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Biomedical subjects

L L Wang

Publications and source records attributed to L L Wang.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Application of microsurgical technique in the intrasinus renalis pyeloureteroplasty in pelvic atresia in children].

Seven cases of pelvic atresia in children were treated by the intrasinus renalis pyeloureteroplasty with the application of microsurgical technique. The site of pelviureteric anastomosis was unobstructed and the hydronephrosis was greatly improved through postoperative examinations of intravenous urography and renogram. This procedure provides clear field, simple performance and high successful rate. The prevention of complete pelviureteric laceration and pelvic atresia in children, the advantages of the microsurgical technique, and the operation precautions are discussed.

Adolescent↗
PubMed1994

[The effects of Panax quinquefolium saponin (PQS) and its monomer ginsenoside on heart].

Experiments have shown that PQS (0.03-3 mg/ml) can inhibit the contractility of papillary muscle of guinea pigs, and on depolarized sample of papillary muscle with high potassium, PQS (0.03-0.3 mg/ml) can increase this contractility. Monomer saponin-Re (10 mg/kg),-Rb3 (30 mg/kg) can inhibit the hemodynamic indication of rats, but pseudogisenoside-F11 (10 mg/kg) acts the other way round. These results prove that PQS contains two components of opposite actions.

Animals↗
PubMed1993

Cloning and nucleotide sequence of frpC, a second gene from Neisseria meningitidis encoding a protein similar to RTX cytotoxins.

Neisseria meningitidis FAM20 has recently been shown to produce two Fe-regulated proteins (FrpA and FrpC) related to the RTX family of cytotoxins. Here we report the cloning and DNA sequence of the locus containing the gene encoding the larger meningococcal RTX protein FrpC. FrpC was highly similar to FrpA throughout much of the predicted protein, with two main differences. Whereas the FrpA protein had 13 copies of the nine-amino-acid repeat units typical of RTX proteins, FrpC had 43 copies. The additional copies in FrpC apparently arose from a threefold tandem amplification of a 600bp DNA fragment encoding the repeats. In addition, the frpC gene lacked good promoter consensus sequences. An open reading frame (ORF1) of unknown function was found immediately upstream of frpC, suggesting the possibility that frpC was cotranscribed with ORF1. A probable promoter was found 300bp upstream of ORF1, and it contained a Fur protein-binding sequence found in the promoters of Fe-regulated Escherichia coli genes. DNA upstream of the ORF1/frpC promoter was homologous to IS1016-like elements surrounding capsulation loci of strains of Haemophilus influenzae. A FrpC-like protein (reactive in immunoblots with monoclonal antibody 9D4; multiple reactive bands of about 200 to 120 kDa) was found in five out of eight meningococcal strains but only in one out of 14 other Neisseria, suggesting that FrpC may participate in the pathogenesis of meningococcal disease.

Amino Acid Sequence↗
PubMed1993

Neisseria meningitidis produces iron-regulated proteins related to the RTX family of exoproteins.

A monoclonal antibody (A4.85) which reacted with Fe-regulated proteins of Neisseria meningitidis, was used to isolate a lambda gt11 clone from N. meningitidis FAM20. Chromosomal fragments flanking the fragment expressing the A4.85 epitope were cloned, and their DNA sequences revealed a 3,345-bp open reading frame predicting a 122-kDa protein. This gene was named frpA (Fe-regulated protein). A computer similarity search of GenBank revealed high levels of similarity to members of the RTX family of cytotoxins, especially in a region of tandem 9-amino-acid repeats. These repeats are found in all members of the RTX family; similar repeats were present 13 times in the predicted FrpA protein. Antigenic relatedness between the meningococcal proteins and the RTX proteins was demonstrated by the reactivity of A4.85 with Escherichia coli hemolysin (HlyA) and Bordetella pertussis adenylate cyclase-hemolysin (CyaA). Similarly, FrpA was recognized by 9D4, a monoclonal antibody directed against B. pertussis CyaA. In addition to the frpA gene, a second gene (frpC) produced a larger RTX-related protein. The frpA and frpC loci were mutagenized in strain FAM20, resulting in the loss of RTX-related proteins. A 120-kDa protein was expressed from the reconstructed frpA gene in E. coli. The biological function of FrpA is unknown, but its similarity to other RTX toxins suggests that it may play an important role in the pathogenesis of meningococcal infection.

Amino Acid Sequence↗
PubMed1993

[Preliminary study of immunophenotype of multiple myeloma cells].

Using the alkaline phosphatase-anti-alkaline phosphatase (APAAP) technique, plasma cells from multiple myeloma (MM, 23 cases), plasma cell leukemia (PCL, 2 cases) and reactive plasmacytosis (RP, 13 cases) were immunophenotyped with a panel of monoclonal antibodies (McAb). The results showed that McAbCD38 was strongly positive in high percentage of MM and RP cases and the CD9 was the next. 9/23 MM expressed CD10. Our results might indirectly support that CD10 is a malignant marker of MM with poor prognosis, a concept proposed by Durie. The results were (1) all RP but 1 acute monocytic leukemia related to RP were CD10 negative. (2) In our series 2 cases of plasma cell leukemia (PCL) expressed CD10; (3) 4 MM cases survived more than 2 years were CD10 negative. A few MM cases also expressed other surface markers of pre-B and B lymphocyte, such as CD19, CD20, CD22, HLA-DR, cytoplasmic mu chain. CD20 was positive in 4/21 MM and negative in all RP cases. 7/22 MM expressed HLA-DR, and 1/13 RP did so, among them there was a significant difference. HLA-DR seems to be another malignant marker of plasma cells. 1 MM expressed CD8, and 1 PCL highly expressed CD4 indicating PCL might be heterogeneous. Lymphoid stem cells may be involved in MM and PLC. We conclude that multiple myeloma cells have different immunophenotypes and CD10, CD20 and HLA-DR may help to differentiate MM from RP.

Antigens, CD↗
PubMed1992

Inhibition of Listeria monocytogenes by fatty acids and monoglycerides.

Fatty acids and monoglycerides were evaluated in brain heart infusion broth and in milk for antimicrobial activity against the Scott A strain of Listeria monocytogenes. C12:0, C18:3, and glyceryl monolaurate (monolaurin) had the strongest activity in brain heart infusion broth and were bactericidal at 10 to 20 micrograms/ml, whereas potassium (K)-conjugated linoleic acids and C18:2 were bactericidal at 50 to 200 micrograms/ml. C14:0, C16:0, C18:0, C18:1, glyceryl monomyristate, and glyceryl monopalmitate were not inhibitory at 200 micrograms/ml. The bactericidal activity in brain heart infusion broth was higher at pH 5 than at pH 6. In whole milk and skim milk, K-conjugated linoleic acid was bacteriostatic and prolonged the lag phase especially at 4 degrees C. Monolaurin inactivated L. monocytogenes in skim milk at 4 degrees C, but was less inhibitory at 23 degrees C. Monolaurin did not inhibit L. monocytogenes in whole milk because of the higher fat content. Other fatty acids tested were not effective in whole or skim milk. Our results suggest that K-conjugated linoleic acids or monolaurin could be used as an inhibitory agent against L. monocytogenes in dairy foods.

Animals↗
PubMed1992

Molecular cloning and mapping of phenol degradation genes from Bacillus stearothermophilus FDTP-3 and their expression in Escherichia coli.

Two genes of the meta pathway of phenol degradation were cloned from a phenol-utilizing strain of Bacillus stearothermophilus and were mapped by subcloning and by use of a Tn5 insertion mutation. They code for phenol hydroxylase and catechol 2,3-dioxygenase, respectively. The gene encoding catechol 2,3-dioxygenase, which is more thermostable than catechol 2,3-dioxygenase encoded by the other gene, shares rather limited homology with that from Pseudomonas putida.

Catechol 2,3-Dioxygenase↗
PubMed1992

[Long-term effect of one-stage urethroplasty with perineoscrotal insular skin tube in the treatment of complex posterior urethral stricture].

Thirty-one cases with complex stricture of posterior urethra were treated with one stage urethroplasty adopted perineoscrotal insular skin tube. The results of follow-up for 1 to 6 years were as follows: All cases urinated normally; The cystourethrography in 21 cases showed that urethrae were unobstructed; The urinary flow studies were carried out in 16 cases and the results showed that urinary flow rate curves were normal and that the maximum flow rate, the mean flow rate and the voiding time were all beyond normal values; The urethroscopy in 8 cases revealed that the surfaces of skin tubes remained smooth and without growth of hair stem. The facts stated as above indicated that this procedure was an ideal method for the treatment of long posterior urethral stricture.

Adolescent↗
PubMed1992

A toxicological and epidemiological study on reproductive functions of male workers exposed to lead.

The reproductive ability of 24 men exposed to lead was observed and the same number of no-exposed men were taken as controls. The influential factors, such as age, smoking and drinking were controlled. The finding shows higher prevalence of congenital epilepsy and heart disease in the filial generation of workers exposed to lead and high rate of teratospermia in the exposed workers. Meanwhile hypospermia, as well as decreased lactate dehydrogenase-x(LDH-x) and succinodehydrogenase (SDH) in sperm were found in exposed group.

Adult↗
PubMed1991

Effect of dimensionality of heterogeneity corrections on the implementation of a three-dimensional electron pencil-beam algorithm.

Electron beam dose distributions were calculated on a three-dimensional grid using three pencil-beam algorithms, each taking into account irregularities in field shape. The algorithms differ in that patient anatomy in either one, two, or three dimensions is used in the calculation of dose to a point. Algorithms were optimized for speed by such techniques as precalculation and storage of several quantities, reordering of pencil-beam and grid-point loops, selection of cut-off values for some calculated quantities, and invoking error function symmetries. Execution times for optimized versions of each of the algorithms as implemented on a three-dimensional treatment planning system were comparable for both the one- and two-dimensional heterogeneity correction requires an additional calculational loop over fan lines. Execution times for the three-dimensional heterogeneity correction were approximately a factor of four longer than those for the two-dimensional correction. For certain geometries, three-dimensional heterogeneity corrections were necessary to calculate dose distributions accurately, in spite of the additional cost in calculation times.

Algorithms↗
PubMed1991

[Late results of testis autotransplantation].

Seven patients with bilateral undescended testes (9 intraabdominal testes and 5 inguinal testes), aged 7 to 29 years, were treated surgically. Testis autotransplantation was done for 9 intra-abdominal testes, and cryptorchidopexy was done for 5 inguinal testes. Follow-up for 5 to 9 years showed that the transplanted testes survived except 1 atrophied helf a year after operation. The size of the transplanted was as big as that of international testis model 15, and their hardness was moderate. Obvious improvement of secondary sex character and sexual function were observed in 6 of the 7 patients. The value of serum testosterone was norma (1450-600ng/dl) in 4 patients. In 4 patients, sperms were found in semen. The wives of 2 of those patients bore a boy and a girl respectively in 2-3 years after operation. Operative treatment and optimal age for testis autotransplantation are discussed.

Adolescent↗
PubMed1991

Studies on the mutagenicity of hair dyes made in China.

A total of 13 commercial hair dye products made in China were tested for mutagenicity in 2 short-term bioassays, the histidine-requiring mutants of Salmonella typhimurium (strains TA98 and TA100) and the micronucleus test with mouse bone-marrow polychromatic erythrocyte cells in vivo. The results showed that the 13 hair dyes were not mutagenic in strains TA98 and TA100 with and without S-9. In the micronucleus test, no mutagenic effect was observed.

Animals↗
PubMed1991

[Full length urethral stricture. One-stage urethroplasty using double island skin tube from perineum and scrotum].

One-stage urethroplasty was performed for 10 patients with full length urethral stricture by using double skin tube from the perineum and scrotum. Follow-up after operations showed that voiding of urine returned to normal and no residual urine was found in all patients. Voiding urethrogram and cystoscopy showed neither stenosis nor hair, stone, urethral cyst and diverticula. This operation is simple and effective in addition to rare complication and no requirement of urethral dilatation. The treatment of full length urethral stricture and tubercular urethral stricture are also discussed.

Adult↗
PubMed1991

Threshold of transmission of Brugia malayi by Anopheles sinensis.

In an area of central China where Brugia malayi is transmitted by Anopheles sinensis, three villages were followed for 4 years without any control measures. Diethylcarbamazine (DEC) had been used in a control programme reducing the parasite rate in Shuiwa from 12.72 to 0.59%, in Gubomen from 3.18 to 1.55% and in Moshi from 5.62 to 2.81% (although this fell the following year to 2.23%) up until the start of the trial. The village populations, the human biting rate, the parous and the gonotrophic cycle were comparable for all the areas, yet the microfilariae rate dropped to 0.18% in Shuiwa, 0.31% in Gubomen, but not in Moshi where it increased from 2.23 to 2.43%. This indicated that Shuiwa and Gubomen were below the threshold of transmission. Due to the small number of positive cases remaining, the density measurements showed less change, but a separate study on 44 individuals followed for 6 years revealed that those above 13 microfilariae per 60 mm3 remained unchanged or increased, while those below progressively decreased their densities. The threshold of transmission of B. malayi by An. sinensis was considered to be between 1.55 and 2.23% of the population, providing no individual had a higher density than 12 microfilariae per 60 mm3.

Animals↗
PubMed1990

Enzymatic synthesis of polyaniline film using a copper-containing oxidoreductase: bilirubin oxidase.

Electroactive polyaniline films have been synthesized by using a copper-containing oxidoreductase, bilirubin oxidase (BOD). Enzymatic polymerization took place on the surface of BOD-adsorbed solid matrix which was in contact with a buffer solution containing aniline. Optimum conditions for enzymatic polymerization of aniline were investigated. Elemental analysis and IR spectroscopy indicated that the enzymatically synthesized film was polyaniline. The cyclic voltammetric studies demonstrated that the polyaniline film was electrochemically reversible in the redox properties in acidic aqueous solutions. Since the film retained enzymatic activity of BOD which was employed as a catalyst for polymerization, enzymatic polymerization seems promising in preparation of immobilized enzyme membranes.

Aniline Compounds↗
PubMed1989

[Late results of testis homotransplantation].

15 patients with testis dysplasia and traumatic anorchidism were treated with testis homotransplantation. 14 of 15 cases have been followed up for 1.5 to 5 years. The transplanted testes of 14 cases were with moderate hardness and obvious improvement of secondary sex characters and sexual function have been observed in these patients. The size of the transplanted testes was as big as that of international testis model 15 in 11 cases. The transplanted testes of 3 cases atrophied 9 to 14 months after operation. The sperms were found in semen or urine collected from the bladders after prostatic massage in 3 cases. Sperm count and sperm motility were normal in 2 cases. The wife of 1 case was impregnated and bore a boy in the fourth year after operation. The value of serum testosterone became normal (450-900 ng/dl) from preoperative low level. Therapeutic effectiveness of testis homotransplantation was evaluated and treatment of rejective reaction of the testis homotransplantation was discussed in the paper.

Adult↗