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61.
Erythropoietin production in a primary culture of human renal carcinoma cells maintained in nude mice 总被引:4,自引:1,他引:4
The present studies report erythropoietin (Ep) production in primary cultures of a human renal carcinoma from a patient with erythrocytosis that has been serially transplanted to BALB/c nude mice. The levels of erythropoietin in the culture media were estimated using the exhypoxic polycythemic mouse assay (EHPCMA), fetal mouse liver erythroid colony- forming technique (FMLC), and a radioimmunoassay (RIA). The spent culture media of the exponentially growing cells contained less than 10 mU/ml of Ep measured by RIA. However, after the cells became confluent, Ep levels (RIA) in the spent media showed a marked increase to approximately 300 mU/ml. Ep levels estimated using the FMLC and EHPCMA were approximately 2/3 and 1/10, respectively, of those measured by RIA. Rabbit antiserum to highly purified human urinary Ep (70,400 U/mg protein) was utilized for immunocytochemical (peroxidase-antiperoxidase method) localization of Ep in the cultured cells. Very few of the cells in exponential growth exhibited Ep-like immunoreactivity, whereas intense Ep-like immunoreactivity was observed in the cytoplasm of the cells maintained in culture for a prolonged period after reaching confluency. The most intense staining was observed in some of the cells forming domes. The domes developed after the cells reached confluency, and their numbers increased with increasing time in confluent culture, in parallel with the increase in Ep levels in the spent media. This primary cell culture system of a renal cell carcinoma maintained in nude mice, which produces immunologically and biologically active Ep, may provide a useful model for studies of the mechanism of Ep production. 相似文献
62.
Lola V. Stamm 《The American journal of tropical medicine and hygiene》2015,93(5):901-903
Pinta is a neglected, chronic skin disease that was first described in the sixteenth century in Mexico. The World Health Organization lists 15 countries in Latin America where pinta was previously endemic. However, the current prevalence of pinta is unknown due to the lack of surveillance data. The etiological agent of pinta, Treponema carateum, cannot be distinguished morphologically or serologically from the not-yet-cultivable Treponema pallidum subspecies that cause venereal syphilis, yaws, and bejel. Although genomic sequencing has enabled the development of molecular techniques to differentiate the T. pallidum subspecies, comparable information is not available for T. carateum. Because of the influx of migrants and refugees from Latin America, U.S. physicians should consider pinta in the differential diagnosis of skin diseases in children and adolescents who come from areas where pinta was previously endemic and have a positive reaction in serological tests for syphilis. All stages of pinta are treatable with a single intramuscular injection of penicillin.The endemic treponematoses, pinta, yaws, and bejel, are caused by spiral-shaped, not-yet-cultivable bacteria of the genus Treponema.1–3 These neglected infectious diseases (NIDs), for which there are no vaccines, present a diagnostic dilemma to physicians because their clinical manifestations must be differentiated from those of other diseases that affect the skin. Moreover, serological tests cannot differentiate the endemic treponematoses from each other or from venereal syphilis, which is caused by the closely related spirochete, Treponema pallidum subspecies pallidum. Unlike venereal syphilis, the endemic treponematoses are usually acquired by children or adolescents living in poor rural communities in tropical climates (see references 1 and 2 for maps showing the geographical distribution of endemic treponematoses). Whereas venereal syphilis has a global distribution and is transmitted primarily by sexual activity, the endemic treponematoses are transmitted by nonsexual, direct skin-to-skin contact with infectious lesions.Pinta, also known as mal del pinto or carate, is the most benign of the endemic treponematoses since it affects only the skin.1–3 Pinta was first described in the sixteenth century in the Aztec and Carib Amerindians by Spanish conquistadors and missionaries.4 In the 1950s, there were an estimated 1 million cases of pinta in Mexico, Central America, and northern South America. Although pinta was most highly endemic in Mexico and Columbia, cases declined in these countries due to treatment campaigns and possibly due to improvements in living standards, access to health services, and hygiene.4,5 The World Health Organization (WHO) lists 15 countries in Latin America where pinta was previously endemic. Because of the lack of surveillance data, the current prevalence of pinta is unknown. However, some findings suggest that pinta has not disappeared. For example, in 1982 and 1983, clinical evidence of pinta was discovered in 20% of the examined inhabitants of a remote village in Panama.6 In 1987 and 1993, pinta cases were reported in native Indians (Ticuna) living in the Amazon border region of Brazil, Columbia, and Peru.7,8 Although the last reported case of pinta in Cuba was in 1975, an active, early pinta lesion was identified in a Cuban female who was visiting Austria in 1999.9 On the basis of these data, it is plausible that pinta has remained endemic in some remote areas of Latin America where access to health services is limited and living standards have not yet risen.1,2Like syphilis, pinta is classified into stages (see references 1–3 for pictures of the clinical stages of pinta). The primary stage is characterized by the presence of one or several papules or erythematous scaly plaques that develop about 3 weeks after infection. The body area most commonly affected is the exposed skin of the extremities. The papule or plaque, which is teeming with infectious treponemes, does not ulcerate, but expands to a diameter of 10 cm or greater. Regional lymphadenopathy is common. During early infection, serological tests for syphilis (STS) may be negative for antibodies to nontreponemal (cardiolipin) and treponemal antigens. Plaques may last for months to years and pigmentary changes may be observed in the plaques. The lesions may heal spontaneously or they may persist and become indistinguishable from the lesions of secondary pinta.The secondary stage usually appears several months after the initial manifestations of the primary stage.1–3 Small disseminated lesions known as “pintids” may coalesce into plaques. The pintids change from an initial red color to brown, slate-blue, black, or gray colors. Different pigmentation may occur within a pintid. The secondary lesions can remain active and infectious for a long time, leading to extensive depigmentation. STS are positive in the majority of untreated cases.The late (tertiary) stage usually develops 2–5 years after initial infection and is characterized by pigmentary abnormalities (i.e., from dyschromic treponeme-containing lesions to achromic treponeme-free lesions), skin atrophy, and hyperkeratosis.1–3 The degree of lesion pigmentation can be different in the same patient, resulting in a mottled appearance of the skin, which can persist lifelong. Lesions may turn into various colors (e.g., brown, gray-blue, or black). STS are positive in virtually all untreated cases.The etiological agent of pinta, Treponema carateum, was not identified until over 30 years after the 1905 discovery of the related agents of venereal syphilis and yaws.4,10–12 Initially, it was thought that a pathogenic fungus caused pinta. However, two observations suggested otherwise. First, laboratory studies of pinta patients'' sera showed that the Wassermann test, an early STS, was positive in the majority of cases. Second, treatments that were effective against syphilis (i.e., mercury and arsenicals) were also effective against pinta. In August 1938, Sáenz and others10 using dark-field microscopy, demonstrated the presence of spirochetes that were morphologically indistinguishable from the T. pallidum subspecies in exudate from a Cuban pinta patient''s lesions. Subsequently, other investigators reported the presence of spirochetes in pinta lesions. Because the presence of these bacteria was insufficient to prove causality, León-Blanco performed skin inoculation experiments on himself and human volunteers with lesion exudate that contained the spirochetes and succeeded in reproducing the early manifestations of pinta.4,12 León-Blanco also showed that some immunity to reinfection develops during pinta. Patients with late-stage pinta could not be reinfected, whereas patients whose early-stage pinta had been cured could be reinfected. Furthermore, León-Blanco and Briceno Ross and Iriarte demonstrated that syphilis and yaws patients, respectively, were not immune to infection with pinta, despite the antigenic similarity of the etiological agents.4,11,12Because animal models are necessary to propagate the T. pallidum subspecies for experimental studies, several investigators attempted to determine if laboratory animals could be infected with T. carateum.11 León-Blanco and Oteiza13 reported infection of one of the four rabbits that they inoculated intradermally with exudate from a pinta patient''s lesions. However, they were unable to successfully passage T. carateum from the rabbit''s lesion to other rabbits. Later, Kuhn and others14 demonstrated that chimpanzees could be infected intradermally and that these animals developed lesions similar to those of pinta patients. Unfortunately, T. carateum isolates are not available for study. Although phylogenetic data obtained via genomic sequencing have enabled the development of techniques to differentiate the T. pallidum subspecies, comparable information is not available for T. carateum.1,2 Thus, despite the morphological and antigenic relatedness of the agents of pinta and syphilis, molecular knowledge of T. carateum is currently insufficient to warrant classification of this spirochete as a T. pallidum subspecies.Pinta can be treated with a single intramuscular injection of long-acting benzathine penicillin (1.2 MU for adults; 0.6 MU for children), which renders the lesions noninfectious in less than 24 hours.1,3,11 Information is scant concerning the efficacy of other antibiotics. Although early pinta lesions heal within several months after penicillin administration, this treatment cannot reverse the skin changes of late pinta that can stigmatize those who were infected.4 Penicillin treatment was the mainstay for the “National Campaign to Eradicate Mal del Pinto” conducted in Mexico (1960s) and for the WHO campaign against the endemic treponematoses (1952–1964).1,2,4 A national campaign against yaws that was conducted in Columbia in the 1950s resulted in an almost parallel decline in the incidence of both yaws and pinta, even though pinta was not specifically targeted.5 Despite the initial success of these campaigns, the endemic treponematoses, particularly yaws, have resurged due to the lack of sustained resources and political will. The WHO has initiated a campaign to eradicate yaws by 2020 that is based on mass treatment of endemic communities with an oral dose of azithromycin, a macrolide antibiotic with demonstrated efficacy against yaws.1,2,15 If T. carateum is sensitive to azithromycin as is likely, this treatment strategy could have a concomitant effect on pinta in areas of Latin America where yaws and pinta may be co-endemic. Moreover, if the endemic treponematoses were rolled into the program area of the Pan American Health Organization''s (PAHO''s) Strategic Plan (2014–2019) that targets selected NIDs and focuses on strengthening national capacity for screening, treatment, and surveillance of NIDs, this could facilitate elimination of pinta and yaws in PAHO member countries and would aid WHO''s yaws eradication campaign (www.paho.org/hq/).The possibility of importation of NIDs such as the endemic treponematoses increases as record numbers of migrants and refugees from Latin America continue to enter the United States for economic or political reasons.2,3,16 Accordingly, physicians should consider pinta in the differential diagnosis of skin diseases for Latin American children and adolescents who come from areas where pinta was previously endemic and have a positive reaction in STS.3,16 This is critical to guide treatment as well as to avoid the inadvertent psychological harm and legal ramifications that can result from making an incorrect diagnosis of syphilis. Although pinta may be a forgotten disease, it is unlikely to be extinct.9,17 相似文献
63.
Immunoglobulin G from patients with heparin-induced thrombocytopenia binds to a complex of heparin and platelet factor 4 总被引:6,自引:3,他引:6
Heparin-induced thrombocytopenia (HIT) is an important complication of heparin therapy. Although there is general agreement that platelet activation in vitro by the HIT IgG is mediated by the platelet Fc receptor, the interaction among the antibody, heparin, and platelet membrane components is uncertain and debated. In this report, we describe studies designed to address these interactions. We found, as others have noted, that a variety of other sulfated polysaccharides could substitute for heparin in the reaction. Using polysaccharides selected for both size and charge, we found that reactivity depended on two independent factors: a certain minimum degree of sulfation per saccharide unit and a certain minimum size. Hence, highly sulfated but small (< 1,000 daltons) polysaccharides were not reactive nor were large but poorly sulfated polysaccharides. The ability of HIT IgG to recognize heparin by itself was tested by Ouchterlony gel diffusion, ammonium sulfate and polyethylene glycol precipitation, and equilibrium dialysis. No technique demonstrated reactivity. However, when platelet releasate was added to heparin and HIT IgG, a 50-fold increase in binding of radio-labeled heparin to HIT IgG was observed. The releasate was then depleted of proteins capable of binding to heparin by immunoaffinity chromatography. Only platelet factor 4-immunodepleted releasate lost its reactivity with HIT IgG and heparin. Finally, to determine whether the reaction occurred on the surface of platelets or in the fluid phase, washed platelets were incubated with HIT IgG or heparin and after a wash step, heparin or HIT IgG was added, respectively. Reactivity was only noted when platelets were preincubated with heparin. Consistent with these observations was the demonstration of the presence of PF4 on platelets using flow cytometry. These studies indicate that heparin and other large, highly sulfated polysaccharides bind to PF4 to form a reactive antigen on the platelet surface. HIT IgG then binds to this complex with activation of platelets through the platelet Fc receptors. 相似文献
64.
Busch MP; Laycock M; Kleinman SH; Wages JW Jr; Calabro M; Kaplan JE; Khabbaz RF; Hollingsworth CG 《Blood》1994,83(4):1143-1148
Blood donations in the United States have been screened for antibody to human T-lymphotropic virus type I (HTLV-I) by HTLV-I enzyme immunoassay (EIA) since November 1988. Specimens repeatedly found to be reactive by EIA undergo confirmation by supplementary serologic tests. We assessed the accuracy of blood center testing of 994 HTLV-I EIA repeat-reactive specimens in five US blood centers between November 1988 and December 1991. Of 410 confirmed HTLV-I/II donations, 407 (99.3%) were infected with HTLV-I/II, as determined by polymerase chain reaction (PCR) (403 cases) and by repeat serologic testing (4 cases). The three false- positive results occurred in the first year of testing. Of 425 HTLV- indeterminate specimens, 6 (1.4%) were found to be infected by PCR (5 with HTLV-II and 1 with HTLV-I). None of 159 confirmatory test-negative donations was PCR positive. Of HTLV-I/II-seropositive specimens, 80.2% to 95.4% could be typed as HTLV-I or HTLV-II by type-specific serologic assays. These results support recommendations that HTLV-I/II- seropositive donors should be advised that they are infected with HTLV- I, HTLV-II, or HTLV-I/II (depending on results of type-specific assays). HTLV-indeterminate donors should be advised that their results only rarely indicate HTLV infection. HTLV confirmatory test-negative donors should be reassured that they are not infected with HTLV-I or HTLV-II. 相似文献
65.
66.
Gestational weight gain (GWG) is an important predictor of adverse pregnancy outcomes including gestational diabetes, preterm birth, delivery by caesarean and post‐partum weight retention. The Institute of Medicine guidelines on GWG are widely adopted, and GWG is widely researched as an outcome of interest in lifestyle interventions during pregnancy. However, estimation of prepregnancy weight and measurement of weight prior to delivery introduce bias into measures of GWG. This review discusses the sources of bias in measures of GWG and the potential effect of bias on the relationship between adverse pregnancy outcomes associated with GWG. Bias in measures of GWG can be minimized by using measured weight at the first antenatal appointment in early pregnancy rather than self‐reported prepregnancy weight and by adjusting for gestational age when the last weight is collected earlier than the delivery date. Bias owing to gestational age is an important potential confounder in the relationship between GWG and adverse pregnancy outcomes. 相似文献
67.
Mazda Adli Katja Wiethoff Christopher Baethge Andrea Pfennig Thomas Stamm Michael Bauer 《International journal of psychiatry in clinical practice》2013,17(3):202-209
Objective. Depression with psychotic features is a severe subtype of major depression associated with the presence of delusions, hallucinations and specific neurobiological features. Despite clinical consensus and guideline recommendations, data comparing the efficacy of combining antipsychotics with antidepressants compared to antidepressants alone remain inconclusive. The aim of the study was to investigate effectiveness and tolerability of the atypical antipsychotic olanzapine in acute depression with psychotic features. Methods. Seventeen inpatients with major depressive disorder with psychosis (MDDp) were treated with a combination of an antidepressant and olanzapine for 6 weeks in a prospective open-label study. Depressive and psychotic symptoms, extrapyramidal and general side effects were assessed every 2 weeks. Sixteen patients were eligible for final analysis. Results. The Brief Psychiatric Rating Scale (BPRS) showed a 30% symptom reduction after week 2, a 45% symptom reduction after week 4 and no considerable improvement thereafter. Depressive symptoms (Bech–Rafaelsen Melancholia Scale, BRMS) receded by 37% after week 2 and 50% after week 4. No extrapyramidal side effects occurred. Conclusion. Olanzapine is effective and tolerable in combination with an antidepressant in an MDDp inpatient sample. The results concur with data supporting good efficacy in negative and depressive symptoms of patients with schizophrenic and schizoaffective diseases. 相似文献
68.
Modern population based oral health management requires a complete understanding of the impact of disease in order to provide efficient and effective oral health care and guidance. Periodontitis is an important cause of tooth loss and has been shown to be associated with a number of systemic conditions. The impact of oral conditions and disorders on quality of life has been extensively studied. However, the impact of periodontitis on quality of life has received less attention. This review summarizes the literature on the impact of periodontitis on oral health‐related quality of life (OHRQoL). Relevant publications were identified after searching the MEDLINE and EMBASE electronic databases. Screening of titles and abstracts and data extraction was conducted. Only observational studies were included in this review. Most of the reviewed studies reported a negative impact of periodontitis on OHRQoL. However, the reporting standards varied across studies. Moreover, most of the studies were conducted in developed countries. 相似文献
69.
70.