Susceptibility to induced visual discomfort during the menstrual cycle while viewing a visual display unit.

PURPOSE: Consistent variations in reports of visual discomfort during the female menstrual cycle are found when virtual reality headsets are used to display moving images. Because little is known about the influence of this cycle on susceptibility to visual discomfort in other situations, we performed a laboratory study using an intensive visual task. METHODS: Twelve female participants, with normal-length menstrual cycles, completed the study. This required them to play a computer game for 30 minutes while viewing the screen through -2.00-D lenses. Questionnaires were used to record symptom changes; visual acuity and near points of accommodation (NPA) and convergence (NPC) were also recorded both before and after the game. The participants performed this task on designated days (5, 12, 19, and 26) of their menstrual cycle chosen because they fall in line with peaks and troughs of ovarian hormone levels. Cycle phase was confirmed by the measurement of salivary estradiol and progesterone levels. RESULTS: The task performed produced clear changes in all metrics examined. Visual discomfort first increased, on average, after 6 minutes; VA declined on average by 0.02 logarithm of the minimum angle of resolution and NPC and NPA both receded by just over 1 cm. However, none of these changes differed significantly at any stage of the menstrual cycle. CONCLUSIONS: We conclude that visual discomfort, generated by providing increased accommodative demand while viewing a visual display unit, does not vary significantly during the menstrual cycle.     

Management of the complications of external beam radiotherapy and brachytherapy

External beam radiation therapy (EBRT) and brachytherapy are common treatment modalities for newly diagnosed prostate cancer. What complications can patients and physicians expect following these therapies? How are these conditions diagnosed and treated? In this article, we examine several of the most common acute and delayed complications of radiation therapy for prostate cancer. In addition, we discuss appropriate follow-up diagnostics for these patients and our suggestions for management of the main complications that may develop.     

Validation of a near-infrared transmission spectroscopic procedure. Part B: Application to alternate content uniformity and release assay methods for pharmaceutical solid dosage forms

NIR analytical methods can be validated to meet the requirement of demonstrating that it is suitable for the analysis of the materials for which it is being used. Applying previously described protocols for NIR methods to the analysis of two types of pharmaceutical products shows that for these products, NIR is suitable as an alternate analytical method for assay and for content uniformity.     

A phase II study of neoadjuvant biochemotherapy for stage III melanoma

BACKGROUND: Phase II studies of biochemotherapy (combining interleukin-2, interferon-alpha, and multiagent chemotherapy) have reported high response rates and a significant number of durable complete responses in patients with metastatic melanoma. METHODS: A pilot Phase II study was performed to explore the safety and activity of neoadjuvant biochemotherapy in patients with Stage III melanoma. Forty-eight patients were enrolled between April 1996 and May 1999. The median age of the patients was 46 years (range, 19-70 years). Two cycles of biochemotherapy were administered prior to and after complete lymph node dissection. Each cycle was comprised of cisplatin, 20 mg/m2 intravenously (i.v.), on Days 1-4; vinblastine, 1.6 mg/m2 i.v., on Days 1-4; dacarbazine, 800 mg/m2 i.v., on Day 1; interleukin-2, 9 x 10(6) IU/m2/day i.v. over 24 hours, on Days 1-4; and interferon-alpha, 5 x 10(6) IU/m2/day subcutaneously, on Days 1-5, every 3 weeks. Twelve patients did not have measurable disease. All patients were evaluable for toxicity and survival. RESULTS: Clinical responses were observed in 14 of 36 patients (38.9%) with measurable disease, including 13 partial responses (36.1%) and 1 complete response (2.8%). Complete pathologic responses were noted in 4 patients (11.1%). Toxicity, although severe, was manageable and typically short-lived. There were no treatment-related deaths reported. At a median follow-up of 31 months, 38 of the 48 patients (79.2%) were alive and 31 patients (64.6%) remained free of disease progression. CONCLUSIONS: Neoadjuvant biochemotherapy appears to have promising activity in patients with Stage III melanoma. A larger multicenter study currently is underway to explore this approach further.     

Immunological memory and late onset autoimmunity

This review will address a paradox that has long fascinated scientists studying the effects of aging on the immune system. Although it has been clearly documented that B and T lymphocytes lose the ability to respond to antigenic or mitogenic stimulation with age, it has nonetheless been noted that the frequency of autoreactive antibodies is higher in older individuals. Given that the majority of the age-associated defects in immune regulation target the na?ve T and B lymphocyte subsets, it has been presumed that this increase in antibodies specific for self antigens was due to changes in the B cell repertoire and/or to differences in the mechanisms responsible for generating immune tolerance in primary responses. However, in this review, we will address an alternative possibility that memory immune responses, first generated when the individual was young, may play a critical role in the appearance of serum autoantibodies by reactivation later in life (recall memory). It has recently been shown, in several different systems, that memory immunity can be maintained over the lifetime of the animal. Thus, memory B cells which are self-reactive may be harbored within an organism as it ages and the potential exists that they become re-activated at a later time, resulting in a vigorous autoreactive recall response. This may occur preferentially in older individuals due to several factors, including deficiencies in immune tolerance with age, progressive age-associated loss of tissue integrity yielding neo-self antigens, and possible re-exposure to an infectious agent which induces an autoimmune memory response through molecular mimicry. Thus, we propose that some of the autoantibodies seen in elderly patients and in older animals may have been produced by memory lymphocytes originally generated against antigens encountered during one's youth, but maintained in a tolerant (non reactive) state until a subsequent triggering event occurs. Possible implications of this model will be discussed.     

Quantitative stability of DNA after extended storage of clinical specimens as determined by real-time PCR

Viral DNA stored for extended periods can be amplified by PCR. However, it is unknown whether stored specimens give accurate quantitative results by newer real-time PCR techniques. We therefore compared herpes simplex virus DNA levels in specimens before and after 16 months of storage. The levels of viral DNA remained stable whether the DNA was stored as purified DNA or unextracted DNA in a whole specimen.     

Embryotoxicity of the pesticide mirex in vitro

Mirex is a pesticide that is environmentally stable, accumulates in body tissues, and is embryo- and feto-toxic at high concentrations in vivo. This study is the first to evaluate the effects of mirex on organogenesis-stage embryos in vitro. Mouse embryos were exposed on gestation day 8.5 for 24 h in whole-embryo culture to mirex at 100, 200, or 400 microg/ml dissolved in xylene and compared with xylene-treated controls (1, 2, or 4 microl/ml, respectively) and untreated controls. Embryos were evaluated for malformations, somite number, total protein content, and visceral yolk sac circulation. Potential embryotoxic mechanisms were evaluated by using PCNA stain for cell proliferation and the TUNEL assay for apoptotic cell death. Mirex-exposed embryos demonstrated increased malformation rates and decreased total embryonic protein contents at > or =200 microg/ml mirex, and decreased somite numbers and VYS circulation at > or =100 microg/ml mirex, compared with xylene-treated controls. There was no difference in PCNA levels or TUNEL staining in mirex-treated embryos compared with xylene-treated controls or untreated controls. Thus, mirex is embryotoxic in vitro to early organogenesis stage mouse embryos at concentrations > or =100 microg/ml, but the effects do not appear to be mediated by changes in cell proliferation or apoptotic cell death.