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PubMed1993

The effects of ultraviolet-B radiation on photosynthesis of different aged needles in field-grown loblolly pine.

We examined the effect of supplemental UV-B radiation (290-320 nm) on photosynthetic characteristics of different aged needles of 3-year-old, field-grown loblolly pine (Pinus taeda L.). Needles in four age classes were examined: I, most recently fully expanded, year 3; II, first flush, year 3; III, final flush, year 2; and IV, oldest needles still present, year 2. Enhanced UV-B radiation caused a statistically significant decrease (6%) in the ratio of variable to maximum fluorescence (F(v)/F(m)) following dark adaptation only in needles from the youngest age class, suggesting transient damage to photosynthesis. However, no effects of enhanced UV-B radiation on other instantaneous measures of photosynthesis, including maximum photosynthesis, apparent quantum yield and dark respiration, were seen for needles of any age. Foliar nitrogen concentration was unaffected by UV-B treatment. However, the (13)C/(12)C carbon isotope ratios (delta(13)C-a time integrated measure of photosynthetic function) of needles in age classes II and IV were 3% (P < 0.01) and 2% (P < 0.05) more negative, respectively, in treated plants than in control plants. Exposure to enhanced UV-B radiation caused a 20% decrease in total biomass and a 4% (P < 0.05), 25% (P < 0.01), and 9% (P < 0.01) decrease in needle length of needles in age classes I, II, and IV, respectively. The observed decreases in delta(13)C, and F(v)/F(m) of the needles in the youngest needle age class suggest subtle damage to photosynthesis, although overall growth reductions were probably a result of decreased total leaf surface rather than decreased photosynthetic capacity. Needles of age class IV had lower light- and CO(2)-saturated maximum photosynthetic rates (39%), lower dark respiration (34%), lower light saturation points (37%), lower foliar nitrogen concentration (28%), and lower delta(13)C (14%) values than needles of age class I. Apparent quantum yield and F(v)/F(m) did not change with needle age. The observed changes in photosynthesis and foliage chemical composition with needle age are consistent with previous studies of coniferous trees and may represent adaptations of older needles to shaded conditions within the canopy.

Journal Article↗
PubMed2006

Below-ground interactions with arbuscular mycorrhizal shrubs decrease the performance of pinyon pine and the abundance of its ectomycorrhizas.

Few studies have examined how below-ground interactions among plants affect the abundance and community composition of symbiotic mycorrhizal fungi. Here, we combined observations during drought with a removal experiment to examine the effects of below-ground interactions with arbuscular mycorrhizal (AM) shrubs on the growth of pinyon pines (Pinus edulis), and the abundance and community composition of their ectomycorrhizal (EM) fungi. Shrub density was negatively correlated with pinyon above- and below-ground growth and explained 75% of the variation in EM colonization. Consistent with competitive release, pinyon fine-root biomass, shoot length and needle length increased with shrub removal. EM colonization also doubled following shrub removal. EM communities did not respond to shrub removal, perhaps because of their strikingly low diversity. These results suggest that below-ground competition with AM shrubs negatively impacted both pinyons and EM fungi. Similar competitive effects may be observed in other ecosystems given that drought frequency and severity are predicted to increase for many land interiors.

Ecosystem↗
PubMed2002

Needle core length in sextant biopsy influences prostate cancer detection rate.

OBJECTIVES: Prostate cancer detection in biopsies increases with the number of sites and total tissue sampled. Its dependence on needle core fragment length is uncertain. METHODS: We surveyed two consecutive series of sextant needle biopsies from two practices in 1998 to 2000: 251 patients from Pennsylvania (group P) and 1596 from Virginia (group V). We tabulated the gross needle core lengths per sextant site and classified the diagnoses as benign or into four nonbenign categories: high-grade prostatic intraepithelial neoplasia; atypical small acinar proliferation, suspicious; atypical small acinar proliferation, suspicious plus high-grade prostatic intraepithelial neoplasia; and cancer. Logistic regression analysis was used to correlate cancer or a nonbenign diagnosis with the total length (sum of six sites) and, after excluding the sites with more than one core, with the length per single core, and the anatomic site of origin (apex, mid-gland, base). RESULTS: The mean total tissue length sampled was 108 +/- 27 mm (range 30 to 275) in group P and 81 +/- 22 mm (range 30 to 228) in group V. Sextant sites with a single core contained a mean of 12.8 +/- 3.5 mm tissue, with a 3.6-fold variation among the middle 95%. Group V core lengths at the apex averaged 11.8 mm, shorter (P = 0.0001) than mid (13.3 mm) or base (12.7 mm). A predictive value of longer length for a nonbenign diagnosis was noted in four of six sextants (P <0.04), with trend strongest at the apex, for which detection was influenced by abnormal digital rectal examination (P = 0.02) or ultrasound (P = 0.04) findings. CONCLUSIONS: The length of single cores sampled by sextant biopsy can vary more than 3.6-fold and represents a quality assurance consideration. The effect of length on cancer or nonbenign detection was maximal at the prostatic apex where the cores were shortest.

Biopsy, Needle↗
PubMed1994

Maturation in Douglas-fir: I. Changes in stem, branch and foliage characteristics associated with ontogenetic aging.

Two experiments were conducted to characterize changes associated with ontogenetic aging in coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and to identify possible maturation "markers" for this species. In the first experiment (Experiment 1), scions of ages 1, 4 and 9 years were collected from four seed zones in field progeny tests and grafted onto 1-year-old rootstocks. In Experiment 2, scions from five full-sib families of ages 1 and 10 years were collected from one progeny test and similarly grafted. Grafts for both experiments were planted in the field in a completely randomized design. The grafts were measured after two and six growing seasons. In Experiment 1, graft diameter, number of terminal bud flushes per year, number of branches, and branch length decreased with age. Plagiotropic angle and needle weight increased. All variables except needle length had a significant age x seed zone interaction. After 6 years, internodal stem diameters, numbers of nodal and internodal branches, and length and diameter of internodal branches decreased with age, and there were age x seed zone interactions with most variables. In Experiment 2, graft height and diameter, number of flushes, number and size of lateral branches, needle length and weight decreased with age. After 6 years, height and diameter, size and number of nodal and internodal branches, and leaf chlorophyll concentration (measured in April) decreased, but there were relatively few age x family interactions. An analysis based on traits that were significantly affected by age, but that did not interact with seed zone or family, indicated that main stem diameter, nodal branch length and nodal branch diameter were the most consistent and reliable maturation markers.

Journal Article↗
PubMed1993

Percutaneous CT biopsy of chest lesions: an in vitro analysis of the effect of partial volume averaging on needle positioning.

OBJECTIVE: Accurate needle biopsy of chest lesions requires knowledge of both the direction of the needle and the exact location of the tip of the needle. The purpose of this study was to analyze and illustrate the relationships between the location of the nodule, the size of the nodule, the CT slice thickness, and the needle length. An understanding of these relationships should minimize localization errors due to partial volume averaging and thus increase the accuracy of biopsies. MATERIALS AND METHODS: Geometric principles were used to determine mathematical relationships between the size of the nodule, the CT slice thickness, the length of the needle, and the direction of the needle. A styrofoam model simulating the patient and the lesion to be sampled was developed so that radiographs and CT scans of the model could be obtained with different needle placements to illustrate the phenomenon of partial volume averaging. RESULTS: The accuracy of the CT-guided biopsy can be increased by reducing the CT slice thickness, using longer needles, minimizing the distance to be traversed within the patient, and maximizing the portion of the lesion contained in the CT section used for needle tip localization. Mathematical equations developed from the in vitro model can be used to select the most appropriate CT section and the best length and angle of the needle. CT scans of the model illustrate the use of these equations. CONCLUSION: We found these principles helpful in improving the accuracy of CT needle biopsies, particularly when the lesions are very small and when an angled approach is required. Ideally, the smallest possible CT slice thickness and the longest possible needles should be used, but some practical limitations exist.

Biopsy, Needle↗
PubMedDate not supplied

Seasonal development of leaf area in a young, widely spaced Pinus radiata D. Don stand.

Measurements of needle elongation and needle death were made at two-week intervals during a year on 250 branch units spread throughout the crowns of six trees (three high-pruned, three low-pruned) in a widely spaced, 6- to 7-year-old Pinus radiata D. Don plantation in New Zealand. The trees were well supplied with nutrients and water. During the year, mean tree height increased by 1.2 m and the cross-sectional area of stem below the green crown (used to predict leaf area) for the average tree increased from 8.7 x 10(3) to 13.9 x 10(3) mm(2). The increase in stem cross-sectional area occurred throughout the year except for two months in early winter (May and June). Elongation of Age 0 needles began in Spring (October), continued through summer, and the mean date for 95% completion of elongation was in autumn (early May), approximately 200 days after elongation began. Mean maximum needle length in the canopy decreased with increasing branch order and was 136 and 94 mm for Order 1 and Order 3 units, respectively. Needle elongation was related to thermal time, using growing degree days with a base temperature of 6 degrees C. The mean maximum rate of needle elongation in the canopy was 0.11 m ( degrees C day)(-1) and this occurred in early summer (mid-December), 47 days after elogation started. Maximum needle length and the rate of elongation increased, and the time taken to reach 95% elongation decreased with increasing height in the canopy. A smaller autumn flush of needles started in summer (January) and the needles elongated linearly at a mean rate of 0.07 mm ( degrees C day)(-1) until the end of the growing season when temperatures fell below the base value. At the end of the year, the mean length of needles from the autumn flush was 66 mm. The density of needles did not change with height in the canopy and there were no significant changes seasonally. The mean density values for Age 1 and Age 0 needles were 336 and 286 kg m(-3), respectively. Dry weight per unit length did not change seasonally for Age 1 needles, but the mean values for Order 1 and Order 2 needles were 0.32 and 0.23 mg mm(-1), respectively. Dry weight per unit length for Age 0 needles increased during the growing season (October to February). This was particularly apparent for Order 1 needles where the mean value increased from 0.12 to 0.25 mg mm(-1). Death of Age 1 needles started in midsummer (mean date was January 24) which coincided with the time of maximum elongation of Age 0 needles, but there were differences in timing among individual trees. The mean rate of death was 1.7% day(-1) and the mean duration was 59 days. Leaf area index for the stand increased from 3.2 to 5.3 (all-surfaces basis) during the year. At the end, 92% of the leaf area had grown during the year and 60% of it was on Order 2 branch units. The models for needle elongation and needle death were used to scale up to seasonal changes in canopy leaf area index. Leaf area index peaked with increasing Age 0 leaf area to 6.1 in summer (January), fell to 4.7 in March as Age 1 needles died, then increased slightly again. The seasonal dynamics are consistent with the hypothesis of Cannell (1989) that the timing of maximum leaf area index within a year is optimal for maximizing biomass production.

Journal Article↗
PubMed2003

Automatic needle segmentation in three-dimensional ultrasound images using two orthogonal two-dimensional image projections.

In this paper, we describe an algorithm to segment a needle from a three-dimensional (3D) ultrasound image by using two orthogonal two-dimensional (2D) image projections. Not only is the needle more conspicuous in a projected (volume-rendered) image, but its direction in 3D lies in the plane defined by the projection direction and the needle direction in the projected 2D image. Hence, using two such projections, the 3D vector describing the needle direction lies along the intersection of the two corresponding planes. Thus, the task of 3D needle segmentation is reduced to two 2D needle segmentations. For improved accuracy and robustness, we use orthogonal projection directions (both orthogonal to a given a priori estimate of the needle direction), and use volume cropping and Gaussian transfer functions to remove complex background from the 2D projection images. To evaluate our algorithm, we tested it with 3D ultrasound images of agar and turkey breast phantoms. Using a 500 MHz personal computer equipped with a commercial volume-rendering card, we found that our 3D needle segmentation algorithm performed in near real time (about 10 fps) with a root-mean-square accuracy in needle length and endpoint coordinates of better than 0.8 mm, and about 0.5 mm on average, for needles lengths in the 3D image from 4.0 mm to 36.7 mm.

Algorithms↗
PubMed2004

A multicenter, open-label, randomized, two-period crossover trial comparing glycemic control, satisfaction, and preference achieved with a 31 gauge x 6 mm needle versus a 29 gauge x 12.7 mm needle in obese patients with diabetes mellitus.

BACKGROUND: Optimal needle length for subcutaneous insulin injection may differ for obese and nonobese patients, which could affect management of diabetes mellitus (DM). OBJECTIVE: The aim of this study was to determine whether 31 gauge (G) x 6 mm (shorter) needles are appropriate alternatives to 29 G x 12.7 mm (longer) needles in obese patients with DM. METHODS: A multicenter, open-label, randomized, 2-period crossover trial was conducted in insulin-treated patients with type 1 or 2 DM with body mass index >or=30 kg/m(2) and glycosylated hemoglobin A(1c) (HbA(1c)) concentration <or=10%. All patients used the same injection device and were randomized to receive 12 weeks of therapy with 1 injection site (thigh or abdomen) and 1 of the 2 needle lengths. Patients used the same injection site but the alternate needle during the second 12-week period. RESULTS: Sixty-two patients (31 men, 31 women; mean [SD] age, 50.5 [10.6] years; age range, 20-73 years) received treatment. Fifty-six patients completed all 24 weeks of treatment. No differences in glycemic control were found. Double-blind assessments of pain scores and leakage measurements, and results from the World Health Organization Diabetes Treatment Satisfaction Questionnaire and most sections of the Insulin Treatment Satisfaction Questionnaire (ITSQ), indicated no differences. However, patients indicated greater satisfaction with the shorter needle on the ITSQ (P < 0.001). The most common adverse event was injection-site bruising (51% [30/59] for the longer needle vs 34% [21/61] for the shorter needle; P = NS). Eighty-nine percent of patients (49/55) preferred the shorter needle (P < 0.001), and 76% (42/55) had a strong, very strong, or extremely strong preference for it. CONCLUSIONS: In obese patients, use of 31 G x 6 mm and 29 G x 12.7 mm needles produced comparable HbA(1c) values, double-blind pain and leakage scores, convenience, and ease of use. However, patients preferred the shorter needle.

Adult↗
PubMed1995

Transvaginal ovum pick-up (OPU) in the cow: a new disposable needle guidance system.

A study was conducted to modify the routinely used ovum pick up (OPU) devices to permit use of disposable needles and to simplify the technique and to make it more economical and practical to use. Long nondisposable needles are commonly used in transvaginal OPU despite several disadvantages. A new OPU device was developed using 19-g disposable needles to eliminate these disadvantages and to make the technique more successful. The disposable needle was connected to silicone tubing by means of a stainless steel connector. The system was inserted into a stainless steel tube, creating a rigid structure within which to move the needle back and forth. A blunt needle can be changed simply by replacing it with a new one, even while the device is in the vagina of a cow. The needle guidance system is incorporated into a new OPU device together with the transducer of an ultrasonographic scanner with an unilateral orientated scanning field, making it possible to utilize the needle length to its maximum. This combination permits easy manipulation of the ovaries, easy positioning of follicles on the puncture line, and enables the use of shorter needles which directly enter the scanned area without loss of useful needle length. As a preliminary result we obtained an overall oocyte recovery rate of 42%. Although this is promising, additional puncture sessions are needed to establish more consistent recovery rates. When OPU is used routinely, application of short disposable needles is more practical and economical.

Journal Article↗
PubMed2006

The role of genetic and chemical variation of Pinus sylvestris seedlings in influencing slug herbivory.

This study investigated the genetic and chemical basis of resistance of Pinus sylvestris seedlings to herbivory by a generalist mollusc, Arion ater. Using feeding trials with captive animals, we examined selective herbivory by A. ater of young P. sylvestris seedlings of different genotypes and correlated preferences with seedling monoterpene levels. We also investigated the feeding responses of A. ater to artificial diets laced with two monoterpenes, Delta(3)-carene and alpha-pinene. Logistic regression indicated that two factors were the best predictors of whether seedlings in the trial would be consumed. Individual slug variation (replicates) was the most significant factor in the model; however, alpha-pinene concentration (also representing beta-pinene, Delta(3)-carene and total monoterpenes due to multicollinearity) of needles was also a significant factor. While A. ater did not select seedlings on the basis of family, seedlings not eaten were significantly higher in levels of alpha-pinene compared to seedlings that were consumed. We also demonstrated significant genetic variation in alpha-pinene concentration of seedlings between different families of P. sylvestris. Nitrogen and three morphological seedling characteristics (stem length, needle length and stem diameter) also showed significant genetic variation between P. sylvestris families. Artificial diets laced with high (5 mg g(-1) dry matter) quantities of either Delta(3)-carene or alpha-pinene, were eaten significantly less than control diets with no added monoterpenes, supporting the results of the seedling feeding trial. This study demonstrates that A. ater selectively feed on P. sylvestris seedlings and that this selection is based, in part, on the monoterpene concentration of seedlings. These results, coupled with significant genetic variation in alpha-pinene concentration of seedlings and evidence that slug herbivory is detrimental to P. sylvestris fitness, are discussed as possible evidence for A. ater as a selective force on the evolution of defensive chemistry in P. sylvestris.

Animals↗
PubMed2001

[The techniques to identify the epidural space do not influence the success rate in combined spinal-epidural anesthesia: a comparison between loss-of-resistance and hanging-drop].

The hanging-drop (HD) technique has been attributed to a negative epidural pressure induced by making a tent of the dura by the Tuohy needle. We, therefore, hypothesized that the HD technique would result in more successful intrathecal placement of the spinal needle in combined spinal-epidural anesthesia (CSEA) compared with the loss-of-resistance (LR). Seventy patients received CSEA using the needle-through-needle method with a spinal needle extending 9 mm beyond the Tuohy needle. Success rate in obtaining cerebrospinal fluid (CSF) at the first attempt was considerably low; 60% in HD and 57% in LR, which was not significantly different. Failure to obtain CSF after 3 attempts was not significantly different between the two techniques; 26% and 31% in HD and LR, respectively. In conclusion, there was no advantage of the HD technique for obtaining CSF in CESA compared with the LR. It seems that spinal needle length beyond the Tuohy needle should be more than 9 mm.

Adult↗
PubMed2001

An in-vitro study to understand successful free-hand ultrasound guided intervention.

AIMS: To describe the optimum conditions for successful free-hand ultrasound guided intervention using an in-vitro experiment. MATERIALS AND METHODS: Optimal free-hand biopsy conditions were determined using targets buried in a purpose-built interventional phantom. The needle/probe distance and probe/phantom surface angle were changed whilst recording the needle track lengths and needle conspicuity. RESULTS: Optimal free-hand conditions included a needle/probe distance of 2-3 cm in combination with a needle/probe angle 55-60 degrees. This enabled excellent needle conspicuity with short needle track length and early needle tip visualization. CONCLUSION: Understanding how to optimize the free-hand conditions will help the interventionalist to obtain greater performance using a variety of puncture devices. This concept is likely to be particularly important to the novice interventionalist as well as to those teaching the free-hand technique.

Biopsy, Needle↗
PubMed2005

Secretion of YscP from Yersinia enterocolitica is essential to control the length of the injectisome needle but not to change the type III secretion substrate specificity.

The length of the needle of the Yersinia Ysc injectisome is determined by a protein called YscP. This protein, which acts both as a molecular ruler and as a substrate-specificity switch for type III secretion is itself secreted by the injectisome. In this report, we address the question why YscP is secreted. By a systematic deletion analysis and by fusing different parts of the molecule to the adenylate cyclase reporter, we identified two independent secretion signals. One of them is encompassed within the 35 N-terminal residues while the second one spans residues 97-137. These two signals are functionally different from Yop secretion signals. When both secretion signals were removed, Yops could still be secreted but the needle length control was lost. YscP possessing only one signal did not control needle length properly but the control was improved when more YscP was produced and secreted. YscP deprived of both signals could not control length, even when overproduced. We conclude from this that YscP needs to be secreted to exert its length control function but not its substrate-specificity switch function.

Bacterial Proteins↗
PubMed1995

Effects of acid mist on needles from mature Sitka spruce grafts. Part II. Influence of developmental stage, age and needle morphology on visible damage.

Mature grafts of five Sitka spruce (Picea sitchensis (Bong.) Carr.) clones were exposed to simulated acid mist comprising an equimolar mixture of H(2)SO(4) and NH(4)NO(3) (1.6 and 0.01 mol m(-3)) at pH 2.5 and 5.0. Mist was applied to potted plants growing in open-top chambers on consecutive days, four times a week, at a precipitation equivalent of 1 mm per day. The total exposure to polluted mist was equivalent to three times that measured at an upland forest in SE Scotland. The aim of the experiment was to characterize the response of juvenile foliage produced by physiologically mature grafts (on seedling root stock) and compare it with the behaviour of juvenile foliage on seedlings. Development of visible foliar damage was followed through the growing season. Measurements of needle length, diameter, weight, surface area, surface was weight and wettability were made on current year needles to determine whether particular foliar characteristics increased susceptibility to injury. Significant amounts (> 10%) of visible needle damage was observed on only one of the five clones. Damage was most severe on the clone with the most horizontal branch and needle habit, but over the five clones there was no relationship between angle of branch display and damage. Likewise no combination of needle characteristics (length, width, area, amount of wax) was indicative of potential susceptibility. A comparison with previous acid misting experiments using seedlings suggests that juvenile foliage on physiologically mature trees is equally susceptible to visible injury as juvenile seedling foliage. Data of budburst differed among clones, and in this experiment exerted the over-riding influence on development of injury symptoms. Foliage exposed to a combination of strong acidity and high sulphate concentrations over the few weeks immediately following budburst suffered most visible injury. The absence of significant amounts of visible damage in UK forests probably reflects the general low susceptibility to visible injury of Sitka spruce exposed to acid mist.

Journal Article↗
PubMed1981

Steerable real-time sonographically guided needle biopsy.

A method for dynamic real-time ultrasonic guidance for percutaneous needle biopsy has been successful in obtaining cytologic and histologic specimens from abdominal masses. The system depends on a real-time ultrasonic transducer that has been rigidly attached to a laterally placed steerable needle holder. Using simple trigonometric functions, a chart has been derived that gives the exact angulation and needle length to produce quick, reliable, guided needle placements. Examples of successful renal, hepatobiliary, and retroperitoneal biopsies are presented. Advantages of this technique include speed, accuracy, low cost, three-dimensional format, and the omission of contrast media and radiation.

Adrenal Gland Neoplasms↗
PubMed2006

An observation on the acupuncture treatment of ischemic wind-stroke with different lengths of needle-retaining time.

OBJECTIVE: To observe the effects of different lengths of needle-retaining time on the therapeutic results of acupuncture treatment for ischemic wind-stroke. METHODS: According to the severity of disease, 251 cases of ischemic wind-stroke were randomly divided into 3 groups and treated by acupuncture, with the needle-retaining time lasting 20, 40, and 60 minutes respectively. Observation was mainly focused on the scores of nervous dysfunction and the clinical therapeutic results. RESULTS: The comparison of the scores of nervous dysfunction in the 3 groups before and after the treatment showed that under Wilcoxon's pair-match symbol rank test, except for horizontal gaze, other indexes all showed significant differences (P < 0.01). In the between-group comparison before and after the treatment, there showed significant or very significant differences in the indexes of myodynamia of the upper limb, myodynamia of hand and the total scores (P < 0.05, P < 0.01). In the between-group comparison by Mann-Whitney rank test of the indexes of myodynamia of upper limb, myodynamia of hand and the total scores, the 20-min. group and the 60-min. group showed significant differences (P < 0.05); and 40-min. group and 60-min. group showed significant differences in myodynamia of upper limb (P < 0.05). In comparison of the therapeutic effects of the 3 groups by Kruskal-wallis rank test, there showed very significant differences (P < 0.01). In the between-group comparison by Mann-Whitney rank test, the 40-min.group and 60-min. group showed significant differences (P = 0.013); while the 20-min. group and 60-min. group showed very significant differences (P = 0.000). CONCLUSION: There is a time-effect relationship between the length of needle-retaining time and the therapeutic effects of acupuncture for ischemic wind-stroke.

Acupuncture Therapy↗