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Biomedical subjects

A Wang

Publications and source records attributed to A Wang.

At least 127 records · Page 7Linked to original sources
PubMed1999

[Effect of kidney deficiency caused by ovariectomy on serum osteocalcin level and tumor necrosis factor in mice with collagen induced arthritis].

OBJECTIVE: To explore the effect of ovariectomy caused Kidney Deficiency on the metabolism of bone in mice with collagen induced arthritis. METHODS: The mice for experiment were immunized with subcutaneous injection of type II collagen to induce arthritis after ovariectomy. Severity of joint swelling, radioimmunoassay of serum estradiol (E2), osteocalcin (OC) and tumor necrosis factor (TNF), and pathological changes of joint, including changes on synovia, articular cartilage and bone, were observed once weekly. RESULTS: The E2 level of ovariectomized mice dropped down obviously, while the contents of OC and TNF increased significantly. Severe pathological changes can be seen in synovial tissues, cartilage and bone. CONCLUSION: Kidney Deficiency caused by ovariectomy exacerbated the pathological changes of collagen-induced arthritis in mice.

Animals↗
PubMed1999

[A clinical study on vaccine of Mycobacterium vaccae in treating pulmonary tuberculosis].

OBJECTIVE: To study the effect of vaccine of Mycobacterium vaccae on cell-mediated immunity and on treating patients with pulmonary tuberculosis. METHODS: Seventy cases of pulmonary tuberculosis with smear positive and initial treatment were classified randomly into group I (35 cases) and group II (35 cases), receiving 2HRZS/4HR and 2HRZS/4HR plus vaccine of Mycobacterium vaccae regimens respectively. Thirty-one multi-drug resistant pulmonary tuberculosis cases were classified into group III, receiving 4 - 6 sensitive antituberculous drugs and vaccine of Mycobacterium vaccae. Improvement of clinical symptoms, resolution of pulmonary lesions, negative conversion of sputum and changes of immunological functions were observed. RESULTS: No significant difference in improvement of symptoms was found in group I and group II (P > 0.05), and the improvement rate of clinical symptoms in group III was found more than 50%. X-ray resolution rates in 4th month were 83% and 89%, and cavity reducing rates 40% and 50% respectively in group I and group II, and no significant differences were found (P > 0.05). X-ray resolution rate was 29%, cavity reducing rate 7% and no deteriorated case was found in group III. Sputum negative conversion rates in 1st, 2nd, 3rd and 4th month were 23%, 51%, 83% and 97% respectively in group I, while 31%, 77%, 89% and 100% in group II, and 3%, 16%, 29% and 32% in group III. Significant difference was found between group I and group II in sputum negative conversion rate in 2nd month after treatment (P < 0.05). After treatment, values of lymphocyte transformation test (LTT), CD(3), CD(4) and CD(4)/CD(8) of the above 3 groups were all higher than that before the treatment (P < 0.05), level of tumor necrosis factor decreased in group II and IL-2, IL-6 increased in group III. CONCLUSIONS: Vaccine of Mycobacterium vaccae is a good immunotherapy preparation, which promotes sputum negative conversion and activation of cell-mediated immunity.

Adolescent↗
PubMed1999

[Gene regulation studies on purine biosynthetic in Salmonella typhimurium IX. Mutation analysis of PUR box 2].

Two consensus bases C and G in 16 bp PUR box were directed mutated to G and A separately by PCR amplification. The binding function of PUR box carrying mutation with PUR protein were examined by gel retardation experiment. The results showed that the PUR box with above mutations could not bind with purR protein extracted from LT2. It proved that the two consensus bases C and G are necessary for PUR box binding with purR protein.

Bacterial Proteins↗
PubMed1999

[Analyze T lymphocyte subsets of HIV/AIDS patients by flowcytometer].

OBJECTIVE: Using flowcytometer (FCM) to detect CD4+, CD8+ lymphocytes in peripheral blood, combine with clinical symptoms to evaluate the HIV/AIDS patients' immune state. METHODS: Anti-coagulated peripheral blood were obtained from 8 HIV-AIDS patients and 5 normal persons. After analyzing their total white cell counts, the whole blood was stained with two-color immunofluorescence using directly conjugated monoclonal antibody pairs, followed by lysis of red erythrocytes, fixation of lymphocytes, and analysis by flowcytometry. Multiplying the CD4 and CD8 percentages by the absolute number of lymphocytes obtained from the total white blood cell (WBC) count divide by the lymphocyte differential percentage, we got the CD4, CD8 counts. RESULTS: The HIV/AIDS patients' CD4 counts were lower than those of normal controls'. Especially, the AIDS patients' CD4 counts were all below 200 cells/mm3 and their clinical symptoms were serious. CONCLUSION: The HIV/AIDS patients' CD4 counts are highly correlated with their clinical symptoms. The result also shows that FCM is accurate, sensitive and reliable in CD4 count.

Acquired Immunodeficiency Syndrome↗
PubMed1999

[Study on chitosan-Zn (II) complex by IR spectroscopy].

A series of chitosan-Zn (II) complexes were synthesized by reaction of chitosan and ZnSO4 in different ratios(chitosan : Zn (II) = 1 : 0.05-1 : 1) in dilute formic acid aqueous solution. The results showed that -NH2, -OH and -NHCO- of chitosan molecule were coordinated to Zn (II) based on the analyse of the IR spectra of chitosan, chitosan-H2SO4 and chitosan-ZnSO4. SO4(2-) of chitosan-ZnSO4 may be crosslinking of chitosan molecule, but Cl-, CH3COO- and NO3- were not crosslinked to chitosan molecule in the chitosan-ZnCl2, chitosan-Zn (CH3COO)2 and chitosan-Zn (NO3)2 complexes.

Chitosan↗
PubMed1998

What does the left atrial v wave signify during balloon commissurotomy of mitral stenosis?

Left atrial v-wave amplitude has been associated with the presence and severity of chronic mitral regurgitation (MR) but it has not been evaluated for the detection of acute MR. We evaluated the left atrial v-wave amplitude of 205 consecutive patients with mitral stenosis immediately before and after stepwise, incremental balloon mitral commissurotomy to determine predictors of large v waves at baseline and an increase in v-wave amplitude after balloon commissurotomy. The sensitivity and specificity of an increase in v-wave amplitude for detecting worsening and severe MR were determined. A large v wave was present in 44% of patients before balloon commissurotomy and was predicted by age, mean left atrial pressure, mean transmitral gradient, mean pulmonary artery pressure, and angiographic severity of MR. There was a strong inverse correlation between v-wave amplitude and calculated left atrial compliance (r = -0.92). An increase in v-wave amplitude after balloon commissurotomy was associated with an increasing probability of worsening or severe MR. This indicator had a sensitivity, specificity, and positive and negative predictive values of 35%, 91%, 64%, 75%, respectively, for detecting any increase in MR. For the detection of severe MR, the sensitivity was 79%, specificity 89%, positive predictive value 42%, and negative predictive value 98%. Thus, left atrial v-wave amplitude reflects left atrial compliance and severity of mitral stenosis before balloon commissurotomy. An increase in v-wave amplitude is an insensitive but very specific indicator of worsening or severe MR during stepwise, incremental balloon mitral commissurotomy.

Atrial Function, Left↗
PubMed1998

Correction of deafness in shaker-2 mice by an unconventional myosin in a BAC transgene.

The shaker-2 mouse mutation, the homolog of human DFNB3, causes deafness and circling behavior. A bacterial artificial chromosome (BAC) transgene from the shaker-2 critical region corrected the vestibular defects, deafness, and inner ear morphology of shaker-2 mice. An unconventional myosin gene, Myo15, was discovered by DNA sequencing of this BAC. Shaker-2 mice were found to have an amino acid substitution at a highly conserved position within the motor domain of this myosin. Auditory hair cells of shaker-2 mice have very short stereocilia and a long actin-containing protrusion extending from their basal end. This histopathology suggests that Myo15 is necessary for actin organization in the hair cells of the cochlea.

Amino Acid Sequence↗
PubMed1998

Association of unconventional myosin MYO15 mutations with human nonsyndromic deafness DFNB3.

DFNB3, a locus for nonsyndromic sensorineural recessive deafness, maps to a 3-centimorgan interval on human chromosome 17p11.2, a region that shows conserved synteny with mouse shaker-2. A human unconventional myosin gene, MYO15, was identified by combining functional and positional cloning approaches in searching for shaker-2 and DFNB3. MYO15 has at least 50 exons spanning 36 kilobases. Sequence analyses of these exons in affected individuals from three unrelated DFNB3 families revealed two missense mutations and one nonsense mutation that cosegregated with congenital recessive deafness.

Amino Acid Sequence↗
PubMed1998

Chromosomal locations of three human nuclear genes (RPSM12, TUFM, and AFG3L1) specifying putative components of the mitochondrial gene expression apparatus.

We have mapped the chromosomal locations of three human nuclear genes for putative components of the apparatus of mitochondrial gene expression, using a combination of in situ hybridization and interspecies hybrid mapping. The genes RPMS12 (mitoribosomal protein S12, a conserved protein component of the mitoribosomal accuracy center), TUFM (mitochondrial elongation factor EF-Tu), and AFG3L1 (similar to the yeast genes Afg3 and Rca1 involved in the turnover of mistranslated or misfolded mtDNA-encoded polypeptides) were initially characterized by a combination of database sequence analysis, PCR, cloning, and DNA sequencing. RPMS12 maps to chromosome 19q13.1, close to the previously mapped gene for autosomal dominant hearing loss DFNA4. The TUFM gene is located on chromosome 16p11.2, with a putative pseudogene or variant (TUFML) located very close to the centromere of chromosome 17. AFG3L1 is located on chromosome 16q24, very close to the telomere. By virtue of their inferred functions in mitochondria, these genes should be regarded as candidates of disorders sharing features with mitochondrial disease syndromes, such as sensorineural deafness, diabetes, and retinopathy.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1998

Multiple copies of the ALA-D gene are located at the Lv locus in Mus domesticus mice.

Incremental differences in delta-aminolevulinate dehydratase (ALA-D; the second enzyme of the heme biosynthetic pathway) activity among inbred mouse strains can be attributed to variation in the number of copies of the ALA-D gene. We have cloned and characterized the Lv locus from an inbred mouse strain (DBA/2J) that has three times the normal ALA-D activity levels. The entire 12-kb ALA-D gene plus 16 kb of flanking DNA are found in 28-kb tandemly repeating units. We used the derived nucleotide sequence surrounding the internal junction of the repeats to survey wild-caught mice and demonstrate that multiple copies of the ALA-D gene occur in 7 of 24 worldwide locations of Mus domesticus mice. Data are consistent with a model that high lead (Pb) in the environment may be providing a selective advantage to mice harboring multiple copies of the ALA-D gene, since the enzyme is potently inhibited by lead.

Animals↗
PubMed1998

Hemifacial spasm: clinical findings and treatment.

Hemifacial spasm (HFS) is a peripherally induced movement disorder characterized by involuntary, unilateral, intermittent, irregular, tonic or clonic contractions of muscles innervated by the ipsilateral facial nerve. We reviewed the clinical features and response to different treatments in 158 patients (61% women) with HFS evaluated at our Movement Disorders Clinic. The mean age at onset was 48.5+/-14.1 years (range: 15-87) and the mean duration of symptoms was 11.4+/-8.5 (range: 0.5-53) years. The left side was affected in 56% instances; 5 patients had bilateral HFS. The lower lid was the most common site of the initial involvement followed by cheek and perioral region. Involuntary eye closure which interfered with vision and social embarrassment were the most common complaints. HFS was associated with trigeminal neuralgia in 5.1% of the cases and 5.7% had prior history of Bell's palsy. Although vascular abnormalities, facial nerve injury, and intracranial tumor were responsible for symptoms in some patients, most patients had no apparent etiology. Botulinum toxin type A (BTX-A) injections, used in 110 patients, provided marked to moderate improvement in 95% of patients. Seven of the 25 (28%) patients who had microvascular decompression reported permanent complications and the HFS recurred in 5 (20%). Although occasionally troublesome, HFS is generally a benign disorder that can be treated effectively with either BTX-A or microvascular decompression.

Adult↗
PubMed1998

Trimethylamine-N-oxide counteracts urea effects on rabbit muscle lactate dehydrogenase function: a test of the counteraction hypothesis.

Trimethylamine-N-oxide (TMAO) in the cells of sharks and rays is believed to counteract the deleterious effects of the high intracellular concentrations of urea in these animals. It has been hypothesized that TMAO has the generic ability to counteract the effects of urea on protein structure and function, regardless of whether that protein actually evolved in the presence of these two solutes. Rabbit muscle lactate dehydrogenase (LDH) did not evolve in the presence of either solute, and it is used here to test the validity of the counteraction hypothesis. With pyruvate as substrate, results show that its Km and the combined Km of pyruvate and NADH are increased by urea, decreased by TMAO, and in 1:1 and 2:1 mixtures of urea:TMAO the Km values are essentially equivalent to the Km values obtained in the absence of the two solutes. In contrast, values of k(cat) and the Km for NADH as a substrate are unperturbed by urea, TMAO, or urea:TMAO mixtures. All of these effects are consistent with TMAO counteraction of the effects of urea on LDH kinetic parameters, supporting the premise that counteraction is a property of the solvent system and is independent of the evolutionary history of the protein.

Animals↗
PubMed1998

Effect of femoral head surface roughness on the wear of ultrahigh molecular weight polyethylene acetabular cups.

We studied the effect of femoral head surface roughness on the wear of ultrahigh molecular weight polyethylene (UHMWPE) acetabular cups using a hip joint simulator and a reciprocating wear tester. Compared with the hip simulator, the reciprocating wear tester severely exaggerates the effect of counterface roughness on UHMWPE wear and drastically underestimates the wear rate of the UHMWPE against smooth undamaged counterfaces. According to the hip simulator test results, the wear rate of the UHMWPE cups is approximately proportional to the square root of the femoral head roughness Ra (center-line-average roughness) rather than to Ra raised to a power greater than one as predicted by pin-on-disk studies. Roughening of the femoral heads by an order of magnitude results in a 2- to 3-fold increase in the wear rate. Therefore, the much wider clinical variations of wear cannot be fully explained by variations in surface roughness of the femoral heads.

Acetabulum↗
PubMed1998

Genetic mapping refines DFNB3 to 17p11.2, suggests multiple alleles of DFNB3, and supports homology to the mouse model shaker-2.

The nonsyndromic congenital recessive deafness gene, DFNB3, first identified in Bengkala, Bali, was mapped to a approximately 12-cM interval on chromosome 17. New short tandem repeats (STRs) and additional DNA samples were used to identify recombinants that constrain the DFNB3 interval to less, similar6 cM on 17p11.2. Affected individuals from Bengkala and affected members of a family with hereditary deafness who were from Bila, a village neighboring Bengkala, were homozygous for the same alleles for six adjacent STRs in the DFNB3 region and were heterozygous for other distal markers, thus limiting DFNB3 to an approximately 3-cM interval. Nonsyndromic deafness segregating in two unrelated consanguineous Indian families, M21 and I-1924, were also linked to the DFNB3 region. Haplotype analysis indicates that the DFNB3 mutations in the three pedigrees most likely arose independently and suggests that DFNB3 makes a significant contribution to hereditary deafness worldwide. On the basis of conserved synteny, mouse deafness mutations shaker-2 (sh2) and sh2J are proposed as models of DFNB3. Genetic mapping has refined sh2 to a 0.6-cM interval of chromosome 11. Three homologous genes map within the sh2 and DFNB3 intervals, suggesting that sh2 is the homologue of DFNB3.

Alleles↗
PubMed1998

Long-term treatment of lupus nephritis with cyclosporin A.

We evaluated the efficacy and safety of long-term treatment with cyclosporin A (CSA) in type IV lupus nephritis. Seventeen patients with biopsy-proven WHO type IV lupus nephritis were enrolled in a prospective, open study. Twelve of the 17 completed 48 months of treatment with CSA and prednisolone. Three patients required the addition of azathioprine, at 12, 38 and 47 months, respectively, for cutaneous disease flare with refractory rashes. One patient was lost to follow-up at 40 months. The mean +/- SD duration of treatment was 43.2 +/- 10.1 months (range 15.7-48 months). A significant reduction of proteinuria and a significant rise in serum albumin were noted 1 month after initiation of treatment. Improvement was maintained throughout the study except for three patients who relapsed with recurrence of nephrotic syndrome. There were no significant changes in serum creatinine level or creatinine clearances throughout the study. Repeat renal biopsy at 12 months following treatment with CSA showed histological improvement, with WHO type II changes in all 17 patients accompanying significant reduction in activity indices. Patients with baseline haemoglobin (Hgb) levels < 12 g/dl showed significant improvement. Serum C3 and C4 levels were not changed significantly. Corticosteroid-sparing effects were noted. Side-effects included hypertension, gum hypertrophy and mild hirsuitism, but were not serious. Combination therapy using CSA and prednisone is effective and safe for long-term treatment in lupus patients with WHO type IV nephritis.

Adult↗