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Biomedical subjects

W Long

Publications and source records attributed to W Long.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Research progress on PGPR/AMF interactions].

As one of the rhizospheric microorganisms PGPR(Plant Growth Promoting Rhizobacteria) and AMF(Arbuscular Mycorrhizal Fungi) play an important role in promoting plant growth. It is of significance to further study and elucidate the interactions between them to utilize and regulate the interactions among rhizospheric microorganisms, and promote and protecte plant growth. Many research results show that on one hand, there exists synergism between PGPR and AMF. AMF can transfer PGPR or act as a media in the process of spread of PGPR along roots, where PGPR create many beneficial conditions for the infection of AMF. Both of them can indirectly enhance the other side's colonization or infection ability through their own promoting role on plant growth. On the other hand, they compete with each other for nutrients and niches, and probably produce some secondary metabolites which cause detrimental effects on the other. However, whether these interactions are synergistic or competitive depends upon the AM fungal or PGPR species involved. So far, the research work is extensive, even in molecular level in some aspects, but not systematic and deep. It is believed however, with the development of techniques in molecular biology and the increasing application of advanced testing methods, the new breakthroughs will be gained in the study and understanding on the interactions.

Bacterial Physiological Phenomena↗
PubMed2000

[Study on the anti-müllerian hormone served as a marker for granulosa cell tumor of ovary].

OBJECTIVE: To probe the experimental basis for anti-mullerian hormone(AMH) served as a specific tumor label in diagnosis of granulosa cell tumor(GCT) of ovary. METHODS: The expression of AMH and its receptor mRNA in early and late GCT of ovary in transgenic mice was studied by using immunohistochemistry, in stiu hybridization and Northern hybridization. Furthermore, the expression of AMH and its receptor mRNA in cultured GCT cells was also determined by using radioiodine labeling method and Northern hybridization. RESULTS: In the early ovary GCT of transgenic mice, immunohistochemistry showed that AMH was positively stained as brownish yellow granulars, which were located in the cell membrane of the tumor, in situ hybridization showed its receptor mRNA was positive as blue granulars, which were also located in the cell membrane. The positive rate of both AMH and its receptor mRNA was 100%. Results by northern hybridization also showed that the positive rate of AMH and its receptor mRNA in the early ovary GCT and GCT cells was 100%. Radioautography indicated that there was a radioactive bright point, the binding rate of 125I labeled AMH with tumor cells reached 100%. CONCLUSIONS: AMH can be served as a specific tumor marker in the diagnosis of difficult and complicated tumors of ovary, and in the diagnosis, treatment and follow-up survey of the early GCT.

Animals↗
PubMed2000

[The relationship of brainstem auditory evoked potential to cerebral blood flow volume in with vertebrobasilar transient ischemic vertigo].

This study was aimed at the relationship of brain-stem auditory evoked potential(BAEP) with cerebral blood flow(CBF) volume and vascular pathological changes in patients with vertebro-basilar transient ischemic vertigo (VBTIV). 65 patients were examined by magnetic resonance angiography(MRA), transcranial Dopplar(TCD) and BAEP; 26 controls were examined by MRA and TCD. In the patient group, MRA showed that vascular pathological changes were obvious in 50 patients, and obscure or absent in 15 patients. The CBF volume [112.3-278.9 ml/min (2s)] of control group was higher than that (48.0-262.0 ml/min) of the patients group (t = 2.43, P < 0.01) in which 15 patients had low CBF volume and 50 patients had normal CBF volume. The BAEP of 47(72.3%) patients was abnormal. Out of 15 patients with low CBF volume, 14(93.3%) had abnormal BAEP, but out of 50 patients with normal CBF volume, only 33(66%) patients had abnormal BAED (chi 2 = 4.34, P < 0.05). In the 50 patients with obscure obvious vascular pathological changes, 40(80%) patients had abnormal BAEP, but in the 15 patients with obscure or without the changes, only 7(43.3%) patients had abnormal BAEP (chi 2 = 4.86, P < 0.05). These results suggested that there might be a close relationship of BAEP with CBF volume and vascular pathological changes.

Adult↗
PubMed1999

Continuous infusion of epoprostenol improves the net balance between pulmonary endothelin-1 clearance and release in primary pulmonary hypertension.

BACKGROUND: Primary pulmonary hypertension results from progressive narrowing of the precapillary pulmonary vasculature. A variety of endothelial abnormalities have been identified, including a net reduction in pulmonary clearance of the vasoconstrictor and smooth muscle mitogen endothelin-1. In many patients, net pulmonary release of endothelin-1 is observed. Chronic infusions of epoprostenol (prostacyclin) improve functional capacity, survival, and hemodynamics in patients with advanced primary pulmonary hypertension. We hypothesized that the epoprostenol infusions, as compared with conventional therapy, might alter the abnormal pulmonary endothelin-1 homeostasis. METHODS AND RESULTS: Using a subset of patients from a larger randomized study comparing epoprostenol plus conventional therapy (n=11 in the present study) with conventional therapy alone (n=7 in the present study), we determined the ratio of plasma endothelin-1 levels in systemic arterial blood leaving the lung to levels in mixed venous blood entering the lung both before randomization and after 88 days of continuous therapy. There were no differences between the 2 groups before therapy, but by day 88, the epoprostenol-treated group had a greater proportion of patients (82%) with an arterial/venous ratio <1 than did the conventional therapy group, in which only 29% of patients had a ratio <1 (P<0.05). CONCLUSIONS: These results suggest that continuous epoprostenol therapy may have a beneficial effect on the balance between endothelin-1 clearance and release in many patients with primary pulmonary hypertension and may provide one explanation for the salutary effect of epoprostenol in this disease.

Antihypertensive Agents↗
PubMed1999

Role of Ca(2+) channels in NE-induced increase in [Ca(2+)](i) and tension in fetal and adult cerebral arteries.

In vascular smooth muscle, elevation of agonist-induced intracellular Ca(2+) concentration ([Ca(2+)](i)) occurs via both Ca(2+) release from intracellular stores and Ca(2+) influx across the plasma membrane. In the cerebral vasculature of the fetus and adult the relative roles of these mechanisms have not been defined. To test the hypothesis that plasma membrane L-type and receptor-operated Ca(2+) channels play a key role in NE-induced vasoconstriction via alterations in plasma membrane Ca(2+) flux and that this may change with developmental age, we performed the following study. In main branch middle cerebral arteries (MCA) from near-term fetal ( approximately 140 days) and nonpregnant adult sheep, we quantified NE-induced responses of vascular tension and [Ca(2+)](i) (by use of fura 2) under standard conditions in response to several Ca(2+) channel blockers and in response to zero extracellular Ca(2+). In fetal and adult MCA, maximal NE-induced tensions (g) were 0.91 +/- 0.12 (n = 10) and 1.61 +/- 0.13 (n = 12), respectively. The pD(2) values for NE-induced tension were both 6.0 +/- 0.1, whereas the fetal and adult maximum responses (%K(max)) were 107 +/- 16 and 119 +/- 7, respectively. The fetal and adult pD(2) values for NE-induced increase of [Ca(2+)](i) were 6.2 +/- 0.1 and 6.4 +/- 0.1, respectively, whereas maximum [Ca(2+)](i) responses were 81 +/- 9 and 103 +/- 15% of K(max), respectively. After 10(-5) M NE-induced contraction, nifedipine resulted in dose-dependent decrease in vessel tone and [Ca(2+)](i) with pIC(50) values for fetal and adult tensions of 7.3 +/- 0.1 and 6.6 +/- 0.1, respectively (P < 0.01; n = 4 each), whereas pIC(50) for [Ca(2+)](i) responses were 7.2 +/- 0.1 and 6.9 +/- 0.1, respectively. The pIC(50) values for tension for diltiazem and verapamil were somewhat lower but showed a similar relationship. The receptor-operated Ca(2+) channel blocker 2-nitro-4 carboxyphenyl-N,N-diphenyl carbamate showed little effect on NE-induced vessel contractility or [Ca(2+)](i). In the absence of extracellular Ca(2+) for 2 min, 10(-5) M NE resulted in markedly attenuated responses of adult MCA tension and [Ca(2+)](i) to 39 +/- 7 and 73 +/- 8% of control values (n = 4). For fetal MCA, exposure to extracellular Ca(2+) concentration resulted in essentially no contractile or [Ca(2+)](i) response (n = 4). Similar blunting of NE-induced tension and [Ca(2+)](i) was seen in response to 10(-3) M lanthanum ion. These findings provide evidence to suggest that especially in fetal, but also in adult, ovine MCA, Ca(2+) flux via L-type calcium channels plays a key role in NE-induced contraction. In contrast, Ca(2+) flux via receptor-operated Ca(2+) channels is of less importance. This developmental difference in the role of cerebrovascular plasma membrane Ca(2+) channels may be an important association with increased Ca(2+) sensitivity of the fetal vessels.

Age Factors↗
PubMed1999

Medial protrusio technique for placement of a porous-coated, hemispherical acetabular component without cement in a total hip arthroplasty in patients who have acetabular dysplasia.

Twenty-four hip replacements were performed with use of a medial protrusio technique to stabilize the fit of a hemispherical metal shell in the acetabulum in nineteen patients who had dysplasia of the hip. All of the hips were followed for a minimum of five years (average, seven years; range, five to thirteen years). Six of the hips were type I, seven were type II, eight were type III, and three were type IV according to the criteria of Crowe et al. The acetabular cup was implanted with the medial aspect of its dome beyond the Kohler line (drawn from the ischium along the ilioischial line) in all hips. An autogenous graft sculpted from the femoral head was used to cover 15 to 30 percent of the superolateral portion of the cup in one type-I hip, four type-III hips, and one type-IV hip. The need for these six bone grafts could have been avoided by reaming two to three millimeters more medially or by allowing 20 percent of the superolateral portion of the cup to be uncovered. Sixty to 84 percent of each bone graft was resorbed, effectively leaving the superolateral portion of the cup uncovered. The amount of the surface of the cup that was beyond the Kohler line averaged 41 percent for the six type-I hips, 43 percent for the seven type-II hips, 41 percent for six of the type-III hips, and 44 percent for one of the type-IV hips. Crossing of the ilioischial and iliopubic lines was noted on the radiographs of two type-III and two type-IV hips. Radiographs of two type-I hips and one type-II hip showed 7 to 17 percent of the surface of the dome of the cup through the internal pelvic wall (beyond the iliopubic line). None of the twenty-four metal shells were revised. A reoperation was performed on two hips to exchange a worn polyethylene insert, and three femoral components that had been fixed without cement were revised because of mechanical loosening. Wear averaged 0.26 millimeter per year in the fourteen hips that had a titanium femoral head and 0.09 millimeter per year in the nine hips that had a cobalt-chromium femoral head. The remaining hip had a ceramic femoral head, and the wear rate was 0.09 millimeter per year. The medial protrusio technique is a predictable, reproducible method for obtaining fixation of a porous-coated, hemispherical acetabular component in a dysplastic acetabulum. The technique permits the use of a porous-coated (bone-ingrowth) component; avoids the use of support bone graft and thereby reduces the operative time; facilitates rehabilitation by permitting earlier weight-bearing of the hip; and permits the use of a modular bearing surface, which may allow future exchange of only this surface rather than revision of the entire acetabular component because of excessive wear.

Acetabulum↗
PubMed1999

"I'Ve had too much done to my heart": the dilemma of addiction and recovery as seen through seven youngsters' lives.

Aware of the dearth of in-depth studies on recovering adolescent addict/alcoholics, we conducted a year-long qualitative study of seven formerly-addicted youth committed to recovery. The research question was: how do addicted youth become and remain sober? Bending to social stress, including racism and ethnic prejudice, three participants relapsed. However, personal commitment augmented by familial, community, spiritual, and educational support encouraged four to remain sober. Learning from both those who failed and succeeded, the theoretical concepts of surrender, social stress, and resiliency helped to interpret the participants' patterns of response and better understand adolescent recovery.

Adolescent↗
PubMed1999

Surrender to win: how adolescent drug and alcohol users change their lives.

Adolescent drug and alcohol addiction is a serious problem in the United States. However, some addicted adolescents do quit drinking and using drugs. This paper offers a phenomenological analysis of seven young adults who managed to surrender their addictions and, for anywhere from five to fifteen years, construct sober identities. The participants came from highly dysfunctional homes, began substance use as children, and were polydrug users. A series of catastrophic life events led them to Alcoholics Anonymous, where they were exposed to self-reflective prayer, a cadre of recovering adolescents and, in particular, adults who offered detached nurturing. This provided the support they needed to confront their addictions through the Twelve Steps of Alcoholics Anonymous.

Adolescent↗
PubMed1999

[The relationship between tumor necrosis factor and injuries of liver graft and lung after orthotopic liver transplantation in rats].

OBJECTIVE: To study the relationship between tumor necrosis factor alpha (TNFalpha) levels and ischemia-reperfusion injury of liver graft and lung after different cold-storage time during the early stage after orthotopic liver transplantation in rats. METHODS: Orthotopic liver transplantation was performed in SD rats. The survival rates, the pathology of liver graft and lung and the peripheral seral ALT levels were observed and the bile secretion volume and TNFalpha activities of post-hepatic blood were examined at regular intervals. The animals were divided into 3 groups: control, 4 h cold-storage group, and 6 h cold-storage group (4 degrees C Ringer's solution). RESULTS: All the animals in the control and the 4 h group survived over 60 days, and none survived over 3 days in the 6 h group. The bile secretion volumes were larger in the control and the 4 h group than in the 6 h group (P < 0.05), and the ALT levels were lower in the control and 4 h group than in 6 h group (P < 0.05). The TNFalpha activity was not detected in the control but elevated significantly in the 6 h group, peaked, 2 h after the operation, and only slightly elevated in the 4 h group at the same time (P < 0.05). There were significant focal necrosis of liver graft and alveolar edema and leukocyte infiltration in the lungs in the 6 h group but no obvious injuries were observed in the 4 h group and the control. CONCLUSIONS: TNFalpha may contribute to the pathogenesis of ischemia-reperfusion injury of liver graft and pulmonary complications during the early stage after orthotopic liver transplantation. TNFalpha possibly originates from Kupffer cells of liver graft.

Animals↗
PubMed1998

Respiratory symptoms in a susceptible population due to burning of agricultural residue.

STUDY OBJECTIVES: To identify characteristics associated with respiratory symptoms due to an episode of air pollution. DESIGN: Mail survey. SETTING: In October 1992, the population of the city of Winnipeg was exposed to elevated levels of particulate matter (total and <10 microm size), carbon monoxide, nitrogen dioxide, and volatile organic compounds due to smoke from adjacent fields where farmers were burning agricultural residue (straw and stubble). PARTICIPANTS: We surveyed 428 participants in the ongoing Lung Health Study (35 to 64 years old, both sexes) with mild to moderate airways obstruction (mean FEV1 percent predicted 73+/-12%), and a high level of airways hyperreactivity (23% of men and 37% of women). RESULTS: While 37% of subjects were not bothered by smoke at all, 42% reported that symptoms (cough, wheezing, chest tightness, shortness of breath) developed or became worse due to the air pollution episode and 20% reported that they had breathing trouble. Those with symptoms were more likely to be female than male and were more likely to be ex-smokers than smokers. Subjects with asthma and chronic bronchitis were also more likely affected. The degree of airways obstruction and the level of bronchial hyperresponsiveness were not associated with increased susceptibility. CONCLUSIONS: Gender, smoking habit, and respiratory symptoms but not bronchial hyperresponsiveness or the degree of airways obstruction are factors influencing susceptibility to symptoms due to air pollution in adult smokers and former smokers.

Adult↗
PubMed1997

A modification of the injury severity score that both improves accuracy and simplifies scoring.

OBJECTIVES: The Injury Severity Score (ISS) has served as the standard summary measure of anatomic injury for more than 20 years. Nevertheless, the ISS has an idiosyncrasy that both impairs its predictive power and complicates its calculation. We present here a simple modification of the ISS called the New Injury Severity Score (NISS), which significantly outperforms the venerable but dated ISS as a predictor of mortality. DESIGN: Retrospective calculation of NISS and comparison of NISS with prospectively calculated ISS. MATERIALS AND METHODS: The NISS is defined as the sum of the squares of the Abbreviated Injury Scale scores of each of a patient's three most severe Abbreviated Injury Scale injuries regardless of the body region in which they occur. NISS values were calculated for every patient in two large independent data sets: 3,136 patients treated during a 4-year period at the American College of Surgeons' Level I trauma center in Albuquerque, New Mexico, and 3,449 patients treated during a 4-year period at the American College of Surgeons' Level I trauma center at the Emanuel Hospital in Portland, Oregon. The power of NISS to predict mortality was then compared with previously calculated ISS values for the same patients in each of the two data sets. MEASUREMENTS AND MAIN RESULTS: We find that NISS is not only simple to calculate but more predictive of survival as well (Albuquerque: receiver operating characteristic (ROC) ISS = 0.869, ROC NISS = 0.896, p < 0.001; Portland: ROC ISS = 0.896, ROC NISS = 0.907,p < 0.004). Moreover, NISS provides a better fit throughout its entire range of prediction (Hosmer Lemeshow statistic for Albuquerque ISS = 29.12, NISS = 8.88; Hosmer Lemeshow statistic for Portland ISS = 83.48, NISS = 19.86). CONCLUSION: NISS should replace ISS as the standard summary measure of human trauma.

Abbreviated Injury Scale↗
PubMed1997

[Fixation of nonunion of pediatric middle and distal shaft of the femur with semicircular dynamic locked intramedullary nail].

From Oct. 1994 to Dec. 1996, 15 nonunions of pediatric middle and distal shaft of the femur due to previous osteomyelitis and pathologic fracture and/or failed internal fixation were treated with semicircular dynamic locked intramedullary nail (SDLIN). SDLIN was composed of a lateral and a medial nail, both of them were inserted into the medullary canal 1.5 cm above the epiphyseal line, and the tails were connected together by a bolt. All the 15 cases used iliac bone autograft for the defect. Follow-uped for an average of 16.3 months, all of them were healed in an average of 4.8 months, and excellent and good results were obtained in 86.7%. The results suggest that the SDLIN is effective and convenient for the fixation of the refractory nonunion of pediatric middle and distal shaft of the Femur.

Adolescent↗
PubMed1997

[Development of three dimensional bone-connecting plate and its clinical application].

Biomechanical assessment showed that the three dimensional plate developed by the authors which had stereo-rigidity in the fixation of long bone fractures was superior to compressive plate and flanged plate in terms of anti-compressive and anti-torsional strength. The anti-bending strength was superior to the flanged plate but inferior to compressive plate. The comprehensive nature of the three dimensional plate remained superior. Clinical application in 112 cases with 85 of them being followed-up for 8-44 months showed that bone union occurred in 45-98 days. The average was 82 days. In 65 cases of them the plates had been removed. No delayed-union or non-union occurred. Preliminary experience showed that the three dimensional plate was a new design for the treatment of long bone fractures. It can be applied to various types of long bone fractures especially the severe comminuted fractures owing to its requirement of proper fixation.

Adolescent↗
PubMed1996

Aerosolized surfactant in adults with sepsis-induced acute respiratory distress syndrome. Exosurf Acute Respiratory Distress Syndrome Sepsis Study Group.

BACKGROUND: Patients with acute respiratory distress syndrome (ARDS) have a deficiency of surfactant. Surfactant replacement improves physiologic function in such patients, and preliminary data suggest that it may improve survival. METHODS: We conducted a prospective, multicenter, double-blind, randomized, placebo-controlled trial involving 725 patients with sepsis-induced ARDS. Patients were stratified according to the risk of death at base line (indicated by their score on the Acute Physiological and Chronic Health Evaluation [APACHE III] index) and randomly assigned to receive either continuously administered synthetic surfactant (13.5 mg of dipalmitoylphosphatidylcholine per milliliter, 364 patients) or placebo (o.45 percent saline; 361 patients) in aerosolized form for up to five days. RESULTS: The demographic and physiologic characteristics of the two treatment groups were similar at base line. The mean (+/- SD) age was 50 +/- 17 years in the surfactant group and 53 +/- 18 years in the placebo group, and the mean APACHE III scores at randomization were 70.4 +/- 25 and 70.5 +/- 25, respectively. Hemodynamic measures, measures of oxygenation, duration of mechanical ventilation, and length of stay in intensive care unit did not differ significantly in the two groups. Survival at 30 days was 60 percent for both groups. Survival was similar in the groups when analyzed according to APACHE III score, cause of death, time of onset and severity of ARDS, presence or absence of documented sepsis, underlying disease, whether or not there was a do-not-resuscitate order, and medical center. Increased secretions were significantly more frequent in the surfactant group; the rates of other complications were similar in the two groups. CONCLUSIONS: The continuous administration of aerosolized synthetic surfactant to patients with sepsis-induced ARDS had no significant effect on 30-day survival, length of stay in the intensive care unit, duration of mechanical ventilation, or physiologic function.

Administration, Inhalation↗