Biomedical subjects

Mei Li

Publications and source records attributed to Mei Li.

142 records · Page 8Linked to original sources

PubMed2002

[Treatment of hyperthyroid atrial fibrillation associated with Graves disease by prednisone].

OBJECTIVE: To investigate the clinical effect of prednisone on hyper thyroid atrial fibrillation associated with Graves disease (HAFGD). METHODS: Twenty-four patients with hyperthyroid atrial fibrillation associated with Graves disease were divided into two groups: traditional antithyroid group (10 cases, with 2 males and 8 females, treated by methimazole 15 approximately 30 mg/d and propranolol 15 approximately 30 mg/d) and prednisone group (14 cases with 3 males and 11 females, treated by methimazole 15 approximately 30 mg/d, propranolol 15 approximately 30 mg/d, and prednisone 30 mg/d). The effects of these two remedies on reversion from atrial fibrillation to sinus rhythm were compared. RESULTS: The cardiac rhythm reverted to sinus rhythm in 12 out of the 14 cases in prednisone group with a reversion rate of 86% and the mean reversion time of 3.8 months (range 3.8 +/- 2.6 months), and in 4 out of the 10 cases in traditional antithyroid remedy group with the mean reversion rate of 40% and mean reversion time of 2.8 months (range 2.8 +/- 1.0 months). The reversion rate was significantly higher in prednisone group than in the traditional remedy group (P < 0.05). CONCLUSION: Treatment of prednisone is more beneficial to reversion of atrial fibrillation into sinus rhythm among patients with HARGD.

Adult↗

PubMed2002

Lipid peroxidation and advanced glycation end products in the brain in normal aging and in Alzheimer's disease.

The cellular distribution of malondialdehyde (MDA) was assessed immunohistochemically in brain specimens from young and normal elderly subjects as well as patients with Alzheimer's disease (AD). MDA was increased in the cytoplasm of neurons and astrocytes in both normal aging and AD, but was rarely detected in normal young subjects. By electron microscopic immunohistochemistry, neuronal MDA formed cap-like linear deposits associated with lipofuscin, while glial MDA deposits surrounded the vacuoles in a linear distribution. In the hippocampus, neuronal and glial MDA deposition was marked in the CA4 region but mild in CA1. By examination of serial sections stained with anti-MDA and antibodies against an advanced glycation end product, N(epsilon)-(carboxymethyl)lysine (CML), neuronal and glial MDA deposition was colocalized with CML in AD, but only neuronal MDA was colocalized with CML in normal aged brains. Glial MDA, although abundant in the aged brain, typically was not colocalized with CML. In AD cases, MDA was colocalized with tau protein in CA2 hippocampal neurons; such colocalization was rare in CA1. MDA also was stained in cores of senile plaques. Thus, while both MDA and CML accumulate under oxidative stress, CML accumulation is largely limited to neurons, in normal aging, while MDA also accumulates in glia. In AD, both MDA and CML are deposited in both astrocytes and neurons.

Adolescent↗

PubMed2002

Crystallization and preliminary crystallographic analysis of manganese superoxide dismutase from Bacillus halodenitrificans.

Manganese superoxide dismutase (GP-MnSOD), a component of the so-called 'green protein' (green protein complex) from the facultative anaerobic halodenitrifier Bacillus halodenitrificans, has been crystallized using the hanging-drop vapor diffusion method. Crystals have unit-cell parameters a=b=93.4 A, c=65.0 A, and belong to the space group P4(3)2(1)2. Preliminary analysis indicates there is one monomer in each asymmetric unit. The structural information from this enzyme will enrich our knowledge on its high catalytic activity and its possible role in green protein complex.

Bacillus↗

PubMed2002

[Effect of serum from patients with Graves' disease on colony forming unit-granulocyte monocyte].

OBJECTIVE: To investigate the effects of serum component from patients with Graves's disease (GD) on the growth of colony forming unit-granulocyte monocyte (GM-CFU). METHODS: Monocytes were obtained from 11 normal persons and 11 GD patients with leukopenia and culture together with sera from 11 GD patients with leukopenia, 11 GD patients without leukopenia, and 11 normal controls for 10 days. Inverted microscopy was used to count the number of colony. RESULTS: Thyroid stimulating immunoglobulin (TSI) and serum from GD patients with leukopenia significantly inhibited the formation of GM-CFU (P < 0.01) while methimazole, thyroxine and serum from GD patients without leukopenia did not have any effect on the formation of GFU-GM (P > 0.05). CONCLUSION: TSI and serum from GD patients with leukopenia remarkably inhibit GM-CFU growth. Autoimmune abnormality may play an important role in the pathogenesis of leukopenia in patients with GD.

Adult↗

PubMed2002

Parallel expression of neurotrophic factors and their receptors in chronic inflammatory demyelinating polyneuropathy.

The mRNA levels of nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), and interleukin-6 (IL-6) were examined in sural nerves of 22 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). The mRNAs for NGF, GDNF, LIF, and IL-6 were upregulated, whereas CNTF mRNA was downregulated significantly in the nerves. The NGF, GDNF, and CNTF, but not LIF mRNA expressions were parallel to those of the cognate receptors, suggesting that these cognate soluble receptors effectively present these factors to maintain and regenerate the axons. Furthermore, IL-6 mRNA expression was significantly parallel to both binding and signal-transducing receptor expression, implying a role of the IL-6 signal for non-neuronal cells in CIDP. These findings indicate that multiple neurotrophic growth factors and cytokines are expressed cooperatively with their concomitant receptors in the nerve lesions of CIDP and play an important role particularly in nerve repair.

Adult↗

PubMed2002

Visual event-related potential changes in two subtypes of multiple system atrophy, MSA-C and MSA-P.

We investigated the visual event-related potentials (ERPs) in two subtypes of multisystem atrophy (MSA) in 15 MSA-C patients, 12 MSA-P patients, and 21 normal control (NC) subjects. We used a visual oddball task to elicit ERPs. No significant changes were seen in N1 or N2 latency, in either MSA-C or MSA-P, compared with the NC group. An early stage of visual information process related to N1 and a visual discrimination process related to N2 might be preserved in both MSA-C and MSA-P. The P3a peak was more frequently undetectable in MSA than in the NC group. Significant P3a amplitude reduction in both MSA-C and MSA-P suggests impairment of the automatic cognitive processing in both MSA-C and MSA-P. Significant difference was found in P3b latency and P3b amplitude only in MSA-C, compared with the NC group. The result suggests the impairment of the controlled cognitive processing after the visual discrimination process in the MSA-C group. We further investigated the correlation between visual ERP changes and magnetic resonance imaging (MRI) data. Quantitative MRI measurements showed reduced size of the pons, cerebellum, perisylvian cerebral area, and deep cerebral gray matter in both MSA-C and MSA-P, and of the corpus callosum only in MSA-P, as compared to NC group. In both MSA-C and MSA-P, P3b latency was significantly correlated with the size on MRI of the pons and the cerebellum. P3b latency in the whole MSA group was also significantly correlated with the size of the pons and the cerebellum. These results indicate that P3b latency changes in parallel with the volume of the pons and the cerebellum in both MSA-C and MSA-P.

Adult↗

PubMed2002

Tropical application of halcinonide cream reduces the severity and incidence of intraperitoneal adhesions in a rat model.

BACKGROUND: Systemic or intraperitoneal administration of corticosteroids has been reported to have conflicting effects on the prevention of peritoneal adhesions. Painting corticosteroid cream directly on the likely site of adhesion formation, owing to its high concentrations and persistent effects, may be a promising approach to prevent peritoneal adhesion formation. METHODS: Adhesions were induced by abrading of the cecum, followed by dropping of 95% ethanol. Sixty Wistar rats were randomly allocated to two control groups with no further treatment of the cecum and to two therapy groups treated with 0.1% halcinonide cream painted directly on the damaged surface of the cecum. After 3 and 7 days, adhesion scores, adhesion incidence, and intraperitoneal leukocytes were evaluated. RESULTS: On both postoperative days 3 and 7, halcinonide cream resulted in a significant decrease in mean adhesion scores (6.80 versus 0.67, 10.40 versus 1.26; P <0.001, P <0.001, respectively). The adhesion incidence was 43.3% for the therapy groups and 100% for controls (P <0.01). On day 3, the total numbers of intraperitoneal leukocytes were 120.73 +/- 24.01 millions for the therapy groups and 270.40 +/- 34.68 for controls (P <0.001). CONCLUSIONS: Painting halcinonide cream directly on the damaged surface of the cecum could effectively reduce the severity and incidence of adhesion, possibly by suppression of early inflammatory exudate and of late fibroblast invasion and proliferation.

Abdomen↗

PubMed2002

Three-dimensional structure of manganese superoxide dismutase from Bacillus halodenitrificans, a component of the so-called "green protein".

A so-called "green protein" has been purified from a moderate halophilic eubacterium, Bacillus halodenitrificans (ATCC 49067), under anaerobic conditions. The protein, which might play an important role in denitrification, dissociates mainly into two components after exposure to air: a manganese superoxide dismutase (GP-MnSOD) and a nucleoside diphosphate kinase. As a first step in elucidating the overall structure of the green protein and the role of each component, the 2.8-A resolution crystal structure of GP-MnSOD was determined. Compared with other manganese dismutases, GP-MnSOD shows two significant characteristics. The first is that the entrance to its substrate channel has an additional basic residue-Lys38. The second is that its surface is decorated with an excess of acidic over basic residues. All these structural features may be related to GP-MnSOD's high catalytic activity and its endurance against the special cytoplasm of B. halodenitrificans. The structure of GP-MnSOD provides the basis for recognizing its possible role and assembly state in the green protein.

Amino Acid Sequence↗

PubMed2002

Multilocus sequence typing scheme for Enterococcus faecium.

A multilocus sequence typing (MLST) scheme has been developed for Enterococcus faecium. Internal fragments from seven housekeeping genes of 123 epidemiologically unlinked isolates from humans and livestock and 16 human-derived isolates from several outbreaks in the United States, the United Kingdom, Australia, and The Netherlands were analyzed. A total of 62 sequence types were detected in vancomycin-sensitive E. faecium (VSEF) and vancomycin-resistant E. faecium (VREF) isolates. VSEF isolates were genetically more diverse than VREF isolates. Both VSEF and VREF isolates clustered in host-specific lineages that were similar to the host-specific clustering obtained by amplified fragment length polymorphism analysis. Outbreak isolates from hospitalized humans clustered in a subgroup that was defined by the presence of a unique allele from the housekeeping gene purK and the surface protein gene esp. The MLST results suggest that epidemic lineages of E. faecium emerged recently worldwide, while genetic variation in both VREF and VSEF was created by longer-term recombination. The results show that MLST of E. faecium provides an excellent tool for isolate characterization and long-term epidemiologic analysis.

Alleles↗

PubMed2002

[Therapeutic vitrectomy for severe uveitis and its complications].

OBJECTIVE: To investigate the therapeutic value of vitrectomy for uveitis and its complications. METHODS: Vitrectomy was performed on 14 patients (14 eyes) with uveitis. In these 14 eyes, there were 6 eyes with severe opacity of vitreous, 5 eyes with cataract, 5 eyes with retinal detachment, and 3 eyes with poor response to medication. Pars plana lenectomy, scleral cryopexy, buckling procedure, endolaser photocoagulation, gas-fluid exchange or silicone oil intraocular tamponade were added according to the different needs. The follow-up varied from 18 to 45 months. RESULTS: Twelve of the 14 eyes obtained better visual acuity, and in the other two light perception remained; less drugs were used after operation in all cases, and the uveitis was controlled. CONCLUSION: Vitrectomy is an effective method for severe uveitis and its complications both in the improvement or stabilization of visual acuity and in the reduction or cessation of systemic treatment.

Adolescent↗

PubMed2002

[Survey on vitamin A deficiency in children under-6-years in China].

OBJECTIVE: To understand the prevalence and spatial distribution of vitamin A deficiency (VAD) in China among children at ages under six years. METHODS: About 8,600 children under 6 years of age in 14 cities and 28 counties of 14 provinces were selected with stratified cluster sampling for survey, including interview with questionnaire for their family information and nutritional status. Blood specimens were collected for measuring serum level of VA with fluorescent spectrophotometry in laboratory. RESULTS: Totally, 8,669 children under 6 (2,877 in urban area and 5,792 in rural area) were surveyed in 14 provinces, with 4,629 males and 4,040 females. Eight cases of night blindness and seven cases of xerophthalmia were found among the children at ages of two to five years. Sixty-one mothers of the children in this group were also found suffering from night blindness. All the cases of night blindness and xerophthalmia both in children and mothers were living in rural areas. Based on their serum levels of VA, 11.7% of the all 1 018 children were diagnosed as VAD, with serum VA concentrations below or equal to 0.70 micro mol/L. Prevalence of VAD was 15.0% and 5.8% in rural (23.3% in the poverty-stricken counties) and urban areas, respectively, and 5.8%, 11.5% and 16.8% in the coastal, inland and remote areas, respectively. The average serum level of VA was 1.20 micro mol/L and 0.99 micro mol/L for urban and rural areas, respectively, with a national average of 1.06 micro mol/L. And, babies under six months of age with an average serum levels of VA < or = 0.70 micro mol/L accounted for 33.4%, and those at ages of four to five years with the same level of VA accounted for 8%. There was significant difference in serum levels of VA between ages, but no significant difference between genders. CONCLUSION: VAD did exist in children of China, especially in the remote and poverty-stricken rural areas and VA supplementation is urgently needed for the children in these regions.

Child↗

PubMed2002

[The experimental study of expression of intercellular adhesion molecule-1 after fluid percussion brain injury].

OBJECTIVE: To determine the changes of intercellular adhesion molecule-1 after traumatic brain injury. METHODS: Use the fluid-percussion model to inflict rat brain and take the samples at 2, 4, 8, 12, 24 hours after brain injury. The samples were studied by immunohistochemistry method combined with image analysis by MIAS image analysis system. RESULT: The expression of ICAM-1 upregulates at 2 hours, reaches peak at 12 hours and falls down at 24 hours after brain injury. CONCLUSION: The changes of ICAM-1 in brain can provide a backup for estimation of injury time and survival period after brain injury which sustained within 24 hours.

Animals↗

PubMed2001

Aggregation Behavior of Nonionic Surfactants Synperonic A7 and A50 in Aqueous Solution.

The aggregation behavior of Synperonic A7 and A50, fatty alcohol ethoxylate nonionic surfactants (C(m)E(n)) with mean polyoxyethylene chain lengths of 7 and 50, respectively, was investigated in aqueous solution by means of surface tension, laser light scattering, steady-state fluorescence, and fluorescence quenching experiments. Surface tension measurements at room temperature indicate that the critical micelle concentration of A7 is 0.1 g/L (0.22 mM) and that of A50 is 0.17 g/L (0.07 mM). Static light scattering measurements reveal that the averaged aggregation number of A7 in water is 417 and that of A50 is 23. When solutions of A7 were allowed to age over a period of months at room temperature, the micelle M(w) and hydrodynamic radius increased. The aggregation numbers found from fluorescence quenching measurements, using excimer formation from 1-ethylpyrene as a probe, were about 300 for freshly prepared solutions of A7 and about 40 for A50. We also found that the presence of air has a strong effect on the data obtained from the fluorescence quenching measurements. Copyright 2001 Academic Press.

Journal Article↗

PubMed2001

Site-specific mutation of the hepatitis B virus enhancer II B1 element: effect on virus transcription and replication.

The hepatitis B virus (HBV) enhancer II (EII) is highly liver-specific and plays an important role in regulating the transcription of all HBV genes. In this report, mutational analysis on the B1F-binding site in the major functional unit of HBV EII is described. The activity of HBV EII in EII-CAT reporter plasmids was significantly decreased when the sequence of the B1F-binding site in EII was mutated. Furthermore, a single point mutation in the B1 element that aborted the binding of B1F caused a dramatic decrease in viral gene transcription initiated from the HBV core promoter, which resulted in a reduction of the production of the HBV e antigen and pregenomic RNA, the template for viral DNA replication. In conclusion, the interaction of B1F with its target binding sequence in the EII region is crucial for liver-specific transcription and DNA replication of the virus.

DNA Replication↗

PubMed2000

[Giant Tumor Cells in the Bone Marrow and Their Significance]

Giant tumor cells and their varieties in the bone marrow were found in 7 patients with abnomal hematopoiesis phenomena. These cells were artificially devided into 5 kinds according to the difference of their morphology. Most of these cells were corresponding to lymphoid-monocytoid-macrophagocytoid cells with Wright's staining, cytochemical stainings, immunocytochemical stainings, flow cytometry examination, electron microscopy and pathologic study. The bone marrows were hypercellular and marked dysplastic hematopoiesis phenomena. Two of the 7 cases were diagnosed as malignant lymphoma with bone marrow biopsy. All cases characteristically showed no lymph node enlargement or hepatosplenomegaly or any local tumor mass. As to the prognosis of these cases, two patients died with survival time of 8 and 17 months, respectively, one was on critical condition at course of 10 months, and the other 4 cases were in comparatively stable condition with courses of 2.5 to 24 months. These patients seem to be a group of rare malignant lymphoid-monocytoid-macrophagocytoid proliferative diseases.

Journal Article↗

PubMedDate not supplied

State syringe and drug possession laws potentially influencing safe syringe disposal by injection drug users.

OBJECTIVE: To review state laws and judicial decisions for potential barriers to proper syringe disposal by injection drug users (IDUs). DESIGN: Using standard legal research methods, this study reviewed drug paraphernalia, syringe prescription, drug possession, and syringe exchange laws and relevant case decisions in 59 jurisdictions. MAIN OUTCOME MEASURES: Drug paraphernalia, syringe prescription, and drug possession laws. RESULTS: Drug paraphernalia laws prohibit all possession of syringes by IDUs in 31 jurisdictions. Syringe prescription laws prohibit possession in 7 jurisdictions. In 53 jurisdictions, IDUs may be subject to prosecution for the possession of drug residue in used syringes. Only two states (HI, RI) have no legal barriers to safe syringe disposal by IDUs. Sixteen jurisdictions that have tried to expand syringe access for IDUs by authorizing SEPs or by deregulating pharmacy sale of syringes continue to have criminal law provisions that could pose barriers to proper disposal. CONCLUSION: IDUs are a significant source of syringes disposed of outside the health care system. Involving IDUs in safe community sharps disposal programs is an important public health goal, but may be frustrated by legal barriers. Although this study looked only at law on the books, and not law as actually applied, ethnographic and survey research indicates that criminal laws do influence the syringe possession behavior of IDUs. The findings of this study suggest that syringe and drug possession laws could deter IDUs from participating in safe syringe disposal programs.

Humans↗