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Ambulatory Use of Handheld Point-of-Care Ultrasound (HH-POCUS) in Rural Brandenburg - A Pilot Study. ULTRASCHALL IN DER MEDIZIN (STUTTGART, GERMANY : 1980) 2022; 43:584-591. [PMID: 33626573 DOI: 10.1055/a-1354-5958] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
PURPOSE This study aims to evaluate the use of handheld ultrasound devices (HHUS) for point-of-care ultrasound (POCUS) to improve outpatient care in rural Brandenburg. MATERIALS AND METHODS A group of general practitioners (n = 9), palliative care physicians (n = 6), emergency physicians (n = 4), and nurses from palliative care services (n = 5) participated in this study. Following a 3-hour workshop and 2 weeks of individual training, participants performed POCUS using HHUS (HH-POCUS). Indications, examination results, and resulting treatment changes (e. g., acute interventions, new medication) were documented in a standardized data entry form. RESULTS 19 physicians with different ultrasound experience and 5 palliative care nurses attended the workshop program and took part in the study. Three of the participating physicians were out of training in ultrasound and received prolonged supervision. Among 427 HH-POCUS examinations, the FAST scan and kidney scan were performed most often. Pain and dyspnea were the most common indications for HH-POCUS. Among the examinations performed by physicians (n = 311), ascites was the most common pathology (27 % of cases). Using a simplified examination protocol, palliative care nurses diagnosed fluid collections, hydronephrosis and transurethral catheter position or urinary retention. In 80.4 % of physician-performed cases, HH-POCUS made a valuable impact on patient management. HH-POCUS contributed to treatment decisions in 49.5 % of cases, including a change of medication in 29.6 % and performance of therapeutic interventions in 19.9 %. Hospital admission or referral to an ambulatory specialist was initiated due to HH-POCUS findings in 17.7 % of patients. CONCLUSION HH-POCUS helped doctors in rural areas to optimize patient care through rapid on-site collection of therapeutically relevant findings. In addition, it was shown that specialized and motivated nurses can independently detect simple ultrasound findings and thus provide clinically relevant information to doctors.
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Handheld Ultrasound (HHUS): Potential for Home Palliative Care. Ultrasound Int Open 2022; 8:E68-E76. [PMID: 36937375 PMCID: PMC10023243 DOI: 10.1055/a-1999-7834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 11/24/2022] [Indexed: 03/19/2023] Open
Abstract
Due to the severity of their disease, palliative care patients often present complex clinical symptoms and complaints like pain, shortness of breath, nausea, loss of appetite, and fatigue. Solely relying on the information available from the history and physical examination often causes uncertainty among palliative care physicians regarding treatment decisions during home visits, potentially leading to unnecessary hospitalizations or transfer to cross-sectional imaging in radiological practices. A rational approach is essential to avoid diagnostic aggressiveness while still providing the imaging information required for optimal palliative care. Bedside use of handheld ultrasound (HHUS) has the potential to expand the diagnostic and therapeutic spectrum in the case of symptom exacerbation but is still underutilized. In this review, we evaluate the potential uses of HHUS in home care settings to provide a more accurate diagnosis of the most common symptoms in palliative patients and to guide bedside interventions such as bladder catheterization, thoracentesis, paracentesis, venous access, and regional anesthesia. Specific training programs for ultrasound in palliative care are currently not available. Adequate documentation is warranted but fraught with technological and privacy issues. Expert supervision and quality assurance are necessary. Despite its limitation and challenges, we suggest that HHUS leads to improved clinical decision-making, expedited symptom relief, and reduced complications without burdening of the patient and costly transfer to hospital or specialty consultations.
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[Perspectives and Challenges of hand-held Ultrasound]. ZEITSCHRIFT FUR GASTROENTEROLOGIE 2022. [PMID: 36170860 DOI: 10.1055/a-1901-9394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The use of handheld ultrasound devices from a technical and data protection point of view, device properties, functionality, documentation, indications, delegation of performance, applications by doctors, students and non-medical staff is examined and discussed.
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Students' Perspectives on Curricular Ultrasound Education at German Medical Schools. Front Med (Lausanne) 2021; 8:758255. [PMID: 34901071 PMCID: PMC8655332 DOI: 10.3389/fmed.2021.758255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/27/2021] [Indexed: 11/26/2022] Open
Abstract
Background: Despite ultrasound being an inherent part of medical education, only a few German medical schools have established a comprehensive ultrasound curriculum. This study aimed to explore medical students' perspectives on ultrasound in medical education (USMed). Results: Between January 1st, 2019 und June 30th, 2019, an online survey was conducted among German medical students via the students' associations and their respective teaching facilities. The survey consisted of 17 items regarding USMed. Statements were rated on a 4-point Likert scale for agreement. In total, 1040 students from 31 German medical faculties participated. The majority (1021, 98.2%) reported a very high to high interest in curricular USMed. Students agreed (n = 945, 90.9%) that USMed would be helpful along their entire course of medical studies. Considering the best starting time for USMed, the opinions of German medical students diverged: students studying in a model curriculum preferred to start in the second year (40.7%) while 49% of the students studying in a traditional curriculum preferred to start in the third year (p ≤ 0.001). An insufficient allotment of time for USMed in the planned curriculum (675, 65%) and a lack of courses run by medical faculty (305, 29.4%) were listed as perceived significant barriers to the participation in USMed. Peer teaching was regarded as an effective method in realizing USMed by 731 (70.3%) students. Conclusion: German medical students are very interested and willing to participate in USMed. There appears to be a high demand for US courses offered by medical schools.
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The influence of weather on migraine - are migraine attacks predictable? Ann Clin Transl Neurol 2014; 2:22-8. [PMID: 25642431 PMCID: PMC4301671 DOI: 10.1002/acn3.139] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/06/2014] [Accepted: 10/07/2014] [Indexed: 01/03/2023] Open
Abstract
Objective The study aimed at elucidating a potential correlation between specific meteorological variables and the prevalence and intensity of migraine attacks as well as exploring a potential individual predictability of a migraine attack based on meteorological variables and their changes. Methods Attack prevalence and intensity of 100 migraineurs were correlated with atmospheric pressure, relative air humidity, and ambient temperature in 4-h intervals over 12 consecutive months. For each correlation, meteorological parameters at the time of the migraine attack as well as their variation within the preceding 24 h were analyzed. For migraineurs showing a positive correlation, logistic regression analysis was used to assess the predictability of a migraine attack based on meteorological information. Results In a subgroup of migraineurs, a significant weather sensitivity could be observed. In contrast, pooled analysis of all patients did not reveal a significant association. An individual prediction of a migraine attack based on meteorological data was not possible, mainly as a result of the small prevalence of attacks. Interpretation The results suggest that only a subgroup of migraineurs is sensitive to specific weather conditions. Our findings may provide an explanation as to why previous studies, which commonly rely on a pooled analysis, show inconclusive results. The lack of individual attack predictability indicates that the use of preventive measures based on meteorological conditions is not feasible.
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57 Rhodiola Crenulata Extract Prophylaxis for Acute Mountain Sickness: A Randomized, Double Blind, Placebo Controlled, Crossover Trial. Ann Emerg Med 2012. [DOI: 10.1016/j.annemergmed.2012.06.336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
AbstractA processing technique based on the principle of phase separation was developed to fabricate three-dimensional microcellular foams to act as templates for cell transplantation. The polymers used to make the foams were polylactic acid (PLLA) and a polyphosphoester (BPA/PP). The resulting foams had relatively uniform, open cells throughout the matrix. The foams could also be fabricated into complex shapes to meet specific design requirements. The foam morphology and microstructure were characterized by mercury porosimetry and scanning electron microscopy. Osteoblast like cells ROS17/2.8 were successfully cultured in the foams. Cell attachment to the foam interior was verified by confocal microscopy. The fabrication technique allows incorporation of drugs or nutrients into the highly porous structure as demonstrated by the intimate dispersion of fluorescein isothiocyanate (FITC) in the matrix.
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A salience-mapping method for testing infants' visual working memory for speed vs. luminance. J Vis 2010. [DOI: 10.1167/10.7.475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Resting brain perfusion in healthy carriers of the serotonin transporter promoter polymorphism. PHARMACOPSYCHIATRY 2009. [DOI: 10.1055/s-0029-1240241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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P.P.6 04 The clinical and molecular characterisation of calpain deficiency in patients with neuromuscular disorders. Neuromuscul Disord 2006. [DOI: 10.1016/j.nmd.2006.05.168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Early diagnosis of CAPD peritonitis using a new test kit for detection of matrix metalloproteinase (MMP)-9. Perit Dial Int 2004; 24:90-1. [PMID: 15104350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
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Optimal cut-off values for obesity: using simple anthropometric indices to predict cardiovascular risk factors in Taiwan. Int J Obes (Lond) 2002; 26:1232-8. [PMID: 12187401 DOI: 10.1038/sj.ijo.0802040] [Citation(s) in RCA: 258] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2001] [Revised: 03/01/2002] [Accepted: 03/13/2002] [Indexed: 12/21/2022]
Abstract
BACKGROUND The increased health risks associated with obesity have been found to occur in Asians at lower body mass indices (BMIs). To determine the optimal cut-off values for overweight or obesity in Taiwan, we examined the relationships between four anthropometric indices and cardiovascular risk factors. METHODS The data were collected from four health-screening centers from 1998 to 2000 in Taiwan. Included were 55 563 subjects (26 359 men and 29 204 women, mean age=37.3+/-10.9 and 37.0+/-11.1 y, respectively). None had known major systemic diseases or were taking medication. Individual body weight, height, waist circumference (WC), and a series of tests related to cardiovascular risk (blood pressure, fasting plasma glucose, triglycerides, total cholesterol, low- and high-density lipoprotein cholesterol) were assessed and their relationships were examined. Receiver operating characteristic (ROC) analysis was used to find out the optimal cut-off values of various anthropometric indices to predict hypertension, diabetes mellitus and dyslipidemia. RESULTS Of the four anthropometric indices we studied, waist-to-height ratio (WHtR) in women was found to have the largest areas under the ROC curve (women=0.755, 95% CI 0.748-0.763) relative to at least one risk factor (ie hypertension or diabetes or dyslipidemia). The optimal cut-off values for overweight or obesity from our study in men and women showed that BMIs of 23.6 and 22.1 kg/m(2), WCs of 80.5 and 71.5 cm, waist-to-hip ratios (WHpR) of 0.85 and 0.76, and WHtR of 0.48 and 0.45, respectively, may be more appropriate in Taiwan. CONCLUSIONS WHtR may be a better indicator for screening overweight- or obesity-related CVD risk factors than the other three indexes (BMI, WC and WHpR) in Taiwan. Our study also supported the hypothesis that the cut-off values using BMI and WC to define obesity should be much lower in Taiwan than in Western countries.
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Four anthropometric indices and cardiovascular risk factors in Taiwan. Int J Obes (Lond) 2002; 26:1060-8. [PMID: 12119571 DOI: 10.1038/sj.ijo.0802047] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2001] [Revised: 02/26/2002] [Accepted: 03/13/2002] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To examine the relationships between four anthropometric measurements and cardiovascular risk factors in Taiwan. DESIGN The data was collected from four nationwide health screen centers in Taiwan from 1998 to 1999. SUBJECTS A total of 38 556 subjects: 18 280 men and 20 276 women, mean age=37.0+/-11.1 y. None had any known major systemic diseases or were currently on medication. MEASUREMENTS Individual body weight, height, waist circumference (WC), and cardiovascular risk factors (blood pressure, fasting plasma glucose, triglycerides, total cholesterol level, low-density and high-density-lipoprotein cholesterol level) were assessed and their relationships were examined. RESULTS In both sexes, with increasing body mass index (BMI), WC, WHpR (waist-to-hip ratio) and WHtR (waist-to-height ratio), there were significantly higher risks of hypertension, impaired fasting glucose, diabetes and dyslipidemia (P<0.001) in almost all age groups. In the age groups older than 65, however, the relationships were statistically inconsistent. CONCLUSIONS In Taiwan, the four anthropometric indexes (BMI, WC, WHpR, WHtR) are closely related to cardiovascular risk factors.
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Abstract
OBJECTIVE To compare the empty zona pellucidae (ZP) of different species for use in the cryopreservation of spermatozoa. DESIGN Prospective study. SETTING An IVF unit of a medical center. PATIENT(S) Patients with azoospermia, oligoasthenozoospermia, or normal spermatozoa. INTERVENTION(S) Human and mouse ZP were prepared by evacuating the cytoplasm of oocytes or embryos. The evacuated ZP were injected with spermatozoa from patients with severe oligoasthenozoospermia and from healthy, fertile men. After the freezing and thawing procedure, the spermatozoa were aspirated outside the ZP. MAIN OUTCOME MEASURE(S) The number of spermatozoa per ZP, the number of motile sperm before freezing and after thawing, the number of sperm lost per ZP after freezing, and the sperm recovery rate were compared according to the different origins of the ZP and the sperm. RESULT(S) The number of spermatozoa, number of motile sperm before freezing and after thawing, number of sperm lost per ZP, and sperm recovery rate were comparable in all groups. The total mean number of motile sperm before freezing and after thawing, the mean number of nonmotile sperm after thawing, the mean number of sperm lost after thawing, and the sperm recovery rate were 14.5%, 11. 8%, 1.0%, 1.5%, and 82%, respectively. CONCLUSION(S) Zona pellucidae are an ideal vehicle for the cryopreservation of sperm collected by testicular sperm extraction or microsurgical epididymal sperm aspiration or from patients with severe oligoasthenozoospermia. There were no differences when human and mouse ZP were used for sperm storage.
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Comparison of a single half-dose, long-acting form of gonadotropin-releasing hormone analog (GnRH-a) and a short-acting form of GnRH-a for pituitary suppression in a controlled ovarian hyperstimulation program. Fertil Steril 2000; 73:817-20. [PMID: 10731546 DOI: 10.1016/s0015-0282(99)00608-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
OBJECTIVE To compare the effect of a single low-dose leuprolide acetate depot (LA depot) and leuprolide acetate (LA) on pituitary down-regulation in women undergoing controlled ovarian hyperstimulation (COH). DESIGN Retrospective study. SETTING An IVF unit of an academic medical center. PATIENT(S) Women who underwent COH and IVF-ET. INTERVENTION(S) Pituitary down-regulation with half-dose LA depot (1.88 mg sc, group 1) or LA (0.5 mg/d sc, group 2) was started on menstrual days 21-23. MAIN OUTCOME MEASURE(S) The concentrations of estradiol (E(2)), FSH, LH, gonadotropin dosages, the numbers of oocytes retrieved, oocytes fertilized and embryos transferred, and pregnancy rates of the two groups were compared. RESULT(S) A total of 289 patients in group 1 and 158 in group 2 were included. There were no statistically significant differences between the two groups in baseline concentrations of E(2) and FSH, concentrations of E(2), FSH, and LH during hCG administration, gonadotropin dosage, the number of oocytes retrieved, the number of oocytes fertilized and embryos transferred, and pregnancy rates. CONCLUSION(S) Single half-dose LA depot offers a useful alternative for pituitary suppression in ovarian stimulation for IVF.
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A role for phospholipase C-gamma-mediated signaling in tumor cell invasion. Clin Cancer Res 1999; 5:2251-60. [PMID: 10473113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
The invasive and metastatic transformation of cancers often results in death. However, the mechanisms that promote this transformation remain unclear. Two closely related receptors, the epidermal growth factor receptor (EGFR) and ErbB2, are overexpressed in a significant percentage of breast and prostate carcinomas, among others, with this up-regulated signaling correlating with tumor progression. Previous studies in our laboratory have demonstrated that an EGFR-phospholipase C (PLC)gamma-mediated motility-associated signaling pathway is rate-limiting for tumor cell invasion in vitro and in vivo in one model of prostate carcinoma. Therefore, we investigated whether this PLCgamma signaling pathway also was rate-limiting for invasion in other tumor cell lines and types and whether this EGFR activity is subsumed by the closely related ErbB2. We determined the effects of PLCgamma signal abrogation by pharmacological (U73122) and molecular (expression of the dominant-negative PLCz) means on the in vitro invasiveness of tumor cells. Inhibition of PLCgamma signaling concomitantly decreased invasiveness of de novo-occurring transgenic adenocarcinoma mouse prostate (TRAMP) lines and the human breast cancer cell lines MDA-468 and MDA-231; these lines present up-regulated EGFR signaling. Because the prostate and breast cancer lines usually present autocrine stimulatory loops involving EGFR, we also examined transgenic adenocarcinoma mouse prostate C1 and MDA-468 treated with the EGFR-specific kinase inhibitor PD153035 to determine whether invasiveness is dependent on EGFR signaling. PD153035 reduced invasiveness to levels similar to those seen with U73122, suggesting that the autocrine EGFR stimulatory loop is functioning to promote invasiveness. To determine whether this signaling pathway also promotes invasiveness of ErbB2-overexpressing tumors, we examined the human breast carcinoma line MDA-361; again, U73122 inhibition of PLCgamma decreased invasiveness. In all situations, the inhibition of PLCgamma signaling did not decrease mitogenic signaling. Thus, the motility-associated PLCgamma signaling pathway is a generalizable rate-limiting step for tumor cell progression.
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Abstract
ADCON-L and ADCON-T/N are two bioabsorbable adhesion barrier gels designed to inhibit post-operative fibrosis around the dura and nerve structure. Two ADCON products were evaluated in animal models emulating their use in neurosurgery. In all studies ADCON-L and ADCON-T/N were safe and effective barriers to post-operative peridural and perineural fibrosis.
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Formation of highly porous polymeric foams with controlled release capability : a phase-separation technique. METHODS IN MOLECULAR MEDICINE 1999; 18:57-65. [PMID: 21370167 DOI: 10.1385/0-89603-516-6:57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The success of many tissue engineering applications depends on a scaffold with the suitable physical properties, one of which might be a macroporous structure that allows cellular ingrowth. Such a porous implant further raises the possibility of delivering chemotactic or growth factors to influence the course of cell proliferation and differentiation in situ. The scaffolds can also be preseeded with cells to accelerate tissue growth or repair. Even in the absence of these payloads, they still provide the benefit of introducing the minimal amount of foreign material into the tissue. Furthermore, by making the porous scaffold, or foam, from biodegradable polymers, the regenerated tissue would be rid of any synthetic component, leading to a more functional biological equivalent, and eliminating concerns of long-term tissue compatibility.
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In vitro and in vivo studies of subcutaneous hydromorphone implants designed for the treatment of cancer pain. Pain 1996; 65:265-72. [PMID: 8826516 DOI: 10.1016/0304-3959(95)00248-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Unrelieved cancer pain remains a significant problem worldwide. Patients receive inadequate analgesia for a variety of complex and multifactorial reasons. Limited availability of opioids secondary to concerns about potential diversion of these medications for illicit use and poor compliance with oral regimens are significant factors in many countries. This study was designed to develop and test an implantable opioid delivery device capable of releasing a potent opioid subcutaneously at a continuous rate for 4 weeks. A low temperature solvent casting technique was used to formulate ethylene vinyl acetate (EVA) copolymer disks containing 50% hydromorphone by weight. The release characteristics of disks of different height and diameter, coated and uncoated, and with and without a central uncoated channel were studied. The effect of temperature and pH were also evaluated. In vitro assessments were conducted in phosphate buffer using UV spectrophotometry. In vivo studies employed New Zealand White Rabbits and a radioimmunoassay. Plasma levels following hydromorphone delivery by polymer, osmotic pump, and intravenous administration were compared. In vitro, uncoated EVA polymer disks measuring 1.05 cm in diameter and 0.27 cm in height released an initial large burst of hydromorphone. Coating the disks with 100-200 microM of poly(methyl-methacrylate) prevented drug egress from the polymer. A central uncoated channel measuring 1.25 mm in diameter in an otherwise coated polymer virtually eliminated the initial burst of drug release and provided near zero-order hydromorphone release at an average rate of 164 micrograms per hour for 4 weeks. Doubling the height of the polymer approximately doubled the release rate while doubling the diameter of the polymer extended the duration of drug release to over 8 weeks. In rabbits, stable plasma hydromorphone concentrations (23-37 ng/ml) were sustained for 4 weeks following implantation of 2 polymers with an uncoated central channel. No initial burst of hydromorphone release was noted. Increasing the number of polymers produced sustained and predictable increases in plasma hydromorphone concentrations. Plasma levels were similar with subcutaneous hydromorphone delivered by polymer and osmotic pump and much less variable than with intravenous bolus hydromorphone. A uniquely configured implantable drug delivery device has been developed using materials which are approved for human use. It safely and reproducibly releases hydromorphone for weeks in vitro and in vivo without an initial burst of drug release. Varying the thickness, diameter, and number of implants provides flexibility in the release rate and duration of release. This implantable opioid delivery device could provide a sustained subcutaneous infusion of hydromorphone to patient with cancer pain in developed and developing nations without pumps, catheters, or extensive outpatient support services. In addition, it should improve compliance and reduce concern regarding illicit diversion of opioids.
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Abstract
A synthetic porous three-dimensional structure that can mimic the architecture of actual tissues, provide sustained release of nutrients or growth factors, and serve as a template for cell seeding would be an ideal substrate for tissue engineering. Poly(l-lactic acid) (PLLA) foams were fabricated for this purpose, based on the principle of phase separation from homogeneous naphthalene solutions. Complex shapes could be readily fabricated, and resulting foams had relatively uniform, open cells throughout the matrix. Densities and total pore-surface areas were in the range of 0.05-0.1 g/cm3 and 0.8-1.3 m2/g, respectively. The loss tangent of these foams ranged from 0.07 to 0.128, as measured by thermomechanical analysis. Naphthalene residue in the resulting foams went below 0.2 wt% after extensive vacuum sublimation. Feasibility of incorporating drugs or nutrients into such a highly porous structure was demonstrated by the dispersion of two model compounds, bromothymol blue (BTB) and sulforhodamine B (SD), in the matrix. Sustained release of BTB from the foam with a porosity as high as 87% was observed for more than 2 months. Alkaline phosphatase, as a model protein to be incorporated, lost approximately 30% of its bioactivity during the fabrication. As a cell-culture substrate, the PLLA foams performed as well as the flat PLLA surface in supporting the growth of rat osteosarcoma cells (ROS 17/2.8) and in maintaining their functions such as alkaline phosphatase activity and osteocalcin synthesis. UMR-106 cells cultured in the foam also expressed a higher degree of mineralization than those cultured on the flat PLLA substrate.
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Abstract
Many tissue engineering applications require a scaffold or template conducive to cell attachment and maintenance of functions. It may also be advantageous in some cases for these scaffolds to have a controlled porous architecture to facilitate cellular or tissue ingrowth. In this study, we have engineered a porous carbohydrate-derivatized substrate for hepatocyte culture. Polystyrene foams, with pore sizes up to 100 microns, fabricated by phase separation from a homogeneous naphthalene solution, were derivatized with lactose and heparin, both of which are known to promote rat hepatocyte attachment and maintenance of its differentiated functions. Rat hepatocytes cultured on these derivatized foams exhibited a rounded cellular morphology with many microvilli evident on the surface of the cells. The hepatocytes showed an increase in albumin secretion for the first 3 days of culture in a defined, serum-free medium, and dropped back to initial levels by the end of 7 days. The production of cytochrome P450-dependent hydroxytestosterone metabolites were also measured. Two testosterone metabolites were maintained and five others were present but decreased over a culture period of 1 week. These carbohydrate-derivatized porous substrates may be useful for large-scale culture of hepatocytes, toxicology screening and for use in a liver assist device.
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Fabrication of Controlled Release Biodegradable Foams by Phase Separation. ACTA ACUST UNITED AC 1995; 1:15-28. [DOI: 10.1089/ten.1995.1.15] [Citation(s) in RCA: 214] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Detection of point mutations of the phenylalanine hydroxylase gene and prenatal diagnosis of phenylketonuria. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1992; 7:205-8. [PMID: 1307495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The known mutant alleles of the human phenylalanine hydroxylase (PAN) gene were analyzed in 25 phenylketonuria (PKU) families from North China by using polymerase chain reaction and allele-specific oligonucleotide dot blot hybridization techniques. The results showed that the six mutations analyzed accounted for 62% of all PKU genes. The three most frequent mutations were R243Q, R413P and Y204C. Seven prenatal gene diagnoses were carried out in 6 PKU families and were confirmed after birth or by examination of aborted materials.
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Hypothermic storage and cryopreservation of cartilage. An experimental study. Clin Orthop Relat Res 1985:15-26. [PMID: 4017330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Osteochondral autografts of femoral condyles in dogs were frozen at different cooling velocities after exposure to either glycerol or dimethyl sulfoxide to determine the freezing regimen best suited for preservation of intact cartilage. Autografts were also subjected to hypothermic storage in tissue culture media for ascertainment of how long they can be stored under these conditions. Autografts maintained in vitro under various conditions of storage were examined after transplantation. Autografts were chosen for this portion of the investigation in order to study the effects of storage uncomplicated by immunologic interactions. No differences were found between the cryoprotective actions of glycerol and dimethyl sulfoxide. The freezing rate that produced the least damage in the cartilage was 2 degrees/min. Cartilage survived ten days of hypothermic storage in tissue culture medium. Allografts frozen by the standard method of glycerolization and cooling at 1 degree/min were also studied. These showed eventual loss of chondrocytes and conversion of hyaline cartilage to fibrocartilage.
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Abstract
The major and minor sialoglycoproteins of the bovine erythrocyte have been solubilized and extensively purified. A comparison of composition revealed that the major glycoprotein had 77% carbohydrate and 23% peptide, and the minor one had 27% carbohydrate and 73% peptide. Molar ratios of sugars were related, however, the major glycoprotein had twice as much galactose and sialic acid as did the minor glycoprotein. Molecular weights, estimated from retardation coefficients of mobility in sodium dodecyl sulfate gel electrophoresis, were 55,000 for the major glycoprotein and 34,000 for the minor glycoprotein. The glycoproteins were studied by electron microscopy before and after delipidation and after ultracentrifugation. The major glycoprotein, prior to delipidation, formed large micelles. After delipidation, the major glycoprotein could not be visualized suggesting that it did not form aggregates in aqueous solution. The minor glycoprotein was visualized as rather uniform spherical aggregates (62 A average diameter) which tended to form short chains and small clumps. These characteristic aggregates were seen both before and after delipidation. After ultracentrifugation, fixation and sectioning both glycoproteins appeared to have formed microcrystalline arrays with average periodicity of 49 A.
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Abstract
Amebal NADPH:flavin oxidoreductase was purified to apparent homogeneity. Molecular weights of 40 000 and 38 000 were estimated by gel filtration and by sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively, indicating that the enzyme is composed of a single polypeptide chain. The enzyme does not contain firmly bound flavin. It exhibited 20-fold selectivity for NADPH over NADH. With the former donor it reduced riboflavin, galactoflavin, FMN, or FAD. Aerobically the reducing equivalents were passed from reduced flavin to oxygen to form hydrogen peroxide. Intact amebae do not produce peroxide when they respire. If the title enzyme functions to reduce flavin in the intact cells some electron carrier must intervene between reduced flavin and oxygen so that the final step produces water instead of peroxide.
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29
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Bordetella pertussis serotypes in Canada. CANADIAN MEDICAL ASSOCIATION JOURNAL 1978; 119:722-4. [PMID: 213182 PMCID: PMC1818801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A study was done to determine the major antigenic factors of Bordetella pertussis strains isolated throughout Canada and whether these isolates have the same antigenic structure as the bacilli in the currently used vaccines. Testing for the major pertussis antigens, factors 1, 2 and 3, was conducted with 440 freshly isolated strains of B. pertussis received from seven canadian provinces between August 1976 and February 1978 and six batches of pertussis vaccine or immunizing agents containing pertussis vaccine. With the aid of specific antisera prepared in rabbits, the antigenic factors were detected by a slide agglutination technique. Almost all (98.9%) of the pertussis strains examined were serotype 1,3. All six batches of pertussis vaccine or immunizing agents containing pertussis vaccine proved to be rich in each of the three main pertussis agglutinogens.
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30
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Gastric distention simulating a left subphrenic abscess. J Nucl Med 1978; 19:438-40. [PMID: 632939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Glucagon-mediated stimulation of (32P) orthophosphate and (14C) serine incorporation into phosphatidylserine in cardiac muscle slices. Endocrinology 1976; 98:251-4. [PMID: 1248447 DOI: 10.1210/endo-98-1-251] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Glucagon stimulated the incorporation of Na2H32PO4 and L-(14C)serine into phosphatidylserine in heart muscle slices. The increase above control was about 2-fold at ten minutes and 6-fold at thirty minutes for (32P) and 12-fold as early as three minutes for (14C)serine. Although a smaller, but significant, incorporation of (32P) into phosphatidylethanolamine was also observed, glucagon did not stimulate the incorporation of (14C)serine into phosphatidylethanolamine. Glucagon did not significantly augment the incorporation of either tracer into phosphatidylcholine, lysophosphatidylcholine, phosphatidylinositol, cardiolipin, phosphatidic acid, or sphingomyelin. Dibutyryl cyclic 3',5'-AMP did not increase the incorporation of (32P) or (14C)serine into phosphatidylserine. Since phosphatidylserine appears to serve a critical role in coupling the glucagon receptor to the catalytic moiety of adenylate cyclase, the data suggest that the hormone may initially increase the amount of its own coupler.
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Parathyroid hormone-mediated incorporation of 32P-orthophosphate into phosphatidic acid and phosphatidylinositol in renal cortical slices. ENDOCRINE RESEARCH COMMUNICATIONS 1976; 3:377-85. [PMID: 188626 DOI: 10.3109/07435807609073911] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Parathyroid hormone increased the incorporation of Na2H32PO4 into phosphatidic acid and phosphatidylinositol in cat renal cortical slices. Incorporation was not observed into any other phospholipid. The effects were seen as early as one minute for phosphatidic acid and ten minutes for phosphatidylinositol. 8-Bromoadnosine 3',5'-monophosphate did not mimic the effects of parathyroid hormone. Concentrations of parathyroid hormone, 1 x 10(-8)M to 1 x 10(-7)M, which increased the incorporation of 32p into phosphatidic acid and phosphatidylinositol maximally, did not alter tissue cyclic AMP levels suggesting that the incorporation of 32p was independent of cyclic AMP.
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