Vitiligo in children and adolescents: association with thyroid dysfunction

Background The clinical characteristics of vitiligo in children and adolescents with an emphasis on thyroid dysfunction have only been reported in a few studies. Objective The purpose of this study was to examine the characteristics of children and adolescents with vitiligo and compare the incidence of thyroid dysfunction between them and controls without vitiligo at the same age. Methods A retrospective analysis of 324 Korean children and adolescents with vitiligo was performed. The results of thyroid function screening tests in them (n = 254) were compared with controls (n = 122). Results Of the total 324 children and adolescents with vitiligo, vitiligo vulgaris was the most common type (42.3%) and the most commonly involved site was the face (54.6%). A total of 15 of 254 (5.9%) patients screened for thyroid function were diagnosed with thyroid disease (four had Hashimoto’s thyroiditis; two, Graves’ disease; seven, subclinical hypothyroidism; and two, subclinical hyperthyroidism). None of the 50 patients with segmental vitiligo showed any thyroid dysfunction (P = 0.047). There was no significant difference in the incidence of thyroid disease between children and adolescents with vitiligo and the control group, in which seven of 122 (5.7%) showed thyroid dysfunction. Conclusion In this study, we demonstrated the characteristics of children and adolescents with vitiligo and also observed no significant difference in the incidence of thyroid disease between children and adolescents with vitiligo and the control group.     

The Individual and Organizational Role of Physicians in Mitigating the Biological,Psychological and Social Health Consequences of Displacement

The number of Internally Displaced People is growing globally with a significant number travelling to countries such as Canada. These individuals have unique health care needs that are significantly impacted by several social determinants of health, which provides a challenge to the physician as they must address the biological, psychological and social factors in order to effectively improve the health of this population. The physician must work at the individual, national, and international levels and collaborate with other health care workers in order to effectively address these complex health care issues. Some recent strategies that show promise in targeting these complex care issues include knowledge sharing among medical professionals, specialized treatment approaches including treatment through telemedicine as well as political advocacy. The application of strategies such as these, along with increased awareness and commitment from physicians, will work to improve health care and prevent negative health outcomes in this growing population.     

Human burst-forming units-erythroid need direct interaction with stem cell factor for further development

To understand the factors that regulate the early growth and development of immature erythroid progenitor cells, the burst-forming units-erythroid (BFU-E), it is necessary to have both highly purified target cells and a medium free of serum. When highly purified human blood BFU-E were cultured in a serum-free medium adequate for the growth of later erythroid progenitors, BFU-E would not grow even with the addition of recombinant human interleukin-3 (rIL-3), known to be essential for these cells. However, the addition of recombinant human stem cell factor (rSCF), which supports germ cell and pluripotential stem cell growth, stimulated BFU-E to grow equally well in serum-free as in serum-containing medium. Limiting dilution studies showed that rSCF acts directly on the BFU-E that do not require accessory cells for growth. Furthermore, rSCF was necessary for BFU-E development during the initial 7 days of culture, until these cells reached the stage of the late progenitors, the colony-forming units-erythroid (CFU-E). These studies indicate that early erythropoiesis is dependent on the direct action of SCF that not only affects early stem cells but is continually necessary for the further development of committed erythroid progenitor cells until the CFU-E stage of maturation.     

Decreased expression of phospholipase C-beta 2 isozyme in human platelets with impaired function

Platelets from a patient with a mild inherited bleeding disorder and abnormal platelet aggregation and secretion show reduced generation of inositol 1,4,5-trisphosphate, mobilization of intracellular Ca2+, and phosphorylation of pleckstrin in response to several G protein mediated agonists, suggesting a possible defect at the level of phospholipase C (PLC) activation (see accompanying report). A procedure was developed that allows quantitation of platelet PLC isozymes. After fractionation of platelet extracts by high-performance liquid chromatography, 7 out of 10 known PLC isoforms were detected by immunoblot analysis. The amount of these isoforms in normal platelets decreased in the order PLC- gamma 2 > PLC-beta 2 > PLC-beta 3 > PLC-beta 1 > PLC-gamma 1 > PLC- delta 1 > PLC-beta 4. Compared with normal platelets, platelets from the patient contained approximately one-third the amount of PLC-beta 2, whereas PLC-beta 4 was increased threefold. These results suggest that the impaired platelet function in the patient in response to multiple G protein mediated agonists is attributable to a deficiency of PLC-beta 2. They document for the first time a specific PLC isozyme deficiency in human platelets and provide an unique opportunity to understand the role of different PLC isozymes in normal platelet function.     

Changing patterns of presentations of patients with HIV-related disease at a tertiary referral centre and its implications for physician training

Highly active antiretroviral therapy (HAART) has been shown to be highly effective in controlling HIV-related disease progression. Our objective was to determine whether HAART had altered the spectrum of HIV-related disease presentations at a tertiary medical referral centre and if a change in the clinical presentations of HIV-infected individuals to the hospital had impacted on physicians' training. A retrospective study which examined all admissions of HIV-infected patients identified between 1 October 1996 to 30 September 1998 using a hospital-designed computer database was undertaken at the Beth Israel Deaconess Medical Center (BIDMC) tertiary medical referral centre. All medical residents were surveyed in order to assess their knowledge of HIV-associated admissions and their confidence treating HIV-infected patients. There were significant changes in the admitting diagnosis for HIV-related illness between 1996 and 1998. Admissions for opportunistic infections (OIs) declined whereas admissions with bacterial infections increased significantly. Use of HAART remained stable between the 2 years of the study. Physicians' overestimated the use of HAART and only 8% of residents felt very comfortable taking care of an HIV-infected patient. In conclusion, the spectrum of presentations with HIV-related disease to a tertiary referral centre continues to change in the HAART era and impacts on physicians' experience of the management of HIV disease.     

Red cell membrane stiffness in iron deficiency

The purpose of this study was to characterize red blood cell (RBC) deformability by iron deficiency. We measured RBC deformability to ektacytometry, a laser diffraction method for determining the elongation of suspended red cells subjected to shear stress. Isotonic deformability of RBC from iron-deficient human subjects was consistently and significantly lower than that of normal controls. In groups of rats with severe and moderate dietary iron deficiency, RBC deformability was also reduced in proportion to the severity of iron deficiency. At any given shear stress value, deformability of resealed RBC ghosts from both iron-deficient humans and rats was lower than that of control ghosts. However, increase of applied shear stress resulted in progressive increase in ghost deformation, indicating that ghost deformability was primarily limited by membrane stiffness rather than by reduced surface area-to-volume ratio. This was consistent with the finding that iron-deficient cells had a normal membrane surface area. In addition, the reduced mean corpuscular hemoglobin concentration (MCHC) and buoyant density of the iron-deficient rat cells indicated that a high hemoglobin concentration was not responsible for impaired whole cell deformability. Biochemical studies of rat RBC showed increased membrane lipid and protein crosslinking and reduced intracellular cation content, findings that are consistent with in vivo peroxidative damage. RBC from iron-deficient rats incubated in vitro with hydrogen peroxide showed increased generation of malonyldialdehyde, an end-product of lipid peroxidation, compared to control RBC. Taken together, these findings suggest that peroxidation could contribute in part to increased membrane stiffness in iron- deficient RBC. This reduced membrane deformability may in turn contribute to impaired red cell survival in iron deficiency.     

Prediction of mortality in community-living frail elderly people with long-term care needs

OBJECTIVES: To develop and validate a prognostic index for mortality in community‐living, frail elderly people. DESIGN: Cohort study of Program of All‐Inclusive Care for the Elderly (PACE) participants enrolled between 1988 and 1996. SETTING: Eleven PACE sites, a community‐based long‐term care program that cares for frail, chronically ill elderly people who meet criteria for nursing home placement. PARTICIPANTS: Three thousand eight hundred ninety‐nine PACE enrollees. The index was developed in 2,232 participants and validated in 1,667. MEASUREMENTS: Time to death was predicted using risk factors obtained from a geriatric assessment performed by the PACE interdisciplinary team at the time of enrollment. Risk factors included demographic characteristics, comorbid conditions, and functional status. RESULTS: The development cohort had a mean age of 79 (68% female, 40% white). The validation cohort had a mean age of 79 (76% female, 65% white). In the development cohort, eight independent risk factors of mortality were identified and weighted, using Cox regression, to create a risk score: male sex, 2 points; age (75–79, 2 points; 80–84, 2 points; ≥85, 3 points); dependence in toileting, 1 point; dependence in dressing (partial dependence, 1 point; full dependence, 3 points); malignant neoplasm, 2 points; congestive heart failure, 3 points; chronic obstructive pulmonary disease, 1 point; and renal insufficiency, 3 points. In the development cohort, respective 1‐ and 3‐year mortality rates were 6% and 21% in the lowest‐risk group (0–3 points), 12% and 36% in the middle‐risk group (4–5 points), and 21% and 54% in the highest‐risk group (>5 points). In the validation cohort, respective 1‐ and 3‐year mortality rates were 7% and 18% in the lowest‐risk group, 11% and 36% in the middle‐risk group, and 22% and 55% in the highest‐risk group. The area under the receiver operating characteristic curve for the point score was 0.66 and 0.69 in the development and validation cohorts, respectively. CONCLUSION: A multidimensional prognostic index was developed and validated using age, sex, functional status, and comorbidities that effectively stratifies frail, community‐living elderly people into groups at varying risk of mortality.