Modeling and correction of digit preference in tuberculin surveys.

SETTING: Human observers generally have a strong tendency to round analog measurements or estimates to 'nice' ending digits, such as 0, 5, or even numbers. This is known as digit preference; it is a well-known phenomenon in frequency distributions of indurations collected in tuberculin surveys. Digit preference can distort estimates of prevalence and other statistical parameters. METHODS: We have developed a statistical model that combines smoothing by penalized likelihood and the transfer of counts from non-preferred to preferred digits, to obtain estimates of: 1) the smooth underlying distribution and 2) the amount of digit preference. RESULTS: To illustrate the validity of the model, it was applied to data from several countries. CONCLUSION: With the proposed model, digit preference can be quantified and frequency distributions of indurations can be corrected for it.     

Development and evaluation of a new chest radiograph reading and recording system for epidemiological surveys of tuberculosis and lung disease.

OBJECTIVE: The development and evaluation of a new chest radiograph reading and recording system (CRRS) for community surveys of tuberculosis (TB) and lung disease. DESIGN: An experienced pulmonologist read 2608 chest X-rays (CXRs) performed as part of a TB prevalence survey using the newly developed CRRS. The kappa (kappa) for inter-reader agreement was calculated after a second reader reported on a stratified random sample of 810 (31%) of the 2608 CXRs. The kappa for intra-reader agreement was calculated from the repeated reporting of a stratified random sample of 104 CXRs. RESULTS: The kappa agreement between the two readers was 0.69 (95%CI 0.64-0.74) for abnormalities consistent with TB and 0.47 (95%CI 0.42-0.53) for any abnormalities. The kappa for intra-reader agreement was 0.90 (95%CI 0.81-0.99) for abnormalities consistent with TB and 0.85 (95%CI 0.74-0.95) for any abnormalities. CONCLUSION: This standardised method for CXR reading and recording provides satisfactory inter- and intra-reader agreement, making it suitable for surveys of TB and other forms of lung disease in the community. Its use will permit comparisons of results obtained in different surveys.     

Risky behavior in teens with cystic fibrosis or sickle cell disease: a multicenter study

OBJECTIVE: To determine the prevalence and age of onset of common risky behaviors such as smoking and sexual activity in teens with cystic fibrosis and those with sickle cell disease and to compare their behaviors with those of adolescents in the general population. DESIGN: Survey. SETTING: All five major pediatric tertiary care centers in North Carolina (study participants with sickle cell disease or cystic fibrosis) and North Carolina public schools (comparison population). PARTICIPANTS: Three hundred twenty-one adolescents with cystic fibrosis or sickle cell disease aged 12 to 19 years (mean age, 15.6 years; 49% female). Demographically matched comparison teens for each group were selected from 2760 in-school adolescents (mean age, 16.0 years; 51% female). MAIN OUTCOMES MEASURES: Prevalence of tobacco and marijuana use, alcohol use, sexual intercourse, sexually transmitted diseases, seat belt use, weapon carrying, and age of onset of these behaviors. RESULTS: Chronically ill teens reported significantly less lifetime and current use of tobacco, marijuana, and alcohol; less sexual intercourse; less weapon carrying, less drunk driving, and more seat belt use than their peers. Nonetheless, 21% of the teens with cystic fibrosis and 30% of those with sickle cell disease had smoked; sexual intercourse was reported by 28% and 51%, respectively. Age of onset of these behaviors was frequently older for the chronically ill teens. CONCLUSION: Teens with cystic fibrosis or sickle cell disease took more potentially damaging health risks than might be expected, although the prevalence was lower than reported by their peers. Future longitudinal studies should examine the relationships between chronic illness, physical and psychosocial maturation, and risky behavior. Screening for psychosocial issues, including risky behaviors, should be incorporated into the routine health care of chronically ill teens.     

解释结核分枝杆菌DNA指纹簇

许多研究已在其结核分枝杆菌分离株共享DNA指纹的基础上定义了患者簇。成簇相当于最近的传播，并且对伴随结核分枝杆菌正在高度传播人群亚组来说，与成簇有关的因素已作为指标被找出。在进行和解释这些研究中值得考虑的提醒应予以注意。例如，根据标志物的稳定性和长时间在人群中的菌株数量，某些并非近期传播的原因使菌株组可能完全相同。如果病例对特定人群是新移民或在研究中不是所有人群中的病例都被包括的话，确定由近期传播引发的病例可能不作为成簇被见到。所见的成簇数量将根据研究持续的时间。在研究的设计、所包括病例的比例、补充和所使用成簇的界定上，研究应给出精确的资料。成簇的数据应至少被年龄、性别和移民状况分开。为了最大的获得信息，研究应涉及一个人群中所有病例的高比例、与传统的流行病学接触调查结合进行(如果可能的话)、并且提供人群中结核病发病资料和患者的年龄、性别、人类免疫缺损病毒状况、耐药性及社会和种族组资料。     

Evaluation of factor VIII-rich cryoprecipitate and the plasma fibronectin-rich, heparin-precipitable fraction prepared from single- donor plasma units

A plasma fibronectin-rich component was prepared by heparin-induced 4 degrees C precipitation of fresh or stored (21 days at 4 degrees C), single-donor plasma. The recovery of plasma fibronectin was 45 percent at a concentration of 0.05 mg heparin per ml (7.5 units/ml) and 75 percent at 0.1 mg per ml (15 units/ml). The biologic activity of plasma fibronectin, as assessed by the spreading of Chinese hamster ovary cells or attachment of monocytes to gelatin-coated surfaces, was similar to that of plasma fibronectin concentrates made from fresh or stored plasma. Only 20 to 30 percent of the factor VIII activity in fresh plasma was recovered in cryoprecipitate produced after the heparin-induced precipitate containing fibronectin was removed. Cryoprecipitate prepared from the supernatant plasma that remains after heparin-induced cold precipitation in the presence of CaCl2 (5 mM) contained approximately 50 percent less factor VIII. The relatively low recovery of factor VIII in cryoprecipitate prepared from fibronectin-depleted plasma makes cryoprecipitation an unsuitable method of producing fibronectin-rich and factor VIII-rich components effectively from a single unit of fresh plasma. However, heparin-induced cold precipitation provides an efficient method for preparing plasma fibronectin concentrates from small plasma pools or single units of stored or fresh plasma.     

Low tuberculosis notification in mountainous Vietnam is not due to low case detection: a cross-sectional survey

Background  

Studies show that tuberculosis notification declines with increasing altitude. This can be due to declining incidence or declining case detection. In Vietnam notification rates of new smear-positive tuberculosis in the central mountainous provinces (26/100,000 population) are considerably lower than in Vietnam in general (69/100,000 population). In order to clarify whether this is explained by low incidence or low case detection, we aimed to assess the prevalence of new smear-positive tuberculosis among adults with prolonged cough in three mountainous provinces in central Vietnam.     

Kaposi's sarcoma (KS)-associated herpesvirus-like DNA sequences in peripheral blood mononuclear cells: association with KS and persistence in patients receiving anti-herpesvirus drugs

Herpesvirus-like DNA sequences (KSHV/HHV-8) have recently been described in AIDS-associated Kaposi's sarcoma (KS) lesions. Many questions remain regarding the role of this virus in KS and the therapeutic implications of this finding. In the current study, KSHV/HHV-8 DNA was detected in peripheral blood mononuclear cells (PBMCs) from human immunodeficiency virus (HIV)-infected patients with KS (34/98) more often than in HIV-infected individuals without KS (12/64, P = .03). The detection of KSHV/HHV-8 DNA did not correlate with the CD4 lymphocyte count. Five patients demonstrated KSHV/HHV-8 DNA in their PBMCs during administration of intravenous foscarnet and/or ganciclovir. The continued detection of KSHV/HHV-8 DNA in the PBMCs of patients receiving these anti-herpesvirus drugs has potential implications regarding the virus-cell relationship of KSHV/HHV-8, as well as for the value of these drugs in treating or preventing KS, but additional studies are needed.     

Interleukin-10 is an autocrine growth factor for acquired immunodeficiency syndrome-related B-cell lymphoma [see comments]

Interleukin-10 (IL-10) is an acid-sensitive protein of 35 kD that has pleiotropic effects including inhibition of cytotoxic T-cell response, induction of major histocompatibility complex type II in B lymphocytes, induction of B-cell growth and differentiation, and autocrine growth factor activity in monocytes. We and others have shown that IL-10 is produced spontaneously by blood mononuclear cells from human immunodeficiency virus-seropositive patients. In an attempt to ascertain the potential role of IL-10 in acquired immunodeficiency syndrome (AIDS)-related B-cell lymphoma, we evaluated the expression of human IL-10 in both tumor-derived B-cell lines and primary tumor cells. Expression of human IL-10 (hIL-10) mRNA and protein was detected in four of five cell lines examined. An IL-10 antisense oligonucleotide inhibited IL-10 mRNA expression and IL-10 protein production. The proliferation of all B-cell lines was inhibited by an antisense oligonucleotide in a dose-dependent manner that was abrogated by the addition of recombinant hIL-10 protein. No effect of antisense oligonucleotide was observed in the B-cell line not producing hIL-10. Evaluation of primary tumor cells from patients with AIDS-lymphoma cells showed similar production and response to IL-10. These data suggest an autocrine growth mechanism for IL-10 in AIDS-related lymphoma cells and that IL-10 may be important in its pathogenesis.     

Deoxycoformycin-induced immunosuppression in patients with hairy cell leukemia

Immune function in patients with hairy cell leukemia (HCL) was examined serially during treatment with alternating monthly cycles of recombinant interferon alpha-2a and 2'-deoxycoformycin (dCF). At presentation, most patients had normal numbers of T lymphocytes and their cells had normal proliferative responses to mitogens [phytohemagglutinin (PHA) and concanavalin A (Con A)] and alloantigens. Patients had severe monocytopenia, decreased delayed-type hypersensitivity (DTH) reactions, and decreased peripheral blood natural killer (NK) activity. Treatment caused a profound decrease in all lymphocyte subpopulations. T cells were more affected than B cells or NK cells. Numbers of CD4+ and CD8+ lymphocytes decreased to levels less than 200 cells/microliters in all patients during treatment. This decrease in T cell number was associated with a marked decrease in proliferative responsiveness to PHA, Con A, and alloantigens. These abnormalities persisted throughout the 14 months of treatment and have continued for up to 6 months beyond discontinuation of treatment. NK cell activity increased during treatment, but cycled depending on the phase of treatment; highest activities were observed after interferon (IFN)-alpha and lower levels of activity were observed after dCF. DTH responses generally did not improve during therapy. Levels of IgM, IgG, IgA, and IgD did not change during treatment, but IgE levels rose in most patients. All immunosuppressive effects were attributable to dCF since patients receiving IFN-alpha 2a alone did not exhibit these same immunosuppressive effects, and patients receiving dCF alone after IFN failure exhibited similar abnormalities. Despite this severe immunosuppression from dCF, life-threatening opportunistic infections have not been observed in our patient population. Six patients developed localized Herpes zoster infection among 21 patients who had received dCF. Pending the results of long-term follow-up, we recommend that dCF be reserved for patients who have failed splenectomy and IFN therapy.