Medical technology assessment: adequate questions, appropriate methods, valuable answers.

Medical Technology Assessment begins with carefully posing the appropriate questions to be examined. Specification of the critical assessment provides the framework for the design to provide the answers. This paper addresses the Technology Assessment process as a sequence of the above steps. The practical requisites of the diversity of questions, the economic, and study design considerations generated are addressed in a systems analysis model of input-process-outcome. Applications and the relative merits of such design consideration are discussed and illustrated. The questions related to medical technologies may come from different groups of people directly or indirectly interested, and having active or passive relationship to a given technology. There are 4 basic issues from which the detailed questions derive. These are the issues of need, effectiveness, safety and cost. The timing of asking questions in the life-cycle of a technology and the adequacy of the answers determines the choice of methods, the extent of an evaluation and the quality of the responses. The reliability, external validity, generalizability, and the clarity of conclusions are the characteristics of a practical and valuable assessment.     

Effects of ultrasound on ultrastructure of human testes

Studies to detect ultrastructural changes in testicular tissues after a fifteen-minute exposure to ultrasonic waves were done in 10 men undergoing bilateral orchiectomies for prostatic carcinoma. Examination of Sertoli cells and germ cells in different stages of differentiation failed to reveal significant differences between exposed and control testes.     

Sulfonylurea-induced decrease of muscle capillary basement membrane thickness in diabetes

Three muscle biopsies were performed in 53 overt type 2 diabetics over a period of approximately 2 years. At baseline, 21 (40%) had an increased capillary basement membrane width in muscle. Thirty-five patients received glipizide and 18 received placebo. In the patients receiving placebo, the mean of the muscle capillary basement membrane width increased from 158.7 +/- 11.5 nm (SEM) to 170.9 +/- 14.7 nm (P = NS), but in those receiving glipizide the value decreased from 192.9 +/- 13.2 nm to 161.0 +/- 10.2 nm (P = 0.02). Plasma glucose and glycosylated hemoglobin A1 decreased significantly (P less than 0.001) after 2 years in patients receiving glipizide. In 15, mean glycosylated hemoglobin A1 reached a normal range, and mean basement membrane width decreased to a level close to that found in subjects without diabetes (P = NS). These findings are consistent with the hypothesis that effective response to oral medication can decrease the basement membrane thickening, suggesting that diabetic microangiopathy is not necessarily progressive.     

环孢菌素A阻断人HL-60抗药性细胞于G1期而诱导敏感细胞凋亡

进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml^-1诱导HL-60细胞发生凋亡,而阻断HR20细胞于G₁期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml^-1处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G₁期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关。     

An endogenous glycosylphosphatidylinositol-specific phospholipase D releases basic fibroblast growth factor-heparan sulfate proteoglycan complexes from human bone marrow cultures

Basic fibroblast growth factor (bFGF) is a hematopoietic cytokine that stimulates stromal and stem cell growth. It binds to a glycosylphosphatidylinositol (GPI)-anchored heparan sulfate proteoglycan on human bone marrow (BM) stromal cells. The bFGF- proteoglycan complex is biologically active and is released by addition of exogenous phosphatidylinositol-specific phospholipase C. In this study, we show the presence of an endogenous GPI-specific phospholipase D (GPI-PLD) that releases the bFGF-binding heparan sulfate proteoglycan and the variant surface glycoprotein (a model GPI-anchored protein) from BM cultures. An involvement of proteases in this process is unlikely, because released proteoglycan contained the GPI anchor component, ethanol-amine, and protease inhibitors did not diminish the release. The mechanism of release is likely to involve a GPI-PLD and not a GPI-specific phospholipase C, because the release of variant surface glycoprotein did not reveal an epitope called the cross- reacting determinant that is exposed by phospholipase C-catalyzed GPI anchor cleavage. In addition, phosphatidic acid (which is specifically a product of GPI-PLD-catalyzed anchor cleavage) was generated during the spontaneous release of the GPI-anchored variant surface glycoprotein. We also detected GPI-PLD-specific enzyme activity and mRNA in BM cells. Therefore, we conclude that an endogenous GPI-PLD releases bFGF-heparan sulfate proteoglycan complexes from human BM cultures. This mechanism of GPI anchor cleavage could be relevant for mobilizing biologically active bFGF in BM. An endogenous GPI-PLD could also release other GPI-anchored proteins important for hematopoiesis and other physiologic processes.     

The examination of physicians' awareness of dementing disorders

Despite a significant increase in the amount of research being conducted on the etiology, diagnosis, and treatment of Alzheimer's disease and other dementing disorders, there has been little assessment of the utilization of this new wealth of information by the primary care physician. It was hypothesized that there would be a wide variation in physicians' knowledge of dementing disorders and the procedures used to diagnose these disorders. To quantitate the present status of primary care physicians' knowledge of dementing disorders and to investigate possible relationships between this knowledge and different physician and practice characteristics, 50 general internists and family practitioners from Winnebago County, Illinois, were interviewed regarding their recall of causes of dementia, procedures used in diagnosing these diseases, treatment recommendations, and comfort in making a differential diagnosis. Results revealed a wide variation in both physicians' familiarity with the causes of dementia as well as the procedures used in making the diagnosis. Although a majority (80%) of the physicians reported some degree of confidence in making a differential diagnosis of dementing disorders, a significant trend was found between physician age and comfort in making the diagnosis, with age being directly correlated with comfort. This was in spite of a significant negative association between physician age and immediate recall of causes of dementia. These data imply that younger physicians are entering the work force with at least better immediate recall of information on dementing disorders, but they have had little opportunity to become comfortable with that knowledge due to a generally smaller geriatric population in their practice.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improving COPD Care in a Medically Underserved Primary Care Clinic: A Qualitative Study of Patient Perspectives

We conducted a focus group study in an urban hospital-based primary care teaching clinic serving an indigent and Hispanic (predominantly Puerto Rican) population in New England in order to learn how patients with Chronic Obstructive Lung Disease (COPD) perceive their disease, how they experience their medical care, and the barriers they face managing their disease and following medical recommendations. The research team included medical doctors, nurses, a medical anthropologist, a clinical pharmacist, a hospital interpreter, and a systems analyst. Four focus groups were conducted in Spanish and English in April and May 2014. The demographic characteristics of the 25 focus group participants closely reflected the demographics of the total COPD clinic patients. The participants were predominantly female (72%) and Hispanic (72%) and had a median age of 63. The major themes expressed in the focus groups included: problems living with COPD; coping with complexities of comorbid illnesses; challenges of quitting smoking and maintaining cessation; dealing with second-hand smoke; beliefs and myths about quitting smoking; difficulty paying for and obtaining medications; positive experiences obtaining and managing medications; difficulties in using sleep machines at home; expressions of disappointment with the departure of their doctors; and overall satisfaction with the clinic health care providers. The study led to the creation of an action plan that addresses the concerns expressed by the focus study participants. The action plan is spearheaded by a designated bilingual and bicultural nurse and is now in operation.     

The association of syphilis with risk of human immunodeficiency virus infection in patients attending sexually transmitted disease clinics

A serologic survey of 4863 patients attending two inner-city sexually transmitted disease clinics was conducted in 1988 1 year after an initial survey to reassess the prevalence and associated risk factors for human immunodeficiency virus (HIV) infection. The HIV seroprevalence rates had not changed significantly (5.2% in 1987, 4.9% in 1988), and remained higher among men (5.6%) than among women (3.6%). The HIV seroprevalence increased steadily with age, to 34 years in women and to 39 years in men. Of patients with a reactive syphilis serologic test result, 24.3% were HIV infected compared with 3.5% of patients with a nonreactive test for syphilis. In multivariate analysis, a reactive serologic test for syphilis was significantly associated with HIV infection in all major risk behavior categories. Among heterosexuals who denied parenteral drug abuse, HIV infection rates were 6.8 and 8.7 times greater for women and men, respectively, who had a reactive serologic test for syphilis. Evidence of heterosexual transmission of HIV was further suggested by a change in HIV seroprevalence in women from 3.0% in 1987 to 3.6% in 1988, a male to female HIV infection ratio of 1.6, and 3.0% prevalence of infection among patients who denied established risk factors. This was most evident among those younger than 25 years, in whom 72% of infected women and 46.2% of infected men denied high-risk behaviors. These data demonstrate the strong association between syphilis and HIV infection and the importance of heterosexual HIV transmission in patients attending sexually transmitted disease clinics. This study underscores the need for a more comprehensive control program for sexually transmitted diseases, including syphilis and HIV infection.