RESUMO
An intrathoracic mass was discovered as an incidental finding in a 14-year-old, spayed, female Rottweiler cross during evaluation of urinary incontinence. Computed tomography suggested a pericardial or pleural location and high adipose content of the mass. The mass was removed via lateral thoracotomy with partial pericardectomy and was diagnosed as a pericardial lipoma. The dog recovered well, and there was no evidence of recurrence approximately one year later. Adipose tumours of the heart and its associated structures are rare in dogs and have been associated with both successful and fatal outcomes.
Assuntos
Doenças do Cão/diagnóstico , Lipoma/veterinária , Pericárdio/patologia , Neoplasias Torácicas/veterinária , Animais , Diagnóstico Diferencial , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/patologia , Doenças do Cão/cirurgia , Cães , Feminino , Lipoma/diagnóstico , Neoplasias Torácicas/diagnóstico , Toracotomia , Tomografia Computadorizada por Raios X/veterináriaRESUMO
Serum antibody titers to Epstein-Barr virus (EBV), an agent that persists in a latent form after the initial infection, were determined in 157 patients with multiple sclerosis and in 81 control subjects. Two patients (1.3%) and five control subjects (6.2%) lacked antibodies to EBV. In the subjects with antibodies, the prevalence of high titers (greater than or equal to 1:160) was significantly greater in patients, 69 (44.5%), than in control subjects, 22 (28.9%). The geometric mean titer of antibodies to EBV was significantly higher in patients, 107.0, than in control subjects, 77.1. There was no association between antibody titers and duration or activity of the disease. These findings further support the contention that patients with multiple sclerosis have a general aberration of the immunological system.
Assuntos
Anticorpos Antivirais/análise , Herpesvirus Humano 4/imunologia , Esclerose Múltipla/imunologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores SocioeconômicosRESUMO
Cyclophosphamide was administered to 14 patients with chronic progressive multiple sclerosis on an intermittent escalating dosage schedule adjusted to maintain numbers of peripheral blood B lymphocytes and helper/inducer (CD4) T cells below the fifth percentile of the normal population. Peripheral blood B cells, T cells, suppressor/cytotoxic (CD8) T cells, CD4 cells, and FcR+-bearing cell numbers and percentages were monitored at one-week to two-week intervals. Clinical status was assessed by neurologic examinations at approximately four-week intervals. Regression analysis revealed a statistically significant correlation between changes in immunologic status and changes in clinical state. The immunologic changes preceded the neurologic changes. Increases in percent of CD8 cells and decreases in percent of CD4 cells forecast improved clinical course. These findings, coupled with other studies, strongly suggest a pathogenetic role for helper and suppressor T cells in the production of clinical signs of multiple sclerosis.
Assuntos
Linfócitos B/efeitos dos fármacos , Ciclofosfamida/administração & dosagem , Esclerose Múltipla/imunologia , Linfócitos T/efeitos dos fármacos , Esquema de Medicação , Humanos , Contagem de Leucócitos/efeitos dos fármacos , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/fisiopatologia , Exame Neurológico , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacosRESUMO
We tested 11 patients with multiple sclerosis for the presence of human T-cell leukemia virus type I (HTLV-I)- or type II (HTLV-II)-related sequences. DNA from blood mononuclear cells was analyzed by the polymerase chain reaction utilizing three different oligonucleotide primer pairs. Two of these primer pairs detect sequences shared between HTLV-I and HTLV-II in either p24, gag protein, or in p21, env transmembrane protein. The third primer pair was synthesized based on regions in the pol gene where amino acid sequences are conserved between HTLV-I, HTLV-II, and the related bovine leukemia virus. The multiple sclerosis samples were consistently negative while appropriate control samples were positive. We conclude that viruses related to HTLV-I, HTLV-II, or bovine leukemia virus are not present in the blood of patients with multiple sclerosis and, therefore, that HTLV-bovine leukemia virus-related viruses are not likely to be involved in the pathogenesis of multiple sclerosis.
Assuntos
DNA Viral/análise , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 2 Humano/genética , Esclerose Múltipla/sangue , Sequência de Aminoácidos , Humanos , Injeções Intravenosas , Leucemia de Células T/sangue , Dados de Sequência Molecular , Paraparesia Espástica Tropical/sangue , Reação em Cadeia da Polimerase , Doenças da Medula Espinal/sangue , Transtornos Relacionados ao Uso de Substâncias/sangueRESUMO
Magnetic resonance imaging (MRI) of the cerebrum, cerebellum, brain stem, and upper cervical cord was performed in 62 individuals with clinically definite chronic, progressive multiple sclerosis (MS). The total area of MRI-demonstrated lesions was measured from film enlargements for each region using an interactive image analysis system. While the MRI was abnormal in 60 (97%) of 62 patients, the visual-evoked potentials in 51 (85%) of 60 patients, the brain stem auditory-evoked potentials (BAEPs) in 24 (46%) of 52 patients, and the somatosensory-evoked potentials (SSEPs) in 45 (89%) of 54 patients, an abnormal intra-blood-brain barrier (BBB) IgG synthesis rate, IgG oligoclonal bands, or both were found in all 62 patients. The total area of MRI abnormality in the cerebrum was significantly correlated only with the intra-BBB IgG synthesis rate, abnormal visual-evoked potentials, impaired performance on the Symbol Digit Modalities Test (SDMT), and one test of standing duration in the quantitative examination of neurologic function (QENF). The brain stem lesion area correlated with the Kurtzke expanded disability status scale and brain stem functional systems score, the ambulation index, abnormal BAEPs, and impaired performance on the SDMT as well as multiple tests of upper and lower extremity function in the QENF. The cerebellar lesion area correlated with impaired performance on the SDMT and primarily upper extremity testing in the QENF.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Barreira Hematoencefálica/imunologia , Encéfalo/fisiopatologia , Potenciais Evocados Auditivos/fisiologia , Potenciais Somatossensoriais Evocados/fisiologia , Potenciais Evocados Visuais/fisiologia , Imunoglobulina G/biossíntese , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/diagnóstico , Adulto , Doença Crônica , Avaliação da Deficiência , Feminino , Humanos , Imunoglobulina G/líquido cefalorraquidiano , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/imunologia , Esclerose Múltipla/fisiopatologia , Exame Neurológico/métodosRESUMO
To our knowledge, this is the first clinical trial in multiple sclerosis (MS) demonstrating the feasibility of directing immunomodulating therapy by monitoring immunologic results. Cyclophosphamide was administered at monthly intervals, escalating the dose until there was a significant reduction in both the number of blood B lymphocytes and helper/inducer (CD4) T cells of 14 patients with chronic progressive MS. The frequency and severity of adverse effects led us to conclude that the regimen is too toxic for the long-term treatment of patients with MS.
Assuntos
Ciclofosfamida/administração & dosagem , Esclerose Múltipla/tratamento farmacológico , Adulto , Idoso , Linfócitos B/imunologia , Ensaios Clínicos como Assunto , Ciclofosfamida/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/imunologia , Linfócitos T/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
A single score is desirable for evaluating progression in clinical trials of MS therapy. Our objective was to develop a more sensitive scoring that would reflect clinical assessment of relative severity of disability. An Illness Severity Score (ISS) was developed as a sum of weights corresponding to ratings of Kurtzke Disability Status Scale and Functional Systems Scales and phase of illness. Weights were computed from clinical comparison of pairs of patients. The score was standardized to have mean 50 and standard deviation 10 in a single clinic population. Score reproducibility (correlation = 0.93) was evaluated by two independent scorings of several patients. The ISS was satisfactory as the primary assessment in a small-scale clinical trial.
Assuntos
Esclerose Múltipla/diagnóstico , Exame Neurológico , HumanosRESUMO
Data bases describing the natural history of patients with multiple sclerosis or the clinical course of patients treated with placebos might serve as "historical controls" in future clinical therapeutic trials. The results of clinical trials with such controls can be misleading. There is a strong tendency for the new treatment to appear efficacious when historical controls are the comparison group. Therefore, claims of efficacy deduced from trials using such controls should be closely questioned. Thus, such comparison groups probably would be useful for preliminary and early phase II (pilot) trials rather than in more definitive phase III (full) trials.
Assuntos
Esclerose Múltipla/terapia , Projetos de Pesquisa , Ensaios Clínicos como Assunto , Avaliação de Medicamentos , Humanos , Esclerose Múltipla/fisiopatologia , Placebos , Distribuição Aleatória , Sistema de RegistrosRESUMO
Success has been reported with use of total lymphoid irradiation (TLI) in organ transplant recipients and in patients with rheumatoid arthritis and other autoimmune diseases. In a well-conducted randomized double blind clinical trial, Cook et al have found that TLI was superior to sham irradiation of patients with multiple sclerosis (MS). However, it is clear from looking at this data that not all patients responded to TLI and that with time disease activity returned. Our own experience with TLI in two MS patients was very disappointing. Despite its apparent benefit in some conditions, considerable drawbacks are associated with TLI. These include high financial cost, unpleasant treatment-related side effects, and the possibility that more serious morbidity as well as mortality may be treatment-related. Furthermore, the optimum therapeutic regimen for TLI has not yet been established. Issues related to cumulative dose, dose per fraction, frequency of fractions, field of irradiation, and interaction with other therapies still need clarification. For these reasons we do not recommend TLI as a treatment for MS.
Assuntos
Terapia de Imunossupressão , Tecido Linfoide/efeitos da radiação , Esclerose Múltipla/radioterapia , Radioterapia/efeitos adversos , Humanos , MasculinoRESUMO
The gliotoxic effect of multiple sclerosis serums and lymphocytes was investigated by the measurement of Cr51 release from prelabeled bovine oligodendroglia. There was no difference in glial toxicity between multiple sclerosis patients and normal controls except for a depression of Cr51 release from bovine oligodendroglia in the presence of autologous serum plus lymphocytes in the multiple sclerosis patients compared with the normal controls. This correlated with the phase of the disease and may be due to the presence of a lymphotoxic factor in the active multiple sclerosis serums.
Assuntos
Linfócitos/imunologia , Esclerose Múltipla/imunologia , Neuroglia/imunologia , Oligodendroglia/imunologia , Animais , Bovinos , Separação Celular , Radioisótopos de Cromo , Testes Imunológicos de Citotoxicidade , Feminino , Humanos , Imunidade Celular , Técnicas In Vitro , Linfotoxina-alfa/análise , Masculino , Fatores de TempoRESUMO
Visual, brainstem auditory, and median nerve somatosensory evoked potential (EP) tests were performed annually during a 3-year, double-blind, placebo-controlled study of azathioprine with or without steroids in chronic progressive MS. Treatment-related visual and somatosensory EP changes became statistically different 1 year before corresponding differences were seen in the Standard Neurological Examination scores. The statistical significance of EP changes was substantially greater than seen for changes in other clinical scales. The degree of significance was increased by using EP latency values, rather than simple criteria for change. EPs are sensitive, objective measurements useful in MS therapeutic trials.
Assuntos
Azatioprina/uso terapêutico , Metilprednisolona/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Adulto , Idoso , Tronco Encefálico/fisiopatologia , Ensaios Clínicos como Assunto , Potenciais Somatossensoriais Evocados/efeitos dos fármacos , Potenciais Evocados Visuais/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/fisiopatologia , Distribuição AleatóriaRESUMO
OBJECTIVE: To determine the antibody response to oligodendrocyte-specific protein (OSP) in patients with MS. BACKGROUND: OSP is a recently identified CNS-specific myelin protein that is abundant and therefore a candidate autoantigen in MS. METHODS: The presence of anti-OSP antibodies was determined using Western blot analysis, peptide blots, and ELISA in patients with MS and in other neurologic and normal control subjects. RESULTS: Using Western blot analysis, seven patients with relapsing-remitting MS (RRMS) were found to contain anti-OSP antibodies in their CSF that were not present in control subjects. Peptide mapping determined that the antibody response was directed to a seven aa peptide (OSP 114-120), which has 71% homology with several common pathogenic proteins. Using OSP 114-120 as antigen, ELISAs were performed on CSF from 85 MS and 51 control patients. Eighty percent of the samples from RRMS patients followed at the University of California at Los Angeles had an ELISA reading above 0.55 optical density units, whereas all 20 control CSF samples had values less than 0.55 U. Similar results were found in specimens from an outside research bank. ELISAs performed on CSF using homologous viral peptides as antigen showed a close correlation with anti-OSP 114-120 ELISA readings, and in some, the readings were higher than those using OSP peptides. CONCLUSIONS: There is a specific humoral response directed against a region of OSP in RRMS patients that cross-reacts with several common viral peptides. This suggests a possible role for molecular mimicry in the development of MS.
Assuntos
Autoanticorpos/líquido cefalorraquidiano , Linfócitos B/imunologia , Esclerose Múltipla/imunologia , Proteínas do Tecido Nervoso/imunologia , Adulto , Idoso , Sequência de Aminoácidos , Formação de Anticorpos , Encéfalo/patologia , Claudinas , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/líquido cefalorraquidiano , Pessoa de Meia-Idade , Esclerose Múltipla/líquido cefalorraquidiano , Esclerose Múltipla/patologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Mapeamento de Peptídeos , Proteínas Recombinantes/imunologia , Valores de Referência , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
We performed a randomized, placebo-controlled, double-blind, comparative clinical trial of 36 weeks of methylprednisolone and 3 years of azathioprine in 98 patients in the chronic progression phase of multiple sclerosis (MS). We demonstrated a trend in favor of the combination therapy for limiting progression. The relapse rate in the azathioprine recipients was half that of the control group, and visual evoked potential latencies were stabilized in those who received the combination. We think that a therapeutic trial of continuous use of the combination of adrenal steroids with azathioprine would be worthwhile if administered early in the course of the disease.
Assuntos
Azatioprina/uso terapêutico , Terapia de Imunossupressão , Esclerose Múltipla/terapia , Ensaios Clínicos como Assunto , Seguimentos , Humanos , Esclerose Múltipla/fisiopatologiaRESUMO
Changes in clinical status and in two measures of immune function were followed for 21 months (median) in 106 multiple sclerosis (MS) patients and cohabitant controls. Antibody titers to measles, cytomegalovirus, and herpesvirus 1 and 2, and leukocyte migration inhibition indexes (LMIs) to measles and streptokinase/streptodornase (SKSD) were measured at 3- to 6-month intervals and at time of exacerbation in the index case. There were 36 exacerbations in 25 patients. Mean baseline antibody titers and LMI to measles were higher in cases than in controls. No consistent changes occurred in antibody titers to any of the viruses, non in LMI to SKSD. LMIs to measles were lower in most MS patients during exacerbations than before or after exacerbations. This apparent improvement in cell-mediated immune response to measles only during exacerbations may reflect aberrant immune regulation in MS patients, response to recrudescence of a latent agent, or some other phenomenon as yet undefined.
Assuntos
Formação de Anticorpos , Esclerose Múltipla/imunologia , Antígenos/imunologia , Inibição de Migração Celular , Humanos , Imunidade Celular , Leucócitos/imunologia , Vírus do Sarampo/imunologia , Recidiva , Linfócitos T Reguladores/imunologiaRESUMO
OBJECTIVE: To compare general neurologists and MS specialists on patients' clinical characteristics and MS care as perceived by patients with MS. METHODS: We sampled all adult patients with MS having physician visits over a 2-year period from a Midwestern managed-care organization and from the fee-for-service portion of 23 randomly selected California neurologists' practices. In mid-1996, 694 subjects were mailed questionnaires; 532 (77%) responded. Sociodemographic/clinical characteristics, recent utilization of services/treatments, unmet needs, symptom care, and research participation were measured. Of 502 subjects (94%) who indicated their usual physician providing MS care was a neurologist, 217 (43%) reported having a general neurologist and 285 (57%) reported having an MS specialist. Comparisons between these two groups were adjusted for comorbidity and disease severity. RESULTS: General neurologist and MS specialist patient groups did not differ on any sociodemographic or clinical characteristic except age (p<0.05). Although health care utilization generally was similar, higher proportions of the MS specialist group were aware of or had discussed interferon beta-1b (IFNbeta-1b) with their physician (p<0.05) and were currently taking it (p<0.05); a smaller proportion of the MS specialist group reported stopping it because of side effects (p<0.01). Overall, levels of unmet need and care for recent symptoms were similar, but the MS specialist group reported more confidence in their physician/carefulness in listening (p<0.05). Twice as many MS specialist subjects had participated in nondrug research (p<0.05); drug study participation was similar. CONCLUSIONS: Patients' perceptions of their care were similar in most ways for those who designated their main MS provider as a general neurologist compared to an MS specialist; however, care differed in potentially important areas. Prospective, longitudinal studies are needed to measure and relate neurologists' training, experience, knowledge, and MS patient volume with both process and outcome measures of quality of MS care.
Assuntos
Esclerose Múltipla/psicologia , Neurologia , Pacientes/psicologia , Autoimagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Coleta de Dados , Feminino , Serviços de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Estados UnidosRESUMO
Ninety-eight patients with multiple sclerosis (MS) in the chronic progression phase entered a 3-year clinical trial to determine if azathioprine (AZ) alone or with adrenal cortical steroids stabilizes the course of MS. In group AM, the patients took AZ throughout and methylprednisolone (MP) for the first 36 weeks. Group AP received AZ and placebo instead of MP. Group PP took placebos for both drugs. We adjusted the AZ to maintain the total white blood cell count within 3,000 to 4,000/mm3; we gave the MP in a fixed dose "pulse" and alternate-day regimen. The "intent-to-treat" groups had no statistically significant differences in the rates of progression among the 3 treatments. Subgroup analysis suggests that patients in the AM group who completed treatment exactly according to protocol did statistically significantly better than the placebo recipients using the sum of Standard Neurological Examination scores, slightly better using the quantitative neuro-performance tests, but no better using Mickey's Illness Severity Scores or Kurtzke's Disability Status Scale. Also, the AZ-treated groups had half the relapse rate of the placebo-treated group. Adverse reactions to AZ accounted for most withdrawals. Hematologic and hepatic abnormalities were significantly associated with AZ, but serious non-MS abnormalities were uncommon and were equally distributed among the 3 groups. Addition of MP to the AZ slightly improved the efficacy of the treatment, but also increased the adverse effects. The benefits of AZ with or without steroids did not outweigh the risks, and therefore we do not recommend this treatment for patients with chronic progressive MS.
Assuntos
Azatioprina/uso terapêutico , Metilprednisolona/administração & dosagem , Esclerose Múltipla/tratamento farmacológico , Adolescente , Adulto , Azatioprina/administração & dosagem , Azatioprina/efeitos adversos , Ensaios Clínicos como Assunto , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Masculino , Distribuição Aleatória , Fatores de TempoRESUMO
HLA types and levels of humoral and cell-mediated immune responses to several antigens were studied in a large group of patients with multiple sclerosis, and in controls. Patients were more likely than controls to have the DRw2 antigen. They had higher mean antibody titers to measles but not to cytomegalovirus, herpes 1, or herpes 2, and had less competent cell-mediated responses. Antibody titers to measles were lower and cell-mediated immune responses were more effective in patients with the DRw2 antigen in patients than in patients without it. This apparent specificity for measles suggests that the etiology of multiple sclerosis is related to the immune response to measles or related viruses.
Assuntos
Antígenos HLA/análise , Esclerose Múltipla/imunologia , Anticorpos Antivirais/análise , Feminino , Antígenos HLA/genética , Humanos , Imunidade Celular , Masculino , Sarampo/imunologiaRESUMO
OBJECTIVE: To measure and compare care for adults with MS across managed care and fee-for-service (FFS) health systems. METHODS: The authors sampled adults with MS having physician visits over a 2-year period from a group model health maintenance organization (HMO) in southern California, from a midwestern independent practice association (IPA) model managed care plan, and from the FFS portion of the practices of a random sample of southern California neurologists. The authors mailed surveys to subjects in mid-1996; 930 of 1,164 (80%) of those eligible responded. The authors measured sociodemographic and clinical characteristics, management of recent changes in mobility, bladder control, and fatigue, use of a disease-modifying agent, assessment of general health symptoms and issues, and unmet information needs. The authors adjusted comparisons between systems for comorbidity, disease severity, and disease type. RESULTS: The groups differed on most sociodemographic and clinical characteristics. There were few differences in symptom management; differences that did exist tended toward more referrals or treatment for the FFS group. Access to the disease-modifying agent available at the time of the survey did not differ across systems, although patients' perceptions of the rationale for not using the drug did vary. General health issues and symptoms were more often assessed in the FFS and IPA systems than in the HMO, but improvement was needed across all three systems of care. There were substantial unmet information needs in all groups and especially high ones in the FFS and HMO samples. CONCLUSIONS: Strategies to improve care for people with MS should be developed and evaluated, particularly in areas like symptom assessment and meeting patient information needs. Where variations in service delivery exist, longitudinal studies are also needed to evaluate the potential impact on outcomes and to evaluate reasons for variation.
Assuntos
Planos de Pagamento por Serviço Prestado , Programas de Assistência Gerenciada , Esclerose Múltipla/economia , Esclerose Múltipla/fisiopatologia , Atividades Cotidianas , Sistemas Pré-Pagos de Saúde/economia , Humanos , Fatores SocioeconômicosRESUMO
Fourteen MS patients took pentoxifylline at varying doses for up to 24 months. In vitro production of tumor necrosis factor alpha was reduced in patients taking 2,400 to 3,200 mg/day of pentoxifylline for 12 weeks or more. Twelve of the 14 patients experienced worsening of the disease during the study according to clinical, MRI, or visual evoked potential criteria. These results provide no hint of efficacy for pentoxifylline as a treatment for MS in progression phase.
Assuntos
Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/fisiopatologia , Pentoxifilina/uso terapêutico , Adulto , Encéfalo/patologia , Progressão da Doença , Relação Dose-Resposta a Droga , Potenciais Evocados Visuais/efeitos dos fármacos , Potenciais Evocados Visuais/fisiologia , Humanos , Linfócitos/imunologia , Imageamento por Ressonância Magnética , Esclerose Múltipla/imunologia , Fatores de Tempo , Falha de Tratamento , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Compared to normal and other neurological disease (OND) controls, multiple sclerosis (MS) pre nylon wool (pre NW) and nylon wool passed (NWP)-peripheral blood cells' natural killer (NK) activity was more sensitive to prostaglandin E (PGE1); it was suppressed to a greater degree and at lower concentrations of PGE1. At the single cell level this was reflected by lower numbers of target-binding cells (TBCs) and fewer killers among the TBCs. ONDs and normal controls were equally sensitive to PGE1. Though PGE-producing cells were depleted in the NWP population of normal and control ONDs, MS patients still had indomethacin-sensitive NK suppressors in the NWP population; these apparently did not suppress at the single cell effector level but at the level of recycling. MS and OND cerebrospinal fluid (CSF) cells' NK activity could not be 'enhanced' by indomethacin. Depression of interferon (IFN)-induced NK by PGE1 was greater in MS than in OND or normal controls perhaps through its effect on IFN-induced recycling. All subjects' cells maintained sensitivity to PGE1 after overnight incubation in the presence of PGE-producing cells (pre NW) or exogenous PGE1. In sharp contrast to normal and OND controls, MS NWP cells were still inhibited by PGE1 even after overnight incubation in the absence of PGE1.