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Dive into the research topics where Peter Y. Lu is active.

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Featured researches published by Peter Y. Lu.


Mayo Clinic Proceedings | 1995

Endometriosis : current management

Peter Y. Lu; Steven J. Ory

OBJECTIVE To review the clinical features, theories of pathogenesis, and current treatment of endometriosis-associated pain and infertility. DESIGN We review the manifestation of endometriosis and the possible mechanisms that lead to its symptoms, examine the efficacy of current therapeutic options for pelvic pain and infertility, and provide specific recommendations for treatment based on the current literature. MATERIAL AND METHODS Endometriosis is the presence of hormonally responsive endometrial tissue occurring outside the uterine cavity. This condition may be asymptomatic but is often found in association with pelvic pain or infertility (or both). The precise pathogenesis has not been clearly established but likely involves retrograde menstruation with subsequent seeding of endometrial glands at extrauterine sites. The definitive diagnosis and staging of endometriosis are performed by laparoscopy. Various strategies have been used to treat endometriosis including expectant, medical, surgical, and combination management. RESULTS The efficacy of treatment varies for pelvic pain and infertility. Endometriosis-associated pain may respond to both medical and surgical management. The use of medical therapy for endometriosis-associated infertility is not supported by current studies. Surgical management of infertility may be efficacious when pelvic anatomy is distorted because of endometriosis. The use of superovulation strategies and in vitro fertilization has been shown to be effective in overcoming endometriosis-associated infertility. CONCLUSION Pelvic pain and infertility in the presence of endometriosis necessitate individualization of therapy to achieve treatment goals. Neither medical nor surgical management is efficacious in all circumstances. As a better understanding of the pathogenesis of endometriosis evolves, treatment of this perplexing condition will probably continue to improve.


Fertility and Sterility | 1994

Dual color fluorescence in situ hybridization to investigate aneuploidy in sperm from 33 normal males and a man with a t(2;4;8)(q23;q27;p21) *

Peter Y. Lu; Diane G Hammitt; Alan R. Zinsmeister; Gordon W. Dewald

OBJECTIVE To establish the relative frequency of aneuploidy in sperm from normal and abnormal subjects using dual color fluorescence in situ hybridization and probes for six different chromosomes. DESIGN Semen from 33 normal males and a patient with a translocation was studied using dual color fluorescence in situ hybridization with probes for chromosomes 4, 7, 8, 12, 18, X and Y. The frequency of aneuploidy for each chromosome is compared with one another and with the patient who had a t(2;4;8)(q23;q27;p21). SETTING Specimens were obtained from patients at the Mayo Clinic, Rochester, Minnesota. RESULTS The percentage of sperm with disomy or nullisomy in normal subjects ranged from 0.2% to 0.6% for each of the chromosomes studied. No statistically significant differences were observed between these chromosomes. The frequency of aneuploidy in sperm from a patient with a t(2;4;8) was 3.3% and 4.8% for chromosomes 4 and 8, respectively. CONCLUSION Fluorescence in situ hybridization was useful to establish the normal range of nullisomic and disomic sperm for six different chromosomes and to study a patient with a clinically significant chromosome abnormality. In normal males, no difference in the frequency of meiotic nondisjunction was observed among the chromosomes studied.


Neuropsychopharmacology | 1996

Examining serotonin function: A modified technique for rapid tryptophan depletion

Lois E. Krahn; Peter Y. Lu; George G. Klee; Pedro R. Delgado; Slong Chi Lin; Ralf C. Zimmermann

Tryptophan (TRP) depletion was used to study serotonin because the ratio of TRP to large neutral amino acids (TRP/LNAA) determines the quantity of TRP that enters the brain. Because TRP is not universally available, a modified technique of TRP depletion was developed where a 1/4 strength preparation of an amino acid mixture (AAM) replaces TRP as the placebo. Seven healthy subjects could not differentiate between the preparations in this double-blind, placebo-controlled study. Urinary 6-hydroxymelatonin sulfate (6-MS) was monitored as a biochemical marker of serotonin. The TRP/LNAA ratio (GG = 0.0001) and 6-MS secretion (GG = 0.024) were decreased, but placebo TRP levels (GG = 0.062) were not altered significantly. This modified technique facilitates the sue of TRP depletion in clinical research.


Journal of Assisted Reproduction and Genetics | 1996

Efficacy of calcium ionophore A23187 Oocyte activation for generating parthenotes for human embryo research

A. Rhoton-Vlasak; Peter Y. Lu; K. M. Barud; Gordon W. Dewald; Diane G Hammitt

AbstractPurpose: Our purpose was to examine the efficacy of Ca-A23187 to activate human oocytes and produce parthenotes for research purposes. We examined the feasibility of using florescence in situ hybridization (FISH) to study the sex chromosome constitution of activated oocytes. Methods: One hundred eight nonfertilized oocytes from our IVF program were exposed to Ca-A23187. Oocyte activation was determined by the presence of pronuclear (PN) development. FISH was done on chromosome preparations using X and Y dual-colored probes. Polyploidic and parthenogenetically activated oocytes from our IVF program served as controls. Results: Of the 108 oocytes, 59 (55%) had no PN, 38 (35%) one PN, 10 (9%) two PN, and 1 (0.9%) three PN. Fifty-seven oocytes (53%) were not recovered following spreading and no chromatin was observed on 14 slides (13%) after FISH. This contrasted with 50 of 227 (22%) and 3 of 227 (1.7%) loss rates, respectively, for controls (P<0.0001). Eight of 49 activated oocytes underwent cleavage. FISH was performed on 37 oocytes. Of 21 zero-PN oocytes, I had no FISH signals, 15 had a single X, 4 had two Xs, and I had four Xs. For one-PN oocytes, two had no FISH signals, seven had one X, and three had two Xs. For two-PN oocytes, two had no FISH signals and two had two Xs. FISH results were consistent with a maternal origin of genetic material. Conclusions: Ca-A23187 resulted in a 45% activation rate, with 16% of oocytes progressing to cleavage before degeneration. Oocyte activation with Ca-A23187 allowed the generation of parthenotes for human embryo research. FISH was useful for evaluation of oocytes and parthenotes.


Psychoneuroendocrinology | 1996

The impact of gender on alpha-methyl-paratyrosine mediated changes in prolactin secretion and 6-hydroxymelatonin sulfate excretion

Ralf C. Zimmermann; Lois E. Krahn; George G. Klee; Peter Y. Lu; Steven J. Ory; Siong Chi Lin

Prolactin (PRL) and melatonin (ML) secretion are mediated by dopamine (DA) and norepinephrine (NE), respectively. Alpha-methyl-para-tyrosine (AMPT) inhibits the production of CNS catecholamines (CA). The purpose of the study is to determine: (1) if AMPT inhibition of ML has the same gender-dependent effect as on PRL secretion; (2) if there is a post AMPT-induced NE depletion mood change in men and/or women. In a randomized, double-blind cross-over fashion, five healthy young males and five females were either given five doses of AMPT 1 g (active) or promethazine 50 mg (placebo) over a 28 h period, separated by 4-6 weeks. The PRL and ML concentrations were collected at regular intervals via an indwelling venous catheter and concurrently, two 12 h urinary 6-hydroxymelatonin sulfate (6-MS) measurements were made. Mood and anxiety states of subjects at baseline and post drug were assessed with appropriate rating scales at regular intervals. Light exposure beginning at dusk and lasting until dawn was controlled to no more than 200 lux during all phases of the study. The PRL secretion showed a significant interaction of drug x time (p = .0001) in women and a non-significant trend (p = .056) in men. No difference in PRL secretion was found between the two genders in the placebo condition, whereas the PRL secretion was significantly higher in the AMPT condition in women when compared to men (df 17,119, F = 1.9, p = .021). Total 24 h urinary 6-MS secretion highly correlated with ML secretion expressed as area under the curve (AUC) during both active and placebo experiments (r = 0.8, p < .01) and (r = 0.86, p < or = .01), respectively. The ANOVA reveals a significant interaction of drug x time for 6-SM excretion. There was no gender difference in AMPT suppression of 6-MS excretion. No mood changes were detected in men or women. We conclude that urinary 6-MS is a reliable indirect measure of the degree of AMPT-induced decrease in CNS NE activity as part of overall AMPT-induced reduction of central catecholamine activities. The pre and post AMPT-induced changes in 6-MS are not gender dependent, dissimilar to the AMPT-induced changes in PRL secretion. Therefore, 6-MS, in addition to PRL, should be measured when applying the AMPT paradigm in future research.


European Neuropsychopharmacology | 1999

The effect of presynaptic catecholamine depletion on 6-hydroxymelatonin sulfate: A double blind study of α-methyl-para-tyrosine

Lois E. Krahn; Siong Chi Lin; George G. Klee; Peter Y. Lu; Steven J. Ory; Ralf C. Zimmermann

Because it is a competitive inhibitor of tyrosine hydroxylase, alpha-methyl-para-tyrosine (AMPT) is used to study psychiatric disorders. Melatonin serves as a biological marker of catecholamine function since its secretion is regulated by noradrenergic neurons via beta-adrenergic receptors in the pineal gland. Ten healthy volunteers were administered AMPT in a double-blind placebo controlled study. When subjects received AMPT, nocturnal 6-hydroxymelatonin sulfate (6-SM) decreased significantly as compared with promethazine (night 1 P=0.002; and night 2 P=0.001). Urinary MHPG also decreased on both study days (DF1,9 F=9.82, GG=0.0121). Nocturnal 6-SM excretion and melatonin secretion correlated highly (r=0.91, P=0.0007). Behavioral ratings did not reveal a difference in symptomatology and did not correlate with changes in 6-SM or MHPG. This study demonstrates in healthy controls that 6-SM reliably reflects presynaptic catecholamine depletion induced by AMPT without the emergence of behavioral symptoms.


Fertility and Sterility | 1996

Minimal stimulation achieves pregnancy rates comparable to human menopausal gonadotropins in the treatment of infertility

Peter Y. Lu; Aeneid L.J. Chen; Elizabeth J. Atkinson; Susan H. Lee; Lisa D. Erickson; Steven J. Ory


American Journal of Obstetrics and Gynecology | 2005

Is early embryonic crowding responsible for premature delivery and low birth weight of singleton pregnancies conceived by assisted reproductive technology

Richard P. Dickey; Steven N. Taylor; Peter Y. Lu; Belinda M. Sartor; Phillip H. Rye


American Journal of Obstetrics and Gynecology | 2004

Twins conceived through in vitro fertilization

Richard P. Dickey; Peter Y. Lu; Belinda M. Sartor


Fertility and Sterility | 2003

Life-table analysis falls short of the mark! Reply of the authors

Richard P. Dickey; Phillip H. Rye; Steven N. Taylor; Peter Y. Lu; Belinda M. Sartor; Roman Pyrzak

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Belinda M. Sartor

Louisiana State University

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Richard P. Dickey

Louisiana State University

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Roman Pyrzak

Louisiana State University

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