Normal values for a clinical test of letter-recognition contrast thresholds

PURPOSE: To investigate the contrast thresholds (CTs) in normal subjects using a high-luminance, letter-recognition task under clinically relevant testing conditions. SETTING: Texas Tech University Health Sciences System, Lubbock, Texas, USA. METHODS: Sixty normal subjects aged 20 to 49 years with a best corrected visual acuity of 20/20 or better in both eyes participated. M & S Technologies software was used to display black-on-white Sloan letters at contrast levels of 25%, 20%, 15%, 12%, and 10% through 1% in 1% decrements. The effects of age, sex, optotype size, eye dominance, ambient illumination level (bright = 625 - 630 lux; dim = <3 lux), and direction of approach to threshold were analyzed using a multivariate, ordinary, least-squares analysis. RESULTS: Age and sex did not influence CTs. Ascending versus descending testing was not statistically significant (P>.5). The effects of room illumination and eye dominance were significant (P<.01). Significant differences were found between 20/30 and 20/50, 20/30 and 20/70, and 20/50 and 20/70 optotype sizes (P<.01 for all comparisons). CONCLUSIONS: A commercially available, computer-based test of CTs was easy to administer and apparently easy for inexperienced subjects to perform. The results suggest criteria for detecting visual problems concerned with familiar but complex spatial-image shapes. This information might be used to assess the effects of treatments such as laser refractive surgery on recognition contrast. Further study is warranted.     

Surveillance mammography after treatment for male breast cancer

Breast Cancer Research and Treatment - To identify the practice patterns related to use of surveillance mammography in male breast cancer (MaBC) survivors. Using administrative claims data from...     

AIDS -- diagnosis and management

HIV infection causes AIDS, a fatal disease. Viral types HIV-1 and HIV-2 have thus far been identified, the latter form presenting mainly in West Africa. HIV-1 is in countries throughout the world, demonstrating a pattern of infection which varies by region. 960 HIV-positive cases have been detected in Pakistan, 52 of which had progressed to AIDS. HIV can be transmitted either horizontally by blood and semen or vertically through the placenta. However, transmission is most common in individuals involved in risk activities or who belong to high-risk groups. Once infected with HIV, people may remain healthy for several years. Clinical progression and the criteria for the diagnosis of AIDS are discussed. Except for the recently exposed, individuals infected with HIV have antibodies which can be detected through laboratory assays. ELISA, polymerase chain reaction, and virus culturing are ways of diagnosing the presence of HIV. The laboratory diagnosis of HIV/AIDS infection, treatment, the prevention of HIV infection, and the need for a practical vaccine against HIV infection are discussed.     

Human herpesvirus 7 in pediatric hematopoietic stem cell transplantation

BACKGROUND: Little is known about the significance of human herpesvirus 7 (HHV-7) in pediatric hematopoietic stem cell transplantation (HSCT). OBJECTIVE: To evaluate children post autologous and allogeneic HSCT, with a positive PCR or immunohistochemistry for HHV-7 either from blood, cerebrospinal fluid (CSF) or any other pathology specimen. Clinical data for these patients were collected examining symptoms and signs, engraftment, acute infectious complications, graft versus host disease (GVHD) where applicable, and survival. RESULTS: Between June 1999 and June 2003, 265 HSCT were performed in The Hospital for Sick Children, Toronto, allogeneic (n = 163) and autologous (n = 102). Nine children were positive for HHV-7 at a median of 21 days (range 16-27 days) post-HSCT. All had allogeneic transplantation. The most common underlying diagnosis was acute leukemia and 7 had matched unrelated donor (MUD) transplantation. Eight of the nine patients had grade II-IV acute GVHD and all of them had multiple infectious episodes with fungal, bacterial and other viral pathogens. Although not fully attributed to HHV-7, the clinical syndrome varied from fever, vomiting and diarrhea to septic shock. Four patients died due to GVHD and sepsis. CONCLUSION: HHV-7 was uncommon post-HSCT. It was associated with severe GVHD and sepsis secondary to severe immunosuppression.