Custom-engineered hydrogels for delivery of human iPSC-derived neurons into the injured cervical spinal cord.

Cervical damage is the most prevalent type of spinal cord injury clinically, although few preclinical research studies focus on this anatomical region of injury. Here we present a combinatorial therapy composed of a custom-engineered, injectable hydrogel and human induced pluripotent stem cell (iPSC)-derived deep cortical neurons. The biomimetic hydrogel has a modular design that includes a protein-engineered component to allow customization of the cell-adhesive peptide sequence and a synthetic polymer component to allow customization of the gel mechanical properties. In vitro studies with encapsulated iPSC-neurons were used to select a bespoke hydrogel formulation that maintains cell viability and promotes neurite extension. Following injection into the injured cervical spinal cord in a rat contusion model, the hydrogel biodegraded over six weeks without causing any adverse reaction. Compared to cell delivery using saline, the hydrogel significantly improved the reproducibility of cell transplantation and integration into the host tissue. Across three metrics of animal behavior, this combinatorial therapy significantly improved sensorimotor function by six weeks post transplantation. Taken together, these findings demonstrate that design of a combinatorial therapy that includes a gel customized for a specific fate-restricted cell type can induce regeneration in the injured cervical spinal cord.

Health status and disease burden of unaccompanied asylum-seeking adolescents in Bielefeld, Germany: cross-sectional pilot study.

OBJECTIVE: This exploratory pilot study aimed to investigate the physical and mental disease burden of unaccompanied asylum-seeking adolescents arriving in Bielefeld, a medium-size city in Germany. METHODS: A cross-sectional survey with purposive sampling of 102 unaccompanied asylum-seeking adolescents aged 12-18 years was performed. Information on general health status, selected infectious and non-communicable diseases, iron deficiency anaemia and mental illness was collected during routine check-up medical examinations upon arrival in Bielefeld, Germany. The data were analysed using descriptive statistics. RESULTS: The analysis revealed a complex disease burden with a high prevalence of infections (58.8%), mental illness (13.7%) and iron deficiency anaemia (17.6%) and a very low prevalence of non-communicable diseases (<2.0%). One in five of the refugees were infected with parasites. Whilst sub-Saharan Africans showed the highest prevalence of infections (86.7%), including highest prevalences of parasites (46.7%), West Asians had the highest prevalence of mental disorders (20.0%). Overall, the disease burden in females was higher. CONCLUSION: A thorough medical and psychological screening after arrival is highly recommended to reduce the individual disease burden and the risk of infection for others. This promotes good physical and mental health, which is needed for successful integration into the receiving society. Barriers to health service access for unaccompanied asylum-seeking adolescents need to be lowered to allow need-specific health care and prevention.

Hemodynamic alterations in vertebrobasilar large artery disease assessed by arterial spin-labeling MR imaging.

BACKGROUND AND PURPOSE: VB artery stenosis is associated with a high risk of recurrent ischemic events, and knowledge about the hemodynamic relevance of VB stenosis is important for clinical decision making. In this study, multiple inflow pulsed ASL MR imaging was assessed for its ability to measure CBF and ATT in patients with VB disease. MATERIALS AND METHODS: ASL was performed on a 3T MR imaging scanner in 41 participants. Twenty-one patients had a history of ischemic events in the VB circulation (14 men, 7 women, age 66 ± 11 years). Clinical data and CE-MRA were used to classify VB disease severity. Twenty age-matched adults were controls. Group and within-VB analyses were performed. Mean CBF and ATT values in the ROIs were adjusted by excluding voxels that did not produce a reliable ASL estimate. RESULTS: CBF was reduced (P < .003) in patients compared with controls, which was significant after excluding voxels with a poor fit. Differences in ATT between patients and controls were not significant after voxel correction. There was a strong correlation between CBF and ATT among patients. Finally, ATT was significantly correlated with VB disease severity (P = .026). CONCLUSIONS: Multiple inflow ASL distinguished patients with VB disease from age matched-controls. VB disease rating was associated with prolonged ATT downstream. ASL may have diagnostic potential among patients in whom risk of intervention is high.

Fabry disease in unselected patients with TIA or stroke: population-based study.

BACKGROUND: Fabry disease (FD) is an X-linked lysosomal storage disorder frequently associated with cerebrovascular disease. In recent years, the prevalence of FD has been reported to be up to 4% in cryptogenic young stroke patients. However, there have been no population-based studies in unselected patients with transient ischaemic attack (TIA) or stroke across the full range of ages. METHODS: We determined the prevalence of FD mutations in consecutive patients from a population-based study of acute TIA or ischaemic stroke (Oxford Vascular Study). Analysis included amplifying of the α-galactosidase A gene by polymerase chain reaction, denaturing high-performance liquid chromatography (dHPLC) analysis and sequencing using standard automated sequencing protocols [Mutation Surveyor software (Softgenetics)] where the dHPLC indicated a possible mutation. RESULTS: Samples of 1046 consecutive patients (52% women; mean age 73.2 years; 15% age <60 years; 572 stroke; 474 TIA) were tested. No patient had a known gene mutation causing FD, giving an upper 95% confidence interval around the estimated frequency of 0.35% overall and 2.37% in the 154 patients aged under 60 years. However, in 5 (0.48%) samples, a known polymorphism or sequence variation in the gene was identified that can be associated with lower than normal enzyme activity in plasma without causing the full clinical manifestation of FD. CONCLUSIONS: Fabry disease is rare in an unselected group of UK patients with TIA or stroke. Larger studies in unselected younger patients with cryptogenic stroke are required to determine whether routine screening is justified in this group.

[Idiopathic orbital inflammation syndrome in childhood--case report and literature review]. / Idiopathische orbitale Entzündung im Kindesalter--Fallbericht und Literaturreview.

BACKGROUND: Idiopathic orbital inflammation syndrome (IOIS) is a rare disease in childhood. There are only ca. 70 case reports in the scientific literature. METHOD: We present a case report and review of literature. CASE REPORT: A 6-year-old girl developed within one week beginning with a discrete, non-traumatic haemorrhage of the lower palpebra a painful proptosis, periorbital swelling, conjunctival chemosis and injection and motility restriction to lateral gaze of the right eye. MRI showed a retrobulbar and eyelid mass with enhancement and signs of haemorrhage without optic nerve involvement. A rapidly performed biopsy excluded malignancies and confirmed the diagnosis of non-specific inflammation. With high-doses of intravenous and later oral prednisolone the symptoms improved significantly. Because of an impairment under tapering of prednisolone an interim elevation of the dose was necessary, but with very slow tapering over 4.5 months the girl became symptom-free except for a minimal, non-relevant abduction deficit. There has been no recurrence in the last 1.5 years. DISCUSSION: In comparison to the clinical features of adults the rarely reported childhood cases show no relevant differences in orbital signs, frequency of bilaterality and pain, recurrence rate and success of therapy. Only iritis and papilloedema seem to be special features of childhood IOIS, these cases tend to a higher rate of recurrences. Histopathological examination is much more necessary than in adults because of the need for exclusion of rhabdomyosarcoma. Our case shows that haemorrhages can also be a sign for an IOIS.

Preliminary evidence of a high risk of bleeding on aspirin plus clopidogrel in aspirin-naïve patients in the acute phase after TIA or minor ischaemic stroke.

BACKGROUND: Aspirin plus clopidogrel (A+C) may be more effective than aspirin only (AO) acutely after TIA and minor stroke, but the risk of bleeding in the acute phase is uncertain. We determined this risk, focusing particularly on aspirin-naïve patients. METHODS: We studied consecutive referrals to the EXPRESS study clinic from 1/4/02 to 31/3/08. A 30- to 90-day course of A+C was given to patients presenting acutely. Bleeding events were identified by face-to-face follow-up, diagnostic coding, and blood transfusion data. Unpublished data from the FASTER pilot trial were also studied. RESULTS: Among 633 EXPRESS patients treated with aspirin (+/- clopidogrel), there were 12 spontaneous bleeds (6 minor, 6 major/life-threatening) within 90 days after assessment, with a higher risk for A+C vs. AO (8/247 vs. 4/386, p = 0.047 overall; 5/247 vs. 1/386, p = 0.03 for major/life-threatening bleeds). The excess of major/life-threatening bleeds on A+C vs. AO was seen in aspirin-naïve patients, (4/137 vs. 0/273, p = 0.01), but not in prior-aspirin patients (1/110 vs. 1/113, p = 0.98). All symptomatic bleeds in the FASTER pilot also occurred in aspirin-naïve patients randomized to A+C (6/104 vs. 0/94, p = 0.03). In a pooled analysis, major/life-threatening bleeding on A+C occurred in 9/241 aspirin-naïve patients (90-day risk = 4.8%, 1.6-8.0) versus 1/204 prior-aspirin patients (p = 0.009). CONCLUSION: Although based on relatively few outcomes, the high risk of major bleeding on A+C acutely after TIA or minor stroke in aspirin-naïve patients is a cause for concern. The potential risk to patients is sufficient to mandate detailed monitoring of bleeding risk in ongoing trials and stratify results by whether patients were aspirin-naïve.

Leukocyte-platelet aggregates in acute and subacute ischemic stroke.

BACKGROUND: Leukocyte-platelet aggregates appear to be a stable and sensitive marker of platelet activation as suggested by studies in coronary heart disease. We tested the hypothesis that leukocyte-platelet aggregates are increased after ischemic stroke and investigated the contribution of different leukocyte subtypes to such increase. METHODS: We serially determined granulocyte-, lymphocyte- and monocyte-platelet aggregates, using flow cytometry at days 1, 2, 3, 5, 7, 10, and 90 in patients with ischemic stroke (n = 45) and in age- and sex-matched healthy control subjects (n = 30). RESULTS: Granulocyte-platelet aggregates (granulocytes with > or =1 platelet/microl) were more common in patients than control subjects from day 1 through day 10 (p < 0.04, respectively), but not on day 90 after stroke. The percentage of granulocytes forming aggregates was increased on days 1-3 after stroke but not at other time points. Lymphocyte-platelet aggregates were not more common at any time point after stroke. Total numbers and percentages of monocytes forming platelet aggregates were significantly increased on day 2 (p = 0.003), but not at other time points after stroke. CONCLUSION: The 3 leukocyte subtypes showed different kinetics regarding aggregate formation with platelets after ischemic stroke. Increase of monocyte-platelet aggregates is short-lived and may reflect an acute reaction to cerebral ischemia, whereas granulocyte-platelet aggregate formation persists into the subacute phase, suggesting that they are a particularly sensitive parameter reflecting both prothrombotic and inflammatory processes after stroke.

Population-based study of risk and predictors of stroke in the first few hours after a TIA.

BACKGROUND: Several recent guidelines recommend assessment of patients with TIA within 24 hours, but it is uncertain how many recurrent strokes occur within 24 hours. It is also unclear whether the ABCD2 risk score reliably identifies recurrences in the first few hours. METHODS: In a prospective, population-based incidence study of TIA and stroke with complete follow-up (Oxford Vascular Study), we determined the 6-, 12-, and 24-hour risks of recurrent stroke, defined as new neurologic symptoms of sudden onset after initial recovery. RESULTS: Of 1,247 first TIA or strokes, 35 had recurrent strokes within 24 hours, all in the same arterial territory. The initial event had recovered prior to the recurrent stroke (i.e., was a TIA) in 25 cases. The 6-, 12-, and 24-hour stroke risks after 488 first TIAs were 1.2% (95% confidence interval [CI]: 0.2-2.2), 2.1% (0.8-3.2), and 5.1% (3.1-7.1), with 42% of all strokes during the 30 days after a first TIA occurring within the first 24 hours. The 12- and 24-hour risks were strongly related to ABCD2 score (p = 0.02 and p = 0.0003). Sixteen (64%) of the 25 cases sought urgent medical attention prior to the recurrent stroke, but none received antiplatelet treatment acutely. CONCLUSION: That about half of all recurrent strokes during the 7 days after a TIA occur in the first 24 hours highlights the need for emergency assessment. That the ABCD2 score is reliable in the hyperacute phase shows that appropriately triaged emergency assessment and treatment are feasible.

Incidence and prognosis of > or = 50% symptomatic vertebral or basilar artery stenosis: prospective population-based study.

The higher risk of early recurrent stroke after posterior circulation transient ischaemic attack or minor stroke versus after carotid territory events could be due to a greater prevalence of large artery stenosis, but there have been few imaging studies, and the prognostic significance of such stenoses is uncertain. Reliable data are necessary to determine the feasibility of trials of angioplasty and stenting and to inform imaging strategies. In the first-ever population-based study, we determined the prevalence of > or = 50% apparently symptomatic vertebral and basilar stenosis using contrast-enhanced MRA in consecutive patients, irrespective of age, presenting with posterior circulation transient ischaemic attack or minor ischaemic stroke in the Oxford Vascular Study and related this to the 90-day risk of recurrent transient ischaemic attack and stroke. For comparison, we also determined the prevalence of > or = 50% apparently symptomatic carotid stenosis on ultrasound imaging in consecutive patients with carotid territory events. Of 538 consecutive patients, 141/151 (93%) had posterior circulation events and had vertebral and basilar imaging, of whom 37 (26.2%) had > or = 50% vertebral and basilar stenosis, compared with 41 (11.5%) patients with > or = 50% ipsilateral carotid stenosis in 357/387 (92%) patients with carotid events who had carotid imaging (OR = 2.74; 95% CI = 1.67-4.51; P = 0.002). Presence of > or = 50% vertebral and basilar stenosis was unrelated to age, sex or vascular risk factors and, in contrast to > or = 50% carotid stenosis was not associated with evidence of coronary/peripheral atherosclerosis. In patients with posterior circulation events, > or = 50% vertebral and basilar stenosis was associated multiple transient ischaemic attacks at presentation (22% versus 3%; OR = 9.29; 95% CI = 2.31-37.27; P < 0.001) and with a significantly higher 90-day risk of recurrent events (OR = 3.2; 95% CI = 1.4-7.0; P = 0.006), reaching 22% for stroke and 46% for transient ischaemic attack and stroke. The prevalence of > or = 50% vertebral and basilar stenosis in posterior circulation transient ischaemic attack or minor stroke is greater than the prevalence of > or = 50% carotid stenosis in carotid territory events, and is associated with multiple transient ischaemic attacks at presentation and a high early risk of recurrent stroke. Trials of interventional treatment are therefore likely to be feasible, but more data are required on the long-term risk of stroke on best medical treatment.

[Intracranial bleeding in acquired hemophilia]. / Intrakranielle Blutung bei erworbener Hemmkörperhämophilie.

Acquired hemophilia is a rare complication in autoimmune disorders and malignancies. It can result in bleedings into skin and muscle, whereas intracranial hemorrhage in adults has so far not been described. We report a patient with acute intracerebral hemorrhage due to acquired hemophilia with factor VIII inhibition. The patient was treated with recombinant factor VIIa and open hematoma evacuation followed by administration of cortisone and cyclophosphamide. After good initial recovery, intracerebral rebleeding occurred and the patient died from brainstem compression.

Isolated diffuse hemangiomatosis of the spleen: case report and review of literature.

Small localized hemangiomas are common neoplasms of the spleen. Isolated diffuse splenic hemangiomatosis, however, is very rare. This lesion can be accompanied by severe hypersplenism and other complications. We report on a case with significant splenomegaly caused by diffuse hemangiomatosis, which was an incidental finding without any clinical disorders. After splenectomy, the normal parenchyma was found to be widely replaced by multiple spongy nodules. Histologically, cavernous vessels were distributed throughout the whole organ, with endothelial cells expressing vimentin, factor VIII and CD 31, but not CD8. Splenic sinus lining cells exhibited a strongly positive reaction with CD8, which became faint and disrupted in highly dilated sinuses in the vicinity of cavernous vessels. In some areas, there seemed to be a gradual transition from cystically dilated splenic sinuses to cavernous vessels. The differential diagnosis must consider other splenic vascular tumors, such as littoral cell angioma, lymphangioma, peliosis of the spleen, and hamartoma. The pathogenesis of diffuse splenic hemangiomatosis is controversial, and a malformative or neoplastic origin is under debate. A derivation from splenic sinusoidal cells was suggested by some authors, but was rejected by others. Our findings cannot exclude a neoplastic origin from splenic sinuses but, finally, the etiology and pathogenesis of this vascular lesion remain uncertain.

Green tea extract and its polyphenols markedly inhibit luminol-dependent chemiluminescence activated by peroxynitrite or SIN-1.

This study is based on a simple chemical interaction of peroxynitrite (OONO-) and luminol, which produces blue light upon oxidation. Since peroxynitrite has a half-life of less than 1 s, a drug known as SIN-1 is used as a peroxynitrite generator. In addition peroxynitrite itself was used directly with a fast injection-mixing system to ascertain whether there are differences between it and the peroxynitrite-generating system (SIN-1) which mimics the natural production of (OONO-). Peroxynitrite is a potent oxidizing compound (1000 times more active than equidose hydrogen peroxide) and it can oxidize carbohydrates, lipids, proteins and nucleic acids. Upon stimulation by inflammation and/or infection, macrophages and neutrophils can be activated to produce large amounts of peroxynitrite. We are interested in simple chemicals that are non-toxic that could inhibit or destroy peroxynitrite, which might otherwise cause inappropriate damage to blood and tissues. Green tea is a complex mixture containing several potent major antioxidant constituents, eg flavins and/or polyphenols. The constituents in green tea may react directly or indirectly with peroxynitrite or its constituents through the process of antioxidation to inhibit light. Alternatively, compounds could produce superoxide which, when reacted with nitric oxide, could produce more peroxynitrite and hence more light with luminol. Therefore, as the tea or antioxidants from tea are diluted, while the peroxynitrite or its precursors are kept at a constant concentration, one can observe unusual behaviour regarding light emission. Initially, at high doses of tea or antioxidant, one observes clear inhibition of the light generated from the reaction of peroxynitrite and luminol. However, at dilute concentrations of antioxidants, one can often observe stimulation of light. Possible reasons for these observations are discussed.

The effect of two handling and slaughter systems on skin damage, meat acidification and colour in pigs.

In order to minimize the high proportion of carcass and meat quality defects recorded in commercially slaughtered pigs, the optimum handling, stunning and bleeding-out conditions must be implemented. In this study improvements in pig handling resulted in the elimination of electric goading within the raceways, which reduced the skin blemish score by 50%. Furthermore, the application of higher stunning voltage (200 V) and the immediate bleeding-out in the prone position improved the post-mortem acidification rate in the Longissimus thoracis (LT) and Semimembranosus (SM) muscles. This resulted in a sharp reduction of the PSE incidence in both muscles. A positive effect on muscle metabolism was also showed by the lower release of CPK into the bloodflow. These results show that, under commercial conditions, the design of slaughter handling systems and the slaughter procedures can have an effect on skin damage and on the quality of the pig meat.

Near-infrared spectroscopic measurement of glucose in a protein matrix.

A method is described for measuring clinically relevant levels of glucose in a protein matrix by near-infrared (near-IR) absorption spectroscopy. Results from an initial screening of major blood constituents identify protein as a major potential interference to the near-IR measurement of glucose in blood. The interference by protein is caused by relatively high concentrations coupled with strong near-IR absorption bands between 5000 and 4000 cm-1 (2.0-2.5 microns). Calibration models based on a simple univariate calibration procedure are not capable of providing accurate glucose concentrations from an independent set of prediction spectra. By use of the multivariate technique of partial least squares (PLS) regression, glucose concentrations can be determined with a 0.35 mM (6.3 mg/dL) standard error of prediction. The spectral range for this calibration model extends from 4600 to 4200 cm-1, and the optimum number of PLS factors is 14. In addition, calibration models based on a combination of digital Fourier filtering and PLS regression have been constructed and evaluated. Superior calibration models are obtained by using a preprocessing digital filtering step to remove spectral features not associated with glucose. The best overall calibration model was obtained by using a Gaussian-shaped Fourier filter defined by a mean position of 0.03f and standard deviation of 0.007f coupled with a 12-factor PLS regression computed over the spectral range from 4600 to 4200 cm-1. This model provided a standard error of prediction of 0.24 mM (4.3 mg/dL) for an independent set of prediction spectra.(ABSTRACT TRUNCATED AT 250 WORDS)

Strategies for coupling digital filtering with partial least-squares regression: application to the determination of glucose in plasma by Fourier transform near-infrared spectroscopy.

Protocols are established for coupling digital filtering techniques with partial least-squares (PLS) regression for use in constructing multivariate calibration models from Fourier transform near-infrared absorbance spectra. Calibration models are developed to predict glucose concentrations in bovine plasma samples. Employing a calibration data set of 300 spectra collected from 55 plasma samples and 3 plasma lots, individual calibration models are developed based on four spectral ranges selected from the region 5000-4000 cm-1. A separate test set of 69 spectra collected from 14 plasma samples is used to evaluate the computed models. Gaussian-shaped bandpass digital filters are implemented by use of Fourier filtering techniques and employed to preprocess spectra to remove variation due to the background absorbance of the plasma matrix. PLS regression is used with the filtered spectra to compute calibration models for glucose. The optimization of the filter bandpass parameters is explored through the use of response surface methods. Through these optimization studies, calibration models are developed that achieve standard errors of estimate and standard errors of prediction in the range 0.4-0.5 mM across the concentration range of 2.5-25.5 mM. It is determined that the use of digital filtering as a preprocessing step significantly improves the performance of the resulting calibration models, minimizes the importance of spectral range in the calibration model development, and reduces the required number of PLS factors in each model.