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PubMed2001

Real-time myocardial blood flow imaging in normal human beings with the use of myocardial contrast echocardiography.

Triggered myocardial contrast echocardiography (MCE) has been used successfully to quantify myocardial blood flow and assess coronary stenosis in animal models, but practical considerations have limited its broad clinical use. Real-time MCE may have practical advantages to assess perfusion and real time myocardial blood flow in human beings. We compared real-time MCE with triggered imaging in 23 normal human volunteers by using an investigational ultrasound contrast agent (DMP-115) and a commercially available ultrasound platform (Acuson Sequoia). Peak myocardial opacification (reflecting myocardial blood volume) after contrast infusion was quantified digitally in gray scale units (GU). In 13 subjects, myocardial blood flow reserve was assessed during dipyridamole infusion with the use of intermittent destruction-replenishment techniques. Real-time MCE resulted in a 30- to 45-GU increase from baseline compared with a 20- to 70-GU increase with triggered imaging. Real-time MCE showed no statistical difference in opacification (P = .131 by analysis of variance) among any of the myocardial regions of interest. Triggered imaging resulted in heterogeneous opacification among the regions of interest (P < .05 by analysis of variance). Dipyridamole did not significantly change peak myocardial opacification (myocardial blood volume) for either technique. Quantification of flow reserve revealed that myocardial blood flow reserve for the dipyridamole group was 3.6 +/- 0.4 (mean +/- 1 standard error of the mean). Real-time MCE is feasible in normal human volunteers and provides homogenous opacification of the myocardium. Furthermore, quantification of myocardial blood flow with real-time MCE in normal human beings produces results that are consistent with the known physiology of the coronary microcirculation.

Adult↗
PubMed2004

Atrial metastasis detected by two-dimensional echocardiography.

With recent improvements in therapeutic procedures and prolongation of survival, the incidence of cardiac metastasis is likely to increase. The aim of the current study was retrospectively to analyze cases of atrial metastases detected by echocardiography at our center. We report on a series of 10 patients with various solid malignancies and secondary atrial involvement detected by echocardiography. Transesophageal and transthoracic echocardiographic studies were performed using an Acuson 128XP, Aspen or Sequoia (Mountain View CA). Seven patients had cardiac symptoms at the time of diagnosis of atrial metastasis. After diagnosis, therapy included surgery, chemotherapy or radiotherapy. Echocardiography was also used in monitoring response to therapy. One patient with Wilms' tumor has remained free of disease for 50+ months and a patient with Kaposi's sarcoma is alive with disease 20+ months after diagnosis. The remaining eight patients died with disease 3-24 months after being diagnosed with atrial metastasis. Atrial metastases can be diagnosed in patients without cardiac symptoms, and is probably more prevalent than was previously recognized. Echocardiography is a useful diagnostic tool in detecting secondary atrial tumors.

Adult↗
PubMed2005

Coronary flow reserve in dipper and non-dipper hypertensive patients.

BACKGROUND: Failure to decrease blood pressure (BP) normally during night-time, which is called non-dipping, in hypertensive individuals is associated with higher cardiovascular morbidity and mortality. In addition, non-dipping BP leads to structural changes in the left ventricle; however, the effect of non-dipping BP on coronary flow reserve (CFR) has not been studied yet. METHODS: In this study, we measured CFR of 22 subjects with non-dipper hypertension, and 15 subjects with dipper hypertension using transthoracic second-harmonic Doppler echocardiography (Acuson Sequoia C256. None of the subjects had any systemic disease or coronary risk factor except hypertension. RESULTS: Age, gender, body mass index, lipids and echocardiographic findings including left ventricular mass index were similar between the groups. Office BP recordings were similar between non-dipper and dipper groups (147.9+/-6.1/93.9+/-4.3 vs 144.0+/-8.0/93.0+/-3.7). Daytime and 24-h ambulatory BP measurements were similar within the groups, but night-time BPs were significantly greater in non-dipper group than those were in dipper group. Left ventricular diastolic and systolic functions, and both baseline and hyperemic peak diastolic coronary velocity as well as CFR, were similar between the non-dipper and dipper groups (CFR: 2.47+/-0.59 vs 2.39+/-0.47). CONCLUSION: CFR were similar in patients with non-dipper and dipper hypertension in the absence of excessive left ventricular hypertrophy and other cardiovascular risk factors.

Adult↗
PubMed2005

Size and composition distribution of airborne particulate matter in northern California: I--particulate mass, carbon, and water-soluble ions.

The San Joaquin Valley (SJV) in California has one of the most severe particulate air quality problems in the United States during the winter season. In the current study, measurements of particulate matter (PM) smaller than 10 microm in aerodynamic diameter (PM10), fine particles (PM18), and ultrafine particles (PM0.1) made during the period December 16, 2000-February 3, 2001, at six locations near or within the SJV are discussed: Bodega Bay, Davis, Sacramento, Modesto, Bakersfield, and Sequoia National Park. Airborne PM1.8 concentrations at the most heavily polluted site (Bakersfield) increased from 20 to 172 microg/m3 during the period December 16, 2000-January 7, 2001. The majority of the fine particle mass was ammonium nitrate driven by an excess of gas-phase ammonia. Peak PM0.1 concentrations (8-12 hr average) were approximately 2.4 microg/m3 measured at night in Sacramento and Bakersfield. Ultrafine particle concentrations were distinctly diurnal, with daytime concentrations approximately 50% lower than nighttime concentrations. PMO.1 concentrations did not accumulate during the multiweek stagnation period; rather, PMO.1 mass decreased at Bakersfield as PM1.8 mass was increasing. The majority of the ultrafine particle mass was associated with carbonaceous material. The high concentrations of ultrafine particles in the SJV pose a potential serious public health threat that should be addressed.

Air Movements↗
PubMedDate not supplied

The Mt. Tyndall incident.

The authors describe the 53-hour rescue of a 6-foot, 1-inch tall, 250-pound hiker in the face of harsh environmental conditions in Sequoia National Park. This 43-year-old man fell 25 feet, injured his leg, and was noted to be hypothermic and hypovolemic. Weather, altitude, and the patient's size delayed and complicated his evacuation. After being carried down 1,500 vertical feet, he was hoisted into a hovering helicopter and flown to University Medical Center in Fresno, California. On arrival, the patient was determined to have a comminuted subtrochanteric right femur fracture, which was ultimately repaired surgically. The authors also discuss some of the unique aspects of wilderness and National Park Service EMS.

Accidental Falls↗
PubMed2004

Non-invasive imaging of coronary arteries in living mice using high-resolution echocardiography.

OBJECTIVE: In vivo mouse coronary artery circulation is still largely unknown. We demonstrate here in vivo coronary flow velocity profiles in anesthesized mice using a novel high-resolution ultrasound technique. METHODS: Seven 10-week-old C57/Bl6 mice were used for ultrasonographic examination under anesthesia. An Acuson Sequoia 512 echocardiograph with a Microson 15L8 transducer was used. Left coronary artery (LCA) anatomy was mapped in situ. RESULTS: The proximal, mid LCA and its anterior (A-LCA) and lateral (L-LCA) branches could be visualized and coronary flow velocity was reproducibly recorded in all animals. Peak flow velocity was 31.3 +/- 1.5 and 20.7 +/- 2.3 cm/s in the mid LCA and L-LCA branches, respectively. Mean flow velocity was 18.4 +/- 0.7 and 13.8 +/- 1.5 cm/s in the respective vessels. Both the peak and mean flow velocities were higher in the mid LCA than in the distal part of the L-LCA (p = 0.006 and 0.01, respectively). Measurements of the velocity time integral show percentage systolic flow was 15.7 +/- 1.6% and 10.2 +/- 1.4% in the mid LCA and L-LCA, respectively. CONCLUSION: Despite the extremely high heart rate in mice, there are striking similarities between murine and human coronary flow velocity profiles. The presented technique and findings confirm the relevance of the mouse as an animal model in cardiovascular research.

Animals↗
PubMed2006

Cryotherapy for renal-cell cancer: diagnosis, treatment, and contrast-enhanced ultrasonography for follow-up.

Cryotherapy is a curative treatment option for patients with small (<4 cm) renal-cell cancers. For the followup of ablated lesions, imaging is the only available method, but the best tool has not yet been determined. The method selected should be able to determine the presence or absence of perfusion in the area and measure the lesion. Usually, contrast-enhanced CT or MRI is used. The accompanying video shows cryotherapy treatment along with contrast-enhanced ultrasound investigations before and afterward. We used a Siemens Acuson Sequoia device with contrast pulse sequence imaging and Sonovue (Bracco) as the contrast agent. The lesion could be identified and measured easily. Because this method enables selective detection of contrast, the presence and absence of perfusion can be determined objectively.

Carcinoma, Renal Cell↗
PubMed1999

Colour Doppler indices of follicular blood flow as predictors of pregnancy after in-vitro fertilization and embryo transfer.

Peak systolic velocity (PSV) of individual follicles has been correlated with oocyte recovery, fertilization rate and embryo quality [in women undergoing in-vitro fertilization (IVF) and embryo transfer]. The present study assessed the role of quantitative and qualitative indices of follicular vascularity in predicting pregnancy after IVF and embryo transfer. A total of 106 women undergoing IVF treatment for infertility who were considered to be at risk of failure (>37 years of age, history of low response to gonadotrophin stimulation, or multiple failed IVF cycles) constituted the study group. PSV was measured from the three largest follicles on both the right and left ovaries on the day of human chorionic gonadotrophin (HCG) administration using an Acuson Sequoia with a 4-8 MHz transvaginal probe. The quality of follicular flow was graded from 1 to 4 according to the amount of visible colour flow around the follicle (grade 1 when one-quarter of the follicle, grade 2 when one-half, grade 3 when three-quarters, and grade 4 when the entire follicle was surrounded by colour). Clinical pregnancies resulted in 11 (10%) of the 106 high-risk women. Women who had PSV >/= 10 cm/s in at least one follicle on the day of HCG administration more often became pregnant than those with PSV <10 cm/s (P = 0.05). All pregnancies occurred in women with grade 3 or 4 follicular blood flow. Qualitative as well as quantitative measurements of follicular flow predict pregnancy after IVF and embryo transfer.

Adult↗
PubMed2001

The evolution of Ty1-copia group retrotransposons in gymnosperms.

A diverse collection of Ty1-copia group retrotransposons has been characterized from the genome of Picea abies (Norway spruce) by degenerate PCR amplification of a region of the reverse transcriptase gene. The occurrence of these retrotransposable elements in the gymnosperms was investigated by Southern blot hybridization analysis. The distribution of the different retrotransposons across the gymnosperms varies greatly. All of the retrotransposon clones isolated are highly conserved within the Picea (spruce) genus, many are also present in Pinus (pine) and/or Abies (fir) genera, and some share strongly homologous sequences with one or more of cedar, larch, Sequoia, cypress, and Ginkgo. Further subclones of one of the most strongly conserved retrotransposon sequences, Tpa28, were obtained from Ginkgo and P. abies. Comparisons of individual sequence pairs between the two species show nucleotide cross-homologies of around 80%-85%, corresponding to nucleotide substitution rates similar to those of nuclear protein-coding genes. Analysis of Tpa28 consensus sequences reveals that strong purifying selection has acted on this retrotransposon in the lineages connecting Ginkgo and Picea. Collectively, these data suggest, first, that the evolution of the Ty1-copia retrotransposon group in the gymnosperms is dominated by germ line vertical transmission, with strong selection for reverse transcriptase sequence, and, second, that extinction of individual retrotransposon types has been comparatively rare in gymnosperm species lineages compared with angiosperms. If this very high level of sequence conservation is a general property of the retrotransposons, then their extreme sequence diversity implies that they are extremely ancient, and the major element lineages seen today may have arisen early in eukaryote evolution. The data are also consistent with horizontal transmission of particular retrotransposons between species, but such a mechanism is unnecessary to explain the results.

Amino Acid Sequence↗
PubMed1993

Effects of thermal wounding, shading and exogenous auxin on some sprouting responses of coast redwood seedlings.

The effects of wounding, shading, and indole-3-acetic acid (IAA) on sprouting responses were examined in coast redwood (Sequoia sempervirens D. Don (Endl)) seedlings. In August, two-year-old seedlings were given one of three thermal wounding treatments made with a blowtorch at the stem base. After 8 months, the heat-wounded seedlings were decapitated above the burl and IAA (0.00% to 1.00% by weight in lanolin) was applied to the cut surface every week for 8 weeks. Throughout the 8-week hormone treatment, the decapitated seedlings were subjected to one of three shading treatments (no shade, 70% shading and complete darkness). At the beginning of June, sprouts were harvested from each stump and measurements made of the length of the tallest sprout, number of sprouts, dry weight of all sprouts, and mean dry weight per sprout. All sprouting parameters showed negative responses to IAA. Shading decreased sprout number and sprout dry weight. Wounding increased maximum sprout length and dry weight per sprout but decreased the number of sprouts. Only the 2-way interaction between IAA and wounding was not significant for any of the responses.

Journal Article↗
PubMed2003

Variation in morphological and biochemical O3 injury attributes of mature Jeffrey pine within canopies and between microsites.

Crown morphology and leaf tissue chemical and biochemical attributes associated with ozone (O3) injury were assessed in the lower, mid- and upper canopy of Jeffrey pine (Pinus jeffreyi Grev. & Balf.) growing in mesic and xeric microsites in Sequoia National Park, California. Microsites were designated mesic or xeric based on topography and bole growth in response to years of above-average precipitation. In mesic microsites, canopy response to O3 was characterized by thinner branches, earlier needle fall, less chlorotic leaf mottling, and lower foliar antioxidant capacity, especially of the aqueous fraction. In xeric microsites, canopy response to O3 was characterized by higher chlorotic leaf mottling, shorter needles, lower needle chlorophyll concentration, and greater foliar antioxidant capacity. Increased leaf chlorotic mottle in xeric microsites was related to drought stress and increased concurrent internal production of highly reactive oxygen species, and not necessarily to stomatal O3 uptake. Within-canopy position also influenced the expression of O3 injury in Jeffrey pine.

Ozone↗
PubMed2001

Passive sampler for measurements of atmospheric nitric acid vapor (HNO3) concentrations.

Nitric acid (HNO3) vapor is an important nitrogenous air pollutant responsible for increasing saturation of forests with nitrogen and direct injury to plants. The USDA Forest Service and University of California researchers have developed a simple and inexpensive passive sampler for monitoring air concentrations of HNO3. Nitric acid is selectively absorbed on 47-mm Nylasorb nylon filters with no interference from particulate NO3-. Concentrations determined with the passive samplers closely corresponded with those measured with the co-located honeycomb annular denuder systems. The PVC protective caps of standardized dimensions protect nylon filters from rain and wind and allow for reliable measurements of ambient HNO3 concentrations. The described samplers have been successfully used in Sequoia National Park, the San Bernardino Mountains, and on Mammoth Mountain in California.

Air Pollution↗
PubMed2001

Spatial distribution of tropospheric ozone in national parks of California: interpretation of passive-sampler data.

The National Park Service (NPS) has tested and used passive ozone samplers for several years to get baseline values for parks and to determine the spatial variability within parks. Experience has shown that the Ogawa passive samplers can provide +/-10% accuracy when used with a quality assurance program consisting of blanks, duplicates, collocated instrumentation, and a standard operating procedure that carefully guides site operators. Although the passive device does not meet EPA criteria as a certified method (mainly, that hourly values be measured), it does provide seasonal summed values of ozone. The seasonal ozone concentrations from the passive devices can be compared to other monitoring to determine baseline values, trends, and spatial variations. This point is illustrated with some kriged interpolation maps of ozone statistics. Passive ozone samplers were used to get elevational gradients and spatial distributions of ozone within a park. This was done in varying degrees at Mount Rainier, Olympic, Sequoia-Kings Canyon, Yosemite, Joshua Tree, Rocky Mountain, and Great Smoky Mountains national parks. The ozone has been found to vary by factors of 2 and 3 within a park when average ozone is compared between locations. Specific examples of the spatial distributions of ozone in three parks within California are given using interpolation maps. Positive aspects and limitations of the passive sampling approach are presented.

Air Pollution↗
PubMed2003

The penalty of a long, hot summer. Photosynthetic acclimation to high CO2 and continuous light in "living fossil" conifers.

Deciduous forests covered the ice-free polar regions 280 to 40 million years ago under warm "greenhouse" climates and high atmospheric pCO2. Their deciduous habit is frequently interpreted as an adaptation for minimizing carbon losses during winter, but experiments with "living fossils" in a simulated warm polar environment refute this explanation. Measured carbon losses through leaf abscission of deciduous trees are significantly greater than losses through winter respiration in evergreens, yet annual rates of primary productivity are similar in all species. Here, we investigate mechanisms underlying this apparent paradox by measuring the seasonal patterns of leaf photosynthesis (A) under pCO2 enrichment in the same trees. During spring, A increased significantly in coastal redwood (Sequoia sempervirens), dawn redwood (Metasequoia glyptostroboides), and swamp cypress (Taxodium distichum) at an elevated pCO2 of 80 Pa compared with controls at 40 Pa. However, strong acclimation in Rubisco carboxylation capacity (Vc,max) completely offset the CO2 response of A in all species by the end of 6 weeks of continuous illumination in the simulated polar summer. Further measurements demonstrated the temporary nature of acclimation, with increases in Vc,max during autumn restoring the CO2 sensitivity of A. Contrary to expectations, the acclimation of Vc,max was not always accompanied by accumulation of leaf carbohydrates, but was associated with a decline in leaf nitrogen in summer, suggesting an alteration of the balance in plant sources and sinks for carbon and nitrogen. Preliminary calculations using A indicated that winter carbon losses through deciduous leaf abscission and respiration were recovered by 10 to 25 d of canopy carbon fixation during summer, thereby explaining the productivity paradox.

Acclimatization↗
PubMed2005

Hand-held miniaturized cardiac ultrasound instruments for rapid and effective bedside diagnosis and patient screening.

RATIONALE, AIMS AND OBJECTIVES: Technological progress in recent years has made it possible that ultrasound industry can now offer affordable, portable and battery-operated ultrasound systems the size of a laptop computer. The purpose of this study was to compare these hand-carried ultrasound instruments with standard echocardiography in order to investigate the facility of a rapid bedside diagnosis in patients with suspected or known cardiovascular disease. METHODS: Fifty consecutive patients were studied with miniaturized ultrasound equipment (SonoHeart) and a conventional scanner (Acuson Sequoia) in a blinded manner. All studies were performed by three board-certified cardiologists skilled and experienced in echocardiographic practice. Investigators were not aware of any previous medical reports. RESULTS: With the new system, adequate images could be obtained in all patients. Left ventricular and left atrial diameters measured with the hand-held system correlated well with those obtained with conventional scanning: r = 0.87, mean difference 3.12 +/- 2.7 mm and r = 0.84, mean difference 2.8 + 2.4 mm, respectively. The presence of left ventricular dysfunction, regional wall motion abnormalities, relevant valvular regurgitation (moderate or more) or valve stenosis was correctly diagnosed in all patients. However, there was a tendency towards underestimating the extent of wall motion abnormalities particularly in patients difficult to image. Discrepancies also frequently occurred in patients with trivial or mild regurgitation, where false-positive and false-negative findings were described. CONCLUSION: Currently available hand-held echocardiography systems can facilitate rapid bedside diagnosis and patient screening. However, this recent development in echocardiography also raises a number of questions and its actual impact on general clinical practice still remains to be evaluated.

Cardiovascular Diseases↗
PubMed1992

Skin tests of pollen grains of taxodiaceae and cupressaceae in children with bronchial asthma.

Atmospheric cedar pollen in the southern region of Okayama Prefecture (situated in south-western Japan) has been counted since 1988. Pollen of different species of the Taxodiaceae family (Cryptomeria japonica, Sequoia sempervirens and Metasequoia glyptostroboides) and Japanese juniper (Juniperus rigida) in the Cupressaceae family, which are propagated mainly in the southern region of Okayama Prefecture, were found among the atmospheric pollen. Scratch tests using the pollen extract from Taxodiaceae and Cupressaceae were performed on children with bronchial asthma. Forty (25%) and 30 (18.8%) of the 160 patients reacted positively to an allergen extract from the pollen grains of Japanese cedar (Cryptomeria japonica) and Japanese juniper, respectively.

Adolescent↗
PubMed2006

Three-dimensional ultrasonography of the urinary bladder: preliminary experience of assessment in patients with haematuria.

OBJECTIVE: To assess the value of three-dimensional (3D) vs two-dimensional (2D) ultrasonography (US) in the diagnostic evaluation of the urinary bladder in patients with haematuria. PATIENTS AND METHODS: In all, 42 patients with painless haematuria and/or irritative voiding symptoms were examined with 2D- and 3D-US. US was done with an Acuson Sequoia unit (Siemens Medical Sol. Mountain View, CA, USA) and the Perspective(R) 3D technique, to assess the presence of bladder lesions, including bladder cancer, bladder wall hypertrophy with trabeculation and diverticula, mucosal bladder folds or re-growth of the prostate mimicking a bladder tumour. The imaging findings were compared with cystoscopy and/or bladder biopsy. RESULTS: In 21 of the 42 patients (50%) cystoscopy with bladder biopsy revealed bladder cancer. Overall, 3D-US gave a correct diagnosis for 36 of 42 patients (86%). All 21 bladder cancers were correctly diagnosed, and 15 (71%) of the 21 benign bladder lesions were correctly identified. By contrast, 2D-US findings gave suspected bladder cancer in all patients. CONCLUSIONS: 3D-US is significantly more accurate than standard 2D-US in the diagnostic evaluation of patients with haematuria. Thus, this diagnostic technique might be useful for routine evaluation of the urinary bladder.

Aged↗
PubMed1999

Transvascular Imaging: Feasibility Study Using a Vector Phased Array Ultrasound Catheter.

BACKGROUND: Transvascular imaging is defined as the acquisition of anatomic and functional information of structures lying beyond the confines of a vascular conduit within which the imaging device resides. Interrogating structures surrounding the vascular conduit is the subject of this feasibility study using a novel underblood, phased array ultrasound-tipped catheter. METHODS: An intravascular catheter (10-F, 3.2-mm-diameter, four-way articulation) tipped with a 5.5- to 10-MHz frequency agile, vector phased array transducer with full Doppler capability (Sequoia, Acuson) was used. The imaging transducer has a wide range of tissue penetration (2 mm to >10 cm from the lens). The catheter was introduced via an 11-Fr femoral venous sheath into the inferior and superior vena cavae and right heart chambers. As the catheter was advanced, attention was directed to visualization of structures surrounding the vessel in which the catheter resided. RESULTS: From the cavae and femoral vein the thoracic, abdominal and femoral arteries could be easily imaged. Anatomy that was visualized included the liver, hepatic veins, gallbladder, and mesenteric vessels. Normal and pathological anatomy and Doppler physiology could be readily appreciated. Doppler (i.e., pulsed- and continuous-wave, color flow, and tissue Doppler) fostered unique transvascular physiological hemodynamic and flow assessment. CONCLUSION: Transvascular imaging is feasible in human subjects using this 10-Fr catheter tipped with a 5.5- to 10-MHz vector phased array transducer. Intravascular navigation to a desired location within the body and the performance of diagnostic or therapeutic procedures at a remote site under direct ultrasound visualization are possible. Full Doppler capability extends the concept of transvascular hemodynamic and physiological assessment.

Journal Article↗