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Integrins Increase Sarcoplasmic Reticulum Activity for Excitation-Contraction Coupling in Human Stem Cell-Derived Cardiomyocytes. Int J Mol Sci 2022; 23:10940. [PMID: 36142853 PMCID: PMC9504605 DOI: 10.3390/ijms231810940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/10/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022] Open
Abstract
Engagement of the sarcoplasmic reticulum (SR) Ca2+ stores for excitation-contraction (EC)-coupling is a fundamental feature of cardiac muscle cells. Extracellular matrix (ECM) proteins that form the extracellular scaffolding supporting cardiac contractile activity are thought to play an integral role in the modulation of EC-coupling. At baseline, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) show poor utilisation of SR Ca2+ stores, leading to inefficient EC-coupling, like developing or human CMs in cardiac diseases such as heart failure. We hypothesised that integrin ligand-receptor interactions between ECM proteins and CMs recruit the SR to Ca2+ cycling during EC-coupling. hiPSC-CM monolayers were cultured on fibronectin-coated glass before 24 h treatment with fibril-forming peptides containing the integrin-binding tripeptide sequence arginine-glycine-aspartic acid (2 mM). Micropipette application of 40 mM caffeine in standard or Na+/Ca2+-free Tyrode's solutions was used to assess the Ca2+ removal mechanisms. Microelectrode recordings were conducted to analyse action potentials in current-clamp. Confocal images of labelled hiPSC-CMs were analysed to investigate hiPSC-CM morphology and ultrastructural arrangements in Ca2+ release units. This study demonstrates that peptides containing the integrin-binding sequence arginine-glycine-aspartic acid (1) abbreviate hiPSC-CM Ca2+ transient and action potential duration, (2) increase co-localisation between L-type Ca2+ channels and ryanodine receptors involved in EC-coupling, and (3) increase the rate of SR-mediated Ca2+ cycling. We conclude that integrin-binding peptides induce recruitment of the SR for Ca2+ cycling in EC-coupling through functional and structural improvements and demonstrate the importance of the ECM in modulating cardiomyocyte function in physiology.
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Functional microvascularization of human myocardium in vitro. CELL REPORTS METHODS 2022; 2:100280. [PMID: 36160044 PMCID: PMC9499876 DOI: 10.1016/j.crmeth.2022.100280] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/14/2022] [Accepted: 08/11/2022] [Indexed: 11/23/2022]
Abstract
In this study, we report static and perfused models of human myocardial-microvascular interaction. In static culture, we observe distinct regulation of electrophysiology of human induced pluripotent stem cell derived-cardiomyocytes (hiPSC-CMs) in co-culture with human cardiac microvascular endothelial cells (hCMVECs) and human left ventricular fibroblasts (hLVFBs), including modification of beating rate, action potential, calcium handling, and pro-arrhythmic substrate. Within a heart-on-a-chip model, we subject this three-dimensional (3D) co-culture to microfluidic perfusion and vasculogenic growth factors to induce spontaneous assembly of perfusable myocardial microvasculature. Live imaging of red blood cells within myocardial microvasculature reveals pulsatile flow generated by beating hiPSC-CMs. This study therefore demonstrates a functionally vascularized in vitro model of human myocardium with widespread potential applications in basic and translational research.
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In vivo grafting of large engineered heart tissue patches for cardiac repair. JCI Insight 2021; 6:e144068. [PMID: 34369384 PMCID: PMC8410032 DOI: 10.1172/jci.insight.144068] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 06/23/2021] [Indexed: 11/20/2022] Open
Abstract
Engineered heart tissue (EHT) strategies, by combining cells within a hydrogel matrix, may be a novel therapy for heart failure. EHTs restore cardiac function in rodent injury models, but more data are needed in clinically relevant settings. Accordingly, an upscaled EHT patch (2.5 cm × 1.5 cm × 1.5 mm) consisting of up to 20 million human induced pluripotent stem cell–derived cardiomyocytes (hPSC-CMs) embedded in a fibrin-based hydrogel was developed. A rabbit myocardial infarction model was then established to test for feasibility and efficacy. Our data showed that hPSC-CMs in EHTs became more aligned over 28 days and had improved contraction kinetics and faster calcium transients. Blinded echocardiographic analysis revealed a significant improvement in function in infarcted hearts that received EHTs, along with reduction in infarct scar size by 35%. Vascularization from the host to the patch was observed at week 1 and stable to week 4, but electrical coupling between patch and host heart was not observed. In vivo telemetry recordings and ex vivo arrhythmia provocation protocols showed that the patch was not pro-arrhythmic. In summary, EHTs improved function and reduced scar size without causing arrhythmia, which may be due to the lack of electrical coupling between patch and host heart.
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Vascularisation of pluripotent stem cell-derived myocardium: biomechanical insights for physiological relevance in cardiac tissue engineering. Pflugers Arch 2021; 473:1117-1136. [PMID: 33855631 PMCID: PMC8245389 DOI: 10.1007/s00424-021-02557-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/15/2021] [Accepted: 03/18/2021] [Indexed: 12/22/2022]
Abstract
The myocardium is a diverse environment, requiring coordination between a variety of specialised cell types. Biochemical crosstalk between cardiomyocytes (CM) and microvascular endothelial cells (MVEC) is essential to maintain contractility and healthy tissue homeostasis. Yet, as myocytes beat, heterocellular communication occurs also through constantly fluctuating biomechanical stimuli, namely (1) compressive and tensile forces generated directly by the beating myocardium, and (2) pulsatile shear stress caused by intra-microvascular flow. Despite endothelial cells (EC) being highly mechanosensitive, the role of biomechanical stimuli from beating CM as a regulatory mode of myocardial-microvascular crosstalk is relatively unexplored. Given that cardiac biomechanics are dramatically altered during disease, and disruption of myocardial-microvascular communication is a known driver of pathological remodelling, understanding the biomechanical context necessary for healthy myocardial-microvascular interaction is of high importance. The current gap in understanding can largely be attributed to technical limitations associated with reproducing dynamic physiological biomechanics in multicellular in vitro platforms, coupled with limited in vitro viability of primary cardiac tissue. However, differentiation of CM from human pluripotent stem cells (hPSC) has provided an unlimited source of human myocytes suitable for designing in vitro models. This technology is now converging with the diverse field of tissue engineering, which utilises in vitro techniques designed to enhance physiological relevance, such as biomimetic extracellular matrix (ECM) as 3D scaffolds, microfluidic perfusion of vascularised networks, and complex multicellular architectures generated via 3D bioprinting. These strategies are now allowing researchers to design in vitro platforms which emulate the cell composition, architectures, and biomechanics specific to the myocardial-microvascular microenvironment. Inclusion of physiological multicellularity and biomechanics may also induce a more mature phenotype in stem cell-derived CM, further enhancing their value. This review aims to highlight the importance of biomechanical stimuli as determinants of CM-EC crosstalk in cardiac health and disease, and to explore emerging tissue engineering and hPSC technologies which can recapitulate physiological dynamics to enhance the value of in vitro cardiac experimentation.
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Influence of perfusable microvasculature on excitation-contraction coupling in IPSC-derived myocardium. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.3590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
The myocardium is one of the most densely vascularised tissues in the body, with dynamic metabolic demand from beating cardiomyocytes (CM) necessitating an intimate relationship with microvasculature. Endothelial cells (EC) produce a diverse array of cardio-active factors which acutely and chronically modulate myocardial phenotype. Disruption of CM-EC signalling results in pathological remodelling, and ultimately organ failure. However, as physiologically relevant recapitulation of CM-EC interaction has been difficult to achieve in vitro, many molecular mechanisms governing their interaction remain poorly understood.
To induce cardiac vasculogenesis in vitro, we have developed microfluidic chips which subject 3D hydrogel cultures to precisely controlled flow. We then co-cultured human cardiac microvascular ECs, human left ventricular fibroblasts (FB), and human induced pluripotent stem cell-derived cardiomyocytes for 5 days under a pro-vasculogenic protocol (0.5 ul/min flow rate, 50ng/ml VEGF, 100ng/ml Ang-1). Via live and fixed immunofluorescence microscopy, we observed spontaneous formation of a microvasculature network with a continuously open lumen embedded within beating myocardium. Simultaneous quantification of iPSC-CM contractility and perfused red blood cell velocity reveals biomimetic pulsatile flow profile within the microvasculature. To evaluate the influence of microvasculature on CM function, we incorporated CMs differentiated from stem cells with the genetically encoded calcium biosensor GCaMP6F. Compared to CM only control, vascularised preparations demonstrate significantly faster calcium transient time to peak (−11.5%, p=0.007) and time to 50% relaxation (−15%, p=0.01). Under static conditions and 1Hz electrical stimulation, presence of EC was associated with reduced iPSC-CM arrhythmia at baseline (p<0.0001) and during 1uM isoprenaline treatment (p=0.0003), while maintaining isoprenaline induced Ca2+ handling quickening.
To the best of our knowledge, this work represents the first fully perfusable model of the myocardial microvasculature, and highlights the importance of EC regulatory influence on CM function. Further work aims to investigate underlying molecular mechanisms to provide therapeutically relevant insight into cardiac biology.
Funding Acknowledgement
Type of funding source: Foundation. Main funding source(s): British Heart Foundation
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FSHD / OPMD / MYOTONIC DYSTROPHY. Neuromuscul Disord 2020. [DOI: 10.1016/j.nmd.2020.08.231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Vascularized Myocardium-On-A-Chip: Excitation-Contraction Coupling in Perfused Cardiac Co-Cultures. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.2319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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P5385Development and preclinical testing of upscaled engineered heart tissue for use in translational studies. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Introduction
The lack of efficacy of stem cell therapy for the treatment of heart failure may be related to the poor retention rates offered by existing delivery methods (intra-coronary/ intramyocardial). Tissue engineering strategies improve cell retention in small animal models but data regarding engineered heart tissue (EHT) patches large enough for human studies are lacking.
Purpose
To upscale EHT to a clinically relevant size and mature the patch in-vitro. Once matured to undergo preclinical testing in a rabbit model of myocardial infarction.
Methods
We developed an upscaled EHT patch (3cm x 2cm x 1.5mm) able to contain up to 50 million human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CM; Fig A/B). Myocardial infarction model was performed by permanent ligation.
Results
The patches began to beat spontaneously within 3 days of fabrication and after 28 days of dynamic culture (Late EHTs) showed the development of several mature characteristics when compared to early patches (<14 days from fabrication). For example, late EHTs contained hiPSC-CMs which were more aligned (hiPSC-CM accumulative angle change: early 2702±778 degrees [n=4] vs late 922±186 [n=5], p=0.042); showed better contraction kinetics (early peak contraction amplitude 87.9±5.8a.u. versus late 952±304a.u.; p<0.001) and faster calcium transients (time to peak: early 200.8±8.8ms [n=5] vs late 147.7±10.2ms [n=6], p=0.004; time to 75% decay: early 274±9.7ms vs late 219.9±2.7ms, p=0.0003).
We then tested the EHT patch in-vivo using a rabbit model (Fig C). Patches were applied to normal (n=5) or infarcted hearts (n=8). Sham operations used non-cellular fibrin patches (n=5). The mean fraction of troponin positive cells in the graft was 27.8±10.3% at 25.2±1.7 days relative to day 0 [n=5] and KU80 (human specific marker) staining confirmed that this was of human origin. CD31 (Fig D) and KU80 staining revealed that the grafts were well vascularized and that the vasculature was not human in origin (therefore were originating from the host). Ex-vivo optical mapping revealed evidence of electrical coupling between the graft and host at 2 weeks and preliminary experiments indicated that the patch improved left ventricular function when grafted onto infarcted hearts. Telemetry recordings in vivo and arrhythmia provocation protocols (ex vivo) indicated that the patch was not proarrhythmic.
Figure 1. A/B) EHT Images; C) 20x troponin T (brown) of rabbit myocardium/EHT (2 weeks after grafting), blue counterstain = haematoxylin, red lines = EHT borders; D) 63x CD31 staining (brown) rabbit/EHT border zone (2 weeks after grafting), blue stain = haematoxylin, red lines = graft/host border zones.
Conclusion
We successfully upscaled hiPSC-CM derived EHT to a clinically relevant size and demonstrated feasibility and integration using a rabbit model of myocardial infarction. Tissue engineering strategies may be the preferred modality of cell delivery for future cardiac regenerative medicine studies.
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Endothelial Cell Regulation of Excitation-Contraction Coupling in Induced Pluripotent Stem Cell Derived Myocardium. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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10
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Engineering Anisotropic Muscle Tissue using Acoustic Cell Patterning. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802649. [PMID: 30277617 PMCID: PMC6386124 DOI: 10.1002/adma.201802649] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/13/2018] [Indexed: 05/16/2023]
Abstract
Tissue engineering has offered unique opportunities for disease modeling and regenerative medicine; however, the success of these strategies is dependent on faithful reproduction of native cellular organization. Here, it is reported that ultrasound standing waves can be used to organize myoblast populations in material systems for the engineering of aligned muscle tissue constructs. Patterned muscle engineered using type I collagen hydrogels exhibits significant anisotropy in tensile strength, and under mechanical constraint, produced microscale alignment on a cell and fiber level. Moreover, acoustic patterning of myoblasts in gelatin methacryloyl hydrogels significantly enhances myofibrillogenesis and promotes the formation of muscle fibers containing aligned bundles of myotubes, with a width of 120-150 µm and a spacing of 180-220 µm. The ability to remotely pattern fibers of aligned myotubes without any material cues or complex fabrication procedures represents a significant advance in the field of muscle tissue engineering. In general, these results are the first instance of engineered cell fibers formed from the differentiation of acoustically patterned cells. It is anticipated that this versatile methodology can be applied to many complex tissue morphologies, with broader relevance for spatially organized cell cultures, organoid development, and bioelectronics.
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A family-wide approach to structure-based inhibitor design for protein tyrosine phosphatases. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308098796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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12
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Abstract
Vertically coupled microring resonator channel-dropping filters are demonstrated in the GaInAsP-InP material system. These devices were fabricated without regrowth. In this method, low-loss single-mode waveguides are removed from the growth substrate and bonded to a GaAs transfer substrate with benzocyclobutene. This permits fabrication of vertically coupled waveguides on both sides of the epilayer. Optical quality facets are obtained by cleaving through the transfer substrate. Operation of single-mode, single-ring optical channel-dropping filters is demonstrated.
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13
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Spondylolysis. Phys Med Rehabil Clin N Am 2000; 11:785-803. [PMID: 11092019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Spondylolysis is a relatively common incidental radiographic finding that, most frequently, is asymptomatic. Isthmic spondylolysis with a lesion in the pars interarticularis may be a significant cause of pain in a given individual, particularly in adolescent athletes involved in sports with repetitive spinal motions. The pars lesion likely represents a stress fracture of the bone caused by the cumulative effect of repetitive stress imposed by physical activity. The lesion frequently presents as focal LBP and can often be identified on plain radiography. Advanced imaging with SPECT, CT, and MR imaging may be needed to ascertain the acuity of the lesion, assist in identifying a particular pars lesion as potentially symptomatic, and to exclude other spinal pathology that may be present. Conservative treatment is usually successful in controlling symptoms and restoring function; only a small percentage of patients require surgical intervention for pain or progressive spondylolisthesis. Based on current evidence, treatment requires activity restriction (i.e., temporary discontinuation of the aggravating sport or activity) and may require bracing to achieve treatment goals, although healing, pain relief or both may occur without brace application. A full understanding of spinal biomechanics and pathophysiology, the role of diagnostic imaging, and treatment options is needed to care for these patients.
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14
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How Does CONDENSATION Behave with a Finite Number of Samples? COMPUTER VISION - ECCV 2000 2000. [DOI: 10.1007/3-540-45054-8_45] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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15
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Impurity-related photoluminescence from silicon at room temperature. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:10661-10665. [PMID: 9975164 DOI: 10.1103/physrevb.50.10661] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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16
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Directional, enhanced fluorescence from molecules near a periodic surface. APPLIED OPTICS 1994; 33:2447-2454. [PMID: 20885594 DOI: 10.1364/ao.33.002447] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We extend the research of Holland and Hall on the use of waveguide modes to enhance the fluorescent signal from a layer of molecules [Opt. Lett. 10,414 (1985)] by incorporating a grating into the basic sample structure. Our measurements show that the combination of the directionality imposed by the grating and the previously reported enhancement mechanism has the effect of increasing the intensity of the signal detected over a narrow angular range from a layer of fluorescing molecules by a factor of ~ 1000 over that from a reference sample. Simultaneously our method allows for both polarization and wavelength discrimination of the emitted radiation because of the characteristic nature of the incorporated grating.
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Diet and heart disease. THE NEW ZEALAND MEDICAL JOURNAL 1989; 102:84-5. [PMID: 2919025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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18
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Peak cerebrospinal fluid platinum levels in a patient with ependymoma: evaluation of two different methods of cisplatin administration. CANCER TREATMENT REPORTS 1986; 70:1437-8. [PMID: 3791256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Peak CSF and serum platinum levels were examined in a patient with ependymoma after each of four consecutive cisplatin doses of 100 mg/m2 administered by either 30-minute or 3-hour infusion. Both infusion lengths produced similar peak CSF platinum levels within 2 hours after the completion. Ultrafiltrate serum platinum levels correlated with the CSF platinum levels, whereas total plasma platinum did not. No differences in clinical toxicity or response were seen between the two methods of administration. Based on these preliminary results, similar peak CSF platinum concentrations are achieved by 30-minute or 3-hour infusions, and ultrafiltrate serum platinum concentrations can be used to predict these levels.
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Neuro-ocular damage in pediatric oncology patients: predictor of long-term visual disability or tool for limiting toxicity? MEDICAL AND PEDIATRIC ONCOLOGY 1986; 14:262-70. [PMID: 3784980 DOI: 10.1002/mpo.2950140505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We present a group of eight pediatric cancer patients with a spectrum of visual afferent pathway abnormalities. Changes include decreased visual acuity, visual field alterations, abnormal visual evoked potentials, changes in the optic disc and nerve fiber layer of the retina, radiation retinopathy, and CNS injury. These changes occur in long term survivors of pediatric malignancy (especially those with prolonged, multimodal, and multicourse therapy), but they may be minimally symptomatic. The changes appear to be analogous to the CNS changes (leukoencephalopathy) described in patients with leukemia and attributed to multimodal therapy. By taking advantage of opportunities to detect adverse effects earlier in the treatment course, the present excellent cure rate may be improved by refinements in therapy that also improve the quality of survival.
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Abstract
In this study we have investigated the presence of immunoreactive calcitonin in the central nervous system and pituitary of sheep. The calcitonin concentrations were determined radioimmunologically by two different antibodies. We have demonstrated calcitonin in extracts of areas of the central nervous system, whole pituitary, thyroid gland and plasma of 21 sheep. The concentrations were (ng/g wet weight, mean values +/- SE): thyroid 16.0 +/- 4.4, pituitary 2.03 +/- 0.34, reticular formation 1.64 +/- 0.25, substantia nigra 1.53 +/- 0.46, dentate nucleus 1.11 +/- 0.27, putamen 1.05 +/- 0.35, hippocampus 0.97 +/- 0.17, fornix 0.96 +/- 0.15, anterior thalamus 0.92 +/- 0.28, mammillary body 0.88 +/- 0.12, cerebellum 0.86 +/- 0.09, caudate nucleus 0.84 +/- 0.11, posterior hypothalamus 0.83 +/- 0.19, epiphysis 0.75 +/- 0.25, thalamus centralis 0.71 +/- 0.10, almond nucleus 0.69 +/- 0.16, medulla oblongata 0.67 +/- 0.15, anterior hypothalamus 0.66 +/- 0.20, precentral gyrus 0.66 +/- 0.16, globus pallidus 0.63 +/- 0.31, postcentral gyrus 0.36 +/- 0.08 and plasma (ng/ml) 0.058 +/- 0.013. Our results demonstrate that immunoreactive calcitonin is present in the central nervous system (CNS) of sheep, compatible with a neurotransmitter function for this hormone.
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Distribution and concentration of immunoreactive parathyroid hormone in brain and pituitary of sheep. KLINISCHE WOCHENSCHRIFT 1985; 63:419-22. [PMID: 3999625 DOI: 10.1007/bf01733667] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have studied the presence of immunoreactive parathyroid hormone (PTH) in the central nervous system and pituitary of sheep. The PTH concentrations were measured radioimmunologically by two different region-specific antibodies. We could demonstrate PTH in various areas of the brain, whole pituitary, parathyroid glands and plasma of 21 sheep. Measurable concentrations of the two different parathyroid regions (35-84 and 44-68 amino acids fragments) were found in all samples.
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Chediak-Higashi syndrome in a child with Hodgkin's disease. AMERICAN JOURNAL OF DISEASES OF CHILDREN (1960) 1971; 121:135-9. [PMID: 5100796 DOI: 10.1001/archpedi.1971.02100130089010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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