Biomedical subjects

Na Man

Publications and source records attributed to Na Man.

4 recordsLinked to original sources

PubMed2007

Transdermal delivery of nonsteroidal anti-inflammatory drugs mediated by polyamidoamine (PAMAM) dendrimers.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used drugs in the world, primarily for symptoms associated with osteoarthritis and other chronic musculoskeletal conditions. However, adverse effects caused by oral administration, such as local or systemic disturbance in the gastrointestinal tract, have limited the clinical applications of these drugs. In the present study we have assessed the ability of polyamidoamine (PAMAM) dendrimers to facilitate transdermal delivery of NSAIDs, using Ketoprofen and Diflunisal as model drugs. In vitro permeation studies with excised rat skins indicated that PAMAM dendrimers significantly enhanced the accumulative permeated amount of both drugs after 24 h, as compared to drug suspensions without PAMAM dendrimers. Similarly, anti-nociceptive studies using the acetic acid-induced writhing model in mice showed a prolonged pharmacodynamic profile for the NSAIDs-PAMAM dendrimer complex after transdermal administration. In addition, blood drug level studies revealed that the bioavailability was 2.73 times higher for the Ketoprofen-PAMAM dendrimer complex and 2.48 times higher for the Diflunisal-PAMAM dendrimer complex, respectively, than the pure drug suspensions. These results demonstrated that PAMAM dendrimers can effectively facilitate skin penetration of NSAIDs and may have the potential applications for the development of new transdermal formulations.

Administration, Cutaneous↗

PubMed2006

[The relationship between serum thyroid autoantibodies, iodine intake, development and prognosis of Graves' disease].

OBJECTIVE: To investigate the relationship of thyroid autoantibodies including serum thyroid stimulating antibody (TSAb), thyroid stimulation blocking antibody (TSBAb) and iodine intake with the development and prognosis of Graves' hyperthyroidism. METHODS: A total of 63 subjects with overt hyperthyroidism were screened out from 3 Chinese rural communities with different iodine intakes at first survey. Serum TSAb, TSBAb, thyrotropin binding inhibitory immunoglobulin (TBII), thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) were detected. The patients were followed up 2 years later. TSAb and TSBAb were measured with recombinant human thyrotropin receptor (rhTSHR)-Chinese hamster ovary cell (rhTSHR-CHO cell) bioassay. RESULTS: At the first survey, the prevalences of positive TSAb, TBII and TSBAb were found in 80.9%, 61.7% and 6.4% of the patients with Graves' disease respectively. TSAb and/or TBII were positive in 91.5% of the patients. The consistent rate of TSAb and TBII was 59.6% in the cases. All indexes mentioned above were higher in the patients than in healthy controls. Positive correlations were found between TSAb and TBII (r = 0.407), TSAb and thyroglobulin (r = 0.301), TSAb and thyroid volume (r = 0.317) respectively. The prevalence of positive TSAb (91.7%) in Graves' patients in iodine excessive area are significantly higher than those in iodine mildly deficient area (66.7%). The positive rates and the titers of TBII, TPOAb and TGAb were not different statistically among the patients in the three communities. At follow-up, the patients with Graves' hyperthyroidism were classified into euthyroid group (G1) and hyperthyroid group (G2) according to their outcomes of the disease. The TSAb titers and the thyroid volume in the cases of G1 decreased significantly, whereas the patients with highly positive TPOAb titers in the first survey and the follow-up were hard to become euthyroid and TSAb may be the secondary factor influencing the thyroid as compared with TPOAb. CONCLUSION: TSAb is more significant than TBII in diagnosing and predicting the outcomes of Graves' hyperthyroidism. The application of both TSAb and TBII could raise the positive rates of thyrotrophin receptor antibody tests. TSAb, TPOAb titers and thyroid volume were factors influencing the prognosis of Graves' hyperthyroidism.

Adolescent↗

PubMed2003

[An epidemiological study on the relationship between selenium and thyroid function in areas with different iodine intake].

OBJECTIVE: To investigate the relationship between selenium status and thyroid dysfunction in 3 areas with different iodine intake. METHODS: An epidemiological research was performed in the rural communities of Panshan County (iodine-deficient area) and Zhangwu County (iodine-sufficient area), Liaoning Province, and Huanghua County, Hebei Province (iodine-excessive area). Serum selenium, TSH, FT3 and FT4 levels were examined in 329 patients with thyroid dysfunction (including clinical hypothyroidism, subclinical hypothyroidism, clinical hyperthyroidism and subclinical hyperthyroidism) and 183 normal inhabitants. RESULTS: The median serum selenium concentrations in Panshan, Zhangwu and Huanghua were 91.4, 89.1, and 83.2 microg/L respectively. There was no difference in serum selenium levels between the patients with subclinical hypothyroidism, clinical hypothyroidism, and clinical hyperthyroidism and their normal controls. The median serum selenium concentration of the subclinical hyperthyroidism patients was 82.6 microg/L, significantly lower than that of the normal controls (87.3 microg/L). The FT3/FT4 ratio was decreased, the FT4 level was increased in the subclinical hyperthyroidism patients in comparison with the normal controls, and no significant difference in FT3 level was found between them. No significant effect of sex and age was found on serum selenium level of normal inhabitants. In normal controls serum selenium was inversely correlated with serum TSH level, and the subjects with serum selenium < or = 80 microg/L had the median TSH level of 2.10 mU/L, markedly higher than that of the subjects with the serum selenium of 80-100 microg/L (1.29 mU/L) and that of the subjects with the serum selenium of 100 approximately 120 micro g/L (1.28 mU/L). For the thyroid dysfunction patients with positive thyroid auto-antibody (TPOAb) in Zhangwu County, the serum selenium was negatively associated with TPOAb level. The serum selenium level of the TPOAb highly positive group (TPOAb > 600 IU/ml) was 83.6 IU/ml, significantly lower than those of the TPOAb lowly positive group and TPOAb moderately positive group (83.6, 92.9 and 95.6 microg/L respectively). CONCLUSION: No obvious effect of selenium status is found on the development of thyroid dysfunction in these three areas. But selenium deficiency can impair thyroid function by means of disturbing thyroid hormone metabolism and decreasing antioxidant ability of the thyroid.

Age Factors↗

PubMed2003

[An epidemiological study on factors affecting serum thyroglobulin levels].

OBJECTIVE: To investigate the effects of several factors affecting serum thyroglobulin (TG) levels among people aged 14 or more. METHODS: We selected Panshan with median urinary iodine (MUI) 83.45 micro g/L as a deficient iodine intake community, Zhangwu with MUI 242.85 micro g/L as a sufficient iodine intake community and Huanghua with MUI 650.87 micro g/L as an excessive iodine intake community. Serum TG and thyroid stimulating hormone (TSH) were measured in 3,335 subjects whose thyroglobulin antibody (TGAb) were negative and thyroid volume were examined using B-ultrasound. RESULTS: In the population with MUI of 80 - 650 micro g/L, serum TG levels presented a "V" curve. An elevated serum TG was found in both the communities with deficient iodine intake and excessive iodine intake. The same trend was shown in the groups with different levels of serum TSH. An elevated serum TG was found in both the groups of TSH < 0.3 mU/L and TSH > 4.8 mU/L. The serum TG levels was positively correlated with thyroid volume and was higher in female subjects than in male. An increased serum TG was found in subjects of aged 50 in the community with deficient iodine intake. CONCLUSION: Serum TG level is affected by gender, amount of iodine intake, serum TSH level and thyroid volume.

Adolescent↗