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Mangiameli SM, Chen H, Earl AS, Dobkin JA, Lesman D, Buenrostro JD, Chen F. Photoselective sequencing: microscopically guided genomic measurements with subcellular resolution. Nat Methods 2023; 20:686-694. [PMID: 37106232 DOI: 10.1038/s41592-023-01845-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 03/13/2023] [Indexed: 04/29/2023]
Abstract
In biological systems, spatial organization and function are interconnected. Here we present photoselective sequencing, a new method for genomic and epigenomic profiling within morphologically distinct regions. Starting with an intact biological specimen, photoselective sequencing uses targeted illumination to selectively unblock a photocaged fragment library, restricting the sequencing-based readout to microscopically identified spatial regions. We validate photoselective sequencing by measuring the chromatin accessibility profiles of fluorescently labeled cell types within the mouse brain and comparing with published data. Furthermore, by combining photoselective sequencing with a computational strategy for decomposing bulk accessibility profiles, we find that the oligodendrocyte-lineage-cell population is relatively enriched for oligodendrocyte-progenitor cells in the cortex versus the corpus callosum. Finally, we leverage photoselective sequencing at the subcellular scale to identify features of chromatin that are correlated with positioning at the nuclear periphery. These results collectively demonstrate that photoselective sequencing is a flexible and generalizable platform for exploring the interplay of spatial structures with genomic and epigenomic properties.
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Affiliation(s)
- Sarah M Mangiameli
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | - Haiqi Chen
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Andrew S Earl
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | - Julie A Dobkin
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Daniel Lesman
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jason D Buenrostro
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA.
| | - Fei Chen
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA.
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Bonasera TA, O'Neil JP, Xu M, Dobkin JA, Cutler PD, Lich LL, Choe YS, Katzenellenbogen JA, Welch MJ. Preclinical evaluation of fluorine-18-labeled androgen receptor ligands in baboons. J Nucl Med 1996; 37:1009-15. [PMID: 8683293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
UNLABELLED A noninvasive method for detecting and quantifying androgen receptors (AR) in metastatic prostate cancer may be helpful in choosing the method of treatment and in better understanding the pathophysiology of this disease. Nine previously synthesized fluorinated androgens exhibited high affinity binding to AR and showed AR-mediated uptake in the ventral and dorsal prostate of the rat. Further evaluation of these agents for PET imaging is needed since sex hormone binding globulin (SHBG), a glycoprotein which binds androgens with high affinity, is absent in rat blood but is present at high levels in the blood of primates. We chose to study three of the nine fluoro-androgens by PET in the baboon. METHODS In this study, 16beta-[18F]fluoro-5 alpha-dihydrotestosterone (I), 16beta-[18F]fluoromibolerone (II) and 20-[18F]fluoromibolerone (III) were synthesized and studied in both a young and old male baboon using PET. Blood samples were withdrawn in three of the 10 studies and analyzed for total radioactivity and percent unmetabolized radioligand. Tissue radioactivity was evaluated semiquantitatively, using prostate absolute, standard and target to nontarget uptake values. RESULTS Prostate uptake was observed with all three 18F-androgens. At 60 min postinjection, compound I gave the highest prostate to soft tissue ratios in both baboons and prostate uptake was shown to be AR-mediated by blocking uptake through the coadministration of testosterone. Compound I gave the highest level of unmetabolized radioligand present in blood up to 45 min postinjection, and gave a 37-fold greater prostate-to-bone ratio at 2 hr postinjection in baboons compared to rats. The favorable behavior of this compound in the baboon may be related to its high affinity for SHBG. CONCLUSION All three compounds can be used to determine AR-positive tissue in primates. Compound I was selected for the evaluation of AR in men with prostate cancer using PET.
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Affiliation(s)
- T A Bonasera
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Levine RL, Dobkin JA, Rozental JM, Satter MR, Nickles RJ. Blood flow reactivity to hypercapnia in strictly unilateral carotid disease: preliminary results. J Neurol Neurosurg Psychiatry 1991; 54:204-9. [PMID: 1903147 PMCID: PMC1014386 DOI: 10.1136/jnnp.54.3.204] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To show relationship between degree of carotid arterial stenosis and cerebral blood flow reactivity (RES%) to induced hypercapnia, fluorine-18-fluoromethane and positron emission tomography (PET) was used to study 18 patients with carotid distribution transient ischaemic attacks (TIA), all free of stroke, who had angiographic-proven unilateral arterial disease. Non-involved carotid arteries were either normal or had non-stenotic plaque. Either normal arteries or nonstenotic ulcerations in the symptomatic carotid arteries were present in five of 18 (28%), ipsilateral carotid stenosis from 50-99% was present in eight of 18 (44%), and ipsilateral internal carotid occlusion was present in five of 18 (28%) patients. In comparison with 14 normal controls, all patients with symptomatic middle cerebral artery (MCA) flow territories had significantly lower mean (SEM) RES% [5.0' (0.2) vs 4.0 (0.9), p less than 0.04]. Symptomatic anterior borderzone (ABZ) RES% was also significantly lower [4.6 (0.4) vs 3.3 (0.9), p less than 0.04], than controls. In patient subgroup comparisons, the 50-99% stenosis subgroup clearly had the lowest MCA RES% [3.4 (0.2)] as well as the lowest ABZ RES% [2.8 (0.4)] on their symptomatic sides. Age, expired pCO2, mean arterial blood pressure, serum glucose, serum haematocrit and number, type and estimated duration of TIAs were not significantly different between subgroups. Linear regression showed a significant relationship between RES% and both measured percentage-stenosis (p = 0.04) and residual luminal diameter (p = 0.05) in symptomatic MCA territories. This approached significance in symptomatic ABZ regions. This preliminary data set suggests that unilateral carotid stenosis can and does result in impaired CO2 reactivity following hypercapnia. The relative normality of CO2 reactivity in those with carotid occlusion is discussed.
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Affiliation(s)
- R L Levine
- William S Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
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Abstract
Alternating hemiplegia of childhood is an unusual disorder characterized by early onset (occurring before 18 months of age); repeated attacks of hemiplegia involving both sides of the body; other paroxysmal phenomena, such as tonic stiffening, dystonic posturing, choreoathetoid movements, ocular motor abnormalities, and autonomic disturbances, in association with bouts of hemiplegia or occurring independently; and evidence of mental or neurologic deficits. A girl was examined because of left hemiplegia at the age of 16 months. The patient had begun exhibiting episodes of alternating hemiplegia at approximately 4 months of age. They consisted of tonic stiffening and dystonia of the right or left extremities, lasting from 30 min to several hours and followed by residual hemiparesis. They were invariably accompanied by ocular motor abnormalities. Magnetic resonance imaging, computed tomography, and angiography all were normal. Single proton emission computed tomography brain images during an acute episode of right hemiplegia demonstrated hypoperfusion of the left cerebral hemisphere. Following improvement of the hemiplegia, the patient was re-evaluated. The uptake of the radiotracer in the left hemisphere was increased. The scan did not demonstrate significant asymmetry in cerebral perfusion.
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Affiliation(s)
- M L Zupanc
- Department of Neurology, University of Wisconsin Hospitals, Madison 53792
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Abstract
A positron emission tomography study using [18F]-fluorodeoxyglucose was undertaken to identify and quantitate whether diaschisis occurred in cerebral cortex, basal ganglia, or thalamus, as well as in cerebellar cortex and dentate nuclei in patients with malignant glioma. The relationship between diaschisis in these cerebral structures and clinically significant hemiparesis in patients was analysed. A 30% decrease in the regional metabolic rate for glucose in the cerebellar hemisphere contralateral to the tumor, and ipsilateral to the motor deficit, was identified and was statistically significant (p greater than 0.001). Decreased metabolism in the cerebellar hemisphere contralateral to the tumor was not seen in patients without hemiparesis. Parietal lobes affected by tumor had a larger decrease in metabolism than did frontal lobes with tumor (p greater than 0.01). The overall metabolism of the unaffected cerebellar hemisphere, relative to the peak metabolic activity of the brain, was not depressed in patients with tumor. In addition, the activity of subcortical nuclei was relatively unaffected by adjacent tumor or motor deficit.
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Affiliation(s)
- J M Rozental
- Neurology Service, Wm. S. Middleton Memorial Veterans Administration Hospital, Madison, WI 53705
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Abstract
Positron emission tomographic scanning with fludeoxyglucose F 18 (18F-fluorodeoxyglucose) was used to study acute changes in gliomas after chemotherapy. In six experimental subjects, scans were obtained before and at days 1, 7, and 30 after treatment. Five control patients with gliomas who did not undergo chemotherapy had two scans, 1 month apart. Ratios were calculated between peak tumor regional cerebral metabolic rate for glucose and contralateral white matter. The percent change in ratios relative to each patient's baseline scan was calculated. Ratios in three stable controls remained unchanged over the study interval; in two controls it increased 155% and 36% and both died of tumor progression. In experimental subjects, ratios increased 20% to 100% 24 hours after chemotherapy and then decreased until at 28 days they varied between 22% above and 35% below baseline. The increased fludeoxyglucose F 18 uptake at 24 hours could be from uncoupling oxidative phosphorylation or shunting glucose to ribose phosphates for salvage nucleoside synthesis.
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Affiliation(s)
- J M Rozental
- Neurology Service, William S. Middleton Memorial VA Hospital, Madison, WI 53705
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Abstract
Nineteen patients with strictly unilateral ischemic stroke as determined by clinical examination, computed tomography, magnetic resonance imaging, and standard angiography underwent cerebral blood flow (CBF) analysis using fluorine 18 fluoromethane and positron emission tomography. Mean flow values for averaged hemispheric, infarct, and homologous contralateral regions of interest (ROIs) were determined. All patient CBF values were significantly below comparable CBF ROIs in neurologically normal controls using Wilcoxon's two-sample rank testing. Multiple regression analysis disclosed a significant correlation between contralateral CBF are both localized CBF in the infarct ROI and patient age. Correlations between contralateral CBF and dependency score or severity of neurologic deficit at time of positron emission tomography, expired PCO2, mean arterial blood pressure, serum glucose or hematocrit, risk factor score, and number of days studied after stroke were not statistically significant. Although we did not identify the biologic mechanisms involved, we conclude that CBF reduction contralateral to a strictly unilateral ischemic infarction is due to a combination of aging and transhemispheric diaschisis.
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Affiliation(s)
- J A Dobkin
- Department of Neurology, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705
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Abstract
We report the vasocapacitance of the cerebral circulation, as determined by cerebral blood flow reactivity to induced hypercapnia using fluoromethane positron emission tomography, in 32 patients with unilateral anterior circulation transient ischemic attacks. A hemodynamic subset of eight patients, defined based on exertional, positional, orthostatic, or cardiac dysrhythmic induction of symptomatology, is characterized by multiple (median, 4.5 attacks per patient), brief (median, 2.5 minutes per attack), continued episodes of hemispheric ischemia including focal limb shaking. Symptomatic middle cerebral artery flow territories show significantly lower (p less than 0.04) and more asymmetric (p = 0.036) vasodilatory responses in the hemodynamic subset. Although ipsilateral internal carotid artery occlusion is more prevalent in the hemodynamic subset, the features of age, mean arterial blood pressure, carbon dioxide values, serum glucose, serum hematocrit, and number or type of risk factors do not differ significantly between groups. These studies of vasocapacitance help validate clinical criteria for cerebral hemodynamic events with an objective physiologic measurement.
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Affiliation(s)
- R L Levine
- Department of Neurology, William S. Middleton Memorial Veterans Administration Hospital, Madison, WI
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Abstract
A specific form of large subcortical hemispheric infarction on computed tomography was identified in 24 of 2198 (1%) stroke registry patients. Combined with 13 cases from earlier literature reports, a characteristic neurologic picture developed. Severe face plus arm plus leg weakness at onset (76%), corticallike features of aphasia and/or contralateral neglect (68%), and premonitory transient ischemic attacks (24%) were frequent. Twenty-two patients (59%) had large vessel arterial occlusive disease. Eight patients (22%) had primary embolic occlusion in the middle cerebral artery territory. During an average follow-up of 16 months, five patients (14%) suffered recurrent stroke or death. The clinical presentation and prognostic features of this distinct stroke subtype are described.
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Affiliation(s)
- R L Levine
- Department of Neurology, William S. Middleton Veterans Administration Hospital, Madison, WI 53705
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Dobkin JA, Schubert TT. Gastric cancer in a young adult. Am J Gastroenterol 1986; 81:607-10. [PMID: 3717128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We report a case of gastric adenocarcinoma in a 23-yr-old white man. Since only 1% of gastric cancers occur in patients under 35 yr or age, the diagnosis is often overlooked. The presence of persistent pain, weight loss, early satiety, anemia, and vomiting are clues to the underlying disorder. Endoscopy is the best means of diagnosis. All ulcers or other suspicious lesions should be biopsied. Prognosis is poor, related to the failure to suspect the diagnosis and to the aggressive nature of the disease. This case points out the importance of the thorough investigation of all patients with suggestive findings regardless of the patient's age.
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