PubMed Health⌕ Search

Biomedical subjects

K H Lu

Publications and source records attributed to K H Lu.

At least 19 recordsLinked to original sources
PubMed2006

Birth of twins after in vitro fertilization with flow-cytometric sorted buffalo (Bubalus bubalis) sperm.

Flow-cytometric sorting of mammalian sperm for production of offspring with the desired sex is one of the most important new biotechnologies available for livestock industry. The objectives of this study were: (i) to sort the sperm into X- and Y-enriched populations and (ii) use the sorted sperm for in vitro fertilization (IVF) to produce sex-preselected embryo and offspring. The results revealed that the accuracy of sorted X- and Y-sperm was 94% and 89%, respectively. There was a decrease in blastocyst development rate in IVF with sorted sperm comparing to unsorted sperm, but the percentage of blastocysts on D6-D8 was not statistically different. Transplantation of the presumed X-embryos derived from IVF into a recipient resulted in the birth of female twins. These results indicated the feasibility of sperm sorting by flow cytometry and in vitro production of sex-preselected embryos and offspring in buffalo.

Animals↗
PubMed2006

Identification of X- and Y-chromosome bearing buffalo (Bubalus bubalis) sperm.

The aim of this study was to identify the difference in DNA content characterizing the X- and Y-chromosome bearing sperm of buffalo. Sperm from six Murrah buffaloes and six Nili-Ravi buffaloes were collected and stained with Hoechst 33342 followed by flow cytometry analysis of the DNA content. Two symmetrical, separate but overlapping peaks presumed to be X- and Y-chromosome bearing sperm were detected. The difference in fluorescence intensity, which related to the DNA content, between the X- and Y-sperm was 3.59+/-0.11% for Murrah buffalo and 3.55+/-0.14% for Nili-Ravi buffalo, respectively. Significant differences were observed among males within each breed, but there were no differences between the averages of the two breeds. The results indicate that flow cytometric sorting of X- and Y-sperm of buffalo is feasible.

Animals↗
PubMed2005

Oral administration of paclitaxel affects the distribution and metabolism of 2-aminofluorene in various tissues of Sprague-Dawley rats.

To evaluate the question of whether or not paclitaxel affects the distribution and metabolism of chemical carcinogens such as 2-aminofluorene (AF) on Sprague-Dawley rats were examined. The AF, acetylated AF and AF metabolites were determined and examined by using high performance liquid chromatography. After having received AF only, AF with paclitaxel at the same time and paclitaxel pretreated for 24 h then treated with AF for 24 h, urine, stool and tissues such as liver, kidneys, stomach, colon, bladder and blood were collected and assayed for AF and its metabolites. Compared to the control group, paclitaxel caused an increase of the metabolites excreted in urine and stool. The major metabolite excreted in urine and stool was 9-OH-AAF. The liver is the major metabolism center and the major residual metabolite of AF in the liver was also 9-OH-AAF.

Acetylation↗
PubMed2004

Effects of heparin and sperm concentration on cleavage and blastocyst development rates of bovine oocytes inseminated with flow cytometrically-sorted sperm.

The objective was to determine the optimal concentration of heparin for sperm capacitation, as well as the optimal sperm concentration for in vitro fertilization using flow cytometrically-sorted sperm from individual bulls. A total of 5327 bovine oocytes and sperm from four bulls were examined. Oocytes from slaughterhouse ovaries were matured in TCM199 for 22-24 h. Flow cytometrically-sorted sperm as well as unsorted control sperm from the same bulls were cryopreserved. For sperm from each of the four bulls, oocytes were inseminated in a three-by-three factorial design plus one control group (three heparin concentrations: 0, 2, and 10 microg/ml and three sperm concentrations: 0.5 x 10(6), 1.5 x 10(6), and 4.5 x 10(6) ml(-1); 10 microg/ml of heparin and 1.5 x 10(6) ml(-1) of sperm were used for the unsorted control). Presumptive zygotes were cultured in chemically defined media, CDM-1 and CDM-2 for 52-54 h and 96 h, respectively. Samples of about 10 oocytes from each of the 10 treatment groups per replicate were fixed at 18-20 h after insemination to determine sperm pronuclei formation and polyspermy. Increased polyspermy resulted as heparin and sperm concentrations increased (P < 0.05). A higher rate of polyspermy was found in oocytes inseminated with unsorted control sperm compared with sorted sperm (P < 0.05). Sperm of one of four bulls tested required no heparin and lower concentration (0.5 x 10(6) ml(-1)) to obtain optimal cleavage and blastocyst rates while optimal parameters for another bull were higher heparin (10 microg/ml) and sperm concentrations (4.5 x 10(6) ml(-1)). Optimal parameters for the other two were intermediate levels of heparin and sperm. Sperm appeared to be partially capacitated during the flow cytometric-sorting process used for sex pre-determination. When heparin and sperm concentrations were optimized for individual bulls, blastocyst production per oocyte was similar for sorted and unsorted sperm for three of the four bulls studied.

Animals↗
PubMed2003

Development of bovine embryos after in vitro fertilization of oocytes with flow cytometrically sorted, stained and unsorted sperm from different bulls.

The objective of this study was to determine the effect of staining bovine sperm, with or without flow cytometry, on in vitro fertilization of bovine oocytes and blastocyst development. Bovine oocytes (n=4273) were fertilized with frozen-thawed sperm from three bulls that was: stained with Hoechst 33342 and sorted (into X- or Y-chromosome-bearing sperm) with flow cytometry; stained but not sorted; and not stained or sorted (Control). Oocytes, aspirated from slaughterhouse ovaries, were matured in TCM199 (supplemented with 10% fetal calf serum and 15 ng FSH, 1.0 microg LH, 1.0 microg E2/ml) for 22-24h at 39 degrees C in 5% CO(2) in air with maximum humidity. Presumptive zygotes were removed from culture and placed in chemically defined medium (CDM-1) 6-7h after insemination and cultured for 65-66h. Embryos that had cleaved by 72h post-insemination were cultured an additional 96h in CDM-2 containing 0.12 IU insulin/ml. Cleavage and blastocyst rates per oocyte inseminated were recorded on Day 3 and Days 7-8 after insemination, respectively. There was no significant difference in blastocyst rate among the three types of sperm; however, cleavage rates with stained and sorted sperm (53.1%) and unsorted, stained sperm (59.9%) were lower (P<0.05) than Control sperm (69.7%). Furthermore, there were significant differences due to semen from different bulls in cleavage and blastocyst rates.

Animals↗
PubMed2002

The effect of paclitaxel on 2-aminofluorene-DNA adducts formation and arylamine N-acetyltransferase activity and gene expression in human lung tumor cells (A549).

In this study, paclitaxel was used to determine inhibition of arylamine N-acetyltransferase (NAT) activity, gene expression and 2-aminofluorene-DNA adduct formation in a human lung tumor cell line (A549). The activity of NAT was measured by HPLC assaying for the amounts of N-acetyl-2-aminofluorene (2-AAF) and remaining 2-aminofluorene (2-AF). Human lung tumor cell cytosols and intact cells were used for examining NAT activity and carcinogen-DNA adduct formation. The results demonstrated that NAT activity, gene expression (NAT1 mRNA) and 2-AF-DNA adduct formation in human lung tumor cells were inhibited and decreased by paclitaxel in a dose-dependent manner. The effects of paclitaxel on the values of the apparent Km and Vmax of NAT from human lung tumor cells were also determined in both examined systems. The result also indicated that paclitaxel decreased the apparent values of Km and Vmax from human lung tumor cells in both cytosol and intact cells. Thus, paclitaxel is an uncompetitive inhibitor to NAT enzyme.

Acetylation↗
PubMed2002

The effect of paclitaxel on gene expression and activity of arylamine N-acetyltransferase and DNA-2-aminofluorene adduct formation in human leukemia HL-60 cells.

N-Acetylation is recognized as the first step in arylamine metabolism. The enzyme responsible for N-acetylation is called arylamine N-acetyltransferase (NAT),which uses acetyl coenzyme A as the acetyl group donor. Paclitaxel has been shown to exhibit antineoplastic and anticancer activity. In this study, paclitaxel was selected to determine the inhibition of arylamine N-acetyltransferase activity, gene expression (NAT mRNA) and DNA-2-aminofluorene adduct formation in human leukemia HL-60 cell line. Paclitaxel (0.01-l microM) did decrease the level of NAT mRNA in a dose-dependent manner. The results demonstrated that paclitaxel inhibited NAT activity and DNA-2-aminofluorene adduct formation in human leukemia HL-60 cells in a dose-dependent manner. Using standard steady-state kinetic analysis, it was demonstrated that paclitaxel was a possible uncompetitive inhibitor to NAT activity in cytosols based on the decrease in apparent values of K(m) and V(max). This report is the first demonstration that paclitaxel affected human leukemia HL-60 cells NAT activity and DNA-2-aminofluorene adduct formation.

Acetylation↗
PubMed2001

Vitamin C inhibited DNA adduct formation and arylamine N-acetyltransferase activity and gene expression in rat glial tumor cells.

Studies have been demonstrated that vitamin C (ascorbic acid) exhibit the protective role of vin in certain types of cancer. Rat glial tumor cells also have been shown have N-acetyltransferase activity. In this study, we reported the effects of vitamin C on arylamine N-acetyltransferase (NAT) activity and DNA adduct formation in rat glial tumor cell line (C6 glioma). The activity of NAT was measured by high performance liquid chromatography assaying for the amounts of acetylated 2-aminofluorene and p-aminobenzoic acid and nonacetylated 2-aminofluorene and p-amonibenzoic acid. Rat C6 glioma cells were used for examining NAT activity and gene expression and 2-aminofluorene-DNA adduct formation. The results demonstrated that NAT activity and 2-aminofluorene-DNA adduct formation in C6 glioma cells were inhibited and decreased by vitamin C in a dose-dependent manner. But vitamin C did not affect NAT gene expression in examined cells. The apparent kinetic parameters (apparent values of Km and Vmax) from C6 glioma cells were also determined with or without vitamin C cotreatment. The data also indicated that vitamin C decreased the apparent values of Km and Vmax from C6 glioma cells.

4-Aminobenzoic Acid↗
PubMed2001

[Experimental study on closing the firearm injured soft tissue defect by skin stretch].

OBJECTIVE: To investigate the availability and effect of skin stretch in closing the firearm injured soft tissue defect. METHODS: Eight white pigs with firearm injured soft tissue defect were divided into 3 groups. Each group I and group II had 3 pigs which were performed skin stretch. The control group had 2 pigs without stretch. The average diameter of the defect in three groups was (7.3 +/- 0.2) cm, (9.1 +/- 0.3) cm, (7.3 +/- 0.2) cm respectively, and the site of defect was on the lateral thigh and buttock. RESULTS: Skin stretch could make a visible reduction of the wound. It was possible to close the wound by direct traction when the diameter of the buttock wound was less than 7 cm, and when the diameter of the lateral thigh wound was less than the radius of thigh. The skin stretch should not last more than 7 days and the best effect appeared in 4 to 5 days after performing the skin stretch. CONCLUSION: The skin stretch can be applied in the repair of the firearm injured soft tissue defect. It has many advantage compared with the tradtional treatment.

Animals↗
PubMed2001

[Effect of subcutaneous tissue trimming on the survival skin area of avulsion skin flap].

OBJECTIVE: To investigate the effect of subcutaneous tissue trimming on the survival skin area of avulsion skin flap. METHODS: Degloving injury was created in bilateral hind limbs of 7 pigs with avulsion injury machine, 4 cm x 10 cm avulsion skin flaps were elevated in degloving areas. Skin flaps in one side were replanted as control without any treatment. Subcutaneous tissue in the skin flaps of another side was partially excised and replanted by trimmed skin flaps. Survival skin flaps was calculated with computer at 7 days after operation. RESULTS: In the control group, the survival skin area was (40.41 +/- 9.23)%, while in the experimental group, the survival skin area was (60.90 +/- 15.26)%. There was significant difference between the two groups (P < 0.05). CONCLUSION: Trimming off subcutaneous tissue does improve the survival area of avulsion skin flap.

Anastomosis, Surgical↗
PubMed2001

Tamoxifen inhibits arylamine N-acetyltransferase activity and DNA-2-aminofluorene adduct in human leukemia HL-60 cells.

Genetic regulation of acetyl coenzyme A-dependent N-acetyltransferase (NAT)and O-acetyltransferase (OAT) activities may play an important role in the metabolic activation of arylamine chemicals and carcinogens. N-acetylation is thought to be the first step in arylamine metabolism. The enzyme responsible for N-acetylation is called NAT. In this study, synthetic non-steroidal antiestrogen tamoxifen was selected for determining the inhibition of arylamine NAT activity, gene expression (NAT mRNA) and DNA-2-aminofluorene adduct formation in human leukemia HL-60 cell line. The results demonstrated that tamoxifen did not affect the level of NAT mRNA in HL-60 cells. But the results also showed that NAT activity and 2-Aminofluorene-DNA adduct formation in HL-60 cells were inhibited and decreased by tamoxifen in a dose-dependent manner when the doses of tamoxifen up to 100 micro M. We also examined the standard steady-state kinetic analysis, and the data showed that tamoxifen may be an uncompetitive inhibitor to NAT activity in cytosols based on the decrease apparent values of Km and Vmax. This report is the first finding that tamoxifen inhibited human leukemia HL-60 cells NAT activity and DNA-2-aminofluorene on adduct formation.

2-Acetylaminofluorene↗
PubMed2000

Early cervical cancer.

Early cervical cancer includes a broad range of disease, from clinically undetectable microinvasive cancer to large, bulky tumors that replace the entire cervix. Further subgrouping of this category is therefore necessary to define the optimal treatment approach for individual cases. The International Federation of Gynecology and Obstetrics (FIGO) staging system stratifies stage I tumors into two broad categories, stage IA (microinvasive) and stage IB (gross tumor). Management of women with stage IA disease is controversial. In the United States, patients with stromal invasion of less than 3 mm and no lymphvascular involvement are usually treated conservatively with simple hysterectomy. In selected patients who desire fertility, cone biopsy with negative surgical margins is also considered. Patients with invasion of more than 3 mm or lymphvascular space involvement are at risk for pelvic lymph node metastasis and are most often treated with radical hysterectomy and pelvic lymphadenectomy. Stage IB1 cervical cancer is managed by either radical surgery or radiotherapy with equivalent recurrence and survival rates. In patients with tumors less than 4 cm in diameter, the decision between radical surgery and radiotherapy is guided by patients' overall health and treatment preferences. For younger women, radical surgery is preferred because ovarian function can be preserved and vaginal stenosis secondary to radiation can be avoided. Radiation therapy is preferred for women who may not tolerate radical surgery. We always prefer primary radiation therapy for patients with tumors larger than 4 cm in diameter. Recent data convincingly demonstrate that the addition of cisplatin-based chemotherapy significantly improves overall survival rates in cervical cancer patients who undergo radiation therapy.

Antineoplastic Agents↗
PubMed2000

Occult ovarian tumors in women with BRCA1 or BRCA2 mutations undergoing prophylactic oophorectomy.

PURPOSE: To review the findings at prophylactic oophorectomy of a series of women who presented to a familial breast and ovarian cancer clinic. MATERIALS AND METHODS: Data from medical charts, operative notes, and pathology reports were collected on women who had undergone prophylactic oophorectomies because of the elevated risk of ovarian cancer. Because only a subset of patients underwent BRCA1 and BRCA2 testing, each patient's risk of hereditary predisposition was calculated using the Berry-Parmigiani model and family history data. RESULTS: From June 1989 to December 1998, 50 women seen at our clinic underwent prophylactic oophorectomy, 33 of whom had a calculated risk of carrying a germline BRCA1 or BRCA2 mutation greater than 25%. Among this group, four incidental tumors were found (four of 33, or 12%); one tumor was noted at the time of surgery and three were noted only in the final pathology. Two patients had microscopic, poorly differentiated serous adenocarcinomas in multiple sites on both ovaries. A third patient had a bilateral serous borderline tumor with micropapillary features. The fourth patient had a microscopic serous borderline ovarian tumor. All four patients had germline BRCA1 or BRCA2 mutations, and three had unremarkable transvaginal ultrasonography examinations within 6 months before prophylactic surgery. CONCLUSION: Foci of malignant tumor are not uncommon in prophylactic oophorectomies performed in women at very high risk for ovarian cancer and may not be detected on ultrasonograms. Surgeons should have a high suspicion of finding cancer in these women at the time of prophylactic surgery, and careful pathologic assessment of the specimens should be conducted.

Adult↗
PubMed2000

[Application of multiple tissue expanders for repair of facial and neck scar].

OBJECTIVE: To repair facial and neck scar using tissue expanding technique. METHODS: From January 1991 to January 1995, 16 cases with facial and neck scar were treated. Multiple tissue expanders were put under the normal skin of facial and neck area, after being fully expanded, the scars were excised and the expended skin flaps were transplanted to cover the defects. The size and number of tissue expanders were dependent on the location of the scars. Normally, 5 to 6 ml expanding volume was needed to repair 1 cm2 facial and neck defect. The incisions should be chosen along the cleavage lines or in the inconspicuous area, such as the nasolabial fold or submandibular region. The design of flap was different in the face and in the neck. In the face, direct advanced flap was most common used, whereas in the neck, transposition flap was often used. Appropriate tension was needed to achieve smooth and cosmetic effect. It was compared the advantages and disadvantages of several methods for repair of the defect after facial and neck scar excision. RESULTS: Fifteen cases had no secondary deformity after scar excision. Among them, 1 case showed blood circulation disturbance and cured through dressing change. Ten cases were followed up and showed better color and texture in the flap, and satisfactory appearances. CONCLUSION: Tissue expanding technique is the best method for the repair of facial and neck scar, whenever there is enough expandable normal skin.

Adolescent↗
PubMed2000

[Development of prefabricated flaps].

OBJECTIVE: To sum up the experimental development and clinical application of prefabricated flap. METHODS: The reported experimental results and clinical application of prefabricated flap extensively reviewed. RESULTS: Previous studies had proved that the revascularization of prefabricated flap mainly through anastomoses of implanted vessels and the original vessels of the flap, the implanted vessels slowly formed a new and complete blood vessel network, which could dominate the whole flap, three to four weeks later, the new vessels were mature and the flap could be transferred. Clinically, the superficial temporal vessels, gastroepiploic vessels, circumflex femoral vessels and thoracodorsalis vessels could be harvested for prefabricated flap with satisfactory results. CONCLUSION: Prefabricated flap provides a new method for the treatment of complicated defects.

Arteries↗
PubMed1999

A population-based study of BRCA1 and BRCA2 mutations in Jewish women with epithelial ovarian cancer.

OBJECTIVE: To determine the frequency of BRCA1 mutations 185delAG and 5382insC and BRCA2 mutation 6174delT in Jewish women with ovarian cancer and in matched controls in a population-based study. METHODS: Forty-eight Jewish women with epithelial ovarian cancer (32 invasive and 16 borderline) and 33 Jewish control subjects were obtained from a population-based, case-control study of ovarian cancer in eastern Massachusetts and New Hampshire. Mutational analysis on exons 2 and 20 of BRCA1 and exon 11 of BRCA2 was conducted on blood samples from patients and controls. RESULTS: Fourteen (44%) of 32 Jewish patients with invasive epithelial ovarian cancer carried either a 185delAG mutation of BRCA1 (n = 8) or a 6174delT mutation on BRCA2 (n = 6). Neither of these mutations was identified in 16 women with borderline ovarian tumors or in 33 controls. No 5382insC mutation of BRCA1 was identified in any of the patients or control subjects in the series. Family history did not predict mutation status. CONCLUSION: BRCA1 185delAG and BRCA2 6174delT mutations are frequent in Jewish women with invasive epithelial ovarian cancer, irrespective of family history. Genetic counseling might be warranted in women with invasive epithelial ovarian cancer based on Jewish ethnicity alone.

BRCA2 Protein↗
PubMed1999

Outcome of pregnancies occurring within 1 year of hydatidiform mole.

OBJECTIVE: To determine the outcome of subsequent pregnancies in patients with partial or complete molar pregnancy who conceive before completing the recommended hCG follow-up of at least 6 months. METHODS: Retrospective record review of patients with partial or complete mole who conceived before the standard gonadotropin follow-up of 6 months was completed during 1980-1998. RESULTS: Sixty-seven patients with molar pregnancy who conceived before completion of hCG follow-up were identified. Thirty-five (52.2%) patients had a prior partial mole, and 32 (47.8%) had a prior complete mole. The mean interval from first achieving undetectable hCG level to new pregnancy was 3.1 and 3.4 months in patients with partial and complete mole, respectively. Eleven patients underwent elective termination, and 12 were lost to follow-up. Of the remaining 44 patients, 33 (75.0%) had live births, 10 had spontaneous abortions, and one had an ectopic pregnancy. A viable pregnancy outcome was achieved in 20 (83.3%) of 24 patients with partial mole and 13 (65.0%) of 20 patients with complete mole. None of the patients developed any evidence of postmolar persistent gestational trophoblastic tumor. None of the live births had any detectable fetal anomalies. CONCLUSION: The risk of persistent tumor is low and reproductive outcome is favorable once undetectable hCG levels are achieved. Pregnancies occurring before the completion of recommended hCG follow-up may be allowed to continue under careful surveillance.

Adolescent↗