High-performance laterally-arranged multiple-bandgap solar cells using spatially composition-graded CdxPb1-xS nanowires on a single substrate: a design study.

In this paper, laterally arranged multiple bandgap (LAMB) solar cells based on CdxPb1-xS alloy nanowires of varying composition on a single substrate are designed to be used together with a dispersive concentrator. Simulation results for a design with six subcells in series connection are presented. The design is based on a unique materials capability achieved in our recent research. An efficiency of 34.9% was obtained for operation without solar concentration, which increased to 40.5%, 41.7%, and 42.7% for concentration ratios of 25, 100, and 240 respectively. The device was also simulated with decreased carrier mobilities to model the possible reduction in absorber conductivity, depending on the nanowire geometry and configuration. For a concentration ratio of unity, decreasing the mobilities to 25% of their original values caused less than a 2.5% absolute drop in efficiency. The LAMB design offers the advantages of an integrated cell platform and the potential for low-cost, high efficiency photovoltaic systems.

No improvement of survival with reduced- versus high-intensity conditioning for allogeneic stem cell transplants in Ewing tumor patients.

BACKGROUND: Outcomes of Ewing tumor (ET) patients treated with allogeneic stem cell transplantation (allo-SCT) were compared regarding the use of reduced-intensity conditioning (RIC) and high-intensity conditioning (HIC) regimens as well as human leukocyte antigen (HLA)-matched and HLA-mismatched grafts. PATIENTS AND METHODS: We retrospectively analyzed data of 87 ET patients from the European Group for Blood and Marrow Transplantation, Pediatric Registry for Stem Cell Transplantations, Asia Pacific Blood and Marrow Transplantation and MetaEICESS registries treated with allo-SCT. Fifty patients received RIC (group A) and 37 patients received HIC (group B). Twenty-four patients received HLA-mismatched grafts and 63 received HLA-matched grafts. RESULTS: Median overall survival was 7.9 months [±1.24, 95% confidence interval (CI) 5.44-10.31] for group A and 4.4 months (±1.06, 95% CI 2.29-6.43) for group B patients (P = 1.3). Death of complications (DOC) occurred in 4 of 50 (0.08) and death of disease (DOD) in 33 of 50 (0.66) group A and in 16 of 37 (0.43) and 17 of 37 (0.46) group B patients, respectively. DOC incidence was decreased (P < 0.01) and DOD/relapse increased (P < 0.01) in group A compared with group B. HLA mismatch was not generally associated with graft-versus-Ewing tumor effect (GvETE). CONCLUSIONS: There was no improvement of survival with RIC compared with HIC due to increased DOD/relapse incidence after RIC despite less DOC incidence. This implicates general absence of a clinically relevant GvETE with current protocols.

Key role of staff competencies for patient and donor safety in a bone marrow transplantation unit: design and implementation of an accredited training and self-assessment program.

Human resources represent at the moment the most critical factor in an hospital setting characterized by a high rate of staff turnover. It is important to ensure a consistent level of expertise and knowledge of professionals who work in health care facilities to provide quality services and simultaneously support the implementation of strategies for patient safety. Unfortunately, the development of effective interventions for training newly added staff and self-evaluation of skills possessed by trained staff are closely related to understanding critical aspects of the organization. At the new Center for Bone Marrow Transplantation and Blood Transfusion Service in Meyer Hospital, during the last year, a group of professional nurses and technicians completed a specific plan to train new staff and, at the same time, a program of self-assessment of skills for experienced staff. The main purpose of this project was to promote skills development by newly added as well as experienced staff, to identify areas of weaknesses, and to correct them with training (organized by the hospital, departmental, or individual) designed to improve performance.

The role of BMT in childhood histiocytoses.

Childhood histiocytoses comprise two main diseases, Langerhans cell histiocytosis (LCH) and hemophagocytic lymphohistiocytosis (HLH). LCH is a rare disorder with obscure pathogenesis. Data on clonality suggested neoplastic origin, yet were not convincing. Dysregulation of cytokines and of DC trafficking and cross-talk are documented. Clinical manifestations and course are highly variable, ranging from self-healing solitary bone lesion to disseminated, multi-organ involvement with 20% fatality rate despite standard chemotherapy. HSCT has been applied in less than 50 cases, outside any trial, with good disease control but elevated early toxicity. The familial form of HLH (FHL) has been recognized as congenital immune deficiency, with mutations of PRF1, Munc13-4, syntaxin11 genes resulting in defective cellular cytotoxicity machinery. Chemo-immunotherapy allows temporary disease control, but HSCT holds as the only procedure with potential for cure. Rapid identification of genetic defects allows differential diagnosis from transient, virus-associated HLH, thus indicating early HSCT. The role of HSCT in childhood histiocytoses is thus very important. Better understanding of the pathogenesis, in particular of genetic and immune function defects, will help to tailor indications and, possibly less toxic, conditioning regimens, reducing treatment-related mortality, and thus disclosing the way to final cure.

[Neurological and psychological evolution of adolescents with vertical transmission HIV infection]. / Evoluzione neuropsichica in adolescenza del bambino HIV positivo per trasmissione verticale.

AIM: Personal experience in a sample group of children with AIDS vertically transmitted followed from birth to adolescence (out of 56 cases with documented HIV infection, 9 who have reached the age of 13 have been studied) is presented. METHODS: The evaluation protocol includes: hematochemical, serological and virological tests to monitor the infectious status, as well as annual EEG, CT/MRI scan to detect anatomical alteration of CNS, neurological examination, intelligence test (WISC-R), interview and projective test (Blacky Pictures) to investigate emotional situation. RESULTS: As to the status of the disease, according to the CDC classification, 2 patients are asymptomatic, 2 paucisymptomatic, 2 with moderate symptoms, 2 severely symptomatic; 1 patient died due to progressive encephalopathy. Of the 2 severely symptomatic cases, 1 presents cortical atrophy and the other basal nuclei calcifications. No one of them has clinical signs of encephalopathy. All patients receive anti-retroviral medications. From tests and interviews emotional problem-emerge, future is seen as menacing and insidious, and defensive mechanisms are fragile and inconstant; denial can lead to a refusal of the pharmacological therapy; families themselves often refuse medical staff the consent to communicate the diagnosis fearing that this could induce unbearable anguish. CONCLUSIONS: It seems important that patients are informed, considering their capacity to make front to the communication, even if one must bear in mind that understanding and accepting the diagnosis may be a long and painful process requiring a long time.

Adherence to antiretroviral therapy and its determinants in children with human immunodeficiency virus infection: a multicentre, national study.

AIM: To investigate rates and determinants of adherence to antiretroviral therapy in Italian children infected with the human immunodeficiency virus (HIV). METHODS: An observational, cross-sectional multicentre study was performed through a structured interview with the caregivers of HIV-infected children. The interview included quantitative information on adherence in the 4 d before interview. Sociodemographic, clinical and psychosocial characteristics of children were recorded. RESULTS: 129 children (median age 96 mo) were enrolled, of whom 94 were on highly active antiretroviral therapy (HAART). Twenty-one (16%) omitted more than 5% of total doses in 4 d and were considered non-adherent. However, only 11% of caregivers reported that therapy had been administered at the correct times. No significant difference was found between age and the stage of HIV infection. Children aware of their HIV status were less adherent. Individual drugs showed a broad adherence pattern and children who received HAART were more adherent. Children receiving therapy from foster parents were more adherent than those receiving drugs from biological parents or relatives. CONCLUSIONS: Adherence is a major problem in children. Psychological rather than clinical or sociodemographic features and types of drug are major determinants of adherence.

Successful treatment of Griscelli syndrome with unrelated donor allogeneic hematopoietic stem cell transplantation.

Griscelli syndrome (GS) is a rare autosomal recessive disorder, characterized by pigmentary dilution of the skin and hair and in most patients by abnormal regulation of the immune system, which results in a syndrome of macrophage hyperactivation, known as hemophagocytic lymophohistiocytosis (HLH). Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment available for genetically induced HLH. Few cases of successful HSCT from a compatible donor have been reported in children with GS. We describe the first patient with GS cured with an allograft from a compatible unrelated bone marrow donor. We used a novel preparative regimen consisting of busulfan, thiotepa and fludarabine. The demonstrated curative effect of HSCT from an unrelated donor in a patient with genetically determined HLH also supports the use of a systematic diagnostic approach in these patients, in order to identify those with a worse prognosis and needing an urgent allograft in a timely manner.

Puberty in perinatal HIV-1 infection: a multicentre longitudinal study of 212 children.

OBJECTIVE: To define age at entry into Tanner stages in children with perinatal HIV-1 infection. DESIGN: Multicentre longitudinal study including 212 perinatally HIV-1-infected children (107 girls and 105 boys) followed-up during puberty (from 8 and 9 years onwards in girls and boys, respectively). Healthy children (843 girls and 821 boys) provided reference percentiles. P2 or B2 stages in girls and P2 or G2 stages in boys defined onset of puberty. METHODS: The cumulative probability [95% confidence limit (CI)] of entry into each stage at different ages was estimated by the Kaplan-Meier product-limit method; differences were evaluated by log rank test. Relationships were tested using the Spearman's rank correlation coefficient. RESULTS: Ages of girls [years (95%CI)] at P2 [12.9 (12.6-13.2)], P3 [13.4 (13.0-13.8)], P4 [14.6 (14.0-15.2)], B2 [12.7 (12.2-13.2)], B3 [13.3 (12.8-14.0)] and B4 [14.6 (14.0-15.2)] stages were > 97th percentile (> or = 21 month delay) of controls. Ages of boys [years (95%CI)] at P2 [12.6 (12.1-13.1)], P3 [13.9 (13.4-14.4)], P4 [14.9 (14.2-15.6)], G2 [12.1 (11.5-12.7)], G3 [13.6 (13.1-14.1)] and G4 [14.9 (14.1-15.7)] stages were at the 75-97th percentiles (< or = 15 month delay). Age at onset of puberty was not related to clinical and immunological condition, antiretroviral treatment, weigh for height and age at onset of severe disease or immune suppression. CONCLUSION: Perinatal HIV-1 infection interferes with sexual maturation. The mechanisms by which this occurs should be elucidated and intervention strategies designed. Intervention could save much psychological distress, since associated linear growth failure can exacerbate adolescents' feelings of being different and unwell.

Human immunodeficiency virus-related cancer in children: incidence and treatment outcome--report of the Italian Register.

PURPOSE: To outline the incidence, presenting features, treatment response, and outcome of human immunodeficiency virus (HIV)-associated malignancies in infancy and childhood, together with the estimated risk of HIV-associated cancer in children born to mothers infected with HIV. PATIENTS AND METHODS: The Italian Register for HIV Infection in Children collected data by specific registration and follow-up forms. By March 1999, 5,060 children were recruited, including 4,889 with perinatal exposure to HIV-1. Overall, 1,331 infected children were enrolled onto the Register and classified according to current Centers for Disease Control criteria; of them, 1,163 were vertically infected (24% of those with perinatal exposure). Of these 1,163, 569 (49%) were considered to have been prospectively followed-up since they had been registered at birth or within the first 3 months of age. RESULTS: Of the 1,331 children observed for a median time of 6.5 years, 35 developed 36 malignancies, four of which occurred in patients with blood-borne risk. For the 1,163 vertically infected children, the cumulative number of years of observation was 7,178 child-years and the cumulative incidence of HIV-associated tumors was 4.18 per 1,000 children/yr (95% confidence interval [CI], 2.92 to 5.98). When only the 569 vertically infected children prospectively followed up since birth were considered, the cumulative number of years of observation was 2,803 child-years. In this group, 10 tumors were observed, with a cumulative incidence of HIV-associated tumors of 3.57 per 1,000 children per year (95% CI, 1.92 to 6.63). CONCLUSION: The risk of cancer was significantly higher but not restricted to symptomatic and/or immune-compromised children. Cancer-directed treatment should be given promptly to these patients, who have a fair chance to survive their tumor in view of potential highly aggressive antiretroviral therapy-associated improvement in survival and quality of life.

Diagnostic value of viral culture, polymerase chain reaction and western blot for HIV-1 infection in 218 infants born to HIV-infected mothers and examined at different ages.

In a prospective longitudinal 10-year (1988 to 1998) study, 308 sequential blood samples from 218 infants born to HIV-1 seropositive women were examined by blood culture, polymerase chain reaction (PCR) and Western Blot (WB) for HIV-1 infection within the first month of life (no. 47 specimens), at 2-6 (no. 125), 7-18 (no. 80), and > 18 (no. 56) months after birth. Clinical status at follow-up after the initial diagnosis of HIV infection was also evaluated. Vertically transmitted HIV infection was diagnosed in 45 children (24 children were diagnosed before 18 months of age), whereas 173 were found to be uninfected (transmission rate 20.6%). Sensitivities of viral culture, PCR and WB were 95.2%, 97.8%, 94.4%, and specificities were 99.5%, 97.6% and 20.7%, respectively. Thus, cumulative positive predictive values (PPV) of blood culture, PCR and WB were 97.5%, 88.2% and 23.4%, while negative predictive values (NPV) were 99.0%, 99.6% and 100.0%, respectively. In view of defining the optimal time of sampling for a correct diagnosis of HIV infection, a PPV of 100.0% was achieved earlier by viral culture (2-6 months of age) than by PCR (7-18 months of age). Meanwhile, a NPV of 100% was obtained earlier by PCR (within the first month of age) than by viral culture (2-6 months). These results indicate that a combination test strategy requiring two blood samples analyzed by viral culture and PCR may confirm or exclude HIV perinatal infection within the first 2 months of life rather than being delayed to later times. Clinical follow-up was performed in 35 children, of whom 7 developed a rapidly progressive disease, 23 showed a slow progression, while 5 children are still younger than 5 years and do not present severe clinical symptoms.