PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Needle loss”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2002

Impact of sawfly defoliation on growth of Scots pine Pinus sylvestris (Pinaceae) and associated economic losses.

Needle defoliation by diprionid sawflies decreases the increment and timber yield of Scots pine Pinus sylvestris L. The aim of this study was to provide approximate estimates of this decrease and preliminary estimates of the economic value of growth losses and tree mortality. Growth loss after needle damage by Diprion pini (Linnaeus) was studied in western Finland. Increment cores were sampled for radial growth measurements from trees subjected to slight, moderate and heavy defoliation. A literature survey was carried out to estimate radial growth losses after defoliation by Neodiprion sertifer (Geoffroy). Calculations for economic consequences were based on previous estimates and on the ongoing 9th Finnish National Forest Inventory. Moderate defoliation by N. sertifer and D. pini reduced volume growth by 21% and 86% and heavy defoliation by 38% and 94%, respectively. Tree mortality in defoliated stands was recorded as approximately 4% after an outbreak of N. sertifer and 30% after an outbreak of D. pini. The estimated average economic value of the losses due to reduced growth and tree mortality reached $40 ha-1 after a single-year outbreak of N. sertifer and $310 ha-1 in the case of D. pini. These preliminary estimates of economic losses indicate a much higher impact of pine sawflies than those revealed by the few earlier studies in Europe.

Animals↗
PubMed1990

Persistent effects of ozone on needle water loss and wettability in Norway spruce.

Four-year-old, seed-grown trees of Norway spruce (Picea abies (L.) Karst.) were exposed in open-top chambers to charcoal-filtered air (8 h daily mean 54 microg O(3) m(-3)) over three consecutive summers (1986-1988). In mid-May 1988, before the third season of fumigation and more than 7 months after exposure to ozone the previous summer had terminated, daily rates of transpiration from intact shoots and water loss from excised needles were measured together with the amount of wax on the needle surface. In mid-July, 92 days after the beginning of the third year of exposure, the wettability of needles was assessed by measuring the contact angle of water droplets on the surface of needles. Exposure to 156 microg O(3) m(-3) resulted in a 16% increase in daily transpiration in current year's needles and a 28% increase in 1-year old needles. These effects were associated with slower stomatal closure in response to increasing water deficit in the needles previously exposed to 156 microg m(-3) ozone. The long-lasting nature of such ozone-induced effects could predispose trees to drought and winter desiccation. No significant effects of ozone were found on the amount of wax covering the needle surface, but a marked increase in the wettability of needles exposed to ozone was observed. The far reaching physiological consequences of these effects in the field and the possibility that similar disturbances may contribute to the decline of high-altitude forests of Norway spruce in Europe are discussed.

Journal Article↗
PubMed2006

The ecology of energy and nutrient fluxes in hemlock forests invaded by hemlock woolly adelgid.

The hemlock woolly adelgid (HWA, Adelges tsugae Annand) is currently causing a severe decline in vitality and survival of eastern hemlock in North American forests. We analyzed the effects of light HWA infestation on vertical energy and nutrient fluxes from the canopy to the forest floor. Canopy throughfall, litter lysimeters, and laboratory litter microcosms were used to examine the effects of HWA-affected and unaffected throughfall on litter type, leachate, and litter chemistry. Early in the season adelgid infestation caused higher dissolved organic carbon (DOC; +24.6%), dissolved organic nitrogen (DON; +28.5%), and K (+39.3%) fluxes and lower inorganic nitrogen fluxes (-39.8%) in throughfall and in adjacent litter solutions collected beneath infested compared to uninfested trees. Needle litter collected beneath uninfested hemlock had significantly lower N concentrations compared to needles collected beneath infested trees, while no difference in N concentrations was found in birch litter. Bacteria were significantly more abundant on hemlock and birch litter beneath infested trees, while yeasts and filamentous fungi showed no consistent response to HWA throughfall. Litter microcosms showed that less DOC was leaching from birch than from hemlock needles when exposed to HWA throughfall. Overall, NH4-N and DON leachate concentrations were higher from birch than from hemlock litter. Thus, HWA-affected throughfall leads to qualitative and quantitative differences in nitrogen export from the litter layer. The N concentration of hemlock litter did not change with time, but the N concentration in birch litter increased significantly during the course of the experiment, especially when HWA-affected throughfall was applied. We suggest a nonlinear conceptual model for the temporal and vertical transition of energy and nutrient fluxes relative to progressing HWA infestation from a pure hemlock to a birch/maple-dominated forest. Progressive needle loss and changes in needle chemistry are likely to produce a humped-shaped DOC curve, while N fluxes initially decrease as infestation continues but rise eventually with hemlock decline and immigration of hardwood species. These findings suggest that it is necessary to understand the biology and specific physiological/trophic effects of exotic pests on their hosts and associated ecosystem processes in order to decipher the temporal dynamics, direction of change, and functional consequences.

Animals↗
PubMed2026

Risk factors and management strategies for needle disengagement from the visual field in pediatric robot-assisted laparoscopic pyeloplasty.

OBJECTIVE: This study aimed to identify risk factors for suture needle disengagement from the visual field during pediatric robot-assisted laparoscopic pyeloplasty (RALP) and propose effective strategies for prevention and management. METHODS: A retrospective cohort study analyzed clinical data from 339 pediatric patients who underwent RALP for ureteropelvic junction obstruction (UPJO) at a single institution between August 2017 and December 2020. Patients were categorized based on the occurrence of needle disengagement from the visual field. Various patient demographics and surgical procedural factors were evaluated. Univariate and multivariate logistic regression, along with LASSO regression, identified independent risk and protective factors. RESULTS: Needle disengagement occurred in 38 (11.21%) of 339 cases. Multivariate logistic regression identified five independent risk factors for needle disengagement: use of a 3-mm auxiliary trocar (OR = 4.69, 95% CI: 1.98-12.53, P < 0.001), non-standard needle holder use (OR = 2.32, 95% CI: 1.04-5.18, P = 0.038), unshaped suture needles (OR = 3.16, 95% CI: 1.44-7.19, P = 0.005), simultaneous use of &#x2265;2 intra-abdominal sutures (OR = 2.46, 95% CI: 1.15-5.48, P = 0.023), and clamping the needle shank during withdrawal (OR = 3.42, 95% CI: 1.40-8.21, P = 0.006). Conversely, sufficient assistant experience (>10 cases) was identified as a protective factor (OR = 0.39, 95% CI: 0.18-0.88, P = 0.021). CONCLUSION: Suture needle disengagement from the visual field during pediatric RALP is associated with specific technical and instrumental factors. Implementing targeted strategies-such as mandating specialized needle holders, preoperative needle shaping, a single-needle workflow, prioritizing clamping the suture thread over the needle shank during withdrawal, and ensuring adequate assistant training-has the potential to significantly reduce significantly mitigate the risk of needle loss and enhance overall surgical safety in pediatric RALP.

Humans↗
PubMed2000

Reduction in turgid water volume in jack pine, white spruce and black spruce in response to drought and paclobutrazol.

Significant reductions in needle water content were observed in white spruce (Picea glauca (Moench) Voss), black spruce (Picea mariana (Mill) B.S.P.), and jack pine (Pinus banksiana Lamb.) seedlings in response to a 10-day drought, although turgor was apparently maintained. When the seedlings were re-watered after the drought, jack pine needles regained their original saturated volume, whereas white spruce and black spruce needles did not. Significant drought-induced reductions in turgor-loss volume (i.e., tissue volume at the point of turgor loss) were observed in shoots of all three species, especially jack pine. Repeated exposure to 7 days of drought or treatment with the cytochrome P(450) inhibitor, paclobutrazol ((2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-pentan-3-ol), reduced seedling height relative to that of untreated controls in all three species. The reductions in saturated and turgor-loss needle volumes in the paclobutrazol-treated seedlings were comparable with those of seedlings subjected to a 10-day drought. The treatment-induced reductions in shoot and needle water contents enabled seedlings to maintain turgor with tissue volumes close to, or below, the turgor-loss volume of untreated seedlings. Paclobutrazol-treated seedlings subsequently survived drought treatments that were lethal to untreated seedlings.

Journal Article↗
PubMed1992

Time-resolving luminescence techniques for possible detection of forest decline. II. Picosecond chlorophyll fluorescence.

Needles from spruces at different environmental and physiological conditions were analyzed by picosecond fluorescence spectroscopy using a novel laser diode and single photon counting detection. The decay curves of chlorophyll fluorescence showed a superposition of three exponentially decaying components with time constants of T1 = 100-200 ps, T2 = 300-500 ps and T3 = 2.0-3.5 ns. A high relative intensity of the long-lived component was found in damaged spruces as well as in trees showing first symptoms of yellowing, needle loss or parasite infection, although all measurements were carried out with green needles which appeared visually intact. Therefore, fluorescence spectroscopy with subnanosecond time resolution seems to be a valuable attempt for an early detection of forest decline.

Chlorophyll↗
PubMed1988

Growth responses of birch and Sitka spruce exposed to acidified rain.

Seedlings of birch and Sitka spruce were grown on a range of British soils for 2 years and exposed to simulated acid rainfall treatments of pHs 5.6, 4.5, 3.5 and 2.5. Both species developed visible leaf injury patterns when exposed to the pH 2.5 treatment. In Sitka spruce this leaf injury was followed by high needle loss during the first winter and greater mortality. Generally, height growth of Sitka spruce was unaffected by treatments, but acid rainfall at pH 2.5 increased the height of birch. Mean height of both species was strongly affected by soil type. Significant soils x treatment effects on the heights of both species indicated that on some soils plant growth responses to the treatments did not fit the general pattern. Hence, while the results indicate that generally ambient acidities of rainfall in the UK are unlikely to adversely affect the growth of birch or Sitka spruce, plants growing on some soils may be susceptible to injury.

Journal Article↗
PubMed1997

Charcot-Marie-Tooth disease type 1A with 17p11.2 duplication. Clinical and electrophysiological phenotype study and factors influencing disease severity in 119 cases.

A clinical and electrophysiological study was performed in 119 Type 1A Charcot-Marie-Tooth disease (CMT1A) patients with proven 17p11.2 duplication. Onset of the first functional manifestations was in the first decade in 50% of cases and before the age of 20 years in 70% of cases. The predominant clinical signs were muscle weakness and wasting in the lower limbs. None of the patients was normal on clinical examination and all presented at least pes cavus or ankle jerk areflexia. Motor nerve conduction velocity (MNCV) was uniformly reduced in all nerves, and was < or = 33 m/s in the median nerve for all patients. Sensory potentials were abnormal in all cases, even where there was no clinical sensory loss. Needle electromyography recruitment was reduced in distal muscles for all patients. MNCV slowing was fully consistent with the presence of duplication even in clinically asymptomatic individuals or in children, confirming the complete electrophysiological penetrance of 17p11.2 duplication and making median nerve MNCV a reliable tool for screening affected at-risk individuals. Functional disability was mild. Ninety-six percent of patients were autonomous; 25% were asymptomatic and diagnosed by systematic family investigation especially on the basis of median nerve MNCV reduction. Early age at onset and greatly reduced median nerve MNCV were predictive of a more severe disease course; the earlier the onset the more reduced the median nerve MNCV and the higher the functional disability tended to be after an equivalent disease duration. Cross-sectional analysis of neurological deficit, functional deficit and MNCV according to disease duration showed that, regardless of age at onset, CMT1A disease with 17p11.2 duplication is a clinically progressive disorder. Neurological deficit and functional disability increased, whereas median nerve MNCV and compound muscle action potential (CMAP) amplitude did not change with disease course. Intrafamilial phenotype variation between parents and children and between siblings was studied in large families. Functional disability and neurological deficit differed widely and the highest range of median nerve MNCV within a family reached 23 m/s. Clinical and electrophysiological data were compared with those of CMT1B patients with peripheral myelin P0 protein point mutation. CMT1A patients were found to be more severely affected with more prolonged distal motor latency and more reduced CMAP amplitude, whereas MNCV did not significantly differ, indicating that peripheral myelin P0 protein point mutation is not always associated with a severe phenotype. The same genetic defect (17p11.2 duplication) results in variable expression within the phenotype, even in siblings with variations in age at onset, clinical severity and MNCV slowing. This phenotypic variation could be due to additional genetic factors related to peripheral myelin protein 22 expression as well as to other endogenous or environmental factors.

Adolescent↗
PubMedDate not supplied

Quality of life is improved in breast cancer patients by Standardised Mistletoe Extract PS76A2 during chemotherapy and follow-up: a randomised, placebo-controlled, double-blind, multicentre clinical trial.

The objective of this randomised, multicentre, double-blind clinical trial was to investigate the impact of PS76A2, an aqueous mistletoe extract standardised to mistletoe lectins, on quality of life (QoL) in breast cancer patients. A total of 352 patients were randomly allocated to 2 groups receiving PS76A2 (15 ng mistletoe lectin/0.5 ml) or matching placebo twice weekly for 4 to 6 cycles of CMF (cyclophosphamide, methotrexate, fluorouracil) chemotherapy followed by 2 months follow-up. The primary efficacy end-point was the change from baseline of 3 FACT-G subscales (physical, emotional and functional well-being) during the fourth CMF cycle. Secondary measures included GLQ-8 (8 linear analogue self-assessment scales), Spitzer's uniscale and haematological variables. The main variables of safety analysis were adverse events, including injection site reactions and clinical laboratory tests. The results showed that physical, emotional and functional well-being improved upon PS76A2, but deteriorated following placebo. The treatment differences were statistically significant for the 3 subscales as well as for the summary score FACT-G, which was analysed as O'Brien's rank sum of its 3 subscales: The total score increased by 4.40 +/- 11.28, indicating a higher QoL after PS76A2, but decreased by 5.11 +/- 11.77 with placebo (p<0.0001). The GLQ-8 sum of 8 LASA scales was analysed as a summary score of GLQ-5 (sum of item nos. 1, 5, 6, 7, 8) and GLQ-3 (sum of item nos. 2, 3, 4). GLQ-5 characterises typical aspects of QoL, while GLQ-3 consists of 3 side-effects of CMF (feeling sick, numbness or pins and needles, loss of hair). GLQ-5 decreased by 42.9 +/- 125.0 upon PS76A2, indicating an improvement in QoL, but increased by 60.3 +/- 94.0 upon placebo (p<0.0001). GLQ-3 deteriorated in both groups (PS76A2: 13.9 +/- 52.4; placebo: 34.5 +/- 57.0), but the differences in favour of PS76A2 were, nevertheless, statistically significant (p=0.0007). The total score GLQ-8 improved by 28.9 +/- 154.6 after PS76A2 and deteriorated by 94.8 +/- 141.1 after placebo (p<0.0001). Spitzer's uniscale improved by 12.2 +/- 30.7 upon PS76A2 and deteriorated by 10.8 +/- 26.1 with placebo (p<0.0001). After follow-up without chemotherapy, a significant treatment difference in favour of PS76A2 was determined by means of FACT-G, GLQ-8 and Spitzer's uniscale. PS76A2 was well tolerated in this trial, with the exception of slight local reactions in 17.6% of the PS76A2 group. In conclusion, PS76A2 (15 ng mistletoe lectin/0.5 ml twice weekly) was shown to be safe and effective in improving QoL in breast cancer patients during chemotherapy and follow-up.

Adult↗
PubMed1990

Advances in venous access devices and nursing management strategies.

VADs are indicated for many persons who require reliable long-term venous access. Nontunneled, tunneled, and venous access ports are constructed of silicone or polyurethane, the most biocompatible materials identified thus far. These devices are inserted in a similar fashion and are extremely versatile. Although VADs represent a major advance in catheter technology, they are not without problems. The most serious and frequently reported complications include infection, thrombosis, and extravasation. Catheter occlusions are another frequent problem, and may be caused by clotted blood or precipitated drug within the catheter. Nursing care centers on prevention and intervention to remove the occlusion. Catheter-related infections may occur at one or more points along the catheter. The most serious are those occurring in the tunnel or as a result of a mural or catheter-tip thrombus. Normal skin flora are most commonly cultured with catheter-related infections. These organisms may be introduced into the body through the catheter hub or less often by migrating along the external catheter. Infections differ in their severity, prognosis, and treatment. Actions to minimize risk (scrupulous care and patient teaching), prompt recognition, and appropriate interventions are crucial. Thrombotic events include fibrin sheaths, patchy thrombotic plaques on the cannulated venous intima, and totally occlusive mural thromboses. Problems associated with these can range from withdrawal occlusion to obstruction of the great vessels and symptoms of superior vena cava syndrome. Mural thrombosis, which probably occurs more frequently than previously suspected, is the most significant risk factor for infection and may also potentiate extravasation. Prompt initiation of therapy will resolve symptoms and maintain the functioning of the catheter. Extravasation can result in transient discomfort or major tissue damage, pain, and functional loss. Needle dislodgment from ports is the most frequent cause. Adequate stabilization of needles and use of nonsiliconized needles are recommended to decrease this risk. Thrombosis at the catheter tip with back tracking of infusate out of the vein to subcutaneous tissues is the second most frequent cause of extravasation and has been reported with tunneled catheters as well as ports. It should be noted that catheter-tip displacement and catheter damage infrequently lead to extravasation. When extravasation is suspected, the infusion is stopped, and the nurse notifies the physician so diagnostic procedures and treatment can be initiated. Other complications occur infrequently but may contribute to patient discomfort, morbidity, and mortality. These include phlebitis, which resolves with conservative management in most instances, and pneumothorax, which occurs in a small percentage of patients within a short period after catheter placement.(ABSTRACT TRUNCATED AT 400 WORDS)

Antineoplastic Agents↗
PubMed2006

Endoscopic ultrasound-guided fine needle aspirate microsatellite loss analysis and pancreatic endocrine tumor outcome.

BACKGROUND & AIMS: The clinical course of pancreatic endocrine tumor (PET) varies depending on tumor aggressiveness, disease extent, and possibly accumulated molecular alterations. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) results, although accurate in diagnosing PET, correlate poorly with PET outcome. The role of detecting key molecular abnormalities in predicting PET behavior and clinical outcome from EUS-FNA material remains unknown. METHODS: Patients with confirmed PET who underwent EUS-FNA during a 32-month period were included. Patient demographics and clinical data were recorded and follow-up information was obtained by contacting their physician to evaluate disease progression. Representative tumor cells were microdissected from the FNA material. DNA was harvested and amplified, targeting a panel of 17 polymorphic microsatellite markers on chromosomes 1p, 3p, 5q, 9p, 10q, 11q, 17p, 17q, 21q, and 22q. The polymerase chain reaction products were subjected to fluorescent capillary gel electrophoresis to detect microsatellite loss. The fractional allelic loss (FAL) was calculated. RESULTS: Twenty-five patients were studied. Thirteen were classified histologically as benign PET limited to the pancreas and 12 as malignant PET (invasive or metastatic). The mean FAL in the benign and malignant PET was 0.03 and 0.37 (P<.0001), respectively. In addition, the mean FAL was significantly greater in those with disease progression as compared with patients with stable disease (0.45 vs 0.09 respectively, P<.0001). CONCLUSIONS: Microsatellite loss analysis of EUS-FNA material from PET can be performed reliably and an FAL value of more than 0.2 is associated with disease progression. This technique may have value in the preoperative assessment and risk stratification of patients with PET.

Adult↗
PubMedDate not supplied

Detection of heterozygosity loss in microdissected fine needle aspiration specimens of breast carcinoma.

OBJECTIVE: To use the polymerase chain reaction (PCR) to detect loss of heterozygosity (LOH) in microdissected cells form cytologic smears obtained by fine needle aspiration (FNA) from 20 cases of invasive breast carcinoma. STUDY DESIGN: In each case, histologic sections of the primary tumor were also available. Tumor and nontumor cells were dissected from both the cytologic smear and tissue section in all cases except in three smears that showed only tumor cells. RESULTS: LOH was identified in 10 of 19 informative cases using two polymorphic DNA markers at chromosome 11q13 (INT-2, PYGM). The same results were obtained in both the cytologic and histologic specimens, including three cases that had hypocellular cytologic smears. CONCLUSION: FNA of breast lesions provides adequate samples for direct microdissection of the cytologic smear to detect LOH using PCR amplification.

Biopsy, Needle↗
PubMed2003

The effect of combined spinal-epidural (CSE) anaesthesia and size of spinal needle on postoperative hearing loss after elective caesarean section.

The exact aetiology of vestibulocochlear dysfunction after spinal anaesthesia is unknown. Low-frequency hearing loss occurs after spinal anaesthesia. The aim of this study was to investigate the effects of combined spinal-epidural (CSE) anaesthesia and size of spinal needle on vestibulocochlear dysfunction, using pure tone audiometry performed pre- and on the first and the second day postoperatively. Forty-five patients who were to undergo elective caesarean section were evaluated. In group I, CSE anaesthesia (18 G Tuohy, 25 G Whitacre pencil-point-design spinal needles) was performed in 15 patients. In group II, spinal anaesthesia was performed in 15 patients with 25 G Whitacre pencil-point-design spinal needles and, in group III, spinal anaesthesia was performed in 15 patients with 22 G Whitacre pencil-point-design spinal needles. In the pre- and on the first and the second day postoperatively, the pure tone audiogram was performed in the audiology laboratory of our hospital, using a calibrated Kamplex Diagnostic Audiometer AC 40 in a noise-free room. When the CSE anaesthesia group and 22 G spinal group were compared for change in hearing between the pre- and postoperative periods, a statistically significant difference was observed at R-right ear 125 Hz (P < 0.025) and at L-left ear 125 Hz (P < 0.023), and at L-left ear 1000 Hz (P < 0.036) and at R-right ear 1500 Hz (P < 0.006), and at L-left ear 1500 Hz (P < 0.022). At other frequencies, the difference was insignificant. When the CSE anaesthesia group and 25 G spinal group were compared for change in hearing between the pre- and postoperative periods, no statistically significant difference was detected at any frequency tested. When 22 G spinal group and 25 G spinal group were compared for change in hearing between the pre- and postoperative periods, there was some hearing loss at low frequency, although this difference did not reach statistical significance. The positive correlation of low-frequency hearing loss and increased pressure in the epidural space (which decrease the risk of cerebrospinal fluid leakage through the dura) suggests that cerebrospinal fluid leakage via the spinal puncture hole is not the only factor involved. Perioperative fluid replacement alone may not prevent hearing loss but CSF loss through the dural puncture site should also be prevented.

Adult↗
PubMed1990

Hearing loss after spinal anesthesia is related to needle size.

Audiograms were performed preoperatively and 2 days postoperatively in 28 patients given spinal anesthesia for transurethral resection of the prostate. In 14 patients 22-gauge and in 14 patients 26-gauge spinal needles were used. Hearing loss of 10 dB or more at any frequency was observed in 13 of 14 patients in the 22-gauge group and in 4 of 14 patients in the 26-gauge group. There was a statistically significant reduction in hearing level in the low-frequency range in patients in whom the 22-gauge needle was used. Hearing loss was unilateral at five frequencies and bilateral at one frequency. No cases of postspinal headache occurred. Audiometry may be a more sensitive indication of cerebrospinal fluid leak than postspinal headache.

Aged↗