Multiple pregnancies: action is taking place.
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Adult↗
Biomedical subjects
R J Chang
Publications and source records attributed to R J Chang.
Pregnancy-associated plasma protein-A gene expression in human ovaries is restricted to healthy follicles and corpora lutea.
Recently, Pregnancy-Associated Plasma Protein-A (PAPP-A) in human follicular fluid was identified as an insulin-like growth factor binding protein-4 protease (IGFBP-4ase). The ability of IGFBP-4ase to inactivate the FSH antagonist, IGFBP-4, has suggested a possible role for PAPP-A in regulating FSH action. Despite growing interest in this protease, the question of whether the PAPP-A gene is expressed in ovaries of normal cycling women is unknown. To fill this basic gap in our knowledge, we have identified the cellular sites of PAPP-A gene expression in normal human ovaries by in situ hybridization. PAPP-A mRNA was low or undetectable in preantral follicles, small (1-2 mm) healthy and atretic antral follicles, larger atretic antral follicles, surface epithelium, tunica albuginea and connective tissue cells. In contrast, an intense PAPP-A hybridization signal was evident in the healthy antral follicles examined from 5 mm to the preovulatory stage. In these follicles, the signal was restricted to the granulosa cells (GC). An intense signal for PAPP-A mRNA was also present in healthy corpora lutea (CL), being localized to a subset of large luteal cells. Collectively, these results provide the first evidence that the gene encoding PAPP-A is expressed in ovaries of normal cycling women and show that the gene is expressed almost exclusively in healthy GC and CL cells. The restricted pattern of PAPP-A expression in normal human ovaries suggests that PAPP-A may be a functional marker of the dominant follicle and its product, the CL. Although the physiological function of ovarian PAPP-A remains to be identified, we hypothesize it might play a role in controlling survival, growth, and/or differentiation of the dominant follicle and CL by inactivating the gonadotropin antagonist, IGFBP-4.
Adult↗
Reversed-phase high-performance liquid chromatographic assay for the adenovirus type 5 proteome.
An RP-HPLC assay was developed for a recombinant adenovirus type 5. During chromatography, intact adenovirus dissociated into its structural components (DNA and proteins) and the viral proteome was separated yielding a characteristic fingerprint. The individual components were identified by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy, N-terminal sequencing and amino acid composition. The assay was utilized to measure adenovirus particle concentration through quantification of structural proteins. Each structural protein provided independent measurement of virus concentration allowing verification of accuracy. The assay sensitivity is at or below 2 x 10(8) particles. Contrary to the benchmark spectrophotometric assay, the RP-HPLC assay was shown to be insensitive to contaminants common for partially purified adenovirus preparations.
Adenoviruses, Human↗
A functional bone morphogenetic protein system in the ovary.
Bone morphogenetic proteins (BMPs) comprise a large group of polypeptides in the transforming growth factor beta superfamily with essential physiological functions in morphogenesis and organogenesis in both vertebrates and invertebrates. At present, the role of BMPs in the reproductive system of any species is poorly understood. Here, we have established the existence of a functional BMP system in the ovary, replete with ligand, receptor, and novel cellular functions. In situ hybridization histochemistry identified strong mRNA labeling for BMP-4 and -7 in the theca cells and BMP receptor types IA, IB, and II in the granulosa cells and oocytes of most follicles in ovaries of normal cycling rats. To explore the paracrine function of this BMP system, we examined the effects of recombinant BMP-4 and -7 on FSH (follicle-stimulating hormone)-induced rat granulosa cytodifferentiation in serum-free medium. Both BMP-4 and -7 regulated FSH action in positive and negative ways. Specifically, physiological concentrations of the BMPs enhanced and attenuated the stimulatory action of FSH on estradiol and progesterone production, respectively. These effects were dose- and time-dependent. Furthermore, the BMPs increased granulosa cell sensitivity to FSH. Thus, BMPs have now been identified as molecules that differentially regulate FSH-dependent estradiol and progesterone production in a way that reflects steroidogenesis during the normal estrous cycle. As such, it can be hypothesized that BMPs might be the long-sought "luteinization inhibitor" in Graafian follicles during their growth and development.
Animals↗
Diagnosis of polycystic ovary syndrome.
The clinical features of polycystic ovary syndrome (PCOS) include hirsutism and irregular menses, which are the results of ovarian hyperandrogenism and chronic, unopposed estrogen secretion. The discovery that most women with PCOS are insulin-resistant and have compensatory hyperinsulinemia, with increased risk for type 2 diabetes mellitus, designates this condition as a reproductive-metabolic disorder. That the symptoms of PCOS may be mimicked by other endocrine disorders of the ovary and adrenal glands warrants careful evaluation to exclude these associated conditions.
Diagnosis, Differential↗
How does warfarin affect the activated coagulation time?
BACKGROUND: The activated coagulation time (ACT) is a rapid measurement of a patient's level of heparin anticoagulation during cardiac catheterization. Patients receiving warfarin therapy occasionally are seen at the catheterization laboratory for emergent procedures. The effects of warfarin on ACT activity have not been previously described. We compared the ACT and the international normalized ratios (INR) in 77 patients receiving warfarin and 57 patients who were not receiving any anticoagulation (controls). RESULTS: Both the mean ACT (131+/-17.0 seconds) and INR (2.5+/-0.90 seconds) of the anticoagulated patients differed from the controls (ACT=115+/-14.5 seconds, INR=1.0+/-0.10 seconds; P< 0.05). The ACT increased linearly with INR in the warfarin group (r=0.70, P< .001). There was no relation between ACT and INR in the control group. CONCLUSION: Patients receiving warfarin therapy will have a linear increase in ACT develop similar to patients receiving heparin therapy.
Adult↗
Evidence for a neutrophil-interleukin-8 system in human folliculogenesis.
OBJECTIVE: This study was conducted to determine whether polymorphonuclear leukocytes (neutrophils) and the potent chemoattractant interleukin-8 are associated with follicle development in the normal human ovary. STUDY DESIGN: We performed a morphometric analysis of neutrophils in 268 human ovarian follicles, of which 199 were preantral and 69 were antral. In each antral follicle the numbers of mitotic, apoptotic, and total granulosa cells were counted to determine healthy and atretic follicles. Interleukin-8 protein and messenger ribonucleic acid were detected by immunohistochemistry and in situ hybridization, respectively. RESULTS: Antral follicles contained relatively large numbers of neutrophils within the theca vasculature. The density of neutrophil was twofold greater (p < 0.05) in atretic versus healthy follicles. The neutrophil index (neutrophils/granulosa cells x 1000) was inversely correlated to the number of granulosa cells per follicle. Immunoreactive interleukin-8 was detected in the theca and granulosa cells of most all antral follicles examined. Interleukin-8 messenger ribonucleic acid was demonstrated in theca and granulosa cells of some but not all follicles examined. CONCLUSIONS: Neutrophils are present in the theca of developing antral follicles, increase in number during atresia, and are associated with expression of interleukin-8 in the follicle wall.
Adult↗
Identification of a linked set of genes in Serpulina hyodysenteriae (B204) predicted to encode closely related 39-kilodalton extracytoplasmic proteins.
A tandem pair of nearly identical genes from Serpulina hyodysenteriae (B204) were cloned and sequenced. The full open reading frame of one gene and the partial open reading frame of the neighboring gene appear to encode secreted proteins which are homologous to, yet distinct from, the 39-kDa extracytoplasmic protein purified from the membrane fraction of S. hyodysenteriae. We have designated these newly identified genes vspA and vspB (for variable surface protein).
Amino Acid Sequence↗
Competitive enzyme-linked immunosorbent assay for biotin.
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Animals↗
Multisite electromyographic analysis of therapeutic touch and qigong therapy.
The influence of complementary healing treatment on paraspinal electromagnetic activity at specific neuromuscular sites was examined in an exploratory pilot study that used a multisite surface electromyographic (sEMG) assessment procedure. The study was a replication and extension of previous research that indicated that complementary healing had a significant effect in normalizing the activity of the "end organ" for the central nervous system (CNS). Multisite sEMG electrodes were placed on the frontalis, cervical (C4), thoracic (T6), and lumbosacral (L3) paraspinals of 44 subjects who were divided into three groups: (1) students/patients of a Qigong practitioner (n = 16); (2) students/patients of a therapeutic touch (TT) practitioner (n = 14); and (3) nonbelievers in complementary healing (n = 14). A traditional ABAC experimental design was used with each subject evaluated for one 20-minute session that included four 5-minute segments. The purpose of this study was to measure the variable energizing effect of Qigong therapy along with the anecdotally and experimentally established relaxation effect of TT therapy relative to patient belief and expectancy. Treatment sessions consisted of Qigong and a modified form of TT intervention for all three groups. Due to the double-blind nature of the study, however, group 1 subjects were aware of only the Qigong intervention; group 2 subjects were aware of only the TT intervention, and group 3 subjects were informed that the study was designed to assess the neuromuscular activity of individuals in a seated position. The results indicated a statistically significant rise in electromagnetic activity for group 1 during the Qigong intervention segment (p < .024). Group 2 demonstrated a modest although overall nonsignificant decrease in multisite sEMG levels for both treatment protocols, whereas group 3 exhibited relatively consistent neuromuscular activity for both control and treatment segments. The results of this study are considered preliminary in nature, however, due to the potential influence of several confounds including psychophysiological factors, established behavior patterns, and the possibility for information transfer due to sensory cues.
Adolescent↗
Pulsatile gonadotrophin secretion in women with polycystic ovary syndrome after gonadotrophin-releasing hormone agonist treatment.
In polycystic ovary syndrome (PCOS), increased luteinizing hormone (LH) pulse frequency has been attributed to either the hypothalamic gonadotrophin-releasing hormone (GnRH) pulse generator or ovarian oestrogen feedback. To address this issue, a detailed examination of pulsatile LH secretion was undertaken during recovery from GnRH agonist (GnRHa) suppression. Each of six women with PCOS and six normal ovulatory women received daily GnRHa treatment for 14 weeks. Frequent blood samples were collected and assayed for gonadotrophins, androgens and oestrogens before, during and up to 4 weeks after treatment. Women with PCOS had higher basal LH pulse frequency and amplitude and increased serum concentrations of LH, androstenedione, testosterone and oestrone than controls. After 3 months of GnRHa treatment, all these parameters were suppressed with no differences observed between the two groups. One week after cessation of GnRHa, LH pulse frequency promptly returned to pre-treatment range with no between-group differences noted, whereas LH pulse amplitude, serum gonadotrophins and ovarian steroids remained maximally suppressed and equivalent in the two groups. Subsequent LH pulse frequency remained constant while LH pulse amplitude and circulating concentrations gradually increased in parallel with a return of serum oestrogen to pre-treatment values. Despite comparable resumption of LH secretion in the two groups, corresponding androgen concentrations in women with PCOS were greater than those of normal ovulatory women. Thus, the immediate restoration of LH pulse frequency after discontinuing GnRHa treatment is largely independent of ovarian oestrogen production and reflects primacy of the GnRH pulse generator in determining basal LH pulse frequency. Equivalent LH pulse frequency rates in the two groups during the recovery period do not suggest an intrinsic hypothalamic-pituitary hyperactivity in PCOS.
Adult↗
Ophthalmic disorders among the homeless and nonhomeless in Los Angeles.
BACKGROUND: Few studies have addressed ocular disorders among the homeless and nonhomeless poor. METHODS: To better understand the health problems of the homeless, ophthalmic disorders were analyzed among 512 homeless and 413 nonhomeless poor individuals receiving vision-screening examinations in Los Angeles. RESULTS: Significantly, more 4- to 17-year-old nonhomeless poor were diagnosed with uncorrected visual acuity worse than or equal to 20/50 without correction (p = 0.001), total refractive errors (p < 0.0005), astigmatism (p = 0.001), and myopia (p < 0.0005) than were a control group of 4- to 17-year-old homeless individuals. More homeless individuals had extraocular muscle imbalance (p < 0.040), but fewer had external eye diseases (p2 = 0.016) than the nonhomeless poor, when age adjusted. In addition, higher rates of glaucoma and cataracts were observed in both homeless and poor nonhomeless populations than in the general population. CONCLUSIONS: Health care professionals should provide vision screenings intended to detect these ocular disorders. Screening and correction of myopia and glaucoma, in particular, can greatly improve the quality of life for those treated.
Adolescent↗
Prevalence of ocular disorders among 6- and 7-year-olds in Santa Monica, California.
BACKGROUND: Undetected ocular disorders can cause serious problems in a child's mental and social development. METHODS: To investigate relationships between ocular disease, gender and ethnicity in children, vision screening examination data was analyzed from the UCLA Mobile Eye Clinic (MEC), collected from 1985 to 1990 on first graders (69.9 percent 6- and 30.1 percent 7-year-olds) in Santa Monica, California. RESULTS: The sample consisted of 1,469 individuals, of whom 48.1 percent were female and 51.9 percent were male. Ethnicity data was available from 1988 to 1990 on 834 individuals, of whom 46.9 percent were Hispanic, 27.9 percent were White. 11.5 percent were Black, 4.4 percent were Asian, and 9.2 percent were of other races. Significantly more females than males had refractive errors, specifically hyperopia and astigmatism, and uncorrected visual acuity of 20/50 or worse in at least one eye. There were no significant associations of ethnicity or sex with any other disease category. The overall prevalences of other diseases were less than 4 percent. Of the 6- and 7-year-olds studied in Santa Monica, California, 18.5 percent had refractive errors. CONCLUSIONS: Screening for ocular disorders at an early age allows for detection of problems, especially refractive errors, that might affect school performance if uncorrected.
California↗
Pituitary responsiveness to gonadotrophin-releasing hormone agonist stimulation: a dose-response comparison of luteinizing hormone/follicle-stimulating hormone secretion in women with polycystic ovary syndrome and normal women.
In polycystic ovary syndrome (PCOS), the mechanism responsible for abnormal gonadotrophin secretion, elevated serum luteinizing hormone (LH) and normal or low follicle-stimulating hormone (FSH) concentrations has not been elucidated. One proposed mechanism, as suggested by previous studies, is an augmented sensitivity of pituitary LH release and a corresponding insensitivity of pituitary FSH release to gonadotrophin-releasing hormone (GnRH) agonist stimulation. This study was designed to further compare gonadotrophin responses to GnRH agonist stimulation within and between individual patients in a dose-response manner. Each of six PCOS and six normal ovulatory women was administered a single s.c. injection of the GnRH agonist [(imBzl)D-His6, Pro9-NEt]-GnRH (D-His) at a dose of 0.01, 0.1, 1 and 10 micrograms/kg on four separate occasions. Blood samples were obtained over a 72 h period following D-His administration. Gonadotrophin responses were measured by (i) the maximal rise from pretreatment baseline values (delta max); (ii) the maximal percentage change from baseline (%delta max); and (iii) the integrated response (mean of the cumulative sum of deviations from baseline). Within-group and between-group dose-responses were compared by two-factor analysis of variance and further characterized using the 'Flexifit' computer program. Our results showed that in both groups, progressive increases of LH and FSH occurred following D-His at doses of 0.01 and 0.1 microgram/kg. Further increases beyond the 0.1 microgram/kg dose were not observed. In PCOS women, delta max and integrated response for LH were significantly greater than those of normal subjects at each dose tested. %delta max of LH was significantly lower in PCOS, reflecting higher pretreatment baseline LH concentrations in this group.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Isolation of extracytoplasmic proteins from Serpulina hyodysenteriae B204 and molecular cloning of the flaB1 gene encoding a 38-kilodalton flagellar protein.
Extracytoplasmic proteins were released from Serpulina (Treponema) hyodysenteriae (strain B204) by treatment of whole cells with a nonionic detergent (Tween 20). Centrifugation of the Tween 20-released proteins at 100,000 x g sedimented 10 major extracytoplasmic proteins with approximate molecular masses of 44, 43.5, 42, 39, 38, 34, 33.5, 33, 31, and 29 kDa. Treatment of the sedimented fraction with 6 M urea solubilized all of the proteins except the 39-kDa protein. Peptide sequences were obtained for the purified 42-, 39-, 38-, 34-, 31-, and 29-kDa proteins. The peptide sequences of the 42-, 38-, and 31-kDa proteins indicate that they likely are components of the periplasmic flagella. The amino-terminal peptide sequence of the 38-kDa protein was used to design an oligonucleotide probe and to clone an S. hyodysenteriae DNA fragment containing the gene encoding this protein. The predicted 290-amino-acid protein sequence derived from the cloned gene was highly homologous to those of several other bacterial flagellar proteins and is preceded by consensus sigma D nucleotide sequences found upstream of other flagellar genes. On the basis of its similarity to the FlaB proteins of other spirochetes, we propose to designate the cloned S. hyodysenteriae gene flaB1 and its encoded protein FlaB1. Vaccination of pigs with FlaB1 or its recombinant counterpart did not protect them from an experimental challenge.
Amino Acid Sequence↗
Menstrual cycle and gonadal steroid effects on symptomatic hyperammonaemia of urea-cycle-based and idiopathic aetiologies.
We report two female patients, one with a known inborn error of ureagenesis and the other of unknown cause, in whom recurrent, transient episodes of severe hyperammonaemia increased in frequency and severity with sexual maturity and parturition. Both responded to ovarian steroids administered continuously to suppress ovulation and menstruation, and ultimately to simple hysterectomy. These studies suggest a new therapeutic approach to defective ureagenesis in female patients and a relationship between ammonia production or disposal and the menstrual cycle.
Adult↗
Determination of biotin concentration by a competitive enzyme-linked immunosorbent assay (ELISA) method.
A method based on competitive enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of biotin concentrations which takes advantage of the extraordinarily high affinity between biotin and avidin. The biotin assay consisted of two steps, (i) a competition reaction between excess streptavidin-conjugated horseradish peroxidase (streptavidin-HRP) and solutions of known biotin concentrations or sample solutions and (ii) the measurement of the residual activities of the free form streptavidin-HRP which were correlated with the initial biotin concentrations. The procedure was modified by including an extra step of antibody-antigen interaction to assay biotin concentration unambiguously in more complex media. The entire assay was completed within 6 with sensitivities of approximately 1 pg/ml for biotin in a simple aqueous medium and 5 pg/ml in complex media. The method offers significant advantages in time, sensitivity and simplicity for determinations of biotin concentrations in various solutions.
Animals↗