Measurement of Epstein-Barr virus DNA loads in whole blood and plasma by TaqMan PCR and in peripheral blood lymphocytes by competitive PCR

Epstein-Barr virus (EBV) DNA load values were measured in samples of whole blood (n = 60) and plasma (n = 59) by TaqMan PCR and in samples of peripheral blood lymphocytes (PBLs) (n = 60) by competitive PCR (cPCR). The samples were obtained from 44 transplant recipients. The whole-blood and PBL loads correlated highly (r(2) > 0.900), whereas the plasma and PBL loads correlated poorly (r(2) = 0.512). Testing of whole blood by TaqMan PCR is an acceptable alternative to testing of PBLs by cPCR for quantifying EBV DNA load.     

Heart development in the spotted dolphin (Stenella attenuata)

Marine mammals show many deviations from typical mammalian characteristics due to their high degree of specialization to the aquatic environment. In Cetaceans, some of the features of limbs and dentition resemble very ancestral patterns. In some species, hearts with a clearly bifid apex (a feature normally present during mammalian embryogenesis prior to completion of ventricular septation) have been described. However, there is a scant amount of data regarding heart development in Cetaceans, and it is not clear whether the bifid apex is the rule or the exception. We examined samples from a unique collection of embryonic dolphin specimens macroscopically and histologically to learn more about normal cardiac development in the spotted dolphin. It was found that during the dolphin's 280 days of gestation, the heart completes septation at about 35 days. However, substantial trabecular compaction, which normally occurs in chicks, mice, and humans at around that time period, was delayed until day 60, when coronary circulation became established. At that time, the apex still appeared bifid, similarly to early fetal mouse or rat hearts. By day 80, however, the heart gained a compacted, characteristic shape, with a single apex. It thus appears that the bifid apex in the adult Cetacean heart is probably particular to certain species, and its significance remains unclear.     

Factors affecting the determination of threshold doses for allergenic foods: how much is too much?

BACKGROUND: Ingestion of small amounts of an offending food can elicit adverse reactions in individuals with IgE-mediated food allergies. The threshold dose for provocation of such reactions is often considered to be zero. However, because of various practical limitations in food production and processing, foods may occasionally contain trace residues of the offending food. Are these very low, residual quantities hazardous to allergic consumers? How much of the offending food is too much? Very little quantitative information exists to allow any risk assessments to be conducted by the food industry. OBJECTIVE: We sought to determine whether the quality and quantity of existing clinical data on threshold doses for commonly allergenic foods were sufficient to allow consensus to be reached on establishment of threshold doses for specific foods. METHODS: In September 1999, 12 clinical allergists and other interested parties were invited to participate in a roundtable conference to share existing data on threshold doses and to discuss clinical approaches that would allow the acquisition of that information. RESULTS: Considerable data were identified in clinical files relating to the threshold doses for peanut, cows' milk, and egg; limited data were available for other foods, such as fish and mustard. CONCLUSIONS: Because these data were often obtained by means of different protocols, the estimation of a threshold dose was very difficult. Development of a standardized protocol for clinical experiments to allow determination of the threshold dose is needed.     

Rhinitis as an independent risk factor for adult-onset asthma

BACKGROUND: For many years, the association between asthma and rhinitis has primarily been attributed to a common allergic background. Recently, it has been suggested that asthma and rhinitis are associated in the absence of atopy. The nature of this association is not well known. OBJECTIVE: The purpose of this study, which was performed in a large, longitudinal community population, was to determine the extent to which rhinitis is an independent risk factor for adult-onset asthma. METHODS: We carried out a nested case-control study from the longitudinal cohort of the Tucson Epidemiologic Study of Obstructive Lung Diseases. One hundred seventy-three incident patients with physician-confirmed asthma were compared with 2177 subjects who reported no asthma or shortness of breath with wheezing. Potential risk factors, including the presence of rhinitis, were assessed before the onset of asthma (patients) or before the last completed survey (control subjects). RESULTS: Rhinitis was a significant risk factor for asthma (crude odds ratio, 4.13; 95% confidence interval, 2.88-5.92). After adjustment for years of follow-up, age, sex, atopic status, smoking status, and presence of chronic obstructive pulmonary disease, the magnitude of the association was reduced but still highly significant (adjusted odds ratio, 3.21; 95% confidence interval, 2.19-4.71). After stratification, rhinitis increased the risk of development of asthma by about 3 times both among atopic and nonatopic patients and by more than 5 times among patients in the highest IgE tertile. Patients with rhinitis with persistent and severe nasal symptoms and a personal history of physician-confirmed sinusitis had an additional increased risk of asthma development. CONCLUSION: We conclude that rhinitis is a significant risk factor for adult-onset asthma in both atopic and nonatopic subjects. The nature of the association between rhinitis and asthma is open to interpretation.     

Culture of menstrual endometrium with peritoneal explants and mesothelial monolayers confirms attachment to intact mesothelial cells

BACKGROUND: To evaluate adhesion of menstrual endometrium (ME) to intact peritoneal mesothelium. METHODS: Explants of peritoneum were cultured for 1 h with ME (n = 6). Specimens were serially sectioned for haematoxylin and eosin stain and immunohistochemistry using an anti-cytokeratin antibody to label mesothelium. Confocal laser scanning microscopy (CLSM) was performed to identify an intact layer of mesothelial cells (MC) underlying sites of ME attachment. Also, ME and MC were labelled with Cell-Tracker dyes. ME was cultured with mesothelial monolayers for 1 h (n = 10). Cultures were examined with differential interference contrast and CLSM. Optical sections were taken and a three-dimensional model was constructed. RESULTS: In the peritoneal explants, ME adhered to intact mesothelium. There was no evidence of transmesothelial invasion. CLSM of sections of the explants demonstrated an intact monolayer of cytokeratin positive cells below the sites of ME implantation. Cytokeratin negative and positive ME cells adhered to mesothelial cells. Likewise, the ME attached to cultured mesothelium. Orthogonal sections and three-dimensional reconstruction confirmed an intact monolayer of mesothelium underlying ME attachment sites. CONCLUSIONS: This study confirms that ME adheres rapidly to intact peritoneal mesothelium. Further studies are needed that characterize the mechanisms of ME adhesion to, and migration through, mesothelial cells.     

Tetrasomy 12pter-12p13.31 in a girl with partial Pallister-Killian syndrome phenotype

A dysmorphic patient was shown to carry a small supernumerary marker chromosome. Multicolor, centromere-multicolor and regular FISH experiments proved the marker to be an analphoid 12pter derived isochromosome. Microdissection of the marker followed by reverse painting and array CGH analysis showed that the isochromosome contains approximately 6 Mb of 12pter-12p13.31 derived sequence. This is only the second report of a marker with a neocentromere 12pter and the molecular fine mapping of the duplicated region further refines the 12p region defining the Pallister-Killian syndrome phenotype. In addition, we show the feasibility of using microdissected chromosomes or chromosomal fragments to molecularly map the chromosomal breakpoints on array CGH. This technology may aid in the identification of chromosomal translocation breakpoints.     

Validation of a brief screening instrument for substance abuse and mental illness in HIV-positive patients

BACKGROUND: Substance abuse (SA) and mental illness (MI) commonly co-occur with HIV infection in the United States and have important implications for clinical management of HIV/AIDS. Yet SA/MI often go untreated due in part to a lack of practical, validated screening tools. SETTING: HIV clinic in academic medical center. METHODS: The 16-item SA/MI Symptoms Screener (SAMISS) targets SA/MI in HIV-positive patients. Consecutive consenting HIV-positive patients completed the SAMISS and then a reference standard diagnostic tool, SCID, the Structured Clinical Interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition). RESULTS: Twenty percent of participants (29/148) had an SA diagnosis and 41% (59/143) had an MI diagnosis in the past year on the SCID; 48% (68/143) had 1 or both. Thirty-seven percent (55/148) screened positive for SA and 69% (99/143) screened positive for MI on the SAMISS. The SAMISS had 86% (95% CI: 68%-96%) sensitivity and 75% (66%-82%) specificity for SA and 95% (86%-99%) sensitivity and 49% (38%-60%) specificity for MI. Patients with SA were likely to show up as false positives for MI and vice versa. CONCLUSION: The SAMISS functioned well as a first-line screening tool for SA/MI in this HIV clinic population. It missed few cases and was easily incorporated into a busy clinical setting. Persons screening positive require a more rigorous confirmatory psychiatric evaluation.