RESUMEN

Non-native tree species are often used as ornamentals in urban landscapes. However, their root-associated fungal communities remain yet to be examined in detail. Here, we compared richness, diversity and community composition of ectomycorrhizosphere fungi in general and ectomycorrhizal (EcM) fungi in particular between a non-native Pinus nigra and a native Quercus macrocarpa across a growing season in urban parks using 454-pyrosequencing. Our data show that, while the ectomycorrhizosphere community richness and diversity did not differ between the two host, the EcM communities associated with the native host were often more species rich and included more exclusive members than those of the non-native hosts. In contrast, the ectomycorrhizosphere communities of the two hosts were compositionally clearly distinct in nonmetric multidimensional ordination analyses, whereas the EcM communities were only marginally so. Taken together, our data suggest EcM communities with broad host compatibilities and with a limited numbers of taxa with preference to the non-native host. Furthermore, many common fungi in the non-native Pinus were not EcM taxa, suggesting that the fungal communities of the non-native host may be enriched in non-mycorrhizal fungi at the cost of the EcM taxa. Finally, while our colonization estimates did not suggest a shortage in EcM inoculum for either host in urban parks, the differences in the fungi associated with the two hosts emphasize the importance of using native hosts in urban environments as a tool to conserve endemic fungal diversity and richness in man-made systems.

Asunto(s)

RESUMEN

We analysed two sites within and outside an urban development in a rural background to estimate the fungal richness, diversity and community composition in Quercus spp. ectomycorrhizas using massively parallel 454-sequencing in combination with DNA-tagging. Our analyses indicated that shallow sequencing ( approximately 150 sequences) of a large number of samples (192 in total) provided data that allowed identification of seasonal trends within the fungal communities: putative root-associated antagonists and saprobes that were abundant early in the growing season were replaced by common ectomycorrhizal fungi in the course of the growing season. Ordination analyses identified a number of factors that were correlated with the observed communities including host species as well as soil organic matter, nutrient and heavy metal enrichment. Overall, our application of the high throughput 454 sequencing provided an expedient means for characterization of fungal communities.

Asunto(s)

RESUMEN

Diverse fungal mutualists, pathogens and saprobes colonize plant leaves. These fungi face a complex environment, in which stochastic dispersal interplays with abiotic and biotic filters. However, identification of the specific factors that drive the community assembly seems unattainable. We mined two broad data sets and identified chemical elements, to which dominant molecular operational taxonomic units (OTUs) in the foliage of a native tree respond most extremely. While many associations could be identified, potential complicating issues emerged. Those were related to unevenly distributed OTU frequency data, a large number of potentially explanatory variables, and the disproportionate effects of outlier observations.

Asunto(s)

RESUMEN

Today, clinicians are challenged to address a woman's contraceptive needs during her reproductive and perimenopausal years and then provide her with a menopausal therapeutic option. This option should offer optimal symptom relief, noncontraceptive health benefits, and a good tolerability profile. The benefits of hormone replacement therapy include control of vasomotor symptoms, reduction of vulvovaginal atrophy, and protection against osteoporosis. Research also points to emerging hormone replacement therapy benefits such as protection against cardiovascular disease, colon cancer, and Alzheimer's disease. One of the primary considerations in the transition from oral contraceptive use to hormone replacement therapy is the tolerability profile of the progestin component of the hormone replacement therapy. Because progestin-related side effects are among the main reasons for discontinuation of hormone replacement therapy, the selection of a formulation that contains the same well-tolerated progestin as in the woman's oral contraceptive can be particularly important to successful use of hormone replacement therapy. Currently in the United States continuous combined hormone replacement therapy is available in 3 formulations and 1 continuous estrogen/intermittent progestin formulation. Although direct comparative trials are lacking, available data suggest that the new, continuous 17beta-estradiol/intermittent norgestimate hormone replacement therapy formulation may offer advantages over regimens that contain older progestins with metabolic disadvantages.

Asunto(s)

RESUMEN

OBJECTIVES: To evaluate the efficacy and safety of different doses of 173-estradiol for the treatment of vasomotor and vulvovaginal symptoms. DESIGN: This was a randomized, double-blind, multicenter, parallel-group study. One hundred forty-five subjects, including naturally postmenopausal women aged 40-60 (who had not experienced menses for at least 12 months), women who had undergone hysterectomy, and women aged 25-60 who had undergone bilateral oophorectomy with or without hysterectomy were studied. Either placebo or 17beta-estradiol (1 mg or 0.5 mg) was given orally every day for 12 weeks, and vasomotor symptoms and vaginal epithelial cytology were evaluated. RESULTS: There were significant differences between placebo and the active treatments in the percentage change from baseline in the number of hot flushes (all hot flushes, 1 mg vs. placebo, p < 0.00 1; 0.5 mg vs. placebo, p = 0.007), with a more substantial proportion of subjects responding in the 1-mg group (mean change in mean number of hot flushes of 83.2%). Both doses were also more effective than placebo in increasing the proportion of mature vaginal cells (end-of-treatment mean values of 0%, 78.5%, and 21.5% for parabasal, intermediate, and superficial cells, respectively, in the 1-mg group; mean values of 0.3%, 80.8%, and 18.9% in the 0.5-mg group; and mean values of 15.2%, 74.7%, and 10.2% in the placebo group). The proportion of subjects reporting no vaginal dryness was greatest in the 1-mg group (mean percentage of days without dryness of 86.1% at weeks 9-12). CONCLUSIONS: For the relief of vasomotor and vulvovaginal symptoms, 17beta-estradiol I mg is effective and has an excellent safety profile.

Asunto(s)

RESUMEN

Positron emission tomography (PET) was used to investigate regions of the brain that are selectively affected during different phases of the normal menstrual cycle. A total of 10 healthy 18-29 year old female volunteers had PET measurements of brain glucose metabolism between days 5 and 9 of the follicular phase when plasma concentrations of oestradiol and progesterone were relatively low and between days 5 and 8 of the luteal phase when plasma concentrations of oestradiol and progesterone were relatively high. Automated algorithms were used to align the PET images in each individual, transform them into the coordinates of a brain atlas, control for variations in whole brain measurements and compute t-score maps of phase-related differences in regional glucose metabolism. The mid-follicular phase was associated with significantly higher glucose metabolism in thalamic, prefrontal, temporoparietal and inferior temporal regions. The mid-luteal phase was associated with significantly higher glucose metabolism in superior temporal, anterior temporal, occipital, cerebellar, cingulate and anterior insular regions. While this study should be considered to be exploratory, it provides normative data for future studies and illustrates how PET can be used to help characterize relationships between phases of the female life cycle, temporally related disorders and local functions of the living human brain.

Asunto(s)

RESUMEN

OBJECTIVE: The null hypothesis is that fetuses with noncoiled umbilical cords diagnosed in the antepartum period will have outcomes no different from those with normally coiled cords. STUDY DESIGN: We prospectively gathered data from Jan. 1 through May 18, 1992, from all fetuses undergoing routine ultrasonographic evaluation. The outcomes of fetuses noted to have noncoiled umbilical cords were compared with those of a control group of fetuses with normally coiled cords. The control group consisted of those subjects undergoing ultrasonography during the study period who were ultimately transferred to our perinatal practice for the remainder of the pregnancy (i.e., the highest-risk patients). Two outcome parameters were selected for comparison: fetal anomalies and fetal death. RESULTS: Six hundred eighty-seven consecutive ultrasonographic examinations were performed. Twenty-five subjects (3.7%) had noncoiled umbilical cords identified ultrasonographically (mean gestational age at diagnosis 20.3 +/- 3.5 [SD] weeks). The control group had 197 subjects. The combined incidence of fetal anomalies or death in the noncoiled group (16%) was significantly greater (p < or = 0.05, relative risk 4.6 [95% confidence interval 1.41 to 14.15]) than that of the control group (3.5%). The noncoiled group had two fetal deaths (8%), whereas two deaths (1%) occurred among controls (p < or = 0.05, relative risk 8 [95% confidence interval 1.16 to 50]). Two (8%) fetal anomalies (anencephaly, prune-belly syndrome) occurred in the noncoiled group, whereas the controls (n = 197) had five fetuses (2.5%) with anomalies (not significant). CONCLUSION: The antepartum identification of noncoiled umbilical cords appears to be a risk factor for suboptimal pregnancy outcome.

Asunto(s)

RESUMEN

Gonadotropin-stimulated steroidogenesis was studied in cultured human granulosa-lutein cells obtained from patients undergoing procedures for in vitro fertilization. The impact of cryopreservation on cell function in vitro was studied. Granulosa cells obtained from in vitro fertilization patients were cultured in serum-supplemented medium or cryopreserved at -135 degrees C for 2-22 months. Fresh (unfrozen) cells (10(5) produced estradiol at a rate of 1320 pmol/l (over 72 h) and progesterone at about 2500 nmol/l. Estradiol production by either fresh or cryopreserved granulosa cells in culture was unaffected by physiological concentrations of follicle-stimulating hormone (7 IU/l). Adding testosterone (10(-7) mol/l) to the medium increased estradiol secretion approximately sixfold. In contrast, progesterone production was not affected by follicle-stimulating hormone or testosterone. No significant differences were observed in cultures of cryopreserved granulosa cells compared to cultures of unfrozen cells with respect to estradiol secretion, the effects of follicle-stimulating hormone or testosterone on estradiol secretion, or progesterone production. Progesterone production by fresh and cryopreserved cells was stimulated by human chorionic gonadotropin. These data indicate that cryopreservation offers the potential to facilitate prospective studies utilizing large numbers of human granulosa-lutein cells in culture.

Asunto(s)

RESUMEN

The disposition of dichloroacetic acid (DCA) was investigated in Fischer 344 rats over the 48 h after oral gavage of 282 mg/kg of 1- or 2-[14C]-DCA (1-DCA or 2-DCA) and 28.2 mg/kg of 2-DCA. DCA was absorbed quickly, and the major route of disposition was through exhalation of carbon dioxide and elimination in the urine. The dispositions of 1- and 2-DCA at 282 mg/kg were similar. With 2-DCA, the disposition differed with dose in that the percentage of the dose expired as carbon dioxide decreased from 34.4% (28.2 mg/kg) to 25.0% (282 mg/kg), while the percentage of the radioactivity excreted in the urine increased from 12.7 to 35.2%. This percentage increase in the urinary excretion was mostly attributable to the presence of unmetabolized DCA, which comprised more than 20% at the higher dose and less than 1% at the lower dose. The major urinary metabolites were glycolic acid, glyoxylic acid, and oxalic acid. DCA and its metabolites accumulated in the tissues and were eliminated slowly. After 48 h, 36.4%, 26.2%, and 20.8% of the dose was retained in the tissues of rats administered 28.2 and 282 mg/kg of 2-DCA and 282 mg/kg of 1-DCA, respectively. Of the organs examined, the liver (4.9-7.9% of dose) and muscle (4.5-9.9%) contained the most radioactivity, followed by skin (3.3-4.5%), blood (1.4-2.6%), and intestines (1.0-1.7%). One metabolite, glyoxylic acid, which is mutagenic, might be responsible for or contribute to the carcinogenicity of DCA.

Asunto(s)

RESUMEN

Human semen was cryopreserved using Human Sperm Preservation Medium, TEST-Yolk buffer, or glycerol alone. Sperm characteristics for each specimen were measured before and after freezing to determine which cryopreservative resulted in better cryosurvival and recovery of motile sperm. Sperm frozen in Human Sperm Preservation Medium had a significantly better recovery of all semen parameters (motility, velocity, and recovery) than either TEST-Yolk or glycerol alone. Statistical analyses also were done to examine the variability between and within donor semen specimens. Differences between donors, between specimens, and measurements within donors all contributed to variability of sperm characteristics. Specimen-to-specimen variability for a given donor represented 12% to 47% of the total variability, whereas processing and measurement variability represented 12% to 41%. Donors also varied in the ability of their sperm to tolerate freezing. There was a relationship between motile count after dilution with cryopreservative and post-thaw motile count. This relationship allows the prediction of poor-thaw survival before freezing a specimen.

Asunto(s)

RESUMEN

Ninety-nine females (mean age 34 years +/- 1) were seen for therapeutic donor insemination using frozen semen. All patients used over-the-counter urinary ovulation predictor kits, with the insemination scheduled either the day after the positive test (group I; n = 46) or consecutively the day of and the day after the positive test (group II; n = 53). Group I patients underwent a total of 113 cycles of insemination (mean 2.5 cycles/patient). Seven pregnancies were achieved in group I for an overall success of 15.2% and a monthly fecundability of 0.06. Group II patients underwent a total of 100 cycles of therapeutic donor insemination (mean of 1.9 cycles/patient). Twenty-one pregnancies were achieved in this group for an overall success rate of 39.6% and fecundability of 0.21. The estimated cumulative probability of conception (F) for 6 months was 0.32 in group I and 0.78 in group II. These data indicate that the F after therapeutic donor insemination with frozen semen is greater if two consecutive inseminations are performed at midcycle.

Asunto(s)

RESUMEN

The purpose of this study was to use fluorescence microscopy to determine the viability and acrosome status of fresh and frozen-thawed human spermatozoa. Sperm cells were stained with the viability stains Hoechst 33258 (H33258) alone, or propidium iodide (PI) alone, and PI in combination with FITC-conjugated Pisum sativum agglutinin (PSA). The PSA stains the acrosome contents of permeabilized acrosome-intact sperm. Viability by fluorescence microscopy was compared to conventional eosin nigrosin staining. The overall viability using H33258 was not significantly different from that using PI. Therefore, PI was used in combination with PSA for simultaneous measurement of viability and acrosome status at the same excitation wavelength (488 nm). By combining PI and PSA, four subgroups of cells could be detected: group I, PI-neg/PSA-neg--viable, physiologic acrosome reacted (AR); group II, PI-neg/PSA-pos--viable, non-AR; group III, PI-pos/PSA-neg--nonviable, non-AR; group IV, PI-pos/PSA-neg--nonviable, degenerative AR. The postthaw sperm exhibited a significantly greater percent of sperm that were acrosome reacted (both viable and degenerative) (groups I and IV) than the fresh semen. We conclude that frozen-thawed sperm may undergo premature break-down of the acrosome prior to interaction with the oocyte, thus explaining the reduced fertility potential of cryopreserved semen.

Asunto(s)

Asunto(s)

RESUMEN

A strain specificity has been demonstrated for the effect of subsequent administration of phenobarbital (PB), in which diethylnitrosamine (DENA)-initiated hepatocarcinogenesis was promoted in C3H mice, inhibited in B6C3F1 (C57BL x C3H) and not affected in C57BL mice. A correlation has been established between the ability of barbiturates and hydantoins to promote tumor formation and their ability to induce liver growth, hepatic DNA synthesis and mixed function oxidase activities. Therefore, we examined in these 3 strains of mice and in C3B6F1 (C3H x C57BL) mice the effect of PB administered in their drinking water for 4 days or 28 days. The liver weight to body weight ratio was increased by PB in all types of mice. Microsomal protein concentrations were increased in C57BL mice after 28 days of treatment, in C3H after both 4 days and 28 days and in B6C3F1 after 4 days of treatment. No effect upon microsomal protein content was observed in C3B6F1 mice. DNA content was increased in C3H mice, both in the 4-day and 28-day treatment groups, while the other strains showed either a decrease or no difference from control. DNA synthesis was elevated in all strains of mice after 4 days of treatment with PB, however, after 28 days of treatment there was either a much reduced increase (C57BL and C3B6F1) or no difference (C3H and B6C3F1) from controls. In all 4 types of mice after 4 and 28 days of treatment, PB increased the concentration of cytochrome P-450, the activity of aminopyrine-N-demethylase (AmDm) and 7-ethoxyresorufin-O-deethylase (ErDe) and the oxidation of testosterone (T). The oxidative metabolites of T were similar in the 4 types of mice.

Asunto(s)

Asunto(s)

RESUMEN

Potential long-term effects of psychological dysfunction associated with infertility were investigated in a descriptive study of 32 previously infertile couples. Comparison was made with the performance of 20 never infertile couples matched for age, number of children, education, and income level, using a standard psychological assessment tool, the Hopkins symptom check list. While infertile, women had slightly elevated mean scores on three subscales: depression, interpersonal sensitivity, and hostility. After resolution of infertility, these scores did not improve. In addition, depression scores were elevated among the previously infertile women compared with a matched, never infertile group. Infertile men scored within the normal range for depression and interpersonal sensitivity and had a borderline mean score for hostility, which was markedly reduced after a normal pregnancy.

Asunto(s)

RESUMEN

This paper presents the results of an anthropometric study of 55 black and 74 white females, ages 23-28 years, employed by a state agency in North Carolina. All subjects were measured for height and arm-span. Correlations of the two measures were obtained for each race independently, and differences between the two races were examined. Correlation of arm-span and height for black subjects was 0.776 and for white subjects was 0.894. Analysis of covariance revealed significant (P less than or equal to 0.001) interaction between race and the relationship between arm-span and height.

Asunto(s)

RESUMEN

A case report is presented of an ampullary ectopic pregnancy which was treated by salpingostomy. Twenty-six days later, the patient underwent repeat operation due to the persistence of trophoblastic tissue within the fallopian tube. A review of the English literature reveals nine cases including our own that have been reported to date. In eight of nine cases, trophoblastic tissue was recovered at the time of the second operation. In the four cases where human chorionic gonadotropin (hCG) titers were available before and after the second procedure, the titers were positive initially and reverted to negative postoperatively. The disappearance curve for human chorionic gonadotropin after excision of an ectopic gestation is discussed. A recommendation is made for a single determination of beta-hCG two weeks after a conservative procedure for an ectopic gestation to screen for persistence of trophoblastic tissue.

Asunto(s)

RESUMEN

Although uncommon, testosterone producing neoplasms of the ovary and the adrenal cortex occur periodically. Forty-seven instances involving the adrenal gland have been published since 1925; five, including the present patient, have occurred since 1981. Confusion concerning the site of the androgen secretion has been generated in the past because of limited roentgenographic study and the poor predicability of selective suppression or stimulating testing of the adrenal gland and the ovary. Of the 22 patients with testosterone producing neoplasms of the adrenal cortex reported since 1973, 45 per cent underwent needless ovarian surgical treatment prior to the correct diagnosis. By recognizing the significant correlation between a serum testosterone of 200 nanograms per deciliter or greater, a serum dehydroepiandrostenone of greater than 6,600 nanograms per milliliter coupled with a thorough pelvic examination, pelvic ultrasound and a more liberal use of high resolution computerized tomography of the adrenal gland, the correct diagnosis can be made. The patient presented herein illustrates the pitfalls inherent in the management of a patient with this problem.

Asunto(s)

RESUMEN

A simple biochemical screening test for prolactin-secreting pituitary tumors is needed because computed tomography is expensive and may be insensitive in the detection of microadenomas. We compared serial prolactin levels following perphenazine stimulation in 20 women with histologically documented tumors to those in 22 normal controls. In addition, seven women who were diagnosed as having functional (nontumor) hyperprolactinemia were tested. All subjects were given perphenazine, 8 mg orally. Baseline and hourly serum prolactins for six hours were compared. A 200% or greater response occurred in all control patients and functional hyperprolactinemic subjects within six hours following medication. Without exception, tumor patients exhibited a markedly blunted or absent response. This markedly diminished response pattern was compatible with the presence of a pituitary adenoma and suggests that the presence of a tumor interferes with normal pituitary secretory responsiveness.

Asunto(s)