Ventriculitis caused byKlebsiella pneumoniae successfully treated with pefloxacin in a neonate

Summary Pefloxacin was applied to a newborn suffering from ventriculitis caused byKlebsiella pneumoniae after failure of routine antibiotics. Treatment was successful. Blood and CSF levels were high, thus documenting good CSF penetration. In addition to this case report, a review of the literature regarding seven neonates with CNS infection treated with fluoroquinolones and from whom CSF levels were obtained, is presented. In conclusion, due to their excellent activity against gram-negative microorganisms, fluoroquinolones may be considered in the treatment of neonatal CNS infections if the pathogen is resistant to routinely used antibiotics. Only limited experience is available with fluoroquinolones in pediatric patients given their potential for cartilage toxicity in young animals.

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Ventrikulitis durchKlebsiella pneumoniae bei einem Neugeborenen. Erfolgreiche Behandlung mit Pefloxacin

Zusammenfassung Nach Versagen von Routineantibiotika wurde Pefloxacin eingesetzt, um eine durchKlebsiella pneumoniae verursachte Ventrikulitis bei einem Neugeborenen zu behandeln. Die Therapie war erfolgreich. Im Blut und im Liquor cerebrospinalis fanden sich hohe Spiegel von Pefloxacin. Die hohe Penetrationsrate von Pefloxacin in den Liquor ist damit dokumentiert. In einer Literaturübersicht werden sieben weitere Fälle von ZNS-Infektionen bei Neugeborenen dargestellt, die unter Bestimmung der Liquorspiegel mit Fluorochinolonen behandelt wurden. Fluorochinolone kommen wegen ihrer hohen Aktivität gegen gramnegative Bakterien für die Behandlung einer gegen herkömmliche Antibiotika resistenten gramnegativen ZNS-Infektion bei Neugeborenen in Frage. Die Erfahrungen mit Fluorochinolonen sind bei pädiatrischen Patienten jedoch wegen der Möglichkeit einer bei jungen Tieren beobachteten Knorpelschädigung begrenzt.

     

Tuberculosis and HIV/AIDS: epidemiological and clinical aspects (world perspective)

Human immunodeficiency virus (HIV) infection is the most powerful known risk factor for progression from latent infection with Mycobacterium tuberculosis to active tuberculosis (TB) disease. The worldwide HIV epidemic has affected TB in every aspect: immunopathology, epidemiology, diagnosis, treatment, and prevention. Of the 42 million people infected with HIV worldwide, more than a quarter of them are also infected with TB, and most live in countries with limited resources for health care in Africa and Asia. This chapter emphasizes HIV-associated TB in resource-limited settings. TB-infected persons with HIV-associated immunosuppression progress to TB disease at a rate of up to 10% per year. Standard TB diagnostic tools have diminished sensitivity in HIV co-infected cases. Standard TB treatment regimens may be less effective, particularly those that do not use a rifamycin throughout. Treatment is further complicated by toxicity, malabsorption, drug-drug interactions and immune reconstitution paradoxical reactions. TB control in the United States was destabilized in part by the HIV epidemic in the early 1990s; massive political will and resources were required to rebuild the public health infrastructure. Africa, Asia, and potentially the former Soviet Union are facing even greater destabilization of TB control due to the dual burden of disease and limited resources. An international response has been initiated but will require even greater political will and resources.     

Are general surgeons able to accurately self-assess their level of technical skills?

Introduction

Self-assessment is a way of improving technical capabilities without the need for trainer feedback. It can identify areas for improvement and promote professional medical development. The aim of this review was to identify whether selfassessment is an accurate form of technical skills appraisal in general surgery.

Methods

The PubMed, MEDLINE^®, Embase^™ and Cochrane databases were searched for studies assessing the reliability of self-assessment of technical skills in general surgery. For each study, we recorded the skills assessed and the evaluation methods used. Common endpoints between studies were compared to provide recommendations based on the levels of evidence.

Results

Twelve studies met the inclusion criteria from 22,292 initial papers. There was no level 1 evidence published. All papers compared the correlation between self-appraisal versus an expert score but differed in the technical skills assessment and the evaluation tools used. The accuracy of self-assessment improved with increasing experience (level 2 recommendation), age (level 3 recommendation) and the use of video playback (level 3 recommendation). Accuracy was reduced by stressful learning environments (level 2 recommendation), lack of familiarity with assessment tools (level 3 recommendation) and in advanced surgical procedures (level 3 recommendation).

Conclusions

Evidence exists to support the reliability of self-assessment of technical skills in general surgery. Several variables have been shown to affect the accuracy of self-assessment of technical skills. Future work should focus on evaluating the reliability of self-assessment during live operating procedures.     

Characterization of non-human primate antisera to acute lymphoblastic leukemia (ALL): evidence for unique antigen(s) on childhood ALL of "T" phenotype

A non-human primate antiserum was prepared to acute lymphoblastic leukemia of T-cell phenotype (T-ALL) and, after absorptions with normal blood elements, reacted by immunofluorescence and microcytotoxicity to all the T-ALL tested. In addition, the antiserum reacted with cells from about 70% of the common ALL studied and immunoprecipitated the common ALL antigen of 100,000 daltons. However, when the anti-T-ALL serum was absorbed with with lymphoblasts from common ALL, it failed to react with common ALL lymphoblasts, yet reacted significantly with cells from patients with T-ALL phenotype and defined a 100,000-dalton membrane component not found on common ALL lymphoblasts. In addition, sequential immunoprecipitation of 125I-labeled T-ALL membranes by anti- common-ALL serum followed by anti-T-ALL serum detected the T-ALL membrane component of 100,000 daltons that was not found on common ALL. Thus, our results demonstrate the presence of of a unique human T-ALL antigen present on all T-ALL distinct from the common ALL antigen.     

In vitro functions of stromal cells from human and mouse bone marrow

Human fibroblastoid cell strains obtained from primary bone marrow cultures and continuous stromal cell lines recently derived from mouse bone marrow were studied. The incidence of fibroblastoid precursors (CFU-F) varied considerably in human bone marrow samples, and no differences could be detected between marrows from a group of myelodysplastic patients (age range 70-82 years) and groups of age-matched controls or younger individuals. A lack of direct correlation between initial clonogenicity and ultimate capacity of fibroblastoid cells to grow in continuous culture was observed in both the normal and the myelodysplastic groups. Despite the apparently normal clonogenicity of CFU-F in patients with myelodysplastic syndromes, some of these marrows failed to grow when subcultured. Normal fibroblastoid cells at 10(4) per culture exhibited myelopoietic activities when cocultured with fresh bone marrow cells. At higher concentrations, these cells inhibited myeloid colony formation. Fibroblastoid cells from only one out of four myelodysplastic patients examined exhibited comparable inhibitory activity. The specificity of the inhibitor(s) was demonstrated by the lack of effect of fibroblastoid cells from normal human bone marrow on the clonogenicity of mouse erythroleukemia cells. Moreover, human foreskin fibroblasts were devoid of such inhibitory activity. These functions of cultured stromal cells may correlate with some of their activities in the bone marrow microenvironment.     

Ultra‐short duration direct acting antiviral prophylaxis to prevent virus transmission from hepatitis C viremic donors to hepatitis C negative kidney transplant recipients

We conducted an adaptive design single‐center pilot trial between October 2017 and November 2018 to determine the safety and efficacy of ultra‐short‐term perioperative pangenotypic direct acting antiviral (DAA) prophylaxis for deceased hepatitis C virus (HCV)‐nucleic acid test (NAT) positive donors to HCV negative kidney recipients (D+/R?). In Group 1, 10 patients received one dose of SOF/VEL (sofusbuvir/velpatasvir) pretransplant and one dose on posttransplant Day 1. In Group 2A (N = 15) and the posttrial validation (Group 2B; N = 25) phase, patients received two additional SOF/VEL doses (total 4) on Days 2 and 3 posttransplant. Development of posttransplant HCV transmission triggered 12‐week DAA therapy. For available donor samples (N = 27), median donor viral load was 1.37E + 06 IU/mL (genotype [GT]1a: 70%; GT2: 7%; GT3: 23%). Overall viral transmission rate was 12% (6/50; Group 1:30% [3/10]; Group 2A:13% [2/15]; Group 2B:4% [1/25]). For the 6 viremic patients, 5 (83%) achieved sustained virologic response (3 with first‐line DAA therapy; and two after retreatment with second‐line DAA). At a median follow‐up of 8 months posttransplant, overall patient and allograft survivals were 98%, respectively. The 4‐day strategy reduced viral transmission to 7.5% (3/40; 95% confidence interval [CI]: 1.8%‐20.5%) and could result in avoidance of prolonged posttransplant DAA therapy for most D+/R ? transplants.     

Surgical delivery of drug releasing poly(lactic-co-glycolic acid)/poly(ethylene glycol) paste with in vivo effects against glioblastoma

Introduction

The median survival of patients with glioblastoma multiforme (astrocytoma grade 4) remains less than 18 months despite radical surgery, radiotherapy and systemic chemotherapy. Surgical implantation of chemotherapy eluting wafers into the resection cavity has been shown to improve length of survival but the current licensed therapy has several drawbacks. This paper investigates in vivo efficacy of a novel drug eluting paste in glioblastoma.

Methods

Poly(lactic-co-glycolic acid)/poly(ethylene glycol) (PLGA/PEG) self-sintering paste was loaded with the chemotherapeutic agent etoposide and delivered surgically into partially resected tumours in a flank murine glioblastoma xenograft model.

Results

Surgical delivery of the paste was successful and practical, with no toxicity or surgical morbidity to the animals. The paste was retained in the tumour cavity, and preliminary results suggest a useful antitumour and antiangiogenic effect, particularly at higher doses. Bioluminescent imaging was not affected significantly by the presence of the paste in the tumour.

Conclusions

Chemotherapy loaded PLGA/PEG paste seems to be a promising technology capable of delivering active drugs into partially resected tumours. The preliminary results of this study suggest efficacy with no toxicity and will lead to larger scale efficacy studies in orthotopic glioblastoma models.     

Platelet-derived growth factor in vivo: levels, activity, and rate of clearance

Platelet-derived growth factor (PDGF) is a potent mitogen for many cultured connective tissue cells. It is present in concentrated form within the platelet alpha-granules and is believed to be released during platelet degranulation at sites of vascular injury. We have used a sensitive radioreceptor assay to measure PDGF levels in whole blood serum from normal humans [17.5 +/- 3.1 (SD) ng/mL] and baboons (2.7 +/- 1.2 ng/mL). PDGF was not detected in plasma from either species. In addition, plasma was found to substantially reduce the ability of added purified PDGF to bind to the cell surface PDGF receptor on cultured cells, suggesting that plasma may contain a PDGF-binding protein that would serve to inactivate PDGF released into plasma. Calculations of PDGF concentrations in serum have been corrected for the effects of the binding protein. 125I-PDGF injected intravenously into normal baboons was cleared rapidly from the plasma (t1/2 = two minutes). The rapid clearance of 125I-PDGF did not result from iodination damage, as purified unlabeled PDGF was cleared with comparable kinetics. The rapid clearance of purified and iodinated PDGF did not result from changes in PDGF structure during purification or from removal of PDGF-associated proteins during purification, as PDGF present in freeze-thaw lysates of fresh platelets was cleared equally rapidly. We conclude that release of PDGF at sites of vascular injury would greatly increase the local concentration of PDGF and that PDGF not localized to the site of injury would be rapidly cleared from the circulation.     

From confluent human iPS cells to self-forming neural retina and retinal pigmented epithelium

Progress in retinal-cell therapy derived from human pluripotent stem cells currently faces technical challenges that require the development of easy and standardized protocols. Here, we developed a simple retinal differentiation method, based on confluent human induced pluripotent stem cells (hiPSC), bypassing embryoid body formation and the use of exogenous molecules, coating, or Matrigel. In 2 wk, we generated both retinal pigmented epithelial cells and self-forming neural retina (NR)-like structures containing retinal progenitor cells (RPCs). We report sequential differentiation from RPCs to the seven neuroretinal cell types in maturated NR-like structures as floating cultures, thereby revealing the multipotency of RPCs generated from integration-free hiPSCs. Furthermore, Notch pathway inhibition boosted the generation of photoreceptor precursor cells, crucial in establishing cell therapy strategies. This innovative process proposed here provides a readily efficient and scalable approach to produce retinal cells for regenerative medicine and for drug-screening purposes, as well as an in vitro model of human retinal development and disease.Irreversible blindness caused by retinal diseases, such as inherited retinopathies, age-related macular degeneration (AMD), or glaucoma, is mainly due to the impairment or loss of function of photoreceptor cells, supporting retinal pigmented epithelium (RPE) or retinal ganglion cells (RGCs). Rescuing the degenerated retina is a major challenge for which specific cell replacement is one of the most promising approaches (1, 2). Pluripotent stem cells, like human embryonic stem cells (hESCs) or induced pluripotent stem cells (hiPSCs), have the ability to be expanded indefinitely in culture and could be used as an unlimited source of retinal cells for the treatment of retinal degenerative diseases (3, 4). Several publications have indicated that hESCs and hiPSCs can be differentiated into RPE cells spontaneously after fibroblast growth factor (FGF) 2 removal (5–7) or by different floating aggregate methods (8–11). Concerning neural retinal cells, a growing body of convergent data has demonstrated the ability of hESCs or hiPSCs to be committed into the neural retinal lineage and further differentiated into cells expressing photoreceptor markers (12–15). Recent innovative approaches using 3D cultures from embryoid bodies (EBs) of hESCs or hiPSCs allowed the self-formation of optic cup (OC) structures (16) or the generation of optic vesicle (OV)-like structures (17), depending on the addition of exogenous molecules and different substrates used. These protocols require multiple steps and trained handling, which are not always compatible with the manufacturing process for therapeutic approach or drug screening that need a large-scale production of cells of interest. Therefore, very simple and reliable approaches minimizing the use of exogenous molecules should be developed to generate hESCs or hiPSC-derived retinal cells.In the present study, we report a new retinal differentiation process using confluent hiPSCs, without cell clumps or EB formation and in the absence of Matrigel or serum. We demonstrate that integration-free hiPSCs derived from adult human dermal fibroblasts (AHDFs) cultured in proneural medium can simultaneously generate RPE cells and self-forming neural retinal (NR)-like structures within 2 wk and that, when switched to floating cultures, structures containing retinal progenitor cells (RPCs) can differentiate into all retinal cell types, including RGCs and precursors of photoreceptors, needed for therapeutic applications.