Effect of diltiazem on coronary reactive hyperemia in patients with flow-limiting coronary artery stenosis

The acute effects of diltiazem on coronary reactive hyperemia were studied in 12 patients with flow-limiting coronary stenosis. Reactive hyperemia was elicited by injection of 8 ml contrast medium into the left coronary artery, while coronary sinus blood flow and left ventricular and aortic pressures were continuously recorded. Relative magnitude of hyperemia was estimated by the ratio of coronary flow at peak hyperemia to baseline flow (hyperemic ratio). Coronary resistance was calculated as the ratio between mean aortic pressure minus left ventricular mean diastolic pressure and coronary sinus blood flow. The 12 patients studied had flow-limiting coronary stenosis since their hyperemic ratio was significantly restrained when compared to that of seven control subjects (1.45 +/- 0.17 vs 2.02 +/- 0.24, respectively; p less than 0.001). The intravenous infusion of diltiazem (0.30 mg X kg-1) reduced heart rate, mean aortic pressure, and myocardial oxygen consumption (all p less than 0.001). After diltiazem the hyperemic ratio was blunted when compared to the basal state (1.36 +/- 0.15 vs 1.45 +/- 0.17, respectively; p less than 0.05), and hyperemia volume was reduced (-33%; p less than 0.001). The decrease in coronary resistance at peak hyperemia was also reduced from -30 +/- 8% to -25 +/- 8% (p less than 0.05). We conclude that diltiazem blunts coronary reactive hyperemia in patients with demonstrated flow-limiting coronary stenosis. This reduction of coronary flow response to a hyperemic stimulus could favorably influence blood flow distribution in patients with significant coronary stenosis.     

Mutations of the Imprinted CDKN1C Gene as a Cause of the Overgrowth Beckwith–Wiedemann Syndrome: Clinical Spectrum and Functional Characterization

Beckwith–Wiedemann syndrome (BWS) is an imprinting disorder associating macroglossia, abdominal wall defects, visceromegaly, and a high risk of childhood tumor. Molecular anomalies are mostly epigenetic; however, mutations of CDKN1C are implicated in 8% of cases, including both sporadic and familial forms. We aimed to describe the phenotype of BWS patients with CDKN1C mutations and develop a functional test for CDKN1C mutations. For each propositus, we sequenced the three exons and intron–exon boundaries of CDKN1C in patients presenting a BWS phenotype, including abdominal wall defects, without 11p15 methylation defects. We developed a functional test based on flow cytometry. We identified 37 mutations in 38 pedigrees (50 patients and seven fetuses). Analysis of parental samples when available showed that all mutations tested but one was inherited from the mother. The four missense mutations led to a less severe phenotype (lower frequency of exomphalos) than the other 33 mutations. The following four tumors occurred: one neuroblastoma, one ganglioneuroblastoma, one melanoma, and one acute lymphoid leukemia. Cases of BWS caused by CDKN1C mutations are not rare. CDKN1C sequencing should be performed for BWS patients presenting with abdominal wall defects or cleft palate without 11p15 methylation defects or body asymmetry, or in familial cases of BWS.     

Applying cultural safety beyond Indigenous contexts: Insights from health research with Amish and Low German Mennonites

People who identify as members of religious communities, such as the Amish and Low German Mennonites, face challenges obtaining quality health care and engagement in research due in part to stereotypes that are conveyed through media and popular discourses. There is also a growing concern that even when these groups are engaged in research, the guiding frameworks of the research fail to consider the sociocultural or historical relations of power, further skewing power imbalances inherent in the research relationship. This paper aims at discussing the uses of cultural safety in the context of health research and knowledge translation with groups of people that are associated with a specific religion. Research with the Amish and Low German Mennonites is provided as examples to illustrate the use of cultural safety in this context. From these examples, we discuss how the use of cultural safety, grounded in critical theoretical perspectives, offers new insight into health research with populations that are traditionally labeled as minority, vulnerable, or marginalized, especially when a dominant characteristic is a unique religious perspective.     

Translocation t(5;12)(q31-q33;p12-p13): a non-random translocation associated with a myeloid disorder with eosinophilia

SUMMARY. To investigate the clinical significance of determination of plasma tissue factor (TF) antigen, we have developed a highly sensitive enzyme-linked immunosorbent assay (ELISA) for plasma TF, using two different monoclonal antibodies against TF apoprotein, 6B4 (catching antibody) and 5G9 (detecting antibody), and tetramethyl benzidine/H₂O₂ as substrates. Titration curves of recombinant human TF in buffer containing Triton X-100 were linear within the range from 50 to 2000pg/ml. The total assay time was 3h. Ultracentrifugation and immunoblot analysis indicated that human plasma and urine contained 50 000 g sedimentable and non-sedimentable forms of TF, both of which were detected by our ELISA method.
Plasma and urine concentrations of TF in healthy subjects and patients with various diseases were measured by the ELISA method. In healthy subjects, plasma and urinary TF levels were found to be 149± 72pg/ml (n = 30) and 175±60pg TF/urine creatinine mg (n = 95). respectively. TF was increased in plasma of patients with disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura, vasculitis associated with collagen diseases, diabetic microangiopathy and chronic renal failure receiving haemodialysis, but not in the plasma of endotoxaemic patients without DIC. The plasma TF/serum creatinine ratio did not show a positive correlation. Measurement of TF antigen in plasma may be useful for evaluating the endothelial damage and cell destruction in TF-containing tissues.     

Fetal liver cells produce both fetal and adult erythrocytes in semiallogeneic radiation chimeras: possible influence of adult environment

Two kinds of erythrocytes are released in the blood of irradiated adult hybrid mice grafted with parental fetal liver cells: fetal antigen- bearing erythrocytes (Ft+ cells) and adult-type Ft- erythrocytes. Both are of parental origin, as determined by immune lysis using histocompatibility alloantigens. The latter cells make up all the recipient's red blood cells 2 mo after receipt of the graft, Ft+ cells then being no longer detected. The transient duality of erythropoiesis in irradiated adults grafted with fetal liver cells has been confirmed by studying the kinetics of CFU-E populations, as characterized by their ability to give rise to Ft+ or Ft- erythrocytes. The results are discussed in terms of environmental factors that influenc erythroid differentiation.     

How Many Have Died from Undiagnosed Human Immunodeficiency Virus–Associated Histoplasmosis,A Treatable Disease? Time to Act

Human immunodeficiency virus (HIV)–associated disseminated Histoplasma capsulatum capsulatum infection often mimics tuberculosis. This disease is well know in the United States but is dramatically underdiagnosed in Central and South America. In the Amazon region, given the available incidence data and the regional HIV prevalence, it is expected that, every year, 1,500 cases of histoplasmosis affect HIV patients in that region alone. Given the mortality in undiagnosed patients, at least 600 patients would be expected to die from an undiagnosed but treatable disease. The lack of a simple diagnostic tool and the lack of awareness by clinicians spiral in a vicious cycle and made a major problem invisible for 30 years. The HIV/acquired immunodeficiency syndrome community should tackle this problem now to prevent numerous avoidable deaths from HIV-associated histoplasmosis in the region and elsewhere.In the Guianas and the Amazon Basin, the prevalence of human immunodeficiency virus (HIV) is approximately 1%. There have been some decreases in incidence in some states in this region, but recent increases in incidence in northern states of Brazil have been reported.^1–3 The population of the Amazon basin is estimated to be approximately 10 million persons,⁴ which would imply that approximately 100,000 persons are HIV positive in the Amazon Basin.The Amazonian environment is suitable for the growth of Histoplasma capsulatum.⁵ For immunocompetent patients, this organism causes mostly benign infections, but in severely immunodepressed HIV-infected patients, infection with this organism leads to a fatal disease in the absence of diagnosis and treatment. There lies the problem. Clinical symptoms are unspecific and often mimic those of tuberculosis.^6,7 Diagnosis is difficult and requires invasive procedures (biopsies, bone marrow smears), and trained staff to detect H. capsulatum, often after weeks of culture.⁸ Severe infections are often fatal within days.⁹ However, death often occurs after long delays in which patients are unsuccessfully treated for unconfirmed tuberculosis. Patients die because they are not treated for a treatable disease and because there is no diagnosis test. With no diagnosis, this possibility is not included in the diagnostic and treatment algorithms of clinicians who, despite unknowingly encountering this disease on a regular basis, have never seen a case because it was never diagnosed. In this context, then why give presumptive treatment of a disease that is not present?It is tragic but it makes total sense. It is even frighteningly tragic when one crunches the numbers to estimate what it means that after 30 years of the HIV epidemic, one of the leading causes of acquired immunodeficiency syndrome (AIDS) in the Amazon¹⁰ still goes largely unrecognized and evolves under the radar of national plans and international funding efforts.The only incidence data available for this region suggests that the incidence of histoplasmosis during the highly active antiretroviral therapy era was 1.5 cases/100 person-years.¹⁰ The historical mortality rate of disseminated histoplasmosis was > 30% despite mycology expertise.^7,8 This finding indicates that for 100,000 HIV patients, there would be 1,500 cases of histoplasmosis/year and 600 deaths/year, and probably more if undiagnosed. This finding also indicates that for more than 30 years the cumulated death rate in the region must have been huge, in the tens of thousands.A rational sceptic could rightly doubt this claim from the generalization of data from the smallest South American territory to the entire Amazon and elsewhere. However, when one reviews the literature, it becomes evident that histoplasmosis is present throughout the region, this fact has been known for decades, and that we should have been paying more attention.⁵ The high prevalence of histoplasmin test reactivity in the region was known even before AIDS was identified in 1981.¹¹ Histoplasmosis has been an AIDS-defining illness since 1993. We should have connected the dots earlier.How could something so huge escape the attention of the HIV/AIDS community in the region? One explanation for this dramatic blind spot is that in the region, the diagnostic capacity for mycology has been insufficient. It has been long argued that medical mycology is a neglected area of biology, and that the often low incidence of mycoses is caused by a lack of medical mycologists rather than the absence of the mycoses.¹² Another explanation is that the standard conceptualization of HIV/AIDS, the usual indicators, and the Joint United Nations Programme on HIV/AIDS terminology and framework did not explicitly entail disseminated histoplasmosis or the regional AIDS-defining illnesses. The anesthetic effect of the familiarity of vertical concepts and vertical programs can make it difficult to reframe the problem and see what was always there.For better diagnostic and treatment, we should know what AIDS is to direct diagnostic hypotheses when caring for individual patients. Misdiagnosing histoplasmosis as tuberculosis, not only delays a life-saving treatment of the individual patient, but it can confound tuberculosis statistics (incidence, resistance, mortality) and make it difficult to evaluate tuberculosis program results.The current financial difficulties should not stand in the way of building the diagnostic capacity for detection of histoplasmosis. It does not necessarily cost much to do the diagnosis. Treatment relies on amphotericin B for severe forms and itraconazole for non-severe forms and prophylaxis.⁷ Both drugs are generic drugs that are perfectly affordable. The toxicity of amphotericin B leads industrialized countries to use the costly liposomal version of the drug. However, The Drugs for Neglected Disease Initiative is releasing a cheap alternative that was developed for treatment of cryptococcosis.¹³ This is an opportunity for resource-limited countries in disease-endemic areas for treatment of histoplasmosis. We should not wait any longer. Every year wasted to build capacity for diagnosis and treatment of histoplasmosis in the Amazon Basin and elsewhere leads to hundreds of deaths that could have been avoided. This is not acceptable.     

Early matched sibling hematopoietic cell transplantation for adult AML in first remission using an age-adapted strategy: long-term results of a prospective GOELAMS study

The LAM2001 phase 3 trial, involving 832 patients with acute myeloid leukemia (AML; median: 46 years) proposed HLA-identical sibling allograft HSCT for all patients with an identified donor. The trial compared reduced-intensity conditioning (RIC) for patients older than 50 years of age (N = 47) and myeloablative conditioning for younger patients (N = 117). BM HSCT was performed in the younger patients, while the older ones received a consolidation course, followed by peripheral blood allo-HSCT using RIC. The incidence of grade II-IV acute GVHD, was 51.9% (95% confidence interval [CI]: 42.1-61.8) and 11.3% (1.6-21.2) after myeloablative or RIC, respectively (P < .0001) and that of chronic GVHD 45.8% (95% CI: 34.8-56.7) and 41.7% (24.7-58.6; NS). Cumulative incidence of nonrelapse mortality at 108 months was 15.8% (95% CI: 9.8-23.2) for myeloablative, and 6.5% (0.2-16.2) for RIC (NS). CI of relapse at 108 months was 21.7% (95% CI: 13.9-28.6) and 28.6% (16.5-43.4; NS). Overall survival at 108 months was 63.4% (95% CI: 54.6-72.2) and 65.8% (52.2-72.2), respectively, after myeloablative or RIC (NS). RIC peripheral blood stem cell allo-HSCT is prospectively feasible for patients between the ages of 51 and 60 years without excess of relapse or nonrelapse mortality, and compares favorably with myeloablative marrow allo-HSCT proposed to younger patients.     

Free and intracellular bacteria on peripheral blood smears: an uncommon situation related to an adverse prognosis

Bacterial infections are responsible for several changes in the cell blood count, which are usually non specific, although some morphological changes of polymorphonuclear neutrophils may be indicative of sepsis. The presence of bacteria on peripheral blood smears is a rare but extreme situation, related in most instances to a fatal prognosis. The presence of both free and intracellular bacteria was observed in the peripheral blood smear of a critically ill patient with a pneumococcal septicaemia which led to a fatal outcome within the next following hours. If the finding of bacteria on the blood smear is a sign of severe sepsis, the literature review shows that less than 10% of septic patients demonstrate bacteria on the blood smear, and routine search for the diagnosis of sepsis is not recommended. Samples taken from infected central venous catheters are another situation of bacteraemia which must be known, but prognosis is usually not fatal if prompt medical care is performed. Some preanalytical conditions are also associated with the presence of bacteria on the peripheral blood smear, but unrelated to infection of the relevant patient.