report a case of intracranial diffuse large B cell lymphoma that spontaneously disappeared without any treatment and then reappeared at different time points and different locations

A Prospective Cohort Study of Fecal miR-223 and miR-451a as Noninvasive and Specific Biomarkers for Diagnosis of Necrotizing Enterocolitis in Preterm Infants

&lt;b&gt;&lt;i&gt;Objective:&lt;/i&gt;&lt;/b&gt; The objective of this study is to evaluate the usefulness of fecal microRNA (miR)-223 and miR-451a, as novel noninvasive biomarkers for early diagnosis of necrotizing enterocolitis (NEC) in preterm infants. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; Among the top-listed target miRNAs in our previous differential microarray analysis, miR-223 and miR-451a were quantified in a pilot validation case-controlled study (NEC vs. non-NEC/nonsepsis infants; &lt;i&gt;n&lt;/i&gt; = 6 in each group). A definitive prospective cohort study (&lt;i&gt;n&lt;/i&gt; = 218) further assessed their clinical usefulness as noninvasive and specific diagnostic biomarkers. Fecal calprotectin was quantified in parallel for comparison. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; Of 43 proven NEC cases in the cohort study, 24 (55.8%) had fecal samples recovered within the first 3 days of clinical presentation. Fecal miRNA-223 (10.5 fold), miR-451a (4.5 fold), and calprotectin (2.1 fold) concentrations were significant higher in NEC compared with the non-NEC group (&lt;i&gt;p&lt;/i&gt; &amp;#x3c; 0.009). Accepting a minimum sensitivity of 0.75, the positive predictive values (PPVs) ranged between 0.19 and 0.20. Combining fecal biomarkers and CRP (Day 1) could marginally increase the PPVs (0.31–0.34) but adversely lowered the sensitivity (0.54–0.63). &lt;b&gt;&lt;i&gt;Conclusions:&lt;/i&gt;&lt;/b&gt; Although fecal miRNA biomarkers and calprotectin concentrations were significantly higher in the NEC group, the considerable overlapping of concentrations between groups and low recovery of stool specimens within 72 h of clinical presentation rendered fecal noninvasive tests of limited clinical value in guiding diagnosis of NEC during the acute phase. A further study is underway to evaluate their roles in surveillance for predicting high-risk premature infants developing NEC. </jats:p

Prospective randomized study of selective neck dissection versus observation for no neck of early tongue carcinoma

Background. There are controversies on the bene-fits of elective neck dissection (END) for oral tongue carcinoma. Method. This is a prospective randomized study of elective selective I, II, III neck dissection versus observation for N0 neck of stage I to II oral tongue carcinoma. There were 35 patients on the observation arm and 36 patients on the END arm. The main outcome assessment parameters are node-related mortality and disease-specific survival rate. Results. There were 11 patients in the observed arm and 2 patients in the END arm who developed nodal recurrence alone without associated local or distant recurrence. All 13 patients were salvaged, and no patient died of nodal recurrence. The 5-year disease-specific survival rate was 87% for the observation arm and was 89% for the END arm; the 2% difference was not significant. Conclusion. Observation may be an acceptable alternative to END if strict adherence to a cancer surveillance protocol is followed. © 2009 Wiley Periodicals, Inc.link_to_subscribed_fulltex

Predisposing Factors, Microbial Characteristics, and Clinical Outcome of Microbial Keratitis in a Tertiary Centre in Hong Kong: A 10-Year Experience

Purpose. To study the risk factors, microbial profile, antibiotic susceptibility pattern, and outcome for microbial keratitis over the past 10 years in a tertiary center in Hong Kong. Methods. All cases with corneal scraping performed in Queen Mary Hospital, Hong Kong from January 2004 to December 2013 were included. Clinical outcome was defined as poor if the final visual acuity (VA) was abnormal or worse than presenting VA, a major complication occurred, or therapeutic keratoplasty was required. Results. 347 scrapes were performed in the 10-year period growing 130 microorganisms (32.3% culture positive rate). Contact lens use was the commonest risk factor. The commonest isolates were coagulase-negative Staphylococcus and Pseudomonas aeruginosa. Fluoroquinolone susceptibility was tested in 47 Gram-negative bacteria with 93.6% susceptibility (100% for Pseudomonas). 90.7% of cases had good visual outcome. Multivariate logistic regression showed age (p=0.03), trauma (p=0.006), and ulcer size >3 mm (p=0.039) to be independently associated with poor outcome. Conclusion. There was no shifting trend in the isolate distribution or emergence of resistant strains in our study. Contact lens wear was the commonest risk factor, with Pseudomonas being the most frequent isolate in this group. It remained 100% susceptible to fluoroquinolones and 97% cases had good visual outcome