Burden of pneumococcal disease: 8-year retrospective analysis from a single centre in Hong Kong

PURPOSE

Streptococcus pneumoniae is a common pathogen involved in community-acquired pneumonia. Invasive pneumococcal disease is often associated with higher co-morbidity rates, but mortality-related findings have been inconclusive. This study investigated predictors of 30-day mortality and invasive pneumococcal disease.

METHODS

This retrospective analysis included adults with pneumococcal disease who were admitted to Pamela Youde Nethersole Eastern Hospital from 1 January 2011 to 31 December 2018. Demographics, microbiological characteristics, and outcomes were compared between 30-day survivors and non-survivors, and between patients with invasive disease and those with non-invasive disease. Intensive care unit (ICU) subgroup analysis was performed. The primary outcome was 30-day all-cause mortality; secondary outcomes were ICU and hospital mortalities, and ICU and hospital lengths of stay.

RESULTS

In total, 792 patients had pneumococcal disease; 701 survived and 91 (11.5%) died within 30 days. Notably, 106 (13.4%) patients had invasive pneumococcal disease and 170 (21.5%) patients received intensive care. Vasopressor use (odds ratio [OR]=4.96, P<0.001), chronic kidney disease (OR=3.62, P<0.001), positive urinary antigen test results (OR=2.57, P=0.001), and advanced age (OR=2.19, P=0.010) were independent predictors for 30-day mortality by logistic regression analysis. Among critically ill patients, chronic kidney disease (OR=4.64, P<0.001), higher APACHE IV score (OR=3.73, P=0.016), and positive urinary antigen test results (OR=2.94, P=0.008) were predictors for 30-day mortality. Logistic regression analysis revealed that chronic kidney disease (OR=3.10, P<0.001) was a risk factor for invasive pneumococcal disease.

CONCLUSION

Advanced age, vasopressor use, chronic kidney disease, and positive urinary antigen test results were independent predictors for 30-day mortality in patients with pneumococcal disease.

Liquid Chromatographic Determination of Major Organic Acids in Apple Juice and Cranberry Juice Cocktail: Collaborative Study

Twelve laboratories collaboratively studied a liquid chromatographic method for determination of quinic, malic, and citric acids in cranberry juice cocktail and apple juice. Samples are passed through a disposable silica cartridge, filtered, and directly injected into the chromatograph. The mobile phase is 0.2M KH2PO4 (pH 2.4). Two reverse phase columns are used, with UV detection at 214 nm. Six samples of cranberry juice cocktail and 6 samples of apple juice were sent to each collaborator. Repeatability and reproducibility coefficients of variation ranged from 1.2 to 7.6% and from 2.9 to 14.7%, respectively, for quinic, malic, and citric acid levels above 0.10%. The precision of the method is satisfactory. The method has been adopted official first action.

Imaging of spindle cell lipoma

AIM

To review the evaluation, diagnosis, and treatment of spindle cell lipoma (SCL) with emphasis on the location of these tumours and the spectrum of magnetic resonance imaging (MRI) and computed tomography (CT) appearances.

MATERIALS AND METHODS

The MRI and CT findings of 27 histopathologically proven SCLs were evaluated retrospectively. Imaging features evaluated included margins, percentage visible fat, MRI signal characteristics, oedema, and contrast enhancement patterns.

RESULTS

Patient ages ranged from 18 to 80 years with an average age of 56.5 years. Men were affected twice as frequently as women (M=18, F=9). SCLs ranged in size from 2 to 10 cm, with an average greatest dimension of 5.5 cm. Five lesions (19%) contained no visible fat on CT or MRI, and the leading differential diagnosis of high-grade soft-tissue sarcoma diagnosis was suggested by referring surgeons. Five lesions (19%) had <50% fatty areas, nine lesions (52%) demonstrated >50% but <90% fat at MRI or CT. Only three of 25 lesions (12%) had an appearance of a typical lipoma on unenhanced MRI sequences. All SCLs that were imaged with contrast medium (n = 18) demonstrated some degree of enhancement, with eight (44%) showing marked enhancement, four (22%) showing moderate, and six (33%) minimal enhancement.

CONCLUSION

SCLs have considerably variable imaging appearances and may have minimal or no visible fat at MRI or CT. Imaging features may make it difficult to distinguish this benign tumour from a potentially higher-grade malignant tumour.

ABCA1 transporter reduces amphotericin B cytotoxicity in mammalian cells

Amphotericin B (AmB) belongs to a group of polyene antibiotics commonly used in the treatment of systemic mycotic infections. A widely accepted mechanism of action of AmB is based on the formation of an oligomeric pore structure within the plasma membrane (PM) by interaction with membrane sterols. Although AmB binds preferentially to ergosterol, it can also bind to cholesterol in the mammalian PM and cause severe cellular toxicity. The lipid content and its lateral organization at the cell PM appear to be significant for AmB binding. Several ATP-binding cassette (ABC) transporters, including ABCA1, play a crucial role in lipid translocation, cholesterol redistribution and efflux. Here, we demonstrate that cells expressing ABCA1 are more resistant to AmB treatment, while cells lacking ABCA1 expression or expressing non-active ABCA1MM mutant display increased sensitivity. Further, a FLIM analysis of AmB-treated cells reveals a fraction of the antibiotic molecules, characterized by relatively high fluorescence lifetimes (> 6 ns), involved in formation of bulk cholesterol-AmB structures at the surface of ABCA1-expressing cells. Finally, lowering the cellular cholesterol content abolishes resistance of ABCA1-expressing cells to AmB. Therefore, we propose that ABCA1-mediated cholesterol efflux from cells induces formation of bulk cholesterol-AmB structures at the cell surface, preventing AmB cytotoxicity.

Neural stem cells promote glioblastoma formation in nude mice

PURPOSE

Neural stem cells (NSCs) have been characterized with the ability of self-renewal and neurogenesis, which has inspired lots of studies to clarify the functions of NSCs in neural injury, ischemic stroke, brain inflammation and neurodegenerative diseases. We focused on the relationship of NSCs with glioblastoma, since we have discovered that recurrent glioblastomas were inclined to be derived from subventricular zone (SVZ), where NSCs reside. We want to clarify whether NSCs are involved in glioblastoma relapse.

METHODS

Immunocytochemistry was used to confirm the stemness of NSCs. The Cell Counting Kit-8 was used to measure the proliferation of cells. Migration abilities were examined by wound healing and transwell assays, and tumor formation abilities were confirmed in nude mice.

RESULTS

We found in experiments that NSCs promoted proliferation of a glioblastoma cell line-Ln229, the migration ability of Ln229 cells was motivated by co-cultured with NSCs. Tumor formation of Ln229 cells was also accelerated in nude mice when co-transplanted with NSCs. In immunohistochemistry, we found that the Sox2- and Ki67-positive cells were much higher in co-transplanted groups than that of control groups.

CONCLUSIONS

These results imply the potential role that NSCs play in speeding up tumor formation in the process of glioblastoma relapse, providing the basis for dealing with newly diagnosed glioblastoma patients, which may help postpone the recurrence of glioblastoma as far as possible through preprocessing the tumor-adjacent SVZ tissue.

Early internationalization of students in a German medical school in the former German Democratic Republic

The growing influence and importance of internationalization in higher education, especially in medical education, inspired anatomists at Columbia University New York, USA and at the Martin Luther University Halle-Wittenberg, Germany, to start a novel international preclinical collaboration project. As part of the anatomy dissection course a group of volunteer medical students from Halle dissected selected areas of the human body with the help of an English, illustrated, iPad-run dissection script (American Dissector). Meanwhile the rest of the students worked with a traditional German text-based dissector. Additionally, participating German students were matched with US students, with whom they connected via video-conferencing and discussed subjects like differences between their health care systems, structure and content of the anatomy course and the differences in their medical education systems. Questionnaires were sent for feedback and checklists confirmed dissection findings. Results indicated that the American Dissector was successfully shared internationally. The majority (62%) found it easier to find structures using the American Dissector compared to the standard dissector and also 62% needed the atlas two times less when using the American Dissector. Furthermore, students enjoyed their interaction with their international peers and the vast majority (77%) wished there were more interactions like this in the medical curriculum. This publication describes an approach to embed internationalization in the preclinical medical curriculum based in the gross anatomy course in a German Medical school, located in East Germany. Considering its history as a former German Democratic Republic faculty this is a meaningful step towardglobalization of medical education in this part of Germany.

Hospitalisation of adults with Down syndrome: lesson from a 10-year experience from a community hospital

BACKGROUND

Life expectancy of individuals with Down syndrome (DS) has improved significantly over the past decades. However, there are sparse data documenting the co-morbidities and hospitalisation of adult patients with DS in the literature. The aim of this study was to characterise the co-morbidities and pattern of hospitalisation in adult patients with DS during a 10-year period at the community hospital as well as to compare hospitalisation parameters with the general adult population during the same years.

METHOD

We reviewed the medical records of 81 hospitalisations from 37 patients with DS aged 21 to 68 years at Metrowest Medical Center during a 10-year period and compared with those of the general adult population during the same time. Co-morbidities were also described.

RESULTS

Adults with DS had a mean age at admission of 48.6 ± 8.8 years with the median length of stay of 3 days (interquartile range 4 days). Male patients were hospitalised longer than female patients (mean 5.0 vs. 2.8 days; P < 0.05), and patients who lived at home were admitted at earlier ages than those who came from residential healthcare facility (mean 41.5 vs. 52.2 years; P < 0.001). The most common cause of hospitalisation was pneumonia/aspiration syndrome (29.6%), and the most common co-morbidity was gastroesophageal reflux disease (GERD)/dysphagia (70.3%). Presence of GERD/dysphagia or seizure disorder was significantly associated with multiple admission and readmission within 1 month (P < 0.05). The mortality rate was 4.9%, and the rate of intensive care unit admission was 8.6%.

CONCLUSIONS

Our cohort did not show statistically significant different hospitalisation parameters such as inpatient mortality and average length of stay when compared with general adult population hospitalised at the same years. The care of adult patients with DS presents challenges in internal medicine due to its unique co-morbid profile and signifies the importance of multidisciplinary approach. In order to improve the care of this patient population, their co-morbidities, particularly GERD/dysphagia and seizure disorder, should be optimally managed and comprehensively addressed when patients are hospitalised.