Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 114
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Phys Rev Lett ; 124(10): 101102, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32216401

RESUMO

In recent years, many γ-ray sources have been identified, yet the unresolved component hosts valuable information on the faintest emission. In order to extract it, a cross-correlation with gravitational tracers of matter in the Universe has been shown to be a promising tool. We report here the first identification of a cross-correlation signal between γ rays and the distribution of mass in the Universe probed by weak gravitational lensing. We use data from the Dark Energy Survey Y1 weak lensing data and the Fermi Large Area Telescope 9-yr γ-ray data, obtaining a signal-to-noise ratio of 5.3. The signal is mostly localized at small angular scales and high γ-ray energies, with a hint of correlation at extended separation. Blazar emission is likely the origin of the small-scale effect. We investigate implications of the large-scale component in terms of astrophysical sources and particle dark matter emission.

4.
J Clin Invest ; 63(3): 494-500, 1979 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-429568

RESUMO

Patients with nephrotic syndrome have low blood levels of 25 hydroxyvitamin D (25-OH-D) most probably because of losses in urine, and a vitamin D-deficient state may ensue. The biological consequences of this phenomenon on target organs of vitamin D are not known. This study evaluates one of these target organs, the bone. Because renal failure is associated with bone disease, we studied six patients with nephrotic syndrome and normal renal function. The glomerular filtration rate was 113+/-2.1 (SE) ml/min; serum albumin, 2.3+/-27 g/dl; and proteinuria ranged between 3.5 and 14.7 g/24 h. Blood levels of 25-OH-D, total and ionized calcium and carboxy-terminal fragment of immunoreactive parathyroid hormone were measured, and morphometric analysis of bone histology was made in iliac crest biopsies obtained after double tetracycline labeling. Blood 25-OH-D was low in all patients (3.2-5.1 ng/ml; normal, 21.8+/-2.3 ng/ml). Blood levels of both total (8.1+/-0.12 mg/dl) and ionized (3.8+/-0.21 mg/dl) calcium were lower than normal and three patients had true hypocalcemia. Blood immuno-reactive parathyroid hormone levels were elevated in all. Volumetric density of osteoid was significantly increased in three out of six patients and the fraction of mineralizing osteoid seams was decreased in all. Evidence for an increase in active lacunae (bone-osteoclast interface) occurred in three out of six patients and in inactive (Howship's lacunae) bone resorption in six out of six. The data indicate that the loss of 25-OH-D in urine of patients with nephrotic syndrome and normal renal function may result in a decrease of blood levels of ionized calcium, secondary hyperparathyroidism and enhanced bone resorption. In addition, the vitamin D-deficient state causes osteomalacia as evidenced by defective mineralization and increased osteoid volume.


Assuntos
Doenças Ósseas/etiologia , Hiperparatireoidismo/etiologia , Síndrome Nefrótica/complicações , Osteomalacia/etiologia , Adulto , Doenças Ósseas/patologia , Osso e Ossos/patologia , Cálcio/sangue , Feminino , Humanos , Hidroxicolecalciferóis/sangue , Síndrome Nefrótica/sangue , Osteomalacia/patologia , Hormônio Paratireóideo/sangue
5.
J Clin Invest ; 62(1): 88-93, 1978 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-659642

RESUMO

Peripheral neuropathy is not an uncommon complication of chronic uremia. Because parathyroid hormone, by raising brain calcium, is partly responsible for central nervous system aberrations in uremia, we studied the relative role of uremia, per se, and(or) parathyroid hormone on peripheral nerve calcium and motor nerve conduction velocity (MNCV). Studies were made in six groups of six dogs each, as follows: (a) normal dogs, (b) thyroparathyroidectomized (T-PTX) animals, (c) dogs with 3 days of uremia produced by bilateral nephrectomy, (d) T-PTX before the induction of acute renal failure, (e) normal dogs receiving 100 U/day of parathyroid extract (PTE) for 3 days, and (f) normal animals receiving 3 days of PTE followed by 5 days without PTE. Calcium content in peripheral nerve (expressed as milligram per kilogram of dry weight) was 252+/-5 (SE) in normal animals and 262+/-4 in T-PTX dogs. It was significantly (P < 0.01) higher in dogs with acute renal failure and intact parathyroid glands (410+/-12) and in normal animals receiving PTE (362+/-7). T-PTX, before acute renal failure, prevented the rise in peripheral nerve calcium (262+/-4) and PTE withdrawal was followed by the return of peripheral nerve calcium to normal (261+/-3). The increments in peripheral nerve calcium were associated with slowing of MNCV. It decreased significantly from 70+/-4 to 43+/-1 m/s after 3 days of acute uremia in dogs with intact parathyroid glands and T-PTX before acute renal failure prevented the fall in MNCV. Administration of PTE to normal animals reduced MNCV from 63+/-3 to 35+/-3 m/s and the withdrawal of PTE restored MNCV to normal (73+/-2 m/s). The results show that (a) excess parathyroid hormone increases peripheral nerve calcium and slows MNCV, (b) T-PTX, previously performed, prevents these changes in acute uremia, and (c) the withdrawal of PTE administration is followed by a reversal of the abnormalities.


Assuntos
Cálcio/metabolismo , Hormônio Paratireóideo/farmacologia , Nervos Periféricos/fisiopatologia , Uremia/fisiopatologia , Animais , Cães , Feminino , Masculino , Condução Nervosa/efeitos dos fármacos , Glândulas Paratireoides/fisiologia , Nervos Periféricos/efeitos dos fármacos , Nervos Periféricos/metabolismo , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/metabolismo , Nervo Isquiático/fisiopatologia , Tireoidectomia , Uremia/metabolismo
6.
J Clin Invest ; 75(3): 1037-44, 1985 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3884663

RESUMO

Evidence has accumulated suggesting that the state of secondary hyperparathyroidism and the elevated blood levels of parathyroid hormone (PTH) in uremia participate in the genesis of many uremic manifestations. The present study examined the role of PTH in glucose intolerance of chronic renal failure (CRF). Intravenous glucose tolerance tests (IVGTT) and euglycemic and hyperglycemic clamp studies were performed in dogs with CRF with (NPX) and without parathyroid glands (NPX-PTX). There were no significant differences among the plasma concentrations of electrolytes, degree of CRF, and its duration. The serum levels of PTH were elevated in NPX and undetectable in NPX-PTX. The NPX dogs displayed glucose intolerance after CRF and blood glucose concentrations during IVGTT were significantly (P less than 0.01) higher than corresponding values before CRF. In contrast, blood glucose levels after IVGTT in NPX-PTX before and after CRF were not different. K-g rate fell after CRF from 2.86 +/- 0.48 to 1.23 +/- 0.18%/min (P less than 0.01) in NPX but remained unchanged in NPX-PTX (from 2.41 +/- 0.43 to 2.86 +/- 0.86%/min) dogs. Blood insulin levels after IVGTT in NPX-PTX were more than twice higher than in NPX animals (P less than 0.01) and for any given level of blood glucose concentration, the insulin levels were higher in NPX-PTX than NPX dogs. Clamp studies showed that the total amount of glucose utilized was significantly lower (P less than 0.025) in NPX (6.64 +/- 1.13 mg/kg X min) than in NPX-PTX (10.74 +/- 1.1 mg/kg X min) dogs. The early, late, and total insulin responses were significantly (P less than 0.025) greater in the NPX-PTX than NPX animals. The values for the total response were 143 +/- 28 vs. 71 +/- 10 microU/ml, P less than 0.01. There was no significant difference in the ratio of glucose metabolized to the total insulin response, a measure of tissue sensitivity to insulin, between the two groups. The glucose metabolized to total insulin response ratio in NPX (5.12 +/- 0.76 mg/kg X min per microU/ml) and NPX-PTX (5.18 +/- 0.57 mg/kg X min per microU/ml) dogs was not different but significantly (P less than 0.01) lower than in normal animals (9.98 +/- 1.26 mg/kg X min per microU/ml). The metabolic clearance rate of insulin was significantly (P less than 0.02) reduced in both NPX (12.1 +/- 0.7 ml/kg X min) and NPX-PTX (12.1 +/- 0.9 ml/kg X min) dogs, as compared with normal animals (17.4 +/- 1.8 ml/kg X min). The basal hepatic glucose production was similar in both groups of animals and nor different from normal dogs; both the time course and the magnitude of suppression of hepatic glucose production by insulin were similar in both in groups. There were no differences in the binding affinity, binding sites concentration, and binding capacity of monocytes to insulin among NPX, NPX-PTX, and normal dogs. The data show that (a) glucose intolerance does not develop with CRF in the absence of PTH, (b) PTH does not affect metabolic clearance of insulin or tissue resistance to insulin in CRF, and (c) the normalization of metabolism in CRF in the absence of PTH is due to increased insulin secretion. The results indicate that excess PTH in CRF interferes with the ability of the beta-cells to augment insulin secretion appropriately in response to the insulin-resistant state.


Assuntos
Teste de Tolerância a Glucose , Falência Renal Crônica/metabolismo , Hormônio Paratireóideo/fisiologia , Animais , Glicemia/metabolismo , Cães , Feminino , Hiperglicemia/sangue , Infusões Parenterais , Insulina/sangue , Insulina/farmacologia , Falência Renal Crônica/sangue , Falência Renal Crônica/fisiopatologia , Nefrectomia , Glândulas Paratireoides/fisiologia , Receptor de Insulina/análise , Tireoidectomia
7.
Med Oncol ; 33(4): 37, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26995224

RESUMO

Pancreatic adenocarcinoma is the fourth leading cause of cancer death. Recently, MM-398 (nanoliposomal irinotecan) was shown to be associated with significant improvement in outcome measures with acceptable toxicities when combined with 5-fluorouracil (5-FU)/leucovorin (LV) compared to 5-FU/LV alone in patients failing one line of gemcitabine-based therapy. There is a paucity of data evaluating the role of irinotecan in combination with 5FU in advanced pancreas cancer (APC). We performed a retrospective analysis of all patients who received mFOLFIRI (minus bolus 5FU and LV). All patients with metastatic disease who had failed at least one line of gemcitabine-based therapy prior to receiving mFOLFIRI were included in this study. Descriptive statistics were used to assess the continuous variables and adverse events (AEs), and Kaplan-Meier methods were used to calculate the median progression-free survival (PFS) and overall survival (OS). Forty patients were included in this analysis. Patients received 1-5 lines of prior therapy (25 % with more than 3 lines of prior therapy). The mean age at diagnosis was 60, and 98 % had ECOG of 1. The mean CA 19-9 at the start of therapy was 33,169 U/ml. The median PFS was 2.59 months [95 % confidence interval (CI) (1.90, 3.54)], and OS was 4.75 months [95 % CI (3.14, 8.98)]. The most common AEs included fatigue (98 %), neuropathy (83 %), anorexia (68 %), nausea (60 %) and constipation (55 %). Grade 3 toxicities included fatigue (13 %) and rash (3 %). There were no observed grade 4 toxicities. In this single-institution retrospective analysis, mFOLFIRI was found to be both tolerable and relatively effective in a heavily pretreated patient population with APC. Future prospective studies should consider evaluating the role of mFOLFIRI in refractory APC.


Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Camptotecina/análogos & derivados , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Adenocarcinoma/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/economia , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Camptotecina/economia , Camptotecina/uso terapêutico , Custos e Análise de Custo , Intervalo Livre de Doença , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Fluoruracila/economia , Fluoruracila/uso terapêutico , Humanos , Infusões Intravenosas , Irinotecano , Leucovorina/administração & dosagem , Leucovorina/efeitos adversos , Leucovorina/economia , Leucovorina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Estudos Retrospectivos , Resultado do Tratamento
8.
J Gen Physiol ; 72(1): 87-100, 1978 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-702108

RESUMO

The increased unidirectional sodium influx found when human erythrocytes are suspended in isotonic salt solutions containing bicarbonate ions as a replacement for chloride ions was examined. The increased sodium movement appears to have the transport characteristics of anion movement. Inhibitors of anion transport such as furosemide, fluorodinitrobenzene (FDNB), and 4-acetamido-4'-isothiocyano-stilbene-2-2'-disulfonic acid (SITS) drastically inhibit these augmented sodium movements. An ion-pair mechanism appears to phenomenologically describe much of the data. A possible role for carbamino groups is considered. Such a model, however, required additional assumptions to explain the selectivity and the anion inhibitor effects.


Assuntos
Bicarbonatos/metabolismo , Eritrócitos/metabolismo , Sódio/metabolismo , Ânions/antagonistas & inibidores , Transporte Biológico Ativo/efeitos dos fármacos , Dinitrofluorbenzeno/farmacologia , Furosemida/farmacologia , Humanos , Técnicas In Vitro , Matemática , Modelos Biológicos , Estilbenos/farmacologia
9.
J Gen Physiol ; 77(3): 233-53, 1981 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6265590

RESUMO

The effect of ether and halothane on the kinetics of sodium and potassium currents were investigated in the crayfish giant axon. Both general anesthetics produced a reversible, dose-dependent speeding up of sodium current inactivation at all membrane potentials, with no change in the phase of the currents. Double-pulse inactivation experiments with ether also showed faster inactivation, but the rate of recovery from inactivation at negative potentials was not affected. Ether shifted the midpoint of the steady-state fast inactivation curve in the hyperpolarizing direction and made the curve steeper. The activation of potassium currents was faster with ether present, with no change in the voltage dependence of steady-state potassium currents. Ether and halothane are known to perturb the structure of lipid bilayer membranes; the alterations in sodium and potassium channel gating kinetics are consistent with the hypothesis that the rates of the gating processes of the channels can be affected by the state of the lipids surrounding the channels, but a direct effect of ether and halothane on the protein part of the channels cannot be ruled out. Ether did not affect the capacitance of the axon membrane.


Assuntos
Axônios/metabolismo , Éter/farmacologia , Etil-Éteres/farmacologia , Halotano/farmacologia , Canais Iônicos/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Potenciais de Ação/efeitos dos fármacos , Animais , Astacoidea/fisiologia , Axônios/fisiologia , Técnicas In Vitro , Cinética , Potenciais da Membrana/efeitos dos fármacos
10.
J Gen Physiol ; 56(2): 180-90, 1970 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-5433466

RESUMO

Addition of a macromolecule to a solution will give rise to a large excluded volume for the centers of the solute molecules. This will cause an apparent increase in solute concentration which is of the same order of magnitude as that associated with the nonsolvent volumes reported in the literature. A critical examination of one of the procedures used for the determination of nonsolvent water-the vapor pressure method of Hill-is given, and it is concluded that, with the use of this method, it is impossible to detect any significant nonsolvent water surrounding bovine albumin for either sugars or polyols. Generally, data reported in the literature for the nonsolvent water of proteins or other macromolecules will be too high unless they are corrected for the excluded volume.


Assuntos
Substâncias Macromoleculares , Concentração Osmolar , Soroalbumina Bovina , Soluções , Hemoglobinas , Métodos , Temperatura
11.
J Gen Physiol ; 54(2): 166-77, 1969 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-5796367

RESUMO

Electron microscopy shows that the transverse tubular system of frog sartorius swells in Ringer fluid in which NaCl is partially replaced by sucrose (sucrose isotonic solutions). At constant tonicity, the degree of swelling is roughly proportional to the decrease in ionic strength and to the sucrose concentration of the bathing solution. Swelling is time-dependent and reversible within 2 hr. The late after potential which follows a train of impulses is prolonged with swelling, but not to the extent expected from the model of Adrian and Freygang. This discrepancy remains unexplained, as does the mechanism of swelling of the transverse tubular system, although some suggestions are offered. One is that the transverse tubular system contains fixed charges and swells like a fixed charge gel.


Assuntos
Músculos/citologia , Animais , Anuros , Eletrofisiologia , Soluções Isotônicas , Microscopia Eletrônica , Músculos/fisiologia , Pressão Osmótica , Sacarose
12.
Arch Intern Med ; 136(12): 1363-5, 1976 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-999418

RESUMO

We describe five patients with acute pancreatitis in whom acute renal failure developed in the absence of hypotension. Pancreatitis was diagnosed clinically, with mean serum and urinary amylase levels of 766 +/- 197 (SE) and 2,378 +/- 572 units/100 ml, respectively. Acute renal failure developed within 24 hours after admission in all patients. It was manifested by oliguria, elevated levels of serum creatinine (mean, 6.9 +/- 1.1 mg/100 ml) and BUN (105 +/-28 mg/100 ml); a urinary sodium level of 72.0 +/- 6.6 mEq/liter; and isosmotic urine (355 +/- 31 mOsm/liter). The mean uric acid level was 18.6 +/- 1.6 mg/100 ml. Blood pressure was recorded frequently, and the lowest mean diastolic pressure was 96 +/- 6 mm Hg. The duration of the oliguric phase of acute renal failure was 8.2 +/- 1.7 days, and all patients recovered from both the acute pancreatitis and acute renal failure. In summary, acute pancreatitis, per se, can precipitate acute renal failure. It occurs early in the course of the pancreatitis, and extreme hyperuricemia is frequent finding that does not adversely affect the recovery of renal function.


Assuntos
Injúria Renal Aguda/etiologia , Pancreatite/complicações , Doença Aguda , Injúria Renal Aguda/terapia , Adulto , Creatinina/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pancreatite/terapia , Diálise Peritoneal , Ácido Úrico/sangue
13.
Arch Intern Med ; 140(8): 1030-3, 1980 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6893118

RESUMO

Since abnormalities in divalent ion metabolism occur early in renal insufficiency, treatment of patients with moderate renal failure with calcitriol could halt and/or reverse these disturbances. The effects of long-term treatment with calcitriol (0.5 microgram/day) in three such patients were evaluated. Serum calcium level rose from 0.3 to 0.7 mg/dL. Blood parathyroid hormone levels were mildly elevated and fell to normal. Intestinal absorption of calcium increased. The patients had hypocalciuria and the urinary calcium level increased. Creatinine clearance remained stable in all patients. Iliac crest biopsy specimens obtained after double tetracycline hydrochloride labeling revealed mild osteomalacia and hyperparathyroid bone disease that healed after therapy. The data show that a small dose of calcitriol is safe and effective for the management of the derangements of divalent ion metabolism in patients with moderate renal failure.


Assuntos
Di-Hidroxicolecalciferóis/uso terapêutico , Hidroxicolecalciferóis/uso terapêutico , Hiperparatireoidismo Secundário/tratamento farmacológico , Falência Renal Crônica/complicações , Osteomalacia/tratamento farmacológico , Adulto , Osso e Ossos/patologia , Calcitriol , Cálcio/metabolismo , Feminino , Humanos , Hiperparatireoidismo Secundário/etiologia , Falência Renal Crônica/metabolismo , Falência Renal Crônica/patologia , Magnésio/metabolismo , Pessoa de Meia-Idade , Osteomalacia/etiologia , Hormônio Paratireóideo/metabolismo , Fósforo/metabolismo
14.
J Clin Endocrinol Metab ; 50(3): 470-4, 1980 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7358832

RESUMO

Patients with the nephrotic syndrome have low blood levels of 25-hydroxyvitamin D3 (25OHD3) due to urinary losses of the sterol. It is not known whether supplementation of this metabolite could raise its blood levels in these patients. The changes in the plasma levels of 25OHD3 and its kinetic behavior were studied after an oral dose of the sterol (200 microgram) in patients with the nephrotic syndrome in an effort to evaluate the usefulness of oral therapy to achieve and maintain normal blood levels of 25OHD3. Normal subjects served as controls. The results showed that intestinal absorption of 25OHD3 is significantly delayed and its elimination rate is significantly enhanced in patients with the nephrotic syndrome compared to control subjects. Despite these abnormalities, the plasma levels of 25OHD3 were within normal values even 48 h after the ingestion of the sterol. These data indicate that oral therapy with 25OHD3 given in proper doses is adequate to maintain normal blood levels of the sterol in patients with the nephrotic syndrome. Therefore, a therapeutic approach could be designed to manage the target organ disease due to 25OHD3 deficiency seen in these patients.


Assuntos
Hidroxicolecalciferóis/sangue , Síndrome Nefrótica/sangue , Adulto , Idoso , Calcifediol , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/tratamento farmacológico
15.
J Clin Endocrinol Metab ; 52(1): 116-21, 1981 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6969729

RESUMO

Patients with nephrotic syndrome (NS) lose 25-hydroxyvitamin D3 (25OHD3) in the urine and have low blood levels of this metabolite. This abnormality may be responsible for the hypocalcemia, i.e. low ionized calcium. The mechanism of the hypocalcemia is not evident. It is possible that the low value of 25OHD results in low blood levels of other vitamin D metabolites, such as 1,25-dihydroxyvitamin D [1,25-(OH)2D] and 24,25-(OH)2D3; a deficiency of these compounds may cause defective intestinal absorption of calcium (alpha) and resistance to the calcemic action of parathyroid hormone (PTH), resulting in hypocalcemia. Studies were performed in 12 patients with NS and normal renal function to evaluate these questions. Blood levels of 25OHD, 1,25-(OH)2D, and 24,25-(OH)2D were all significantly (P < 0.01) lower in NS (4.0 +/- 0.8 ng/ml, 7.0 +/- 2.3 pg/ml, 1.8 +/- 0.2 ng/ml, respectively) compared to normal subjects (37.0 +/- 1.5 ng/ml, 37.0 +/- 1.2 pg/ml, and 3.4 +/- 0.2 ng/ml). Both alpha (0.21 +/- 0.2 vs. 0.27 +/- 0.1; P < 0.05) and the calcemic response to PTH (0.50 +/- 0.1 vs. 1.35 +/- 0.16 mg/dl; P < 0.01) in NS subjects were significantly lower than normal. The data indicate that 1) a deficient state of all of these vitamin D metabolites exists in patients with NS and normal renal function, 2) this abnormality underlies the defect in alpha and the resistance to the calcemic response to PTH, and all participate in the genesis of the hypocalcemia, 3) secondary hyperparathyroidism develops, and 4) both vitamin D deficiency and elevated blood levels of PTH are responsible for the bone lesions in these patients.


Assuntos
Cálcio/sangue , Síndrome Nefrótica/sangue , Vitamina D/sangue , 24,25-Di-Hidroxivitamina D 3 , Adolescente , Adulto , Calcifediol , Calcitriol , Di-Hidroxicolecalciferóis/sangue , Feminino , Humanos , Hidroxicolecalciferóis/sangue , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue
16.
Neurology ; 29(12): 1590-4, 1979 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-228217

RESUMO

Papovaviruses can induce experimental brain neoplasms in animals, and some papovaviruses have been implicated in the formation of various human tumors. We examined a series of seven human brain tumors removed at craniotomy for the presence of viral DNA sequences by the technique of DNA-DNA hybridization. Simian virus 40 (SV40) DNA was labeled in vitro and used as a "probe" for detecting related DNA sequences in cellular DNA extracted from brain tumors. SV40-related DNA sequences were found in DNA extracted from one tumor, a glioblastoma multiforme. It was calculated that approximately 1.2 viral genome equivalents per diploid cell were present in the tumor. Since the rate of reassociation of the probe deviated from ideal second-order kinetics, it is surmised that either only a portion of the SV40 genome was present in tumor cells or, alternatively, that the probe detected a related human papovavirus.


Assuntos
Neoplasias Encefálicas/análise , DNA de Neoplasias/análise , DNA Viral/análise , Glioblastoma/análise , Vírus 40 dos Símios/análise , Infecções Tumorais por Vírus/análise , Animais , Humanos , Neoplasias Meníngeas/análise , Meningioma/análise
17.
Neurology ; 27(8): 736-40, 1977 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-196234

RESUMO

Papovaviruses appear to be neurotropic and one, JC virus, is implicated as the cause of one type of demyelinating disease, progressive multifocal leukoencephalopathy. To investigate whether human papovaviruses play a role in multiple sclerosis, radioactively labeled DNA from BK virus, human papilloma virus, and simian virus 40 was used as a probe in order to detect related unlabeled DNA sequences in DNA isolated from multiple sclerosis brain and/or spinal cord. Labeled viral probes were denatured and DNA allowed to reassociate in the presence of excess unlabeled DNA from multiple sclerosis tissue or from controls. The reassociation rate of the probe is proportional to the concentration of viral DNA present, and an increase in the reassociation rate of the probe over that of control reactions would indicate the presence of unlabeled viral DNA in multiple sclerosis cellular DNA. However, addition of DNA derived from multiple sclerosis patients did not increase rates of reassociation of viral probes. Known human papovaviruses probably have no role in the pathogenesis of multiple sclerosis.


Assuntos
DNA Viral , DNA , Esclerose Múltipla/etiologia , Papillomaviridae , Polyomaviridae , Vírus BK , Genótipo , Humanos , Técnicas In Vitro , Radioisótopos do Iodo , Esclerose Múltipla/microbiologia , Desnaturação de Ácido Nucleico , Vírus 40 dos Símios
18.
Arch Ophthalmol ; 116(9): 1232-4, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9747687

RESUMO

A 62-year-old man developed bilateral granulomatous iridocyclitis after uncomplicated cataract surgery. On ophthalmic examination, we found moderate inflammation in the anterior chamber and vitreous, with granular crystalline deposits on the iris, intraocular lens, and capsular bag. Biopsy of the lens capsule and vitreous revealed periodic acid-Schiff-positive, diastase-resistant bacilli consistent with Tropheryma whippelii. Electron microscopy and polymerase chain reaction confirmed the diagnosis of Whipple disease. A jejunal biopsy specimen also revealed T whippelii. Treatment with trimethoprim-sulfamethoxazole, cefixime, rifampin, and doxycycline resulted in improvement of systemic symptoms, but intraocular inflammation persisted. Intraocular inflammation was eventually reduced with the intravenous administration of ceftriaxone sodium.


Assuntos
Actinobacteria/isolamento & purificação , Infecções por Actinomycetales/diagnóstico , Infecções Oculares Bacterianas , Granuloma/diagnóstico , Iridociclite/diagnóstico , Doença de Whipple/diagnóstico , Actinobacteria/genética , Infecções por Actinomycetales/tratamento farmacológico , Infecções por Actinomycetales/microbiologia , Antibacterianos , DNA Bacteriano/análise , Quimioterapia Combinada/uso terapêutico , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/microbiologia , Granuloma/tratamento farmacológico , Granuloma/microbiologia , Humanos , Iridociclite/tratamento farmacológico , Iridociclite/microbiologia , Jejuno/microbiologia , Cápsula do Cristalino/microbiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Corpo Vítreo/microbiologia , Doença de Whipple/tratamento farmacológico , Doença de Whipple/microbiologia
19.
QJM ; 97(11): 705-16, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15496527

RESUMO

Modern biotechnology has resulted in a resurgence of interest in the production of new therapeutic agents using botanical sources. With nearly 500 biotechnology products approved or in development globally, and with production capacity limited, the need for efficient means of therapeutic protein production is apparent. Through genetic engineering, plants can now be used to produce pharmacologically active proteins, including mammalian antibodies, blood product substitutes, vaccines, hormones, cytokines, and a variety of other therapeutic agents. Efficient biopharmaceutical production in plants involves the proper selection of host plant and gene expression system, including a decision as to whether a food crop or a non-food crop is more appropriate. Product safety issues relevant to patients, pharmaceutical workers, and the general public must be addressed, and proper regulation and regulatory oversight must be in place prior to commercial plant-based biopharmaceutical production. Plant production of pharmaceuticals holds great potential, and may become an important production system for a variety of new biopharmaceutical products.


Assuntos
Indústria Farmacêutica , Plantas Geneticamente Modificadas/metabolismo , Proteínas Recombinantes/biossíntese , Anticorpos/metabolismo , Biotecnologia/métodos , Tecnologia Farmacêutica/métodos , Vacinas/biossíntese
20.
Health Psychol ; 8(5): 503-24, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2698349

RESUMO

Cardiovascular and hormonal responses to a structured interview, an electronic video game, a cold pressor test, and exercise on a bicycle ergometer were assessed in eighty-three 25- to 44-year-old normotensive Black and White men and women. Blacks showed significantly greater diastolic blood pressure (DBP) responses than Whites during the cold pressor test, which were not accounted for by an increase in plasma catecholamines. Exercise produced reliably greater systolic blood pressure (SBP) increases in Black women than in Black men or White women. Men showed significantly greater SBP and DBP changes than women during the video game. These findings suggest that the pattern of physiological reactivity elicited by challenge is related to the race and sex of the subjects.


Assuntos
Nível de Alerta/fisiologia , População Negra , Pressão Sanguínea/fisiologia , Epinefrina/sangue , Frequência Cardíaca/fisiologia , Norepinefrina/sangue , Fibras Adrenérgicas/fisiologia , Adulto , Temperatura Baixa , Teste de Esforço , Feminino , Coração/inervação , Humanos , Masculino , Resolução de Problemas/fisiologia , Valores de Referência , Renina/sangue
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa