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Biomedical subjects

Y Lu

Publications and source records attributed to Y Lu.

1,012 records · Page 57Linked to original sources
PubMedDate not supplied

The successful use of hyperstimulated washed therapeutic donor insemination after standard therapeutic donor insemination has failed.

OBJECTIVE: To investigate whether an aggressive therapeutic donor insemination regimen (stimulated folliculogenesis and ovulation plus intrauterine insemination) can produce a better fecundability rate than a more traditional insemination regimen (non-stimulated folliculogenesis plus LH-timed intracervical insemination) in women who have failed to become pregnant during an initial series of six traditional insemination cycles. DESIGN: A retrospective comparison of fecundability rates was undertaken between women undergoing the traditional insemination protocol and those who voluntarily switched to ovarian hyperstimulation coupled with intrauterine insemination. PARTICIPANTS: Eight-two women who failed to become pregnant during an initial series of six intracervical insemination cycles. RESULTS: Fecundability was 5.6% in cycles of continued urinary LH-timed intracervical insemination and 19.4% when the more aggressive regimen was applied. The difference in fecundability between protocols was significant (P < .005). CONCLUSION: After an initial series of donor inseminations has failed, a more aggressive insemination regimen involving ovarian hyperstimulation followed by washed intrauterine insemination provides a higher fecundability rate than continued intracervical insemination.

Adult↗
PubMedDate not supplied

Role of hydroxyl radical in silica-induced NF-kappa B activation in macrophages.

Nuclear transcription factor kappa B (NF-kappa B) is a multiprotein complex that regulates a variety of genes important for immunity and inflammation. The present study investigates the silica-induced activation of this transcription factor in mouse macrophage cell line RAW 264.7 cells, the role of free radical reactions in the mechanism of the activation, and its possible inhibition. Tetrandrine, a benzylisoquinoline alkaloid, which has been used as an antifibrotic drug to treat the lesions of silicosis and has been characterized as a hydroxyl radical (.OH) scavenger, inhibited the NF-kappa B activation induced by silica, lipopolysaccharide (LPS), and phorbol 12-myristate 13-acetate (PMA). Catalase, metal chelator, deferoxamine, and the silanol group (SiOH) blocker, poly(2-vinylpyridine-N-oxide) (PVPNO), also inhibited silica-induced NF-kappa B activation. Electron spin resonance (ESR) spin trapping measurements show that both deferoxamine and PVPNO decreased silica-mediated .OH radical generation from H2O2. It is shown that Fe(II) and not Fe(III) is able to cause NF-kappa B activation. The antioxidant, ascorbate, attenuated the NF-kappa B activation induced by silica but not by LPS. The .OH radical scavenger, sodium formate, inhibited NF-kappa B activation induced by silica but had only a minor effect on NF-kappa B activation induced by LPS. The results indicate that silica-mediated free radical generation via the Fenton or Fenton-like reaction (M(n)+ + H2O2-->M(n + 1)+ + OH- + .OH) and silanol groups on the silica surface play an important role in silica-induced NF-kappa B activation.

Alkaloids↗
PubMedDate not supplied

CCR5 chemokine receptor genotype frequencies among Puerto Rican HIV-1-seropositive individuals.

Some individuals remain uninfected by human immunodeficiency virus type 1 (HIV-1), despite multiple sexual contacts with subjects with confirmed HIV-1 infection. Several studies have confirmed that individuals who are homozygous for a 32 base pair (bp) deletion mutation in the chemokine receptor gene CCR5, designated as delta 32/ delta 32, are protected against HIV-1 infection. Heterozygotes of the same chemokine receptor deletion mutation are, however, not protected from acquiring HIV-1 infection but seemingly have slower progression to acquired immunodeficiency syndromes (AIDS). Genotype frequencies of the delta 32 CCR5 mutation vary markedly among different ethnic groups; heterozygosity is found in approximately 15% of Caucasians, about 5-7% of Hispanics and African Americans and 1% or less of Asians. The ethnic background of Puerto Ricans is highly complex and usually includes admixture of Caucasian, Caribbean Indian and African traits to a varying extent. This study was conducted to examine the frequencies of the delta 32 CCR5 mutation among Puerto Ricans who are infected with HIV-1. Samples were received from different geographical regions of the island. Of 377 samples tested, 94.2% were wild type (non-deletion mutant) homozygotes, 5.8% were delta 32 CCR5 heterozygotes, and none were delta 32 CCR5 homozygotes. The incidence of CCR5 delta 32/w heterozygous mutation among Puerto Ricans seems to be somewhat lower than what was reported with US Hispanics. Some age and gender associated bias of the mutation frequency were observed with the study population, the reason for which is unclear at present.

Adolescent↗