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Biomedical subjects

C M Peterson

Publications and source records attributed to C M Peterson.

At least 19 recordsLinked to original sources
PubMed1995

A structural assignment for a stable acetaldehyde-lysine adduct.

Acetaldehyde is the first oxidation product of ethanol in vivo. Lysine residues in proteins such as hemoglobin have been implicated as target structures for acetaldehyde adducts resulting from ethanol consumption. Although the presence of both stable and unstable acetaldehyde-hemoglobin adducts has been established, the structural characterization of the adducts has received relatively little attention. As a model for such adduct formation, we studied the peptide pentalysine in vitro. Pentalysine has several potential sites for adduct formation. The amino-terminal amine group as well as the epsilon-amine groups of each lysine side chain can serve as potential sites for modification by acetaldehyde. Mass spectrometry, nuclear magnetic resonance, and Raman spectroscopy were employed to demonstrate that acetaldehyde forms a stable linkage to lysine amine groups via a Schiff base.

Acetaldehyde↗
PubMed1995

Metabolic parameter, bleeding, and weight changes in U.S. women using progestin only contraceptives.

Our objective was to determine the effect of progestin-only contraceptives on metabolic parameters, bleeding patterns, and weight changes during the first year of use. Seventy-one women (> 95% Caucasian), who were advised regarding contraception alternatives, self-selected levonorgestrel implants (n = 44), depo-medroxyprogesterone acetate (n = 22), or oral norethindrone (n = 5). One year later, 11 levonorgestrel implant and five depomedroxyprogesterone acetate patients were randomly selected to compare (pre- and post-progestin use) levels of cholesterol, triglycerides, low density lipoprotein (LDL), high density lipoprotein (HDL), very low density lipoprotein (VLDL), apolipoproteins A-1 and B-100, bilirubin, and sex hormone binding globulin. Monthly bleeding and spotting records were kept in each group. Body weights were also monitored in each group. No statistically significant differences in metabolic parameters were found between pre- and post-progestin use in the levonorgestrel implant and depo-medroxyprogesterone acetate groups. Continued bleeding patterns were more prominent in the levonorgestrel implant and oral norethindrone groups than in patients receiving depo-medroxyprogesterone acetate. No significant weight gain was detected in any group. No changes in metabolic parameters or weight were noted over the one year of use of levonorgestrel implants or depo-medroxyprogesterone acetate. Depo-medroxyprogesterone acetate had the highest incidence of amenorrhea.

Administration, Oral↗
PubMed1995

Multiple endocrine neoplasia presenting as primary amenorrhea: a case report.

BACKGROUND: Primary amenorrhea is rarely secondary to hyperprolactinemia. This case highlights the importance of obtaining a complete family history to identify patients who may have hyperprolactinemia secondary to multiple endocrine neoplasia type 1 syndrome. CASE: A 16-year-old female presented with primary amenorrhea and was noted to have hyperprolactinemia. Her family history revealed an extensive family tree consistent with multiple endocrine neoplasia type 1 syndrome. She was diagnosed subsequently with the syndrome, having both pituitary and parathyroid adenomas. CONCLUSION: A detailed family history of patients with hyperprolactinemia secondary to a pituitary adenoma may prompt a serum calcium measurement, which may identify patients at risk for development of multiple endocrine neoplasia type 1 syndrome.

Adolescent↗
PubMed1995

A hook-traction technique for Norplant removal.

We describe a simple technique to facilitate the removal of difficult-to-remove Norplant implants. Through a standard skin incision for Norplant removal, the fibrous capsule surrounding the implant is secured using either a dermatologic skin hook or a 25-gauge hypodermic needle fashioned into a hook with a hemostat. Traction is applied to bring the fibrous sheath into the incision site, where the implant tip is dissected free using a scalpel. The precisely localized countertraction afforded by this technique provides increased accuracy and speed for the removal of difficult-to-extract implants. Tissue trauma is minimized and the need to extend the skin incision is reduced.

Contraceptive Agents, Female↗
PubMed1995

Fasting plasma glucose and glycosylated plasma protein at 24 to 28 weeks of gestation predict macrosomia in the general obstetric population.

The purpose of this study was to modify the traditional gestational diabetes screening process in order to provide a test that might more reliably detect those women at risk of delivering a macrosomic infant despite a negative test for gestational diabetes mellitus (GDM). Pregnant women (n = 160) were screened for GDM at 24 to 28 weeks' gestation using the traditional 50 g glucose challenge test (GCT). In addition, glycosylated hemoglobin, glycosylated serum protein, and glycosylated plasma protein (GPP) were analyzed from blood drawn at this same time. If the patient's challenge test was positive (140 mg/dL or higher), a 100 g oral glucose tolerance test (OGTT) was performed. Twenty-three women had a positive GCT (14.4%) and five (3.13%) were excluded from further study because they received treatment for gestational diabetes based on a positive OGTT. None of the GCT-negative or the GCT-positive-OGTT-negative patients received treatment. Gestational age at delivery, infant gender, and birthweight were retrieved from birth records. Although several correlations with infant birthweight were found, the fasting plasma glucose (FPG) and GPPs proved most significant. The FPG on the OGTT significantly correlated with infant birthweight (p < 0.001; r = 0.94). A value greater than 90 mg/dL proved to be 100% sensitive and 64% specific for infant birthweight more than 4000 g. The relationship of the GPP and subsequent infant birthweight was also significant (p < 0.001; r = 0.81). A GPP greater than 23% proved to be 100% sensitive in predicting birthweight above 4000 g (11 of 11 infants); however, the test had a 52% specificity.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗
PubMed1995

The binding of recombinant human relaxin to human spermatozoa.

Porcine relaxin has been reported to stimulate various human sperm functions. In this paper we report that human recombinant relaxin binds to human sperm with a high affinity (Kd = 6.5 x 10(-10)). The bound 125I-relaxin was not displaced by insulin, or human chorionic gonadotropin, however, it was displaced by unlabeled relaxin. In sperm function studies, recombinant human relaxin stimulated sperm motility, zona-free hamster egg penetration, and the acrosome reaction.

Acrosome↗
PubMed1995

Validated fluorimetric HPLC analysis of acetaldehyde in hemoglobin fractions separated by cation exchange chromatography: three new peaks associated with acetaldehyde.

Stable hemoglobin-acetaldehyde adducts present in hemoglobin fractions separated by polyaspartic acid cation exchange chromatography were quantified by fluorimetric HPLC. The fluorescent species eluted from the HPLC was confirmed by mass spectrometry to be consistent with the expected product from reaction of acetaldehyde, 1,3-cyclohexanedione (CHD), and ammonium ion. Hemolysate (2.2 mM hemoglobin) was incubated in equivalent volumes of either phosphate-buffered saline or 5 mM acetaldehyde at 37 degrees C for 30 min and washed three times with H2O to remove free acetaldehyde and labile adducts before the injection of 14.7 mg hemoglobin onto the cation exchange column. Fluorimetric HPLC analysis of hemolysate samples either with or without in vitro reaction with acetaldehyde revealed that most acetaldehyde resides in the hemoglobin A0 fraction. The reaction with acetaldehyde in vitro resulted in a significant increase in fast-eluting minor hemoglobin species on cation exchange chromatography concomitant with increased acetaldehyde in the HbA1a+b, HbA1c, and HbA1-AcH fractions. We report three new cation exchange chromatographic peaks after reaction with acetaldehyde: HbA1-AcH-3, HbA1c-1, and HbA0-1. Each new peak was found to associate with a significant quantity of CHD-reactive acetaldehyde. These experiments provide additional evidence that stable adducts form between acetaldehyde and hemoglobin and that these adducts occur in multiple hemoglobin species separated by cation exchange chromatography. Further characterization and structural assignment of these species are warranted in view of their potential utility as markers for ethanol intake.

Acetaldehyde↗
PubMed1995

Acetaldehyde-serum protein adducts inhibit interleukin-2 secretion in concanavalin A-stimulated murine splenocytes: a potential common pathway for ethanol-induced immunomodulation.

Variable immunobiological changes occur with alcohol consumption. Previous studies have shown that acetaldehyde forms stable adducts with serum proteins, including albumin. These adducts are elevated in persons and animals consuming ethanol. We examined the effect of serum protein-acetaldehyde adducts formed with fetal bovine serum (FBS) on concanavalin A-stimulated murine splenocytes. Interleukin-2 (IL-2) secretion and IL-2 receptor (IL-2R) expression were determined as a function of the effect of the acetaldehyde-protein adduct(s). FBS was incubated with acetaldehyde (500, 100, 50, 25, 10, and 0 microM) for 1 hr at 37 degrees C. Excess acetaldehyde was removed by ultrafiltration using a 500 molecular weight cut-off membrane in 3 volumes. Free as well as bound acetaldehyde was quantified using fluorigenic HPLC before and after incubation. Recovered acetaldehyde correlated with the amount added (r2 = 0.996). Splenocytes were cultured for 48 hr in complete medium containing 5% acetaldehyde-treated and 5% untreated FBS with 4 micrograms/ml concanavalin A. Although cell viability was unchanged, acetaldehyde-treated FBS mixed with native FBS decreased IL-2 secretion in a dose-dependent manner. The percentage of cells expressing IL-2R was reduced only at the highest acetaldehyde-FBS dose. Therefore, immunological effects ascribed to ethanol may result in part from the toxic properties of acetaldehyde-protein adducts on IL-2 secretion.

Acetaldehyde↗
PubMed1995

Levels of Tap-1 and Tap-2 mRNA and expression of Kd and Db on splenic lymphocytes are normal in NOD mice.

It has been reported that the level of Tap-1 (transporter associated with antigen processing) mRNA and the expression of class I on splenocytes are low in NOD mice. Class I expression at 37 degrees C depends on an adequate supply of peptides, so a decrease in Tap could lead to lower class I levels. Since hypoexpression of class I correlated uniformly with the development of diabetes, it has also been suggested that Tap-1nod is diabetogenic. However, others report normal Tap-1 and class I levels in NOD mice. We examined Tap-1 and Tap-2 mRNA levels in NOD/Smrf mice using a reverse transcriptase-polymerase chain reaction method that detects > or = 25% changes in mRNA. We also assessed class I expression with three monoclonal antibodies. No difference in Tap-1 or Tap-2 mRNA levels for females of different ages or between diabetic and nondiabetic animals was observed. Tap-1 mRNA levels were identical between NOD/Smrf and BALB/cJ mice. Kd expression was significantly lower on NOD lymphocytes than in BALB/cJ cells, but the difference was due to the smaller size of the NOD splenic lymphocyte. When cells of the same size were analyzed, no difference in class I levels was observed. Class I levels were also identical in diabetic and age-matched nondiabetic NOD and BALB/c females. Both NOD Tap-1 mRNA and class I were increased by interferon-gamma. We find no evidence for impaired NOD Tap gene activity or class I expression, as previously reported for this strain.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Association of an androgen-responsive T cell phenotype with murine diabetes and Idd2.

T cells are involved in the induction and suppression of autoimmune diabetes in nonobese diabetic (NOD) mice. Because the incidence of diabetes is 13-fold greater in NOD/Smrf females, we searched for T cell phenotypes that showed sexual dimorphism and associated with diabetes in backcross segregants. The percentage of CD4+PBL was higher in NOD/Smrf females than males, was intermediate in [NOD X NON] F1 mice and approximated a 1:1 distribution in F1 mice backcrossed to either NOD or NON parental strains, suggesting primary control of the phenotype by an incompletely dominant gene, but not excluding additional effects by other genes. We term this primary gene Tlf(T lymphocyte frequency) because it also influenced the percentage of CD8+ T cells, although to lesser extent and independently from the MHC previously shown to lower the CD8+ T cell fraction in NON mice. Tlf segregated with diabetes in BC1 females, suggesting linkage with at least one diabetic locus. Genotyping of markers for Idd1, Idd2, and Idd3/10 revealed that Tlf mapped with Idd2 on chromosome 9. Dihydrotestosterone simultaneously lowered CD4+ PBL levels and prevented diabetes in NOD females while, in vitro, it had a differential effect on Con A elicited cytokines, increasing IL-2 22% and decreasing IL-4 39% (p < 0.0001). Thus the Tlf phenotype in NOD females, like diabetes, can be modulated by androgens.

Animals↗
PubMed1994

Apraclonidine and brimonidine effects on anterior ocular and cardiovascular physiology in normal and sympathectomized monkeys.

Apraclonidine and brimonidine administered topically to one eye of ketamine-anesthetized normal cynomolgus monkeys each produced a dose-related bilateral reduction in intraocular pressure which was not dependent on intact sympathetic innervation. Brimonidine was more potent and efficacious (10-12 mmHg maximum intraocular pressure reduction 2 hr after 200 micrograms) but produced a shorter-lasting effect than apraclonidine (4 mmHg maximum intraocular pressure reduction 1-6 hr after 600-1000 micrograms). Apraclonidine had little effect on pupil diameter, but brimonidine produced a dose-related bilateral miosis which was dependent on intact sympathetic innervation. Neither drug significantly affected refractive error. Topical brimonidine, but not apraclonidine, produced a dose-dependent reduction in mean arterial blood pressure, while both drugs lowered heart rate. A dose-dependent bilateral reduction in aqueous humor flow rate calculated over a 6-hr period following drug administration was produced by both topical apraclonidine (maximum 30-35% reduction with 600 micrograms) and brimonidine (maximum 30-45% reduction with 50-250 micrograms), which was not dependent on intact sympathetic innervation. Maintenance of blood pressure by intravenous infusion of angiotensin II had no effect on the aqueous humor flow suppression produced by 100 micrograms of topical brimonidine, but pentobarbital anesthesia abolished it. Intracameral injection of 10 micrograms brimonidine in rhesus monkeys produced an ipsilateral approximately 15% reduction in aqueous humor flow calculated for the 1-3 hr post-injection period. The cardiovascular and contralateral ocular effects observed with both drugs are presumably related to the monkeys' small body weight, and the magnitude of IOP reduction for a given degree of flow suppression would be greater in hypertensive than in normotensive eyes. Caution must therefore be exercised in extrapolating from our data in ocular normotensive monkeys to the glaucomatous human.

Adrenergic alpha-Agonists↗
PubMed1993

Interleukin-1 beta (IL-1 beta) modulates prostaglandin production and the natural IL-1 receptor antagonist inhibits ovulation in the optimally stimulated rat ovarian perfusion model.

The rat ovarian perfusion model with bursa removed and intact was used to further characterize the effects of interleukin-1 beta (IL-1 beta) and the natural IL-1 receptor anatagonist (IRAP) on ovulation, steroidogenesis, and prostaglandin production. Twenty-six- to 27-day-old female Sprague-Dawley rats were injected sc with 25 IU PMSG, and 48 h later, the right ovary was dissected (with bursa removed and intact for various experiments) and placed in the perfusion chamber. Ovaries were exposed to various doses of IL-1 beta alone, IL-1 beta with LH, and IL-1 beta with LH and isobutylmethylxanthine (IBMX). The natural IL-1 receptor antagonist was also added to the chambers with LH and IBMX. IL-1 beta at 0.8 (n = 3) and 8.0 (n = 4) nM did not induce LH-independent ovulation in PMSG-stimulated ovaries with bursa removed. In bursa-intact perfusions (n = 3), one ovulation was produced in each compared to control ovaries with bursa intact (n = 3) given an ovulatory trigger of LH alone [2.3 +/- 0.6 (+/- SD) ovulations; P < 0.02]. IL-1 beta enhanced, in a dose- and gonadotropin-dependent fashion, the production of prostaglandin E2 (PGE2) in PMSG-stimulated ovaries with bursa removed given an ovulatory trigger of LH and IBMX compared to that in controls. PGF2 alpha and 6-keto-PGF1 alpha were also modulated by IL-1 beta. Estradiol and progesterone production were not affected. The natural IRAP inhibited ovulation (7.8 +/- 3.9 ovulations vs. 12.4 +/- 1.5; P < 0.04) in PMSG-stimulated ovaries given LH and IBMX as the ovulatory trigger compared to that in controls. This inhibition of ovulation was not associated with reduced steroid or PG levels. IL-1 beta appears to play a potentially significant role in the process of ovulation. The functional importance of the bursa in this model is highlighted in this study. IL-1 beta modulates PG, but not steroid, production. IRAP inhibited ovulation without significantly affecting PG or steroid production.

1-Methyl-3-isobutylxanthine↗
PubMed1992

The Diabetes in Early Pregnancy Study: changes in cholesterol, triglycerides, body weight, and blood pressure. The National Institute of Child Health and Human Development--the Diabetes in Early Pregnancy Study.

This study examined changes in cholesterol, triglycerides, body weight, and blood pressure during pregnancy in 312 diabetic and 356 control women recruited within 21 days after conception. Cholesterol values rose in both groups but were significantly lower in diabetic women at each time point (166 vs 178 mg/dl at week 12, p = 0.0004). Triglyceride values also rose in both groups. Triglyceride levels did not differ between groups up to week 8 of gestation, but by weeks 10 to 12 they were significantly lower in diabetic women than in controls (75 vs 89 mg/dl at week 12, p = 0.0004). Although they were no heavier at entry, diabetic women gained significantly more weight between weeks 6 and 8 (p less than 0.001), resulting in a mean difference between groups of 1 kg. Systolic blood pressure increased steadily and significantly in the diabetic but not the control women (115.8 +/- 16.2 SD vs 109.3 +/- 11.8 mm Hg, p = 0.0006 at term). Diastolic blood pressure was higher in diabetic women on entry (70.7 vs 67.3 mm Hg, p = 0.0006) and throughout gestation. Significant correlations were found in the diabetic group between maternal blood pressure and lipids and infant birth weight. These newly found differences in cholesterol and triglyceride levels, weight gain, and blood pressure between type I diabetic and control women during gestation may have long-term cardiovascular implications.

Adult↗
PubMed1992

Laboratory and clinical comparison of a rapid versus a classic progesterone radioimmunoassay for use in determining abnormal and ectopic pregnancies.

A rapid, solid-phase, nonextraction progesterone kit (n = 36) was compared with an established extraction method, liquid phase tritium radioimmunoassay for progesterone (n = 79). Logistic regression of the rapid method over the extraction method gave a correlation coefficient of r = 0.968. Logistic regression gave a discriminatory zone (abnormal vs normal pregnancy) of 22.58 ng/ml by the rapid method compared with 15 ng/ml for the extraction method (log Y = 0.253 + 0.936 log X). Similar sensitivity (100% and 100%), specificity (63% and 59%), and predictive values of positive and negative tests (positive predictive value = 91% and 75%, negative predictive value = 100% and 100%) were found using a discriminatory level of 15 and 20 ng/ml for the extraction method (n = 79) and rapid method (n = 76), respectively. Clinically, curettage for patients with values less than these discriminatory zones would have given unacceptable rates for termination of a potentially normal pregnancy (38%). Clinical comparison of abnormal (ectopic or abortion) and normal (term pregnancy) outcomes in two populations of women presenting with first-trimester bleeding revealed that progesterone levels would accelerate the workup in only a small percentage (27%, 15 of 56) of patients with ectopic pregnancies. The rate of ruptured ectopic pregnancies in the observed patients was similar (20%, 3 of 15) to studies using progesterone levels prospectively. Therefore in this retrospective analysis progesterone levels would have given no greater benefit than conventional management.

Abortion, Spontaneous↗
PubMed1992

Photodynamic therapy of human ovarian epithelial carcinoma, OVCAR-3, heterotransplanted in the nude mouse.

OBJECTIVE: Our objective was to develop an animal model for the study of photodynamic therapy in the treatment of human ovarian epithelial carcinoma. STUDY DESIGN: The human ovarian carcinoma OVCAR-3 was heterotransplanted into nude, athymic mice and treated with photodynamic therapy consisting of the hematoporphyrin derivative Photofrin II 10 ng/kg and argon-pumped dye laser light at 630 nm (200 J/cm2). Growth of tumors on one side of seven mice (treated tumors, n = 7) was compared with contralateral tumors (control tumors, n = 8) not exposed to laser. Hematoporphyrin derivative uptake was determined in tumor and other tissues. RESULTS: Photodynamically treated tumors were completely ablated, and all remained absent. Hematoporphyrin derivative uptake was nonselective for tumor compared with other tissues. CONCLUSION: This model provides reproducible parameters for the study of photodynamic therapy in the treatment of gynecologic malignancies and demonstrates the need for methods to increase selective uptake of hematoporphyrin derivatives.

Animals↗
PubMed1992

The relationship between contraceptives, sexual practices, and cervical human papillomavirus infection among a college population.

Four hundred and sixty-five college women were evaluated to determine if specific variables of social and sexual behavior correlated with the presence of human papillomavirus (HPV) DNA in the genital tract, and if these associations differed between women who were HPV DNA positive, HPV DNA positive/clinically (cytologically) negative, or who reported previous HPV-related disease by a history of an abnormal Papanicolaou (Pap) smear or genital warts. HPV positive women had more sexual partners in the recent past, more sexual episodes per month, and used spermacides less commonly than controls. Similarly, self-reporters were more likely to have more lifetime sexual partners and earlier age of onset for sexual activity. Cytologically negative HPV positive women were distinguished only by more sexual episodes per month and sexual partners in the past year (borderline significance). Alcohol use was significantly more frequent in all groups, underscoring this variable as a risk factor for both HPV DNA positivity and related disease in young women. Potential explanations for differences between women with clinically and non-clinically related HPV positivity are discussed, with emphasis on the need for followup studies to determine if an epidemiologically distinct subset of HPV DNA positive but clinically negative women are at risk for subsequent cervical disease.

Adolescent↗