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1.
Otol Neurotol ; 43(6): 709-716, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35761466

ABSTRACT

OBJECTIVE: To report long-term patient reported outcome measures (PROMs) after standardized round window rein-forcement (RWR) with thin cartilage and perichondrium for superior semicircular canal dehiscence syndrome (SSCDS). METHODS: Cross-sectional survey in 2020 and retrospective longitudinal study of outcomes at 3 months, 1 year, and last follow-up after 28 consecutive RWRs. Endpoints were the last follow-up for PROMs and 1 year postoperatively for audiometry and cVEMP. RESULTS: At the last follow-up (mean 2.4 years postoperatively), improvement was reported for 19/28 ears (68%) in symptoms overall; for 17/27 ears (63%) in auditory symptoms, and for 12/24 (50%) in vestibular symptoms. Nine ears (32%) required further surgery. No major complications occurred. On the group level, postoperative improvement at 3 months declined significantly for auditory and vestibular symptoms over time, and stayed stable beyond 1 year. Improved ears had on average 2.9 years follow-up. Improvement correlated significantly with SSCD length, and was associated with contralateral dehiscence. Thirteen ears (46%) had another potential cause of vestibular symptoms. This group showed significantly less improvement. Audiometric test results did not predict PROMs. CONCLUSIONS: Since long-term outcomes do not compare with those reported for plugging and repair, RWR is not suggested as a first line intervention for SSCDS. Considering the stable rates of improvement on average 2.9 years postoperatively and the absence of major complications, RWR may be an alternative to plugging or repair in fragile patients who do not accept the risk of complications with more invasive surgery, and who accept that results may deteriorate over time.


Subject(s)
Otologic Surgical Procedures , Semicircular Canal Dehiscence , Cross-Sectional Studies , Humans , Longitudinal Studies , Otologic Surgical Procedures/methods , Retrospective Studies , Semicircular Canals/surgery
2.
Laryngoscope ; 132(2): 443-448, 2022 02.
Article in English | MEDLINE | ID: mdl-34487348

ABSTRACT

OBJECTIVES: Head trauma may cause dislodgement of otoconia and development of benign paroxysmal positional vertigo (BPPV). The risk of developing BPPV is expected to be highest shortly after the trauma, then decrease and approach the risk seen in the general population. The aim of this study was to estimate the risk-time curve of BPPV development after head trauma. STUDY DESIGN: Prospective observational study. METHODS: Patients with minimal, mild, or moderate head trauma treated at the Department of Neurosurgery or the Department of Orthopedic Emergency at Oslo University Hospital, were interviewed and examined for BPPV using the Dix-Hallpike and supine roll maneuvers. BPPV was diagnosed according to the International diagnostic criteria of the Bárány Society. Telephone interviews were conducted at 2, 6, and 12 weeks after the first examination. RESULTS: Out of 117 patients, 21% developed traumatic BPPV within 3 months after the trauma. The corresponding numbers were 12% with minimal trauma, 24% with mild, and 40% with moderate trauma. The difference in prevalence between the groups was significant (P = .018). During the first 4 weeks after the trauma, it was observed 20, 3, 0, and 1 BPPV onsets, respectively. No BPPV cases were seen for the remainder of the 3-month follow-up. CONCLUSION: The risk of developing BPPV after minimal-to-moderate head trauma is considerable and related to trauma severity. Most cases occur within few days after the trauma, but any BPPV occurring within the first 2 weeks after head trauma are likely due to the traumatic event. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:443-448, 2022.


Subject(s)
Benign Paroxysmal Positional Vertigo/etiology , Craniocerebral Trauma/complications , Benign Paroxysmal Positional Vertigo/epidemiology , Female , Humans , Injury Severity Score , Male , Middle Aged , Prospective Studies , Risk Assessment , Time Factors
3.
BMC Nurs ; 20(1): 58, 2021 Apr 09.
Article in English | MEDLINE | ID: mdl-33836734

ABSTRACT

BACKGROUND: In-hospital fall incidents are common and sensitive to nursing care. It is therefore important to have easy access to valid patient data to evaluate and follow-up nursing care. The aim of the study was to validate the nursing documentation, using a specific term in the registered nurses´ (RNs´) discharge note, regarding inpatient falls according to the outcome of a digitalized data extraction tool and the discharge note itself. METHODS: At a teaching hospital, 31,571 episodes of care were eligible for inclusion in this retrospective cohort study. A stratified sampling including five groups was used, two with random sampling and three with total sampling. In total, 1232 episodes of care were reviewed in the electronic patient record using a study-specific protocol. Descriptive statistics were used. RESULTS: In total, 590 episodes of care in the study cohort included 714 falls. When adjusted for the stratified sampling the cumulative incidence for the study population was 1.9%. The positive predictive value in total for the data extraction tool regarding the presence of any fall, in comparison with the record review, was 87.4%. Discrepancies found were, for example, that the RNs, at discharge, stated that the patient had fallen but no documented evidence of that could be detected during admission. It could also be the opposite, that the RNs correctly had documented that no fall had occurred, but the data extraction tool made an incorrect selection. When the latter had been withdrawn, the positive predictive value was 91.5%. Information about minor injuries due to the fall was less accurate. In the group where RNs had stated that the patient had fallen without injury, minor injuries had actually occurred in 28.3% of the episodes of care. CONCLUSIONS: The use of a specific term regarding fall in the RNs´ discharge note seems to be a valid and reliable data measurement and can be used continuously to evaluate and follow-up nursing care.

4.
Scand J Occup Ther ; 28(6): 446-456, 2021 Aug.
Article in English | MEDLINE | ID: mdl-32544360

ABSTRACT

BACKGROUND: There is growing evidence that people with serious mental illness have impaired capacity for processing sensory inputs which affects daily occupation. Although this is known, research regarding the target groups experiences of sensory inputs in daily occupations is lacking. AIM: To investigate the experience of sensory input and strategies used in daily occupations among people with serious mental illness. MATERIAL AND METHODS: Fourteen people with serious mental illness were interviewed regarding their experiences of sensory processing and strategies for managing sensory inputs in daily occupations. Data were analysed using content analysis. RESULTS: Sensory processing issues affected occupational engagement and strategies to control inputs were intuitively used to cope with sensory challenges. Informants either ignored, reduced or avoided sensory inputs. Informants also enabled daily life through strategies such as creating a home that provides rest, finding a safe place, using nature and animals for relaxing and using effects of calming and alerting occupations. DISCUSSION: Specific sensory inputs were difficult to process, which was experienced as stressful and affected occupations negatively. The results imply a need for further research exploring the management of sensory input and the use of sensory modulation approaches to enable engagement in daily activities.


Subject(s)
Mental Disorders , Occupations , Adaptation, Psychological , Humans
5.
Int J Pharm ; 511(1): 223-235, 2016 Sep 10.
Article in English | MEDLINE | ID: mdl-27349793

ABSTRACT

Hydroxypropyl cellulose (HPC) and ethyl cellulose (EC) can be used for extended release coatings, where the water-soluble HPC may act as a pore former. The aim was to investigate the effect of the molecular weight of HPC on the microstructure and mass transport in phase-separated freestanding EC/HPC films with 30% w/w HPC. Four different HPC grades were used, with weight averaged molecular weights (Mw) of 30.0 (SSL), 55.0 (SL), 83.5 (L) and 365 (M) kg/mol. Results showed that the phase-separated structure changed from HPC-discontinuous to bicontinuous with increasing Mw of HPC. The film with the lowest Mw HPC (SSL) had unconnected oval-shaped HPC-rich domains, leaked almost no HPC and had the lowest water permeability. The remaining higher Mw films had connected complex-shaped pores, which resulted in higher permeabilities. The highest Mw film (M) had the smallest pores and very slow HPC leakage, which led to a slow increase in permeability. Films with grade L and SL released most of their HPC, yet the permeability of the L film was three times higher due to greater pore connectivity. It was concluded that the phase-separated microstructure, the level of pore percolation and the leakage rate of HPC will be affected by the choice of HPC Mw grade used in the film and this will in turn have strong impact on the film permeability.


Subject(s)
Cellulose/analogs & derivatives , Polymers/chemistry , Water/chemistry , Cellulose/chemistry , Cellulose/pharmacokinetics , Delayed-Action Preparations/chemistry , Delayed-Action Preparations/pharmacokinetics , Drug Liberation , Molecular Weight , Polymers/pharmacokinetics , Water/metabolism
6.
J Control Release ; 222: 151-8, 2016 Jan 28.
Article in English | MEDLINE | ID: mdl-26686080

ABSTRACT

The characterization of the pore structure in pharmaceutical coatings is crucial for understanding and controlling mass transport properties and function in controlled drug release. Since the drug release rate can be associated with the film permeability, the effect of the pore structure on the permeability is important to study. In this paper, a new approach for characterizing the pore structure in polymer blended films was developed based on an image processing procedure for given two-dimensional scanning electron microscopy images of film cross-sections. The focus was on different measures for characterizing the complexity of the shape of a pore. The pore characterization developed was applied to ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) blended films, often used as pharmaceutical coatings, where HPC acts as the pore former. It was studied how two different HPC viscosity grades influence the pore structure and, hence, mass transport through the respective films. The film with higher HPC viscosity grade had been observed to be more permeable than the other in a previous study; however, experiments had failed to show a difference between their pore structures. By instead characterizing the pore structures using tools from image analysis, statistically significant differences in pore area fraction and pore shape were identified. More specifically, it was found that the more permeable film with higher HPC viscosity grade seemed to have more extended and complex pore shapes than the film with lower HPC viscosity grade. This result indicates a greater degree of connectivity in the film with higher permeability and statistically confirms hypotheses on permeability from related experimental studies.


Subject(s)
Cellulose/analogs & derivatives , Cellulose/chemistry , Delayed-Action Preparations/chemistry , Drug Delivery Systems , Permeability , Porosity , Viscosity , Water/chemistry
7.
Transpl Int ; 28(1): 42-51, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25176389

ABSTRACT

In a 36-month, open-label, multicenter trial, 202 kidney transplant recipients were randomized at week 7 post-transplant to convert to everolimus or remain on cyclosporine: 182 were analyzed to month 36 (92 everolimus, 90 controls). Mean (SD) change in measured GFR (mGFR) from randomization to month 36 was 1.3 (14.0) ml/min with everolimus versus -1.7 (15.4) ml/min in controls (P = 0.210). In patients who remained on treatment, mean mGFR improved from randomization to month 36 by 7.9 (11.5) ml/min with everolimus (n = 37) but decreased by 1.4 (14.7) ml/min in controls (n = 62) (P = 0.001). During months 12-36, death-censored graft survival was 100%, patient survival was 98.9% and 96.7% in the everolimus and control groups, respectively, and 13.0% and 11.1% of everolimus and control patients, respectively, experienced mild biopsy-proven acute rejection (BPAR). Protocol biopsies in a limited number of on-treatment patients showed similar interstitial fibrosis progression. Donor-specific antibodies were present at month 36 in 6.3% (2/32) and 18.0% (9/50) of on-treatment everolimus and control patients with available data (P = 0.281). During months 12-36, adverse events were comparable, but discontinuation was more frequent with everolimus (33.7% vs. 10.0%). Conversion from cyclosporine to everolimus at 7 weeks post-transplant was associated with a significant benefit in renal function at 3 years when everolimus was continued.


Subject(s)
Calcineurin Inhibitors/therapeutic use , Kidney Transplantation , Renal Insufficiency/surgery , Adult , Aged , Biopsy , Cyclosporine/therapeutic use , Everolimus , Female , Fibrosis/physiopathology , Glomerular Filtration Rate , Graft Rejection , Graft Survival , Humans , Immunosuppression Therapy , Immunosuppressive Agents/therapeutic use , Kidney/physiology , Male , Middle Aged , Renal Insufficiency/therapy , Sirolimus/analogs & derivatives , Sirolimus/therapeutic use , Treatment Outcome
8.
Int J Pharm ; 458(1): 218-23, 2013 Dec 15.
Article in English | MEDLINE | ID: mdl-24076231

ABSTRACT

The major aims of this work were to study the effect of the molecular weight (Mw) of ethyl cellulose (EC) on the drug release profile from metoprolol succinate pellets coated with films comprising EC and hydroxypropyl cellulose (HPC) with a weight ratio of 70:30, and to understand the mechanisms behind the different release profiles. A broad range of Mws was used, and the kinetics of drug release and HPC leaching followed. The higher the Mw of EC, the slower the HPC leaching and the drug release processes. Drug release occurred by diffusion through the pores created in the coating by the HPC leaching. A novel method was used to explain the differences in the release profiles: the effective diffusion coefficient (De) of the drug in the coating film was determined using a mechanistic model and compared to the amount of HPC leached. A linear dependence was found between De and the amount of HPC leached and, importantly, the value of the proportionality constant decreased with increasing Mw of EC. This suggests that the Mw of EC affects the drug release profile by affecting the phase separated microstructure of the coating and the hindrance it imparts to drug diffusion.


Subject(s)
Cellulose/analogs & derivatives , Drug Implants/chemistry , Cellulose/chemistry , Diffusion , Molecular Weight , Particle Size
9.
Eur J Pharm Sci ; 48(1-2): 240-8, 2013 Jan 23.
Article in English | MEDLINE | ID: mdl-23159668

ABSTRACT

Films of ethyl cellulose (EC) and water-soluble hydroxypropyl cellulose (HPC) can be used for extended release coatings in oral formulations. The permeability and microstructure of free EC/HPC films with 30% w/w HPC were studied to investigate effects of EC molecular weight. Phase separation during film spraying and subsequent HPC leaching after immersion in aqueous media cause pore formation in such films. It was found that sprayed films were porous throughout the bulk of the films after water immersion. The molecular weight affected HPC leaching, pore morphology and film permeability; increasing the molecular weight resulted in decreasing permeability. A model to distinguish the major factors contributing to diffusion retardation in porous films showed that the trend in permeability was determined predominantly by factors associated with the geometry and arrangement of pores, independent of the diffusing species. The film with the highest molecular weight did, however, show an additional contribution from pore wall/permeant interactions. In addition, rapid drying and increasing molecular weight resulted in smaller pores, which suggest that phase separation kinetics affects the final microstructure of EC/HPC films. Thus, the molecular weight influences the microstructural features of pores, which are crucial for mass transport in EC/HPC films.


Subject(s)
Cellulose/analogs & derivatives , Drug Delivery Systems , Cellulose/chemistry , Delayed-Action Preparations/chemistry , Microscopy, Electron, Scanning , Molecular Weight , Permeability , Porosity , Viscosity
10.
PLoS One ; 7(7): e41090, 2012.
Article in English | MEDLINE | ID: mdl-22911746

ABSTRACT

Sulforaphane-induced activation of the transcription factor NF-E2 related factor 2 (Nrf2 or the gene Nfe2l2) and subsequent induction of the phase II antioxidant system has previously been shown to exert neuroprotective action in a transient model of focal cerebral ischemia. However, its ability to attenuate functional and cellular deficits after permanent focal cerebral ischemia is not clear. We assessed the neuroprotective effects of sulforaphane in the photothrombotic model of permanent focal cerebral ischemia. Sulforaphane was administered (5 or 50 mg/kg, i.p.) after ischemic onset either as a single dose or as daily doses for 3 days. Sulforaphane increased transcription of Nrf2, Hmox1, GCLC and GSTA4 mRNA in the brain confirming activation of the Nrf2 system. Single or repeated administration of sulforaphane had no effect on the infarct volume, nor did it reduce the number of activated glial cells or proliferating cells when analyzed 24 and 72 h after stroke. Motor-function as assessed by beam-walking, cylinder-test, and adhesive test, did not improve after sulforaphane treatment. The results show that sulforaphane treatment initiated after photothrombosis-induced permanent cerebral ischemia does not interfere with key cellular mechanisms underlying tissue damage.


Subject(s)
Cerebral Infarction/metabolism , NF-E2-Related Factor 2/metabolism , Neuroprotective Agents/pharmacology , Thiocyanates/pharmacology , Animals , Cerebral Infarction/genetics , Cerebral Infarction/pathology , Disease Models, Animal , Gene Expression Regulation/drug effects , Gliosis , Isothiocyanates , Male , Mice , Motor Activity/drug effects , NAD(P)H Dehydrogenase (Quinone)/genetics , NAD(P)H Dehydrogenase (Quinone)/metabolism , NF-E2-Related Factor 2/agonists , Neuroprotective Agents/administration & dosage , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sulfoxides , Thiocyanates/administration & dosage
11.
Scand J Infect Dis ; 44(9): 641-9, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22680834

ABSTRACT

BACKGROUND: The aims of this study were to investigate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in residents living in Swedish nursing homes, and if carriage of resistant bacteria was related to antibiotic treatment, other risk factors, and/or staff's adherence to guidelines for infection control. METHODS: Five hundred and sixty residents from 9 nursing homes on a total of 67 wards participated in the study and had microbiological cultures taken. Faecal samples were obtained from 495 residents (88.3%). ESBL-positive residents were followed for 2 y with repeated sampling. Two hundred and ninety-six [corrected] staff members were interviewed and observed regarding familiarity with and adherence to infection control guidelines. RESULTS: No resident was positive for MRSA or VRE. Fifteen of the residents were found to be ESBL-positive. Residents living on wards where ESBL-positive residents were identified had been treated more frequently with antibiotics (42%), compared to those on wards where no residents with ESBL were found (28%; p = 0.02). ESBL-positive Escherichia coli isolates from residents living in adjacent rooms were found to be closely genetically related when analysed by pulsed-field gel electrophoresis, indicating transmission between residents. Staff adherence to infection control guidelines sometimes revealed shortcomings, but no significant differences regarding compliance to the guidelines could be found. CONCLUSION: Carriage of resistant bacteria was uncommon and only ESBL-producing Enterobacteriaceae were identified in Swedish nursing homes. Usage of antibiotics was higher on wards where ESBL-positive residents were detected and there was an indication of transmission of ESBL between residents.


Subject(s)
Bacterial Infections/epidemiology , Bacterial Infections/microbiology , Carrier State/epidemiology , Carrier State/microbiology , Health Knowledge, Attitudes, Practice , Infection Control/statistics & numerical data , Nursing Homes/statistics & numerical data , Aged , Aged, 80 and over , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacteria/genetics , Bacteria/isolation & purification , Drug Resistance, Bacterial , Electrophoresis, Gel, Pulsed-Field , Feces/microbiology , Female , Guideline Adherence , Humans , Infection Control/standards , Male , Middle Aged , Nursing Staff , Prevalence , Risk Factors , Sweden/epidemiology
12.
Neurol Res ; 33(6): 614-24, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21708071

ABSTRACT

BACKGROUND: Reactive gliosis and scar formation after brain injury can inhibit the recovery process. As many glial cells utilize gap junctions for intercellular signaling, this study investigated whether two commonly used gap junction blockers, octanol and carbenoxolone, could attenuate reactive gliosis following a minor traumatic brain injury. METHODS: Octanol (710 mg/kg) or carbenoxolone (90 mg/kg) was administered 30 minutes before or after a needle track injury in adult male Sprague-Dawley rats. To mark dividing cells, animals were injected with bromodeoxyuridine (BrdU; 150 mg/kg) intraperitoneally two times per day, 8 hours apart and killed 2 days later. Immunohistochemistry for BrdU and markers for reactive glial cells [glial fibrillary acidic protein (GFAP), ED1, and NG2] were investigated using immunohistochemistry and western blot techniques. RESULTS: Two days after injury, increased cellular proliferation, activated astrocytes and microglia, and upregulation of NG2 expression were observed surrounding the injury site. Octanol and carbenoxolone administrated prior to injury significantly decreased cell proliferation by 60 and 70% respectively. The distance of GFAP immunoreactive astrocytes from the wound margin was decreased by 32 and 18% when octanol was administrated prior to or post injury respectively. Treatment with octanol also decreased the number of reactive microglia by 55% and, when administrated prior to injury, octanol reduced the distance of NG2 expression from the wound by 48%. CONCLUSION: The present study demonstrates that two important components of reactive gliosis, cellular activation and proliferation, can be attenuated by octanol and carbenoxolone.


Subject(s)
Brain Injuries/drug therapy , Carbenoxolone/therapeutic use , Gliosis/drug therapy , Octanols/therapeutic use , Animals , Animals, Newborn , Brain Injuries/complications , Brain Injuries/pathology , Cells, Cultured , Gliosis/etiology , Gliosis/pathology , Male , Rats , Rats, Sprague-Dawley , Treatment Outcome
13.
Neuropharmacology ; 60(2-3): 343-53, 2011.
Article in English | MEDLINE | ID: mdl-20888844

ABSTRACT

Oxidative stress is a major contributor to slowly developing diseases like Parkinson's disease, Alzheimer's disease and cancer and one of the main causes of tissue damage following ischemic insults in the brain. Nrf2 is a transcription factor responsible for much of the inducible cellular defense against oxidative stress. Nrf2 can also be activated by xenobiotics like sulforaphane, a component highly enriched in cruciferous vegetables such as broccoli. Ingestion of broccoli or sulforaphane results in long-term protection against radical damage, although absorbed sulforaphane is cleared from the body within a few hours. Here we have examined whether the prolonged protection induced by sulforaphane is explained by a slow down regulation of the Nrf2 response. Furthermore, to simulate daily ingestion of sulforaphane, we examined the hypothesis that repeated transient sulforaphane stimulation results in an accumulation of Nrf2-mediated gene expression and an increased protection against oxidative damage. The kinetics of sulforaphane-induced Nrf2 response was studied in astrocytes, a cell type known to be highly involved in the defense against oxidative stress in the brain. Sulforaphane stimulation for 4 h induced an Nrf2-dependent increase of Nqo1 and Hmox1 mRNA that remained elevated for 24 h, and the corresponding proteins remained elevated for over 48 h. In addition, peroxide-clearing activity and the levels of glutathione were elevated for more than 20 h after stimulation for 4 h with sulforaphane, resulting in an increased resistance to superoxide-induced cell damage. Repeated sulforaphane stimulation resulted in an accumulation of mRNA and protein levels of Nqo1 and a persistent cell protection against oxidative damage. These findings indicate that brief stimulation of the Nrf2 pathway by sulforaphane results in long-lasting elevation of endogenous antioxidants in astrocytes. The findings also demonstrate that part of this response can be built up by repeated transient stimulation, possibly explaining how intermittent intake of sulforaphane can result in long-term protection from radical-induced disease.


Subject(s)
Astrocytes/metabolism , Gene Expression Regulation , NF-E2-Related Factor 2/biosynthesis , Oxidative Stress/physiology , Superoxides/toxicity , Thiocyanates/administration & dosage , Animals , Animals, Newborn , Astrocytes/drug effects , Cell Death/drug effects , Cell Death/physiology , Cells, Cultured , Free Radicals/antagonists & inhibitors , Free Radicals/metabolism , Gene Expression Regulation/drug effects , Isothiocyanates , Oxidative Stress/drug effects , RNA, Messenger/biosynthesis , Rats , Rats, Sprague-Dawley , Sulfoxides
15.
Transplantation ; 89(2): 155-60, 2010 Jan 27.
Article in English | MEDLINE | ID: mdl-20098277

ABSTRACT

BACKGROUND: Pancreas oxygenation during cold storage has been established in islet isolation and transplantation to prevent ischemic tissue damage using perfluorodecalin (PFD) as hyperoxygen carrier. However, studies in humans and pigs provided conflicting results about the efficiency of PFD for pancreas oxygenation. The aim of this study was to compare PFD with a newly developed oxygen carrier composed of perfluorohexyloctane and polydimethylsiloxane 5 (F6H8S5) for long-term storage of human pancreata. METHODS: After 24-hr storage in preoxygenated PFD or F6H8S5, pancreata were processed using Liberase HI for pancreas dissociation and a Ficoll gradient for islet purification. Islet quality assessment was performed measuring glucose-stimulated insulin release, viability, islet ATP content, and posttransplant function in diabetic nude mice. RESULTS: Compared with PFD, F6H8S5 significantly increased the intrapancreatic partial oxygen pressure and islet ATP content. This corresponded to an increase of islet yield, recovery after culture, glucose stimulation index, viability, and improved graft function in diabetic nude mice. CONCLUSIONS: The present findings indicate clearly that F6H8S5 improves isolation outcome after prolonged ischemia compared with PFD. This observation seems to be related to the significant lipophilicity and almost pancreas-specific density of F6H8S5. Moreover, these characteristics facilitate pancreas shipment without using custom-made transport vessels as required for PFD.


Subject(s)
Islets of Langerhans/cytology , Organ Preservation Solutions , Pancreas , Animals , Blood Substitutes/pharmacology , Cell Culture Techniques , Cell Separation/methods , Diabetes Mellitus, Experimental/surgery , Fluorocarbons/pharmacology , Humans , Insulin/analysis , Islets of Langerhans Transplantation/methods , Mice , Mice, Nude , Organ Preservation/methods , Oxygen/analysis , Swine , Tissue Donors
18.
Biomed Microdevices ; 10(5): 727-37, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18523888

ABSTRACT

Breast cancer is the leading cause of cancer deaths among non-smoking women worldwide. At the moment the treatment regime is such that patients receive different chemotherapeutic and/or hormonal treatments dependent on the hormone receptor status, the menopausal status and age. However, in vitro sensitivity testing of tumor biopsies could rationalize and improve the choice of chemo- and hormone therapy. Lab-on-a-Chip devices, using microfluidic techniques, make detailed cellular analysis possible using fewer cells, enabling working with a patients' own cells and performing chemo- and hormone sensitivity testing in an ex vivo setting. This article describes the development of two microfluidic devices made in poly(dimethylsiloxane) (PDMS) to validate the cell culture properties and analyze the chemosensitivity of MCF-7 cells (estrogen receptor positive human breast cancer cells) in response to the drug staurosporine (SSP). In both cases, cell viability was assessed using the life-stain Calcein-AM (CAAM) and the death dye propidium iodide (PI). MCF-7 cells could be statically cultured for up to 7 days in the microfluidic chip. A 30 min flow with SSP and a subsequent 24 h static incubation in the incubator induced apoptosis in MCF-7 cells, as shown by a disappearance of the aggregate-like morphology, a decrease in CAAM staining and an increase in PI staining. This work provides valuable leads to develop a microfluidic chip to test the chemosensitivity of tumor cells in response to therapeutics and in this way improve cancer treatment towards personalized medicine.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Biological Assay/instrumentation , Breast Neoplasms/drug therapy , Microfluidic Analytical Techniques/instrumentation , Biological Assay/methods , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Survival/drug effects , Dimethylpolysiloxanes/chemistry , Drug Evaluation, Preclinical , Female , Fluoresceins/metabolism , Fluorescent Dyes/metabolism , Humans , Polymers/chemistry , Reproducibility of Results , Sensitivity and Specificity , Staurosporine/pharmacology , Time Factors
19.
Electrophoresis ; 27(24): 5073-80, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17124709

ABSTRACT

This paper presents a study in which different commonly used microchip materials (silicon oxide, borosilicate glass, and PDMS) were analyzed for their effect on human promyelocytic leukemic (HL60) cells. Copper-coated silicon was analyzed for its toxicity and therefore served as a positive control. With quantitative PCR, the expression of the proliferation marker Cyclin D1 and the apoptosis marker tissue transglutaminase were measured. Flow cytometry was used to analyze the distribution through the different phases of the cell cycle (propidium iodide, PI) and the apoptotic cascade (Annexin V in combination with PI). All microchip materials, with the exception of Cu, appeared to be suitable for HL60 cells, showing a ratio apoptosis/proliferation (R(ap)) comparable to materials used in conventional cell culture (polystyrene). These results were confirmed with cell cycle analysis and apoptosis studies. Precoating the microchip material surfaces with serum favor the proliferation, as demonstrated by a lower R(ap) as compared to uncoated surfaces. The Cu-coated surface appeared to be toxic for HL60 cells, showing over 90% decreased viability within 24 h. From these results, it can be concluded that the chosen protocol is suitable for selection of the cell culture material, and that the most commonly used microchip materials are compatible with HL60 culturing.


Subject(s)
Coated Materials, Biocompatible/toxicity , Electrophoresis, Microchip/standards , Materials Testing , Apoptosis , Cell Proliferation , Cell Survival/drug effects , Copper/toxicity , Cyclin D1/genetics , HL-60 Cells , Humans , RNA, Messenger/analysis , Silicon Dioxide/toxicity
20.
Anal Chem ; 78(7): 2220-5, 2006 Apr 01.
Article in English | MEDLINE | ID: mdl-16579600

ABSTRACT

This report describes a rapid solid-phase melting curve analysis method for single-nucleotide polymorphism (SNP) genotyping. The melting curve analysis is based on dynamic allele-specific hybridization (DASH). The DNA duplexes are conjugated on beads that are immobilized on the surface of a microheater chip with integrated heaters and temperature sensors. SNP on PCR products were scored, illustrating the sensitivity and robustness of the system. The method is based on random bead immobilization by microcontact printing. Single-bead detection and multiplexing were performed with a heating rate more than 20 times faster than conventional DASH. Analyses that took more than 15 min could be performed in less that 1 min, enabling ultrarapid SNP analysis. In addition, an array version of the chip was implemented enabling the preparation of an array of bead arrays for high-throughput and rapid SNP genotyping.


Subject(s)
In Situ Hybridization/methods , Microchip Analytical Procedures/methods , Microspheres , Polymorphism, Single Nucleotide/genetics , RNA, Double-Stranded/analysis , Alleles , Base Sequence , Equipment Design , Genotype , Lab-On-A-Chip Devices , Polymerase Chain Reaction/methods , RNA, Double-Stranded/genetics , Temperature
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