Respiration-Based Measurement of Lung Deposition of a Fluorescent Dextrane Aerosol in a Marmoset Monkey

A technique for measurement of respiration-based lung deposition of an aerosol was investigated and subsequently applied in a pilot study with a marmoset monkey. The technique consisted of an aerosol exposure system for a marmoset using a face mask and a previously constructed monkey chair, a method for recovery of fluorescent dextrane from lung material, and respiration measurement of the marmoset by whole-body plethysmography. In the pilot study, a ketamine-anesthetized marmoset was exposed for 20 min to an FITC–dextrane aerosol atmosphere (200 μg/L air, particle size 1.5 μm mass median aerodynamic diameter [MMAD]). It was found that 3.4% of the inhaled aerosol was deposited in the lungs; the aerosol was distributed over the lung lobes with an higher concentration at the distal side.     

Phenotypic and functional reversal within the early human hematopoietic compartment

The fate of phenotypically defined human hematopoietic stem cells (hHSCs) in culture and the link between their surface marker expression profile and function are still controversial. We studied these aspects of hHSC biology by relating the expression of the early lineage markers (ELM) CD33, CD38, and CD71 on the surface of human umbilical cord blood (UCB) CD34(+) cells to their long-term nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse repopulation activity (LT-SRA). In uncultured UCB samples, LT-SRA was largely confined to the small CD34(+)ELM(-) cell fraction. CD34(+) cells expressing ELM markers at their surface usually lacked LT-SRA. After culturing UCB CD34(+) cells for 6 days in serum-free medium and on a feeder layer of Rat2 cells, the number of CD34(+)ELM(-) cells stayed roughly the same or showed a slight increase and the LT-SRA was preserved, suggesting a close association between LT-SRA and the CD34(+)ELM(-) phenotype. Indeed, transplantation of CD34(+)ELM(-) cells isolated from cultured UCB CD34(+) cells resulted in long-term hematopoietic reconstitution of conditioned NOD/SCID mice, whereas CD34(+)ELM(+) cells derived from the same cultures were devoid of LT-SRA. Remarkably, roughly 1% of the cells recovered from cultures initiated with isolated CD34(+)ELM(+) cells had lost ELM surface expression. Concurrently, the cultured CD34(+)ELM(+) cells acquired LT-SRA, suggesting that hematopoietic stem cells (HSCs) may arise by the dedifferentiation of early hematopoietic progenitor cells. The latter finding challenges the paradigm of unidirectional hematopoietic differentiation and opens new opportunities for HSC expansion prior to transplantation.     

An osteochondral culture model to study mechanisms involved in articular cartilage repair

Although several treatments for cartilage repair have been developed and used in clinical practice the last 20 years, little is known about the mechanisms that are involved in the formation of repair tissue after these treatments. Often, these treatments result in the formation of fibrocartilaginous tissue rather than normal articular cartilage. Because the repair tissue is inferior to articular cartilage in terms of mechanical properties and zonal organization of the extracellular matrix, complaints of the patient may return. The biological and functional outcome of these treatments should thus be improved. For this purpose, an in vitro model allowing investigation of the involved repair mechanisms can be of great value. We present the development of such a model. We used bovine osteochondral biopsies and created a system in which cartilage defects of different depths can be studied. First, our biopsy model was characterized extensively: we studied the viability by means of lactate dehydrogenase (LDH) excretion over time and we investigated expression of cartilage-related genes in osteochondral biopsies and compared it with conventional cartilage-only explants. After 28 days of culture, LDH was detected at low levels and mRNA could be retrieved. The expression of cartilage-related genes decreased over time. This was more evident in cartilage-only explants, indicating that the biopsy model provided a more stable environment. We also characterized the subchondral bone: osteoclasts and osteoblasts were active after 28 days of culture, which was indicated by tartrate acid phosphatase staining and alkaline phosphatase measurements, respectively, and matrix deposition during culture was visualized using calcein labeling. Second, the applicability of the model was further studied by testing two distinct settings: (1) implantation of chondrocytes in defects of different depths; (2) two different seeding strategies of chondrocytes. Differences were observed in terms of volume and integration of newly formed tissue in both settings, suggesting that our model can be used to model distinct conditions or even to mimic clinical treatments. After extensive characterization and testing of our model, we present a representative and reproducible in vitro model that can be used to evaluate new cartilage repair treatments and study mechanisms in a controlled and standardized environment.     

Supplementation with a fish oil-enriched, high-protein medical food leads to rapid incorporation of EPA into white blood cells and modulates immune responses within one week in healthy men and women

Immune modulatory effects of EPA and DHA are well described. However, these fatty acids must be effectively incorporated into cell membrane phospholipids to modify cell function. To address the absence of human data regarding short-term incorporation, the present study investigated the incorporation of EPA and DHA into white blood cells (WBC) at different time points during 1 wk of supplementation with a medical food, which is high in protein and leucine and enriched with fish oil and specific oligosaccharides. Additionally, the effects on ex vivo immune function were determined. In a single-arm, open label study, 12 healthy men and women consumed 2 × 200 mL of medical food providing 2.4 g EPA, 1.2 g DHA, 39.7 g protein (including 4.4 g L-leucine), and 5.6 g oligosaccharides daily. Blood samples were taken at d 0 (baseline), 1, 2, 4, and 7. Within 1 d of nutritional intervention, the percentage of EPA in phospholipids of WBC increased from 0.5% at baseline to 1.3% (P < 0.001). After 1 wk, the percentage of EPA rose to 2.8% (P < 0.001). Additionally, the production of proinflammatory cytokines in LPS-stimulated whole blood cultures was significantly increased within 1 wk. Nutritional supplementation with a fish oil-enriched medical food significantly increased the percentage of EPA in phospholipids of WBC within 1 wk. Simultaneously, ex vivo immune responsiveness to LPS increased significantly. These results hold promise for novel applications such as fast-acting nutritional interventions in cancer patients, which should be investigated in future studies.     

Meningeal irritation

Diagnosing meningitis requires the information from both history-taking and physical examination in its entirety. In adults with a history that makes meningitis a possibility, specific tests used to diagnose meningeal irritation, such as for Kernig or Brudzinski signs or nuchal rigidity, probably do not affect the reliability of the diagnosis. In small children and the elderly, Kernig and Brudzinski signs are also probably of little or no diagnostic value.     

Catastrophic antiphospholipid syndrome during pregnancy

Antiphospholipid syndrome (APS) had been previously diagnosed in three pregnant women aged 32, 27 and 36 years, respectively. All three of them were using low-molecular weight heparin for the prevention of thromboembolic complications. The first two women were admitted because of foetal growth retardation. In the first patient, either HELLP syndrome or exacerbation of APS was suspected. A caesarean section was performed due to foetal distress. The patient's condition deteriorated further postoperatively. Multiple infarctions in liver and placenta were identified. Catastrophic antiphospholipid syndrome (CAPS) was diagnosed. Despite intensive medical treatment including anticoagulation the patient died of massive pulmonary embolism. The second patient suffered from thrombocytopaenia, disturbances in hepatic function and epigastric pain. CAPS was diagnosed. The condition improved after treatment with glucocorticoids, but because of a poor foetal prognosis, delivery was induced and a lifeless son was born. The third woman was admitted due to pyelonephritis. Shortly thereafter, symptoms of HELLP syndrome developed and she was administered glucocorticoids. Hepatic infarcts and petechiae developed, indicating CAPS. Delivery was induced and a girl was born. Glucocorticoid treatment was resumed and combined with immunoglobulins and plasmapheresis. The patient recovered and was discharged together with her daughter. CAPS is a life-threatening variation of APS. It is characterised by multiple thromboses and rapidly progressive multi-organ failure. Mortality is high, but seems to diminish with treatment by immunosuppressive therapy. In pregnancy, clinical signs of CAPS are similar to those of HELLP syndrome. Since the treatment for HELLP syndrome is different from CAPS, a correct diagnosis is essential. Because of the rarity of this condition in combination with high rates of perinatal and maternal mortality, care for pregnant patients with APS should be centralised in academic centres and close cooperation between obstetricians and internal medicine is necessary.     

Perceived risk,anxiety, and behavioural responses of the general public during the early phase of the Influenza A (H1N1) pandemic in the Netherlands: results of three consecutive online surveys

Background  

Research into risk perception and behavioural responses in case of emerging infectious diseases is still relatively new. The aim of this study was to examine perceptions and behaviours of the general public during the early phase of the Influenza A (H1N1) pandemic in the Netherlands.     

Stereotactic body radiotherapy for oligometastatic soft tissue sarcoma

Background

Stereotactic body radiotherapy (SBRT) is emerging as a novel treatment option in metastatic soft tissue sarcoma (STS). The aim of our study was to evaluate the effectiveness of exclusive SBRT on disease control and survival in oligometastatic (≤?3 synchronous lesions) STS.

Materials and methods

In total, 16 consecutive patients, accounting for 26 metastases (including 21 lung and 5 lymph node or soft tissue metastases), were treated at our institution with SBRT. Patient- and treatment-related characteristics were collected. Local control (LC), overall survival (OS), distant metastases-free survival (DMFS), and time to initiation of chemotherapy or best supportive care (corrected disease-free survival, cDFS) were assessed.

Results

Four-year OS was 54% and median OS was 69 months [95% confidence interval (CI) 20–118 months]. LC of 26 lesions at 4 years was 78%. Median DMFS and cDFS were 17 (95% CI 5–30 months) and 28 months (95% CI 5–52 months), respectively. Disease-free interval <?24 months from primary tumor treatment to first metastasis was the only predictor of reduced LC, cDFS, and OS (p?=?0.022, 0.023, and 0.028, respectively). No acute or chronic grade ≥?3 toxicity was observed. Median follow-up was 36 months (IQR 18–71 months).

Conclusions

In patients with oligometastatic STS, SBRT yields satisfying local control with minimal toxicity. Median OS was 69 months. Repeated SBRT may be considered to extend disease-free and systemic therapy-free interval. Increased time from primary tumor to first metastasis identifies patients with potentially greater benefit from SBRT.