Possible horizontal transfer of the vanB2 gene among genetically diverse strains of vancomycin-resistant Enterococcus faecium in a Korean hospital

A total of 25 isolates of vanB-containing Enterococcus faecium were recovered from patients in a single Korean hospital over a 20-month period. There were two distinct vanB2 patterns among the 11 pulsed-field gel electrophoresis types; 17 contained the prototype vanB2 and 8 contained a novel vanB2 with a 177-bp deletion in vanY(B). Both vanB2 genes were transmissible in vitro at a mean frequency of 1.1 x 10(-8) transconjugants/donor. These results suggest the horizontal spread of vanB2 is occurring among genetically diverse strains of E. faecium in Korean hospitals.     

Resolution of gastritis induced by Helicobacter pylori 4-5 weeks after successful eradication of infection using a triple therapy regimen of pantoprazole, amoxycillin and clarithromycin for one week.

This open-label study was designed to determine the extent of histological resolution of gastritis induced by Helicobacter pylori infection 4-5 weeks after successful eradication of the infection. Eradication was achieved using a triple therapy regimen consisting of a twice daily dose of pantoprazole 40 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg taken for 1 week only. No other medications were given thereafter. Four biopsies were processed for histological examination of each patient, two from the antral and two from the corporeal mucosa, first at the start of the study and then again 4 weeks after cessation of the medication trial. Scoring for H. pylori colonization and the severity of gastritis was determined for each patient according to the Sydney system. 53 of 57 patients in this study had their H. pylori infection successfully eradicated by the regimen mentioned and could be histologically evaluated. According to the severity of gastritis in the antral mucosa, patients were studied in 3 groups: mild, moderate and severe gastritis. 17 of 19 cases with mild gastritis showed complete resolution of the inflammation, with residual inflammatory changes persisting in 2 cases only. 22 of the 26 cases with moderate gastritis showed almost complete recovery except for minor residual inflammatory changes as judged by irregularity of intracytoplasmic mucine storage. Persistent residual inflammatory changes in the lamina propria were detected in 4 cases. Of the 8 cases with severe gastritis 5 showed subsidence of the inflammatory changes, but the mucosa in these cases revealed some scarring, distortion of the glandular epithelium and atrophy. In 3 cases residual inflammation persisted. CONCLUSION: One-week therapy with a twice daily dose of pantoprazole 40 mg, clarithromycin 500 mg and amoxicillin 1,000 mg, used to eradicate H. pylori causing active inflammation of the gastric mucosa, has led to subsidence of the acute inflammatory changes in all the cases with residual inflammation persisting in 17%. Severe gastritis may cause irreparable damage to the gastric mucosa. The density of H. pylori colonization does not appear to be related to the severity of gastritis, nor to the successful eradication achieved.     

Fluorescein test for the detection of striae in the corneal flap after laser in situ keratomileusis

PURPOSE: To report a technique for detecting striae in the corneal flap after laser in situ keratomileusis. METHODS: Fluorescein dye was instilled in the eye, and the patient was asked to blink. The tear film was examined at the slit lamp with the cobalt filter 1 or 2 seconds after blinking. RESULTS: The uneven pattern of pooling in the tear film was a sensitive indicator of the presence of striae in the flap. CONCLUSION: This technique may be useful in detecting minimal striae in the corneal flap in patients with unexplained suboptimal visual acuity after laser in situ keratomileusis.     

Differential response of A 68930 and sulpiride in stress-induced gastric ulcers in rats

Dopamine is linked to gastrointestinal functions. However, its exact nature in stress-induced gastric pathology is still not clear. In the present study, an attempt has been made to identify the effects of dopamine in stress-induced gastric ulcers, and concurrent alterations in various ulcer-influencing factors such as plasma corticosterone levels, gastric mucosal PGE₂ content and proton pump activity. The dopamine D₁ receptor agonist (A 68930) and antagonist (SCH 23390), and D₂ receptor agonist (quinpirole) and antagonist (sulpiride) were used to evaluate their effects on acute stress (single immobilization for 150 min) and chronic unpredictable stress (two different types of stressors for 7 days) induced gastric ulcers in rats. Acute and chronic unpredictable stress significantly increased the gastric ulcer severity, adrenal hypertrophy and corticosterone levels, while gastric mucosal dopamine levels were decreased. Pretreatment of sulpiride (60 mg/kg) significantly reverted the acute stress-induced alterations, while A 68930 (0.25 mg/kg) significantly restored the acute and chronic unpredictable stress-induced alterations. In contrast, administration of SCH 23390 (0.1-0.5 mg/kg) and quinpirole (0.1-0.5 mg/kg) failed to alter acute stress-induced alterations. Further, A 68930 and sulpiride showed different response on proton pump inhibition under in-vitro condition. A 68930 (10-50 μg/ml) inhibited the gastric H⁺ K⁺-ATPase activity comparable to positive control omeprazole, while sulpiride (10-50 μg/ml) had no effect. A 68930 also normalized the decreased gastric PGE2 content observed during chronic unpredictable stress. The histopathological evaluation of gastric mucosal tissue supported the observations regarding the gastroprotective effect of sulpiride during acute stress and of A 68930 during both acute and chronic unpredictable stress conditions. Our results provide important insights into the mechanism of dopamine-regulated pathways, which cause an overall pathophysiology of gastric stress ulcers and implicating the importance of D₁ agonist in ulcer protection. Thus, current study highlights the need to evaluate anti-stress and anti-ulcer agents in terms of their ability to modulate dopaminergic transmissions.     

Feasibility of using computer simulation to predict the postoperative outcome of the minimally invasive Nuss procedure: Simulation prediction vs. postoperative clinical observation

The Nuss procedure is the most minimally invasive and commonly used surgical correction for pectus excavatum (PE) by using a prebent pectus bar to elevate the deformed chest wall. However, there are some complications associated with this procedure such as postoperative pain as well as surgical uncertainties because of human judgment. It is therefore important to understand the biomechanical effect of the pectus bar on PE thoraces undergoing an operation to alleviate the postoperative pain as well as to improve surgical outcome. The current study incorporated the finite element method (FEM) to simulate the entire Nuss procedure including the flipping process of the pectus bar on a preoperative PE patient-specific thorax model, in conjunction with comparison against the postoperative CT scans. The mid-sagittal sternovertebral elevation was found to be within 5.32?mm, whereas the transverse sternal deviations ranged from 1.59 to 3.02?mm. The average discrepancy between the predicted contour and postoperative CT contour was approximately 3%. On a different note, the stress and strain distributions largely concurred with reported findings. High bilateral stress was seen to occur at the back of ribs near the vertebral column, and particularly over the second to fifth ribs, whereas the greatest strain was found to be confined to the regions of costal cartilages. It is evident that the FEM is a feasible and robust approach in predicting the outcome of the mechanical surgical procedure. This contributes to the future development of a predictive tool incorporated in surgical planning to enhance surgical management of PE.     

Characterization of the extended-spectrum beta-lactamase reference strain, Klebsiella pneumoniae K6 (ATCC 700603), which produces the novel enzyme SHV-18

Klebsiella pneumoniae K6 (ATCC 700603), a clinical isolate, is resistant to ceftazidime and other oxyimino-beta-lactams. A consistent reduction in the MICs of oxyimino-beta-lactams by at least 3 twofold dilutions in the presence of clavulanic acid confirmed the utility of K. pneumoniae K6 as a quality control strain for extended-spectrum beta-lactamase (ESBL) detection. Isoelectric-focusing analysis of crude lysates of K6 demonstrated a single beta-lactamase with a pI of 7.8 and a substrate profile showing preferential hydrolysis of cefotaxime compared to ceftazidime. PCR analysis of total bacterial DNA from K6 identified the presence of a bla(SHV) gene. K6 contained two large plasmids with molecular sizes of approximately 160 and 80 kb. Hybridization of plasmid DNA with a bla(SHV)-specific probe indicated that a bla(SHV) gene was encoded on the 80-kb plasmid, which was shown to transfer resistance to ceftazidime in conjugal mating experiments with Escherichia coli HB101. DNA sequencing of this bla(SHV)-related gene revealed that it differs from bla(SHV-1) at nine nucleotides, five of which resulted in amino acid substitutions: Ile to Phe at position 8, Arg to Ser at position 43, Gly to Ala at position 238, and Glu to Lys at position 240. In addition to the production of this novel ESBL, designated SHV-18, analysis of the outer membrane proteins of K6 revealed the loss of the OmpK35 and OmpK37 porins.     

Significance of hemolysis on extracorporeal life support after cardiac surgery in children

Hemolysis is common during extracorporeal life support (ECLS). Elevated levels of circulating plasma free hemoglobin (FHb) has been linked to the development of hemoglobinuria nephropathy. Its clinical significance in patients receiving ECLS remains unknown. Medical records of 104 children <3 years old who required ECLS after repair of congenital heart disease were reviewed. Forty-two patients required continuous renal replacement therapy (CRRT) during ECLS (CRRT group), and 62 patients did not (no-CRRT group). For all patients, FHb level and the degree of fluid overload at the end of ECLS predicted the mortality rate during ECLS. Compared with the no-CRRT group, the CRRT group had a higher mortality rate during ECLS, a higher peak FHb level during ECLS, a higher FHb level at the end of ECLS, and more days of ECLS. In the CRRT group, the FHb level at the end of ECLS predicted death during ECLS. In the no-CRRT group, the peak FHb level was associated with a worse renal function. In conclusion, elevated FHb levels were associated with renal dysfunction and death during ECLS in children undergoing cardiac surgery. Further studies are needed to elucidate the cause–effect relationship in our findings.