ThinPrep-processed fine-needle samples of breast are effective material for RNA- and DNA-based molecular diagnosis: application to p53 mutation analysis. (17/299)

BACKGROUND: Fine-needle sampling is the least invasive method of in vivo breast carcinoma sampling and can provide material for breast carcinoma diagnosis. The aim of the current study was to assess the accuracy of molecular diagnosis techniques using fine-needle sample (FNS) material stored in PreservCyt (Cytyc Corp., Boxborough, MA). METHODS: The p53 tumor suppressor gene was chosen as a model because it can be used for DNA, RNA, and protein analysis. Molecular analysis was performed using a yeast functional assay and DNA sequencing. p53 accumulation was evaluated by immunocytochemistry. RESULTS: DNA and protein analysis indicated that samples stored for periods of several months, either at room temperature, 4 degrees C, or -20 degrees C, can be processed reliably. For RNA-based diagnosis, samples were still intact after 5 months of storage in PreservCyt at 4 degrees C. In addition, using FNS material that was stored for 16 months at 4 degrees C, the authors detected p53 mutations with either the functional assay for separating alleles in yeast (an RNA-based functional assay) or direct cDNA sequencing. CONCLUSIONS: Fine-needle samples stored in PreservCyt at 4 degrees C are very good material for molecular diagnosis techniques. In addition, it is feasible to adopt a strategy of storing excess FNS material to create cellular banks that will be invaluable for future gene studies.  (+info)

Applications of experimental techniques to epidemiological studies of non-Hodgkin's lymphoma: use of archival tissues. (18/299)

Archival tissues, particularly formalin-fixed paraffin-embedded tumors, have become increasingly valuable in studies of the etiology of cancer. In non-Hodgkin's lymphoma, subclassification of tumors by immunophenotyping and identification of oncogenic viruses has allowed more accurate interpretation of associated epidemiological information. One such example is adult T-cell leukemia/lymphoma, which is not a single histopathological entity and usually is associated with human T-cell lymphotropic virus, type I. In addition to confirming the diagnosis, the pattern of virus distribution, utilized recently in studies of Epstein-Barr virus and human herpesvirus-6-associated lymphoma, has suggested which tumors are more likely to have the virus playing a passenger role (virus detected in uninvolved tissues) and in which tumors the virus may have an etiological role (virus restricted to tumor cells). Preservation and cataloguing of tumors and relevant clinical and demographic data may play an increasingly important role in demographic studies.  (+info)

Saving the "library of life". (19/299)

A broad program of freezing species in threatened ecospheres could preserve biodiversity for eventual use by future generations. Sampling without studying can lower costs dramatically. Local labor can do most of the gathering. Plausible costs of collecting and cryogenically suspending the tropical rain forest species, at a sampling fraction of 10(-6), are about 2 billion dollars for a full century. Much more information than species DNA will be saved, allowing future biotechnology to derive high information content and perhaps even resurrect then-extinct species. Parallel programs of in situ and other ex situ preservation are essential to allow later expression of frozen genomes in members of the same genus. This is a broad proposal that should be debated throughout the entire scientific community.  (+info)

The importance of various factors relating to the morphological quality of corneas used for PKP by the Warsaw Eye Bank from 1996 to 2002. (20/299)

To examine the effect of various factors such as: donor's age, cause of death, time between death and preservation and duration of preservation on the morphological quality of corneas used for Penetrating Keratoplasty (PKP). Our purpose was to assess the role of the above factors influencing the corneal overall rating and endothelial cell density. The present data regarding the donor's age and time between death and preservation of corneas obtained from eye banks belonging to the European Eye Bank Association and Polish eye banks were compared. Corneoscleral buttons and data concerning donors were obtained by eye bank technicians and collected in Warsaw Eye Bank in the years 1996-2002. The quality of the corneas recovered was evaluated by means of slit lamp Nikon NS-IV and specular microscope KONAN. Cardiorespiratory failure and cardiac arrest were the most frequent cause of the donors' death. In many cases donors with confirmed brain death who were given the corneas, were also donors of internal organs like heart, kidneys, pancreas and liver. The number of donors with disseminated neoplasm disease--complete disadvantage for removing corneas increased during the eye bank activity. The epithelial and endothelial layers sometimes underwent mechanical trauma in the group of donors because of sudden death. From 1996 to 2002 more than 50% of the donors were over 60 years of age. There were many problems with receiving corneas from younger donors. The overall rating tissues which were obtained in a very short time after death (to 5 hours) was higher (Excellent and Very Good) compared with corneas removed 8-12 hours after the donor's death. The increasing percentage of endothelial cell loss was observed in all the corneas after about 7 days of preservation in the medium. The mean endothelial cell density slightly decreased with donor's age, but its suggested range of the factors possibility of finding the corneas with high number of endothelial cell density both in younger and older donors. The average time from death to preservation was similar in eye banks preserving corneas at +4 degrees C (8-10 hours) compared with eye banks using mainly the organ culture method. The rating of the morphological state of corneas suitable for PKP depends on the time between death and preservation, donor's age, cause of death and time of preservation of corneas. Corneas obtained shortly after the donor's death showed a higher endothelial cell density and better overall rating than those removed after relatively longer period after the donor's death. An increasing percentage of endothelial cell loss was observed after 7 days of preservation independent of other factors.  (+info)

Frozen cancellous bone allografts: positive cultures of implanted grafts in posterior fusions of the spine. (21/299)

We have carried out a study on the behaviour pattern of implanted allografts initially stored in perfect conditions (aseptically processed, culture-negative and stored at -80 degrees C) but which presented positive cultures at the implantation stage. There is no information available on how to deal with this type of situation, so our aim was to set guidelines on the course of action which would be required in such a case. This was a retrospective study of 112 patients who underwent a spinal arthrodesis and in whom a total of 189 allograft pieces were used. All previous bone and blood cultures and tests for hepatitis B and C, syphilis and HIV (via PCR techniques) were negative. The allografts were stored by freezing them at -80 degrees C. A sample of the allograft was taken for culture in the operating theatre just before its implantation in all cases. The results of the cultures were obtained 3-5 days after the operation. There were 22 allografts with positive culture results (12%) after implantation. These allografts were implanted in 16 patients (14%). Cultures were positive for staphylococci coagulase negative (ECN) in 10 grafts (46%), Pseudomonas stutzeri in two grafts (9%), Corynebacterium jeikeium in two grafts (9%), staphylococci coagulase positive in two grafts (9%) and for each of the following organisms in one case each (4%): Corynebacterium spp., Actinomyces odontolyticus, Streptococcus mitis, Peptostreptococcus spp., Rhodococcus equi and Bacillus spp. No clinical infection was seen in any of these patients. Positive cultures could be caused by non-detected contamination at harvesting, storing or during manipulation before implantation. The lack of clinical signs of infection during the follow-up of our patients may indicate that no specific treatment different from our antibiotic protocol is required in the case of positive culture results of a graft piece after implantation.  (+info)

Stored human tissue: an ethical perspective on the fate of anonymous, archival material. (22/299)

The furore over the retention of organs at postmortem examination, without adequate consent, has led to a reassessment of the justification for, and circumstances surrounding, the retention of any human material after postmortem examinations and operations. This brings into focus the large amount of human material stored in various archives and museums, much of which is not identifiable and was accumulated many years ago, under unknown circumstances. Such anonymous archival material could be disposed of, used for teaching, used for research, or remain in storage. We argue that there are no ethical grounds for disposing of the material, or for storing it in the absence of a teaching or research rationale. Nevertheless, with stringent safeguards, it can be used even in the absence of consent in research and teaching. Regulations are required to control the storage of all such human material, along the lines of regulations governing anatomy body bequests.  (+info)

Ovarian tissue banking for cancer patients: is ovarian cortex cryopreservation presently justified? (23/299)

The effect of chemotherapy and radiotherapy on future fertility is of concern to patients and their families. Whereas sperm banking is commonly performed, female gametes are not so amenable to cryopreservation. One alternative includes postponing cancer treatment to enable ovulation induction and oocyte aspiration. Whenever possible, retrieved oocytes should be fertilized in vitro prior to cryopreservation. Frozen embryos could serve to produce pregnancies if ovarian failure occurs. Donor sperm can be offered to single patients, as frozen-thawed unfertilized oocytes yield poor pregnancy rates. Ovarian cortex cryopreservation should still be considered an experimental technology as no pregnancies have been obtained in humans. Therefore, ovarian cortex banking should be used only for young girls, adolescents and when IVF is contraindicated. Reattachment of ovarian vasculature could prevent ischaemic follicular loss and enable ovarian transplantation in the future. This procedure is currently under investigation in animals. At the present time, we recommend urgent IVF in most patients requesting fertility preservation. Ovarian cryopreservation should be offered when emergency IVF is not possible.  (+info)

Taskforce 7: Ethical considerations for the cryopreservation of gametes and reproductive tissues for self use. (24/299)

This seventh statement of the ESHRE Task Force on Ethics and Law considers ethical questions and specific dilemmas surrounding the cryopreservation of gametes and reproductive tissue. This is of particular relevance with advancing techniques for cryopreservation and the desire of many individuals to preserve fertility after cancer, chronic illness, iatrogenic complications of treatment or simply with advancing age.  (+info)