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David Diaz

Publications and source records attributed to David Diaz.

8 recordsLinked to original sources
PubMed2006

Accurate apoptosis measurement requires quantification of loss of expression of surface antigens and cell fragmentation.

BACKGROUND: The use of ratiometric cell enumeration methods emerges as a more accurate method of measurement of the occurrence of apoptosis in cell cultures. These new flow cytometry methods were used to quantify the impact of cell fragmentation and loss of lineage antigen (LAg) expression on measurement of apoptosis. METHODS: Highly purified human lymphocyte populations were negatively sorted and cultured for 24 h. Apoptotic cells were identified using annexin V, 7-amino-actinomycin D and their LAgs were stained with antibodies. A new indicator, the apoptotic rate, was used to determine apoptosis occurrence and its validity compared with the widely accepted percentage of apoptotic cells (apoptotic index, AI). RESULTS: Loss of LAg expression and cell fragmentation were observed under all conditions assayed and for all cell populations studied. CONCLUSIONS: Current methods for quantifying of apoptosis involving AI systematically underestimate apoptosis occurrence in all populations and conditions, especially among cells undergoing spontaneous apoptosis.

Antigens, Surface↗
PubMed2004

A nonincisional, Doppler-guided transvaginal approach to uterine artery identification and control of uterine perfusion.

STUDY OBJECTIVE: To determine the location and depth of uterine arteries from the vaginal fornix using a Doppler-guided nonincisional transvaginal approach. DESIGN: Observational study (Canadian Task Force classification II-3). SETTING: Two women's health and fertility centers. PATIENTS: One hundred nine healthy premenopausal women (age >18 yrs). INTERVENTION: Transvaginal uterine artery identification. MEASUREMENTS AND MAIN RESULTS: After uterine size and position were determined, with a standard bivalve speculum in place, uterine arteries were located bilaterally using the DWL Multi-Dop B+ system with 8-MHz probe (Sipplingen, Germany) in toggle mode. Continuous Doppler mode was used to locate uterine arteries, and pulsed Doppler to estimate depth of the arteries from the vaginal fornix. The average uterine size was less than 8 weeks, with the largest measuring 18 weeks' gestational size. The right uterine artery could be identified between 8 and 11 o'clock positions, and was most commonly found at the 9 o'clock position (average depth 9.30 mm, range 4-17 mm). The left uterine artery could be identified between 1 and 4 o'clock positions and was most commonly found at the 3 o'clock position (average depth 8.88 mm, range 4-15 mm). CONCLUSION: Due to ease of identification of uterine arteries transvaginally, despite differences in parity, uterine size, and position, access to and occlusion of uterine arteries with a Doppler-guided device might offer an alternative to invasive procedures intended to occlude uterine artery blood flow in women with symptomatic uterine leiomyomas.

Adult↗
PubMed2003

Assessment of chronic exposure to cigarette smoke and its change during pregnancy by segmental analysis of maternal hair nicotine.

This study aimed to investigate the association between biomarkers of fetal exposure to smoking during the whole pregnancy, nicotine in maternal and newborns hair samples, and quantitative measurement of smoking intake and exposure evaluated by maternal self-reported questionnaire. Study subjects were 150 mothers and their newborns from a hospital in Barcelona. A questionnaire including smoking habits was completed in the third trimester of pregnancy and on the day of delivery. Nicotine content was measured in two subsequent segments of maternal hair accounting for the first and last months of pregnancy, and in fetal hair. The geometric mean of nicotine concentration in maternal hair discriminated between nonexposition (3.84 and 2.80 ng/mg in distal and proximal hair segment, respectively) and exposition to cigarette smoke during pregnancy (6.06 and 4.30 ng/mg in distal and proximal hair segment, respectively) (P<0.05), and between these two classes and active smoking (14.40 and 11.08 ng/mg in distal and proximal hair segment, respectively). Maternal hair nicotine was able to differentiate levels of exposure to tobacco smoke and levels of intake. Nicotine concentration in hair from newborns did not differentiate between exposure and nonexposure to environmental tobacco smoke (ETS) in nonsmoking mothers. Finally, chronic exposure to cigarette smoke during pregnancy, assessed by maternal hair nicotine, correlated negatively with anthropometric parameters of newborns.

Adult↗
PubMed2002

Current practice of internal jugular venous cannulation in a university anesthesia department: influence of operator experience on success of cannulation and arterial injury.

OBJECTIVE: To describe current cannulation of the internal jugular vein (CIJV) practice in a university anesthesia department. DESIGN: Prospective, observational, and not randomized. SETTING: Operating rooms of the Hospital of the University of Pennsylvania. PARTICIPANTS: Elective surgical patients requiring CIJV (n = 426). INTERVENTIONS: CIJV performed by real-time ultrasound visualization (U-CIJV) or by anatomic landmarks (AL-CIJV). MEASUREMENTS AND MAIN RESULTS: A total of 462 procedures were studied in 426 patients. Overall cannulation failure was 2.1% with U-CIJV and 13.8% with AL-CIJV (p = 0.0001). Cumulative CIJV success by the sixth needle pass was 94.0%, regardless of technique. Junior operators performed 75.3% of CIJV, of which 86.8% was U-CIJV. First-pass success across operators was 60% to 70% for U-CIJV and 50% to 80% for AL-CIJV. Arterial puncture rates averaged 7.0%, regardless of technique (p = 0.45). The junior operator may be more at risk for arterial puncture during U-CIJV. CONCLUSION: U-CIJV offers incomplete protection against arterial injury in this practice compared with the literature. A possible solution is the ultrasound needle guide, which may minimize arterial injury, especially with junior operators.

Arteries↗