Can ultrasound predict the severity of acute pancreatitis early by observing acute fluid collection?
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Acute Disease↗
Biomedical subjects
L Dai
Publications and source records attributed to L Dai.
[A preliminary study on ecological response of dominant tree species in Korean pine broadleaf forest at Changbai Mountain to soil water stress and their biomass allocation].
Pot culture experiments were conducted to examine the ecological response and biomass allocation of Pinus koraienes, Fraxinus mandshurica, Juglans mandshurica, Tilia amurensis, and Quercus mongolica. The five dominant species in the Korean pine-broadleaf forest at Changbai mountain. Their seedlings were grown under three different soil moistures, e.g., 85%-100% (CK), 65%-85% (MW) and 45%-65% (LW) of field water-holding capacity. The results showed that drought significantly decreased the individual leaf area, number of fine root, root length, and individual biomass of seedlings. The root proportions of T. amurensis and F. mandshurica increased with increasing soil water content, but the leaf proportion of J. mandshurica and Q. mongolica in MW treatment was higher than that of CK and LW. There was no significant difference in stem proportions of 5 tree species among different water stress treatments. The response of the biomass of 5 tree species to water stress was significant, the total biomass of T. amurensis, F. mandshurica, J. mandshurica and P. koraienes in MW and LW decreased by 32.8%, 43.6%, 26.2% and 23.8%, respectively, while that in Q. mongolica increased by 4.8%, indicating that Q. mogolica was the most drought-tolerent species among 5 tested species.
Biomass↗
[Decomposition processes of Tilia amurensis leaves in the Changbai Mountain forest ecosystem].
A 4-year field experiment was carried out in the Changbai Mountain to study the decomposition process of Tilia amurensis leaf and its affecting environmental factors. The results reveal that the decomposition process of Tilia amurensis leaves could be expressed by an exponent equitation. With the increase of elevation and the change of vegetation types, the decomposition rate in 1-5 standard experimental fields was -0.391, -0.339, -0.257, -0.198 and -0.125, respectively, indicating that the decomposition rate was decreased with ascending elevation. The maximum decomposition took place when the environment was in the shadow of 60%-80%. The leaves were acceleratively decomposed when the tested moisture was increased. Moisture affected the decomposition process more strongly than light.
Biodegradation, Environmental↗
Detailed deletion mapping on chromosome region 9p21 in human periampullary neoplasms.
OBJECTIVE: To further define the extent of chromosome 9p21 deletion in periampullary neoplasms. METHODS: The loss of heterozygosity at 5 microsatellite polymorphic markers on chromosome 9p21 was detected by polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and silver staining in 35 specimens of periampullary neoplasms and their matching blood samples. RESULTS: Fifty percent (4/8) of pancreatic cancer cases showed the loss of heterozygosity at one or more microsatellite loci, with the more frequent sites of D9S974 (37.5%) and D9S942 (28.6%), and some showing consecutive allelic loss. Sixty-two point five percent (5/8) of ampullary carcinoma cases showed loss of heterozygosity at one or more of the loci, frequent site of loss being D9S942 (42.9%) and the next most frequent being IFNA (37.5%) and D9S171 (37.5%). Loss of one locus was observed in 14.2% (1/7) of insulinoma. CONCLUSION: The minimal common region of chromosome deletion in periampullary neoplasms is defined between the D9S974 and D9S942 loci within a 15 kb interval in 9p21, suggesting the involvement of a novel tumor suppressor gene in their carcinogenesis.
Adolescent↗
Imaging diagnosis of cervical spine and spinal cord injuries in children.
OBJECTIVE: To provide the experience in imaging diagnosis of cervical spine and spinal cord injuries in children. METHODS: Imaging data of cervical spine and spinal cord injuries in 62 children were retrospectively reviewed. The routine radiography including the lateral, anteroposterior and open-mouth odontoid views were performed in all the patients. Tomography was available for 25 patients, and flexion-extension lateral views for 28 patients, CT scanning for 21 patients, MRI for 26 patients. RESULTS: Of these patients, 46 patients were identified with in juries of upper cervical spine (9 with atlantal arch fracture, seven with axial fracture, 21 with odontoid fracture, 1 with atlantal arch fracture combining with odontoid fracture, and 1 with atlantal transverse ligament disruption); 7 patients sustained injuries of lower cervical spine (3 fractures of vertebral body, 2 dislocations and 6 fracture-dislocations); 2 patients had multiple noncontiguous cervical injuries; and 3 had cervical spinal cord injury without radiographic abnormalities (SCIWORA). CONCLUSIONS: Imaging assessment is of great importance in the diagnosis of cervical spine and spinal cord injuries in children. Whenever cervical spine and spinal cord injuries are suspected for children patients, and the three-views should be routinely indicated. MRI should be routinely performed in all children with cervical SCIWORA.
Adolescent↗
[Expression of cytokeratin 7 and 20 in ovarian metastatic carcinomas].
OBJECTIVE: To study the distinctive clinicopathologic and immunohistochemical difference between ovarian metastatic carcinomas and primary ovarian carcinomas. METHODS: The clinical and pathological features of 27 cases of ovarian metastatic carcinomas (gastric carcinomas 12 cases, colon carcinomas 11 cases, others 4 cases) obtained from our department were reviewed. Immunostainings for CK (AE1/AE3), CK7, CK20, CEA, vimentin, nm23 were performed with SP staining methods. RESULTS: On gross examination, metastasis from gastric adenocarcinoma were usually bilateral, while solid (11/12) and metastases from colonic adenocarcinoma were more often unilateral and cystic (7/11). Microscopically, metastases from gastric adenocarcinoma revealed signet ring cells or poorly differentiated adenocarcinomas (12/12), whereas metastases from colonic adenocarcinomas showed similar morphology of endometrioid adenocarcinoma (8/11). The majority of ovarian metastases of gastric carcinoma (7/12) and colon carcinoma (8/11) were CK20 positive. In particular, CK20 was invariably expressed in colon cancer metastases. Most of the ovarian metastatic carcinomas from the gastrointestinal tract failed to react with immunostaining of CK7. A combined use of CEA, vimentin and nm23 had made a correct classification for 11/12 cases of the gastric carcinoma, 10/11 cases of the colonic cancer. CONCLUSIONS: CK7 and CK20 have been proved to be useful antibodies in distinguishing between metastatic carcinomas and primary carcinomas of the ovary. Combined use of a panel of antibodies can give more significant results.
Adenocarcinoma↗
[The change in resistance of Pseudomonas aeruginosa to gentamicin during in vitro subculturing].
OBJECTIVE: To observe the change in resistance of Pseudomonas aeruginosa (PA) to gentamicin (GM) during in vitro subculturing. METHODS: Twenty -- six strains of PA with resistance to GM isolated from burn patients were subcultured in vitro for 30 generations. The strains were also divided into high level (20 strains) and medium level (6 strains) of resistant groups according to their MIC (minimum inhibition concentration) values. The MIC and MBC (minimal bactericidal concentration) levels were examined in every strains of the 1st, 10th, 20th, and 30th filial generations of PA strain. RESULTS: There was no significant general difference of MIC and MBC values among the filial generations in each group (P < 0.05) when multiple comparisons of MIC and MBC mean values were made among every filial generations in high and medium levels of GM resistant groups. CONCLUSION: There was no evident difference in GM resistance among all the filial generations of PA. The result indicated that, the PA with different levels of GM resistance clinically found might come from different PA strains.
Anti-Bacterial Agents↗
A case of Erdheim-Chester disease with bilateral orbital involvement.
PURPOSE: To describe a case of Erdheim-Chester disease with bilateral orbital involvement. METHODS: A 43-year-old female with bilateral proptosis was presented. Its clinical features, image findings, pathological character and therapeutic effect were evaluated. RESULTS: CT demonstrated bilateral, diffuse orbital mass. Histopathologic assessment revealed a diffuse xanthogranulomatous process with clusters of lipidladen histocytes. Numerous Touton giant cells were scattered throughout the lesion. Renal and heart failure happened during a 6-year follow-up period. Long bones roentgenogram demonstrated diffuse symmetrical sclerosis with extensive, lytic lesions. Systemic administration of corticosteroids, chemotherapy, immunoglobulin and traditional Chinese medicine showed good therapeutic result. CONCLUSIONS: An administration of systemic corticosteroids, chemotherapy, immunoglobin and traditional Chinese medicine can control Erdheim-Chester disease. Further exploration of its pathogenesis and collection of useful clinical data are required.
Adult↗
[Analysis on the sex ratios at birth for deliveries in hospitals in China from 1987 to 1992].
OBJECTIVE: To estimate the sex ratios at birth (SRB) for livebirths in hospitals in China. METHODS: Data were collected by the birth defects monitoring network. The livebirths with gestation of 28 weeks or over delivered in hospitals of 30 provinces, municipalities and autonomous regions all over the country from 1987 to 1992 were analyzed and used for calculating the SRB. RESULTS: The high male bias in SRB was observed in the data from most areas, and there was an upward trend of SRB, especially in rural areas. The SRB for livebirths in the hospitals of urban areas was normal from 1987 to 1989, and rose to 108.9 in 1992. The SRB for rural areas was high and was 109.9 in 1987, and rose to 111.8 in 1992. The SRB for livebirths given by the mothers under 20 years of age and coming from lower educational background was higher than that for others. The SRB for higher parities was even higher. CONCLUSION: The SRB in China is high; this is possibly related to sex-preference. Under-reporting of female neonates and "missing females" are not the main causes of the rising SRB.
China↗
Magnetic resonance imaging of acute central cord syndrome: correlation with prognosis.
OBJECTIVE: To report the magnetic resonance imaging (MR) findings of acute cervical central cord syndrome and to determine their correlation with the prognosis. METHODS: MRI findings of 35 patients with acute central cord syndrome were studied and compared with the recovery rate of ASIA score at presentation and in follow-up. RESULTS: MRI data demonstrated spinal cord compression for 32 patients, spinal cord swelling for 16 patients, and abnormal signal intensity within the spinal cord for 19 patients, including 14 with edema and 3 with hematoma. No significant difference of the recovery rate was noted between the patients treated nonoperatively and operatively (P > 0.05). There was a significant inverse correlation between the recovery rate and the degree of spinal cord compression as shown in MRI scans (P < 0.01). The presence of hematoma in MRI scans was associated with poor prognosis, as demonstrated by a significant difference of the recovery rate (P < 0.01) among the patients with normal intensity, edema and hematoma within the spinal cord. CONCLUSIONS: MRI scans provide an efficient assistance for decision-making and accurate prognostic information regarding neurological function, and therefore should routinely be performed within the early phase of acute central cord syndrome.
Adult↗
Thoracic spine fractures.
OBJECTIVE: To investigate the unique characteristics and treatment of thoracic spine fractures. METHODS: Seventy-seven patients with thoracic spine fractures were retrospectively reviewed. Of these, there were 37 compression fractures, 34 fracture-dislocations, 3 burst fractures and 3 burst-dislocations. Twenty-six patients had a complete lesion of the spinal cord, 14 sustained a neurologically incomplete injury, and 37 were neurologically intact. Fifty-three patients were treated nonoperatively and 24 treated operatively. RESULTS: All patients were followed up for 2 approximately 15 years. None of the 26 patients with a complete lesion recovered any significant function. Of 37 neurologically intact patients, 13 had local pain although all of them remained normal function. Two of 14 patients with incomplete paraplegia returned to normal, 7 recovered some function and 5 did not recovered. CONCLUSIONS: Because of the unique anatomy and biomechanics of the thoracic spine, the classification commonly applied to thoracolumbar fractures is not suitable for thoracic fractures. Fusion and instrumentation are indicated when the fractures are unstable, while patients with incomplete lesion of the spinal cord may be the candidates for supplemented decompression.
Adolescent↗
Peroxidase-catalyzed asymmetric sulfoxidation in organic solvents versus in water.
Peroxidase-catalyzed asymmetric sulfoxidations, while synthetically attractive, suffer from relatively low reaction rates due to poor substrate solubilities in water and from appreciable spontaneous oxidation of substrates (especially aryl alkyl sulfides) with H(2)O(2). In this work, we found that both of these shortcomings could be alleviated by switching from aqueous solutions to certain nearly anhydrous (99.7%) organic solvents as sulfoxidation reaction media. The rates of spontaneous oxidation of the model prochiral substrate thioanisole in several organic solvents were observed to be some 100- to 1000-fold slower than in water. In addition, the rates of asymmetric sulfoxidation of thioanisole in isopropyl alcohol and in methanol catalyzed by horseradish peroxidase (HRP) were determined to be tens to hundreds of times faster than in water under otherwise identical conditions. This dramatic activation is due to a much higher substrate solubility in organic solvents than in water and occurs even though the intrinsic reactivity of HRP in isopropyl alcohol and in methanol is hundreds of times lower than in water. Sulfoxidation of thioanisole catalyzed by four other hemoproteins (soybean peroxidase, myoglobin, hemoglobin, and cytochrome c) is also much faster in isopropyl alcohol than in water.
Biotechnology↗
Aligned Coaxial Nanowires of Carbon Nanotubes Sheathed with Conducting Polymers M.G. is grateful for a joint scholarship from Wollongong University and CSIRO; S.H. and L.D. thank the support from the Department of Industry, Science, and Technology (DIST), Australia; R.P.G. and Z.L.W. thank the support of US NSF grants (DMR-9733160), and the NSF of China.
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Journal Article↗
Nanomechanics of individual carbon nanotubes from pyrolytically grown arrays.
The bending modulus of individual carbon nanotubes from aligned arrays grown by pyrolysis was measured by in situ electromechanical resonance in transmission electron microscopy (TEM). The bending modulus of nanotubes with point defects was approximately 30 GPa and that of nanotubes with volume defect was 2-3 GPa. The time-decay constant of nanotube resonance in a vacuum of 10(-4) Torr was approximately 85 micros. A femtogram nanobalance was demonstrated based on nanotube resonance; it has the potential for measuring the mass of chain-structured large molecules. The in situ TEM provides a powerful approach towards nanomechanics of fiberlike nanomaterials with well-characterized defect structures.
Journal Article↗
Genomic organization of three novel toxins from the scorpion Buthus martensi Karsch that are active on potassium channels.
The cDNA and genomic DNA of three novel toxins from the scorpion Buthus martensi Karsch that are active on K(+) channels, designated BmKTX (where KTX is kaliotoxin), BmTX1 and BmTX2, were cloned and sequenced. On the basis of their known amino acid sequences, gene-specific primers for 3' and 5' rapid amplification of cDNA ends (RACE) were designed and synthesized. By overlapping the two partial cDNA sequences obtained by 3' and 5' RACE, their full-length cDNA sequences were completed. BmKTX encodes a signal peptide of 22 amino acid residues and a mature toxin of 38 residues, whereas BmTX1 and BmTX2 encode signal peptides of 20 and 21 residues respectively and a mature toxin of 38 residues for each. Their cDNA-deduced amino acid sequences were totally consistent with those determined except that the C-terminus of BmKTX had an additional Gly residue, which was removed during post-translational processing and was indispensable for the amidation of its C-terminal Lys residue. In addition, the first deduced amino acid for both BmTX1 and BmTX2 is Gln instead of pyro-Glu in the reported toxins, which obviously also undergoes post-translational processing. The genomic DNA species of these three toxins were also amplified by PCR, then cloned and sequenced. They all consisted of two exons disrupted by a small single intron. All of these introns were inserted within the signal peptides at position -6 for BmKTX and at position -5 for both BmTX1 and BmTX2 upstream of the mature toxins, and consisted of 87, 87 and 80 bp respectively.
Amino Acid Sequence↗
Central cord injury complicating acute cervical disc herniation in trauma.
STUDY DESIGN: A retrospective study on 24 patients with acute central cervical cord injury caused by traumatic disc herniation. OBJECTIVES: To determine the correlation of disc herniation with central cord injury and to evaluate the role of anterior cervical decompression and interbody fusion in management of this injury. SUMMARY OF BACKGROUND DATA: Acute cervical disc herniation has been documented as a causative factor in spinal cord injury but has been infrequently reported with central cord syndrome. METHODS: Between 1989 and 1994, 24 patients with acute cervical disc herniation and central cord syndrome were studied. These patients underwent anterior decompression and fusion, and were followed for 2 to 7 years, with an average follow-up period of 3 years and 8 months. The degree of disc herniation and neurologic scores were rated. RESULTS: During follow-up period, the American Spinal Injury Association motor score in 24 patients was increased to 86.46 +/- 10.22 from 47.79 +/- 19.66. The age of the patients was very negatively correlated with recovery rate (P < 0.01), but no correlation was observed between severity of cord compression and neurologic scores (P > 0.05). Postoperative neurologic improvement in patients with fracture or dislocation was very significantly slower (P < 0.01) than in those without these injuries. CONCLUSIONS: Far more common than previously expected, acute disc herniation in cervical spine injury is the one of principal cause for central cord syndrome. Magnetic resonance imaging assessment and surgical intervention are required.
Acute Disease↗
The gene cloning and sequencing of Bm-12, a chlorotoxin-like peptide from the scorpion Buthus martensi Karsch.
According to the known amino acid sequence of Bm-12, a short chain insect neurotoxin from the venom of the scorpion Buthus martensi Karsch (BmK) with considerable primary sequence homology to chlorotoxin, the gene specific primers were designed and synthesized for 3' and 5'RACE (Rapid Amplification of cDNA Ends). The two partial cDNA fragments obtained by 3' and 5'RACE were cloned and sequenced, and the full length cDNA sequence of Bm-12 was then completed by overlapping these two partial cDNA sequences. The predicted amino acid sequence consists of 59 amino acid residues including a putative signal peptide of 24 residues and a mature toxin of 35 residues. The predicted amino acid sequence of Bm-12 was almost consistent with the determined, different only in one residue at position 27, Lys was replaced by Gly. Based on the determined cDNA sequence, and using the total DNA isolated from the scorpion venom glands as a template, the genomic DNA of Bm-12 was also amplified by PCR and sequenced. The genomic DNA sequence revealed an intron of 93 bp present within the signal peptide region.
Amino Acid Sequence↗
Os odontoideum: etiology, diagnosis, and management.
BACKGROUND: There have been few reports of os odontoideum since the initial description. METHODS: Forty-four patients with os odontoideum treated during the period 1980 through 1996 were reviewed. There were 33 males and 11 females. Their ages ranged from 7 to 56 years, with an average of 24.6 years. Five patients with no symptoms were treated conservatively. Thirty-nine patients underwent operative treatment including nine posterior atlantoaxial fusions and 33 occipitocervical fusions. RESULTS: The patients were followed up for one to 16 years, with an average of 6.5 years. Five patients treated conservatively have remained stable. All 39 treated patients achieved solid arthrodesis. The results were satisfactory. CONCLUSIONS: We conclude that fusion is indicated if atlantoaxial instability or clinical symptoms are significant, and that occipitocervical fusion should be considered in the operative management of os odontoideum if atlantoaxial arthrodesis is impossible.
Adolescent↗