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L H Chen

Publications and source records attributed to L H Chen.

At least 19 recordsLinked to original sources
PubMed2026

[Analysis of clinical spectrum and genotype characteristics of 9 cases of Fabry disease].

Objective: To investigate the genetic characteristics and clinical phenotypes across different genotypes in patients with Fabry disease. Methods: Clinical data of 9 confirmed FD patients treated from June 2019 to December 2025 at the Affiliated Huai'an No.1 people's Hospital of Nanjing Medical University were retrospectively analyzed. The diagnostic criteria for FD included α-galactosidase A (α-GalA) activity, GLA gene sequencing, globotriaosylsphingosine levels, and renal biopsy findings, supplemented by clinical symptoms and signs. Genetic testing was performed on both the proband and their family members. Proband underwent next-generation sequencing of the GLA gene using the long-range PCR. Family members were verified by conventional PCR combined with Sanger sequencing. Variants were classified according to the 2015 American College of Medical Genetics and Genomics guidelines for sequence variation interpretation. Results: Of the 9 patients, 4 were males and 5 were females. The mean α-Gal A activity was (0.47±0.13) μmol·L-1·h-1 in males and (2.38±0.91) μmol·L-1·h-1 in females. The mean age at diagnosis was (43.0±16.7) years. The main clinical manifestations included renal impairment in 7 cases (proteinuria, chronic kidney disease, or end-stage renal disease), cardiac involvement in 8 cases (myocardial hypertrophy, arrhythmia, etc.), and autonomic nervous system symptoms in 6 cases (hypohidrosis). Pathogenic or likely pathogenic GLA variants were identified in all 9 patients, of which 8 were classified as pathogenic and 1 as a variant of uncertain significance. Three patients underwent family screening: in one case, the variant was possibly inherited from the maternal grandmother; one case was confirmed as a de novo mutation; and in one case, paternal inheritance could not be excluded. Renal biopsy in one patient revealed characteristic myeloid bodies and zebra bodies. Among the 9 patients, 1 received agalsidase α and 8 received agalsidase β, with one case developing infusion-associated reactions after 12 infusions. During the follow-up period, one patient died due to cardiac complications. Conclusions: FD patients exhibit a broad clinical spectrum and diverse genotypes. Atypical presentations should be closely monitored to enable early diagnosis and treatment, thereby improving prognosis.

Humans↗
PubMed1996

Catalytic role of the amino-terminal proline in 4-oxalocrotonate tautomerase: affinity labeling and heteronuclear NMR studies.

4-Oxalocrotonate tautomerase (EC 5.3.2-; 4-OT), a hexamer consisting of 62 residues per subunit, catalyzes the isomerization of unsaturated alpha-keto acids, converting unconjugated ketones to the conjugated isomers via a dienolic intermediate. The recently solved crystal structure of an isozyme of 4-OT suggests that the amino-terminal proline is the catalytic base [Subramanya, H. S., Roper, D. I., Dauter, Z., Dodson, E. J., Davies, G. J., Wilson, K. S., & Wigley, D. B. (1996) Biochemistry 35, 792-802]. In support of this proposed role, we have found that the active-site-directed irreversible inhibitor 3-bromopyruvate (3-BP) blocks the amino terminus of 4-OT to Edman degradation and results in the disappearance of the 15N resonance of Pro-1 (delta = 49.2 ppm at pH 6.40 and 42 degrees C) in the 15N NMR spectrum of uniformly 15N-labeled 4-OT. Furthermore, covalent bonding between a 15N resonance of 4-OT and the methylene carbon of the reduced, 3-(13)C-labeled lactyl adduct derived from [3-(13)C]-bromopyruvate was then directly demonstrated using two heteronuclear NMR methods, an 1H-(13)C HSQC experiment and a novel inverse correlation experiment which we call H(C)N. The chemical shift of the modified 15N resonance (delta = 86.5 ppm) is consistent with that of an alkylated and cationic, amino-terminal proline. Affinity labeling with 2-(14)C-labeled bromopyruvate indicates that the ultimate stoichiometry of modification is I equiv of 3-BP per 4-OT monomer. However, an analysis of the residual enzyme activity after differing extents of fractional modification with 3-BP indicates that modification of three active sites per hexamer abolishes essentially all activity of the hexamer. Thus, 4-OT exhibits half-of-the-sites stoichiometry with 3-BP. Finally, the pH dependence of kinact/KI for affinity labeling by 3-BP yields a pKa value of 6.7 +/- 0.3, in reasonable agreement with the pKa values found for kcat/KM for the non-sticky substrate 2-hydroxy-2,4-pentadienoate and by direct NMR titration of Pro-1 [Stivers, J. T., Abeygunawardana, C., Mildvan, A. S., Hajipour, G., & Whitman, C. P. (1996) Biochemistry 35, 814-823]. These results strongly implicate the amino-terminal proline as the general-base catalyst on 4-OT.

Affinity Labels↗
PubMed1995

Sequence verification of human creatine kinase (43 kDa) isozymes by high-resolution tandem mass spectrometry.

Amino acid sequencing by recombinant DNA technology, although dramatically useful, is subject to base reading errors, is indirect, and is insensitive to posttranslational processing. Mass spectrometry techniques can provide molecular weight data from even relatively large proteins for such cDNA sequences and can serve as a check of an enzyme's purity and sequence integrity. Multiply-charged ions from electrospray ionization can be dissociated to yield structural information by tandem mass spectrometry, providing a second method for gaining additional confidence in primary sequence confirmation. Here, accurate (+/- 1 Da) molecular weight and molecular ion dissociation information for human muscle and brain creatine kinases has been obtained by electrospray ionization coupled with Fourier-transform mass spectrometry to help distinguish which of several published amino acid sequences for both enzymes are correct. The results herein are consistent with one published sequence for each isozyme, and the heterogeneity indicated by isoelectric focusing due to 1-Da deamidation changes. This approach appears generally useful for detailed sequence verification of recombinant proteins.

Artifacts↗
PubMed1995

Case-control study of passive smoking and the risk of small-for-gestational-age at term.

There is concern about the effects of passive smoking during pregnancy on fetal growth. The authors conducted a case-control study of the association of maternal exposure to passive smoking during pregnancy and the risk of term small-for-gestational-age (SGA) infants in a population of white women who did not smoke during pregnancy and had only a small percentage of users of illegal drugs and alcohol. A total of 111 cases, defined as singleton term (> or = 37 weeks) infants with birth weights < or = 10th percentile for gestational age were compared with 124 term, non-SGA controls. All were identified from Contra Costa, California birth certificates for January 1-September 30, 1991. Subjects were interviewed face-to-face to collect information on exposure to passive smoking during pregnancy. The estimated relative risk for term SGA in association with passive smoke exposure during pregnancy was not increased (> or = 30 hours: odds ratio (OR) = 0.41, 95% confidence interval (Cl) 0.12-1.29) and the risk of term SGA did not increase with increasing hours of exposure to passive smoking. Controlling for parity, weight gain, prepregnancy weight, maternal age, prenatal care, education, income, alcohol consumption, and work during pregnancy in multivariate analysis did not change the findings (> or = 30 hours: OR = 0.47, 95% Cl 0.13-1.69). In this study, maternal exposure to passive smoking during pregnancy was not associated with an increased risk of term SGA. Although difficulties in precisely assessing exposure limit these findings, they should provide some reassurance to women who cannot avoid passive exposure to cigarette smoking during pregnancy.

Case-Control Studies↗
PubMed1995

Potent antiplatelet, anti-inflammatory and antiallergic isoflavanquinones from the roots of Abrus precatorius.

Five isoflavanquinones have been isolated from the roots of Abrus precatorius L. (Leguminosae). Three of them are new and designated as abruquinones D, E, and F. The pharmacological activities of the isoflavanquinones have been evaluated. The results indicated that abruquinones A, B, and D exhibited remarkable inhibitory effects on the platelet aggregation. The IC50 of abruquinones A and B for the inhibition of the platelet aggregation induced by arachidonic acid (AA) and collagen were less than 5 micrograms/ml, and of abruquinone D, was less than 10 micrograms/ml for that induced by AA. On the other hand, abruquinones A, B, D, and F showed strong anti-inflammatory and antiallergic effects. The IC50 of abruquinones A, B, D, and F for the inhibition of superoxide formation were less than 0.3 micrograms/ml, for the inhibition of the release of both beta-glucuronidase and lysozyme from rat neutrophils and the release of both beta-glucuronidase and histamine from mast cells were less than 1 microgram/ml.

Animals↗
PubMed1995

Uterine perforation during elective first trimester abortions: a 13-year review.

OBJECTIVE: The purpose of this study was to determine the incidence, presentation, management and outcome of uterine perforation during elective first trimester abortions. METHODS: We conducted a retrospective study of 40 patients, including 2 transferred patients, who sustained uterine perforation during elective abortions from January 1980 to December 1992. RESULTS: The incidence of uterine perforation was 0.8 per 1,000 procedures (0.08%). There were 8 (20%) nulliparae and 3 (7.5%) grand multigravidae. 82.5% of the cases occurred when the abortion was performed by medical officers or junior registrars under training. The commonest perforating instrument was the suction cannula (25%) followed by the uterine sound (22.5%) and the dilator (20%). Three (7.5%) cases were treated conservatively, 33 (82.5%) cases underwent emergency operation, 2 (5%) cases were discovered during subsequent sterilisation, and 2 (5%) cases suffered undiagnosed perforation and were re-admitted for emergency surgery. Morbidity included post operative fever (12.5%), bowel injury (7.5%), retained conceptus (5%) and wound breakdown (2.5%). There was no mortality. CONCLUSION: A careful assessment of the uterine size and position, vigilance in the use of uterine sound and dilators, greater care in the use of suction cannula, and experience in vacuum aspiration will decrease the incidence of uterine perforation during elective abortions. A high degree of suspicion, early diagnosis and treatment will prevent the potential complications that may arise from uterine perforation.

Abortion, Induced↗
PubMed1994

The ompA 5' untranslated region impedes a major pathway for mRNA degradation in Escherichia coli.

The unusual longevity of the Escherichia coli ompA transcript is determined by its 5' untranslated region (UTR), which functions in vivo as an mRNA stabilizer. Here we show that this 5' UTR can prolong the lifetime in E. coli of a variety of heterologous mRNAs to which it is joined, either as a gene fusion or as an operon fusion. Statistical extrapolation suggests that it is quite likely that most E. coli mRNAs could be stabilized in this manner. We conclude that the ompA 5' UTR impedes a major pathway for mRNA degradation in E. coli and that stabilization by fusion to this UTR does not require translational readthrough of the heterologous mRNA segment by ribosomes that initiate translation at the ompA ribosome-binding site. Additional experiments indicate that the E. coli ribonuclease whose action is slowed by the ompA 5' UTR is not RNase III.

Bacterial Outer Membrane Proteins↗
PubMed1994

Extramedullary plasmacytoma of the head and neck.

Extramedullary plasmacytoma (EMP) is an uncommon malignant plasma cell neoplasm which usually presents as soft tissue mass in the head and neck. We retrospectively reviewed 7 cases with EMP of the head and neck between 1978 and 1992. All patients were male. Their ages ranged from 27 to 66 years. M-protein was identified in 5 patients (IgG-kappa in 3, IgG-lambda in 1 and Lambda light chain in 1). All but one were treated with local irradiation. Three patients received chemotherapy. All patients have been alive for 37+ to 116+ months since the diagnosis of EMP. One patient had a cervical node recurrence 9 years after local irradiation and the other one who refused local irradiation but received chemotherapy developed multiple myeloma 5 years later. Based on our experience and the review of the literature, it is recommended that irradiation to the primary sites and the involved cervical nodes is the treatment of choice. Additional chemotherapy may be considered in patients with disease progression, recurrence, or dissemination. The M-protein is a useful parameter to assess tumor control or disease progression.

Adult↗
PubMed1993

Femoral shaft fractures complicated by fracture-dislocations of the ipsilateral hip.

A series of 16 consecutive adults with femoral shaft fractures complicated by fracture-dislocations of the ipsilateral hip joint was prospectively studied. There were 11 posterior dislocations and five central dislocations. The treatment consisted of early closed reduction of the dislocation with the assistance of an external fixator, delayed reamed intramedullary nailing of the femoral fracture, and conservative or surgical treatment of the hip joint according to the indications. The follow-up period was 2-8 years (median, 3.5 years). Although an 18.8% (3 of 16) complication rate was noted, the outcome was satisfactory for all 16 hip joints. When such complicated combined injuries are sustained, the technique described here is the most reasonable treatment.

Adolescent↗
PubMed1993

Effects of chronic alcohol feeding and murine AIDS virus infection on liver antioxidant defense systems in mice.

Whether ethanol (ETOH) abuse could contribute to the development of acquired immunodeficiency syndrome (AIDS) among human immunodeficiency virus (HIV)-positive drug abusers is a critical question for which little experimental information is available. This study was designed to determine if chronic ETOH feeding and murine AIDS virus infection cooperatively affected liver antioxidant defense systems in C57B1/6 female mice. Mice were divided into two groups and fed the Lieber-DeCarli liquid ETOH diet containing ETOH at a concentration to provide 31% of total caloric intake or an isocaloric liquid control (control) diet in which dextrin-maltose replaced ETOH. One week after the initiation of ETOH feeding, half of the mice in each diet group (8 mice) were injected intraperitoneally with murine retrovirus (MAIDS) stock. After 3 and 5 weeks of ETOH feeding, half of the mice in each of the four treatment groups (4 mice) were killed, and livers were excised for biochemical analysis. Liver reduced glutathione (GSH) levels and activities of glutathione peroxidase (GP), glutathione reductase (GR), glutathione transferase (GT), catalase and superoxide dismutase (SOD), and serum ETOH concentrations were determined. The results demonstrated that serum ETOH concentrations were significantly elevated in ETOH-MAIDS group when compared with the ETOH group. Moreover, chronic ETOH feeding and MAIDS infection independently depressed liver antioxidant defense capability, and together led to an additive inhibition of GSH and SOD activities. In addition, MAIDS infection inhibited an ETOH-induced increase in catalase and GT activities. These results suggest that alcohol abuse could contribute to the development of AIDS by inhibiting the protective capability of an infected individual against oxidative stress.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Comparison of radiotherapy and surgical results of early stage glottic cancer: a retrospective analysis.

From March 1977 to October 1989, 85 patients with early stage glottic cancer were treated with either radiotherapy or surgery at Chang Gung Memorial Hospital (CGMH). Patients were excluded from the analysis of local control if they died or remained disease-free with a follow-up period of less than two years. Of the 26 patients treated with definitive radiotherapy, initial control of the primary lesions was achieved in 100% of stage T1s, 76% of T1, and 57% of T2 patients. Surgical salvage of radiation failure was achieved in 83% of the patients, giving the ultimate local control of 100% for T1s, 94% for T1, 86% for T2 patients. Of the 44 patients treated with definitive surgery, initial control of the primary lesions was achieved in 100% for T1s, 95% for T1, and 78% for T2 patients. Salvage of the surgical failure was 50%, giving the ultimate control in this group of 100% for T1s, 95% for T1, 83% for T2. There was no difference in either initial or ultimate control of T1 and T2 lesions between patients treated with primary radiotherapy and primary surgery. Voice preservation rates were 73% and 34% in the radiotherapy and surgery group, respectively. When divided into two groups according to the times they were being treated, we found that surgery preserved a comparable number of larynges as radiotherapy did after 1988 (60% vs 77%, p = 0.33). It is concluded that radiotherapy and surgery could achieve the same good local control results and long-term survival and comparable functional results of early stage glottic cancer, if conservative surgery is carefully selected for each patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Effects of captopril on myocardial ultrastructure in diabetic rats].

Diabetic rat models were established with intraperitoneal injection of streptozotocin. The animals were randomly divided into four groups: Group 1, normal control (n = 5); Group 2, diabetic control (n = 4); Group 3, diabetics treated with PZI (n = 5); Group 4, diabetics treated with PZI and captopril (n = 5). Specimens taken from free wall of the left ventricle were observed under electron microscope after 10-week treatment, and the volume density (Vv), numerical density on area (Na), numerical density (Nv) and mean volume (V) of mitochondria were measured with stereological quantitation. The results showed that the myocardial changes in Group 4 were much less severe than those in Group 3 and similar to those in Group 1. There was significant difference in Nv (P < 0.05) but not in Vv, Na and V between Group 4 and Group 1. While the changes of Group 3 were relatively obvious. As comparing Group 3 with Group 1, there were significant differences in all of the four parameters (P < 0.05-0.01). It is implied that the renin-angiotensin system may be involved in the pathogenesis of diabetic cardiomyopathy, since captopril can improve and reverse the cardiomyopathy of diabetic rats.

Animals↗
PubMed1992

4-Oxalocrotonate tautomerase, an enzyme composed of 62 amino acid residues per monomer.

The xylH gene encoding 4-oxalocrotonate tautomerase (4-OT) has been located on a subclone of the Pseudomonas putida mt-2 TOL plasmid pWW0 and inserted into an Escherichia coli expression vector. Several of the genes of the metafission pathway encoded by pWW0 have been cloned in E. coli, but the overexpression of their gene products has met with limited success. By utilizing the E. coli alkaline phosphatase promoter (phoA) coupled with the proper positioning of a ribosome-binding region, we are able to express functional 4-OT in yields of at least 10 mg of pure enzyme/liter of culture. 4-OT has been previously characterized and shown to be an extremely efficient catalyst (Whitman, C. P., Aird, B. A., Gillespie, W. R., and Stolowich, N. J. (1991) J. Am. Chem. Soc. 113, 3154-3162). Kinetic and physical characterization of the E. coli-expressed protein show that it is identical with that of the 4-OT isolated from P. putida. The functional unit is apparently a pentamer of identical subunits, each consisting of only 62 amino acid residues. This is the smallest enzyme subunit reported to date. The amino acid sequence, determined in part from automated Edman degradation and also deduced from the primary sequence of xylH, did not show homology with any of the sequences in the current data bases nor with any of the sequences of enzymes that catalyze similar reactions. We propose that the active site of 4-OT may be established by an overlap of subunits and comprised of amino acid residues belonging to several, if not all, of the subunits.

Amino Acid Sequence↗
PubMed1992

Effects of the peroxisome proliferators ciprofibrate and perfluorodecanoic acid on hepatic cellular antioxidants and lipid peroxidation in rats.

The purpose of this study was to determine if hepatic cellular antioxidants and indices of oxidative damage are altered by administration of the peroxisome proliferators ciprofibrate and perfluorodecanoic acid (PFDA). Rats were fed 0.01% ciprofibrate in the diet or were injected with PFDA (0.5 or 5.0 mg/kg, i.p.) every 4 weeks for 6, 14, 30, 54, and 78 weeks. Peroxisomal fatty acyl-CoA oxidase and catalase activities were increased by both ciprofibrate and PFDA throughout the study. Neither ciprofibrate nor PFDA increased the levels of malonaldehyde or conjugated dienes, but ciprofibrate decreased these indices at early time points. Ciprofibrate decreased the following cellular antioxidants or antioxidant enzymes: vitamin C, vitamin D, DT-diaphorase, glutathione peroxidase, glutathione-S-transferase, and glutathione reductase; superoxide dismutase and glutathione were not affected. PFDA decreased DT-diaphorase and increased superoxide dismutase, but did not affect other cellular antioxidants. This study shows that administration of the peroxisome proliferators ciprofibrate and PFDA did not increase indices of lipid peroxidation, but that cellular antioxidant defenses were inhibited for a prolonged period of time by the peroxisome proliferator ciprofibrate.

Acyl-CoA Oxidase↗
PubMed1992

Preliminary results of concurrent radiotherapy and chemotherapy with cis-platinum, vincristine, and bleomycin in bulky, advanced cervical carcinoma: a pilot study.

Twenty-four patients with bulky (greater than 4 cm), advanced (stages IIB-IVA) carcinoma of the uterine cervix were prospectively treated with a concurrent combination of radiotherapy (RT) and chemotherapy (CT). RT consisted of 4400 cGy (22 fractions) to the whole pelvis and a 1400-cGy boost to the parametrium. This was followed by two to three intracavitary brachytherapy courses. CT consisted of one to four course (median, three) of cisplatin (50 mg/m2) on Day 1, vincristine (1 mg/m2) on Day 2, and bleomycin (25 mg/m2) on Days 2-4. CT was started on the first day of external radiation and the scheduled course interval was 21 days. Among the 20 evaluable patients who completed at least one course of chemotherapy and a full course of radiation, 13 (65%) achieved complete response and 5 (25%) had partial response. Fatal complication occurred in 1 patient with stationary disease who died of septic shock due to ruptured pyometra. The other patient with primary stage IVA disease had progressive disease with ascites appearance after two courses of CT and later expired. Transient drug fever occurred in 19 (40.4%) of the 47 bleomycin-containing CT cycles. Grade 2 or 3 hematological toxicities occurred in 16 (30.2%) of a total of 53 CT cycles. Treatment delays of 1 to 7 days occurred in 15 (28.3%) CT cycles. Except for the case of septic shock, all of the other toxicities were generally tolerable and reversible. From this preliminary result we concluded that this particular combination of RT and CT in bulky, advanced cervical carcinoma is effective in enhancing local pelvic tumor control and well tolerated if strict selection of accrued patients is applied. Further investigation to assess its impact on long-term survival is in progress.

Adenocarcinoma↗
PubMed1992

Use of an oligonucleotide probe to detect Vibrio parahaemolyticus in artificially contaminated oysters.

A 26-mer oligonucleotide specific to Vibrio parahaemolyticus was synthesized from a 1,275-bp thermostable direct hemolysin (tdh) gene. This oligonucleotide probe specifically reacted with DNA from 89 of 95 V. parahaemolyticus isolates but not with DNA from other vibrios or other enteric and nonenteric organisms (n = 48). The probe hybridized with Southern blots of 0.5-kb HindIII-restricted chromosomal DNA fragments from all but five V. parahaemolyticus test isolates. The probe could be used to directly identify V. parahaemolyticus in artificially contaminated food without an isolation step.

Animals↗