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Simons BD, Lee PA, Altshuler BL. Matrix models, one-dimensional fermions, and quantum chaos. PHYSICAL REVIEW LETTERS 1994; 72:64-67. [PMID: 10055567 DOI: 10.1103/physrevlett.72.64] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Chklovskii DB, Lee PA. Transport properties between quantum Hall plateaus. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:18060-18078. [PMID: 10008445 DOI: 10.1103/physrevb.48.18060] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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104
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Ubbens MU, Lee PA, Nagaosa N. Superfluidity in the two-dimensional gauge-field model: A renormalization-group analysis. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:13762-13773. [PMID: 10007778 DOI: 10.1103/physrevb.48.13762] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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105
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Simons BD, Lee PA, Altshuler BL. Exact pair correlation of the one-dimensional quantum gas with 1/r2 repulsion derived from the sympletic Dyson ensemble. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:11450-11452. [PMID: 10007470 DOI: 10.1103/physrevb.48.11450] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Lee PA. Fertility in cryptorchidism. Does treatment make a difference? Endocrinol Metab Clin North Am 1993; 22:479-90. [PMID: 7902276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The testis which remains nonscrotal beyond puberty will not produce sperm. While much of the data presented imply that therapy of cryptorchidism during childhood will decrease the likelihood of infertility, the available data do not substantiate this. There are also inadequate data to indicate whether treatment at very young ages in childhood decreases the risk of infertility. In fact, it is not clear that fertility rates among males who were unilaterally cryptorchid is different than that of the unaffected male population! Therefore, verification is needed to determine whether or not fertility is decreased in cryptorchidism. Paternity is a better index for verification than sperm counts since it is known that men with subnormal sperm counts may have normal paternity rates. Such verification using paternity may require more than fathering a child, such as the age of the father at the birth of the first child, length of marriage or partnership before birth of the first or subsequent children, or duration of intercourse without contraception to birth. Because of the multiple etiologies of the cryptorchid state, factors such as the relative size of the testis before treatment, and the position of the testis and the histology of the testis need to be considered since the small testis, the abdominal testis and the testis with the most histologic changes would appear to be at the greatest risk for defects in spermatogenesis. Until these data become available, most physicians are likely to recommend treatment of the undescended testis when detected if the child is older than six months. However, it must be remembered that there are no data to indicate benefit of early treatment. Before treatment is initiated, the physician must be careful to rule out a retractile testis. Also, the possibility of ascent of the testis which may occur during midchildhood, the age of physiologically normal hypogonadotropism, must be remembered. The testis which was previously normally descended but resides much of the time during midchildhood years within the inguinal canal may be a variant of normal and not require therapy. The approach to the patient with cryptorchidism must involve a careful history and repeated examinations looking for a cause and for accurate position of the testis. If the testis can be moved from the nonscrotal position into the scrotum, the potential function of the testis should not be harmed.(ABSTRACT TRUNCATED AT 400 WORDS)
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Siegel SF, Lee PA. Polycystic ovary syndrome. Curr Opin Pediatr 1993; 5:400-6. [PMID: 8374664 DOI: 10.1097/00008480-199308000-00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Polycystic ovary syndrome, characterized by hyperandrogenism and menstrual irregularities, is a heterogeneous group of disorders that can disrupt normal hypothalamic-pituitary-ovarian function. Ovarian physiology is reviewed with regard to possible etiologies for excessive androgen secretion. Similar features may be present in errors in steroidogenesis, hyperprolactinemia, androgen-secreting tumors, and Cushing's syndrome. Analysis of the interrelationships between the reproductive axis and carbohydrate metabolism suggests that the associated insulin resistance can induce hyperandrogenism. Improved understanding of the various etiologies may expand the therapeutic options for patients.
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Manfras BJ, Swinyard M, Rudert WA, Ball EJ, Lee PA, Kühnl P, Trucco M, Böhm BO. Altered CYP21 genes in HLA-haplotypes associated with congenital adrenal hyperplasia (CAH): a family study. Hum Genet 1993; 92:33-9. [PMID: 8365724 DOI: 10.1007/bf00216142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Disorders of the CYP21 gene, which is located within the major histocompatibility complex on the short arm of chromosome 6, are the leading causes of congenital adrenal hyperplasia (CAH). The coding gene and a highly homologous pseudogene are tandemly arranged with the two genes for the fourth component of complement (C4A and C4B). To analyse the prevalence rates of mutations of the CYP21 genes and the segregation of the CYP21 genes with their corresponding human leucocyte antigen (HLA)-haplotypes, 21 families with one or two children with the severe form of 21-hydroxylase deficiency were studied. Mutations of the CYP21 gene on their corresponding HLA-haplotype were detected by hybridisation of polymerase chain reaction (PCR)-amplified genomic DNA with sequence-specific oligonucleotides and solid phase direct sequencing. Our study has shown the following. (1) A single basepair mutation (A-->G or C-->G) within the second intron is the most frequent mutation leading to impaired 21-hydroxylase activity. This mutation is only detected in HLA-haplotypes associated with the salt-wasting form of CAH. (2) A large deletion of part or all of the CYP21 gene is associated with the HLA-haplotype A3, BW47, C6, DR7, DR53, DQ2 but is also observed in other HLA-haplotypes and can be detected by a simple rapid PCR restriction fragment length polymorphism method. (3) Two alleles of the coding CYP21 gene differing in a leucine codon within the first exon, (formerly described as a mutation associated with 21-hydroxylase deficiency) have been found with an equal distribution in patients with 21-hydroxylase deficiency, non-disease HLA-haplotypes and the local healthy controls.
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Hatsugai Y, Lee PA. Numerical study of localization of Dirac fermions on a lattice in two dimensions. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:4204-4207. [PMID: 10008886 DOI: 10.1103/physrevb.48.4204] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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111
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Kocova M, Siegel SF, Wenger SL, Lee PA, Trucco M. Detection of Y chromosome sequences in Turner's syndrome by Southern blot analysis of amplified DNA. Lancet 1993; 342:140-3. [PMID: 8101256 DOI: 10.1016/0140-6736(93)91345-m] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Only about half of all patients with Turner's syndrome are monosomy 45,X on karyotyping and there are grounds for supposing that cryptic mosaicism for at least part of the Y chromosome may be present in some patients. If so this would be clinically important because of the risk to patients of gonadal neoplasms and virilisation. We have used a very sensitive method to detect Y chromosomal segments in eighteen patients with Turner's syndrome, none of whom had evidence of Y chromosomal material by cytogenetic analysis. In DNA from peripheral blood lymphocytes and/or fibroblasts we looked for specific nucleotide sequences from the sex-determining region of the Y chromosome (SRY gene) and repetitive sequences located at the centromeric region (DYZ3). By polymerase chain amplification (PCR) one patient had a definite positive signal and two patients had faintly positive signals for the SRY gene. Southern blot analysis of PCR material with a SRY-specific probe confirmed that these patients were positive for SRY and revealed another three. No patient was positive for DYZ3, suggesting that only a small portion of Y was present. These results suggest that "pure" 45,X monosomy is less frequent than previously supposed. Long-term follow-up of patients with Y sequences is needed to determine their risk for subsequent gonadal neoplasms and virilisation.
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112
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Simons BD, Lee PA, Altshuler BL. Exact description of spectral correlators by a quantum one-dimensional model with inverse-square interaction. PHYSICAL REVIEW LETTERS 1993; 70:4122-4125. [PMID: 10054052 DOI: 10.1103/physrevlett.70.4122] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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113
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Lee PA, Matson JR, Pryor RW, Hinshaw LB. Continuous arteriovenous hemofiltration therapy for Staphylococcus aureus-induced septicemia in immature swine. Crit Care Med 1993; 21:914-24. [PMID: 8504662 DOI: 10.1097/00003246-199306000-00022] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES The goals of this study were: a) to evaluate the efficacy of controlled, continuous arteriovenous hemofiltration in improving morbidity and mortality rates in an immature swine model of Staphylococcus aureus-induced septicemia; b) to determine if ultrafiltrate from septic animals contained mediators that produce pathophysiologic changes observed in untreated S. aureus septic pigs. DESIGN Prospective, randomized, controlled study with age-matched controls. SETTING U.S. Department of Agriculture-licensed biomedical research facility. SUBJECTS Sixty-five weaned Poland-China swine (4 to 6 wks of age; 5 to 10 kg). INTERVENTIONS Part 1: Animals received a lethal dose of live S. aureus (8 x 10(9) colony-forming units/kg) over 1 hr. The three treatment groups included: hemofiltration group 1 (eight filtered, eight nonfiltered animals), plasma filtration fraction = 5.5%; hemofiltration group 2 (six filtered, six nonfiltered animals), filtration fraction = 16.6%; and hemofiltration group 3 (six filtered, six nonfiltered animals), filtration fraction = 33.4%. A control, nonseptic group of animals (n = 4) was filtered to obtain "clean" ultrafiltrate (hemofiltration group 4). Part 2: Sterile ultrafiltrate concentrate batches obtained from each group of filtered, septic animals were concentrated and infused into healthy, nonseptic pigs (reinfusion groups 1 through 3). MEASUREMENTS AND MAIN RESULTS Physiologic, biochemical, and hematologic variables were measured in all animals every 1 to 3 hrs. Overall length of survival was also recorded. In hemofiltration groups 1 through 3, filtered animals survived significantly longer than matched, nonfiltered (sham-filtered) animals. Increments in survival time increased directly with filtration fraction. Ultrafiltrate concentrate from septic pigs produced death (LD41) and disease similar to those rates observed in untreated S. aureus-septic pigs. Infusion of clean ultrafiltrate concentrate produced no response. CONCLUSIONS Continuous arteriovenous hemofiltration significantly improved survival rates in swine with S. aureus-induced sepsis. Resultant ultrafiltrate concentrate contained mediators responsible for some pathophysiologic responses observed in this animal model.
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Meir Y, Wingreen NS, Lee PA. Low-temperature transport through a quantum dot: The Anderson model out of equilibrium. PHYSICAL REVIEW LETTERS 1993; 70:2601-2604. [PMID: 10053604 DOI: 10.1103/physrevlett.70.2601] [Citation(s) in RCA: 186] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
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115
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Halperin BI, Lee PA, Read N. Theory of the half-filled Landau level. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:7312-7343. [PMID: 10004728 DOI: 10.1103/physrevb.47.7312] [Citation(s) in RCA: 829] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Abstract
No differences were seen in performance on either verbosequential or visuospatial neuropsychological tests among three groups of women. There were also no differences among the phases of the menstrual cycle on any of the tests. The design of this study was to sample performance of women on verbosequential and visuospatial neuropsychological tests during phases of the normal menstrual cycle in regularly menstruating women, and at comparable time points among women taking oral contraceptives and among those who had amenorrhea. Serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone were assayed to document these hormone levels at each time point for each group. These data are consistent with previous results in our laboratory but conflict with other reports in which shifts in cognitive function were related to fluctuations in estrogen. The only indications of positive results were weak correlations with gonadotropins and cognitive function across subjects. While some of these correlations replicated previous results, they were weak and should be considered with caution.
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Blatt J, Lee PA. Severe acne and hyperandrogenemia following dactinomycin. MEDICAL AND PEDIATRIC ONCOLOGY 1993; 21:373-4. [PMID: 8388076 DOI: 10.1002/mpo.2950210513] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The etiology of dactinomycin-associated acne has not previously been studied. An 81/2 year old girl with embryonal rhabdomyosarcoma of the left petrous bone was prepubertal at the time of presentation. Treatment according to a current Intergroup Rhabdomyosarcoma Study regimen consisted of vincristine, dactinomycin, and cyclophosphamide at 3 to 6 week intervals, as well as hyperfractionated radiotherapy to the tumor bad. Severe acne of the forehead developed within 10 days of starting therapy and resolved over the next 2 months. Serial measurements of serum hormones documented periodic increases in androgen levels coincident with courses of dactinomycin. These observations support a relationship between drug, dermatitis, and hormone levels. Study of other patients will be of interest to document the frequency, degree, and mechanism of hyperandrogenemia following dactinomycin.
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Abstract
Five children, three girls and two boys, were treated for precocious puberty secondary to hypothalamic hamartoma by resection of the hamartoma. The patients' ages at onset of pubertal development ranged from 6 to 19 months. The hamartomas ranged in size from 6 to 10 mm; four were pedunculated, one was sessile, and all were located below the tuber cinereum. The hamartomas were excised via a right subtemporal approach, with transection at the inferior surface of the hypothalamus; two were adherent posteriorly to the basilar artery and brain stem, and the adhesions were divided. Postoperatively, three children exhibited a transient oculomotor paresis and one other child required eye-muscle surgery. The symptoms and signs of precocious puberty completely regressed postoperatively in all patients. Preoperative hormone assays of testosterone, luteinizing hormone, and follicle-stimulating hormone were within the pubertal range in all five children; postoperative assays fell to prepubertal levels. The children have been followed for 0.5 to 10.5 years (mean 5.0 years) postoperatively, without evidence of recurrence of precocious puberty. One child has begun spontaneous puberty at a normal age. It is concluded that complete resection of hypothalamic hamartomas causing precocious puberty is curative.
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Clopper RR, Voorhess ML, MacGillivray MH, Lee PA, Mills B. Psychosexual behavior in hypopituitary men: a controlled comparison of gonadotropin and testosterone replacement. Psychoneuroendocrinology 1993; 18:149-61. [PMID: 8493299 DOI: 10.1016/0306-4530(93)90066-t] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nine gonadotropin-deficient hypopituitary men were cycled through periods of treatment with testosterone (T), gonadotropin (Gn), and placebo (Pl) using a blind cross-over design. Self-reports of sexual behavior, recordings of nocturnal penile tumescence (NPT), and sex steroid levels were obtained during each treatment period. Subjects had significantly higher plasma T during the T and Gn treatments than during the control periods. Similarly, self-reported frequency of ejaculation and ratings of libido as well as duration measures of NPT were significantly higher on T and Gn. Two thirds of the sample had no sociosexual experience. Behavioral differences between the T and Gn periods were minimal. These data support the hypothesis that Gn and T are equally effective in stimulating specific aspects of male psychosexual behavior.
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Lee PA, Bellinger MF, Songer NJ, O'Leary L, Fishbough R, LaPorte R. An epidemiologic study of paternity after cryptorchidism: initial results. Eur J Pediatr 1993; 152 Suppl 2:S25-7. [PMID: 8101807 DOI: 10.1007/bf02125430] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Paternity has been studied among married men who were formerly cryptorchid. Forty-one of 52 formerly unilateral cryptorchid men were married, 10 of 11 bilaterally cryptorchid and 36 of 42 control men. Thirty-two of the 41 of the unilateral group (78%) had fathered children, 6 of 10 in the bilateral group (60%) and 24 of 36 controls (67%). These limited data from the initial phase of this study of paternity after cryptorchidism do not show any correlation between paternity or time of unprotected intercourse to conception and age of surgery or pretreatment testicular size or location. However, these data suggest that paternity is not decreased after unilateral cryptorchidism.
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121
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Ubbens MU, Lee PA. Flux phases in the t-J model. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:8434-8439. [PMID: 10002608 DOI: 10.1103/physrevb.46.8434] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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122
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Lee PA, Nagaosa N. Gauge theory of the normal state of high-Tc superconductors. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:5621-5639. [PMID: 10004351 DOI: 10.1103/physrevb.46.5621] [Citation(s) in RCA: 248] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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123
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Kinaret JM, Meir Y, Wingreen NS, Lee PA, Wen XG. Many-body coherence effects in conduction through a quantum dot in the fractional quantum Hall regime. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:4681-4692. [PMID: 10004225 DOI: 10.1103/physrevb.46.4681] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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124
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Dahl RE, Siegel SF, Williamson DE, Lee PA, Perel J, Birmaher B, Ryan ND. Corticotropin releasing hormone stimulation test and nocturnal cortisol levels in normal children. Pediatr Res 1992; 32:64-8. [PMID: 1321974 DOI: 10.1203/00006450-199207000-00012] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This study examined hypothalamic-pituitary-adrenal axis functioning in a group (n = 25) of very carefully screened normal children with considerable attention to issues of adaptation and procedural stress. The subjects (mean age 10.3 +/- 1.6 y) were selected as "supernormal" controls as a part of a large psychobiologic study of childhood depression. After careful acclimatization over 24 h, the subjects underwent all-night sampling of plasma cortisol every 20 min, then the following evening had a corticotropin releasing hormone (CRH) stimulation test (using human CRH). Human CRH resulted in a rapid stimulation of adrenocorticotropin and cortisol. Adrenocorticotropin levels increased from 6.8 +/- 3.5 (+/- SD) pmol/L (30.7 +/- 16.1 pg/dL) to a peak of 11.6 +/- 5.5 pmol/L (52.9 +/- 24.8 pg/mL) at 15 min with return to baseline levels by 60 min. Cortisol levels increased from 131.4 +/- 59.7 nmol/L (4.8 +/- 2.2 micrograms/dL) to a peak of 427.0 +/- 113.5 nmol/L (15.5 +/- 4.1 micrograms/dL) at 30 min with return to baseline by 120 min. The cortisol peak was significantly greater (p less than 0.05) in boys [474.6 +/- 129.7 nmol/L (17.2 +/- 4.7 micrograms/dL)] than in girls [366.9 +/- 52.4 nmol/L (13.3 +/- 1.9 micrograms/dL, p less than 0.05)]. Age, body mass index, and pubertal status were not significantly related to hypothalmic-pituitary-adrenal axis measures. Nocturnal cortisol reached a nadir at 160 +/- 60 min after sleep onset (0102 h) and a peak 480 +/- 60 min after sleep onset (0612 h). Nocturnal cortisol levels were significantly (positively) correlated with human CRH-stimulated cortisol (r = 0.56, p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)
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Nagaosa N, Lee PA. Quantum disordered spiral states. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:10719-10727. [PMID: 10000977 DOI: 10.1103/physrevb.45.10719] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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