Martian subsurface cryosalt expansion and collapse as trigger for landslides.

On Mars, seasonal martian flow features known as recurring slope lineae (RSL) are prevalent on sun-facing slopes and are associated with salts. On Earth, subsurface interactions of gypsum with chlorides and oxychlorine salts wreak havoc: instigating sinkholes, cave collapse, debris flows, and upheave. Here, we illustrate (i) the disruptive potential of sulfate-chloride reactions in laboratory soil crust experiments, (ii) the formation of thin films of mixed ice-liquid water "slush" at -40° to -20°C on salty Mars analog grains, (iii) how mixtures of sulfates and chlorine salts affect their solubilities in low-temperature environments, and (iv) how these salt brines could be contributing to RSL formation on Mars. Our results demonstrate that interactions of sulfates and chlorine salts in fine-grained soils on Mars could absorb water, expand, deliquesce, cause subsidence, form crusts, disrupt surfaces, and ultimately produce landslides after dust loading on these unstable surfaces.

Universality and scaling in the disordering of a smectic liquid crystal.

We present experimental and theoretical studies of the effects of quenched disorder on one-dimensional crystal ordering in three dimensions. This fragile smectic liquid crystal layering, the material with the simplest positional order, is also the most easily deformed periodic structure and is, therefore, profoundly affected by disorder, introduced here by confinement in silica aerogel. Theory and experiment combine to characterize this system to an extraordinary degree, their close accord producing a coherent picture: crystal ordering is lost, giving way to extended short-range correlations that exhibit universal structure and scaling, anomalous layer elasticity, and glassy dynamics.

The Physician's Duty to Warn Their Patients About the Risks Associated with Medical Intervention: A Review and Discussion.

Since the landmark case of Montgomery v Lanarkshire in 20151, much has been written in medical press regarding the implications for medical practice. The moral duty - varied though it has been over this time, has been discussed since the earliest days of the medical profession. The law has sought to define this duty in response to changes in society, and the nature of the relationship between doctor and patient. The moral and legal duty are intrinsically linked, but the latter must surely follow the former for "the law has little to do with morally required forms of communication in the clinic and in the research environment."2 The common law nature of this process has resulted in an inconsistent and often tortuous path as societal standards have shifted. Accordingly, the ultimate definition of the legal doctrine, "informed consent," has changed since its relatively recent entry into the medicolegal vocabulary. These parallel shifts in the legal and moral duty to disclose risk have resulted in a confusing melee of evidence and recommendations for clinicians. We address the development of the law of "informed consent," as the legal mirror of the moral duty upon a clinician to disclose risk to their patient.

Auditory sensory memory and working memory processes in children with normal hearing and cochlear implants.

There can be wide variation in the level of oral/aural language ability that prelingually hearing-impaired children develop after cochlear implantation. Automatic perceptual processing mechanisms have come under increasing scrutiny in attempts to explain this variation. Using mismatch negativity methods, this study explored associations between auditory sensory memory mechanisms and verbal working memory function in children with cochlear implants and a group of hearing controls of similar age. Whilst clear relationships were observed in the hearing children between mismatch activation and working memory measures, this association appeared to be disrupted in the implant children. These findings would fit with the proposal that early auditory deprivation and a degraded auditory signal can cause changes in the processes underpinning the development of oral/aural language skills in prelingually hearing-impaired children with cochlear implants and thus alter their developmental trajectory.

1,3,5-Trialkyl-2,4,6-triiodobenzenes: novel X-ray contrast agents for gastrointestinal imaging.

Examination of the gastrointestinal (GI) tract has been performed for decades using barium sulfate. Although this agent has many recognized limitations including extreme radiopacity, poor intrinsic affinity for the GI mucosa, and very high density, no alternative contrast agents have emerged which produce comparable or better contrast visualization. In fact, the various techniques of the GI radiologic examination (i.e., single contrast, double contrast, biphasic) were developed to compensate for its limitations. Each of these techniques requires complex patient manipulation to achieve adequate mucosal coating or compression to overcome the marked radiopacity of barium sulfate in order to obtain a diagnostically useful examination. A series of novel radiopaque oils, the 1,3, 5-trialkyl-2,4,6-triiodobenzenes, was designed to improve the efficacy, stability, and safety of barium formulations. These substances were prepared in two steps from 1,3,5-trichlorobenzene. Compound 17 (1,3,5-tri-n-hexyl-2,4,6-triiodobenzene), formulated as an oil-in-water emulsion, was found to be well-tolerated in rodents (mice, hamsters, rats) following acute oral and/or intraperitoneal administrations at 4 times the anticipated human clinical dose. No metabolism of 17 was detected in rat, hamster, dog, monkey, or human hepatic microsomes, suggesting the lack of oral toxicity was a consequence of poor absorption. In imaging experiments in dogs, emulsions of 17 have demonstrated excellent mucosal coating and improved radiodensity relative to barium sulfate suspensions. On the basis of the preliminary imaging and toxicity data, compound 17 was selected as a potential development candidate.

Follow-up of adolescent trauma victims: a new model of care.

A comprehensive model of service delivery for the rehabilitative care of adolescents with closed head injuries is presented. Our data show that the Glasgow Coma Scale score on hospital admission correlates with the length of time required for follow-up. Adolescents with mild closed head injuries require more follow-up than adults with comparable injuries because of adolescent developmental stages that complicate the recovery process. Anticipatory guidance has helped the patient and family cope with stresses. Finally, we have identified a typical pattern of difficulties during the recovery process including: impaired judgment, reduced attention span, irritability, short-term memory loss, and ongoing memory deficits.

A discotic disguised as a smectic: A hybrid columnar bragg glass

We show that discotics, lying deep in the columnar phase, can exhibit an x-ray scattering pattern which mimics that of a somewhat unusual smectic liquid crystal. This exotic, new glassy phase of columnar liquid crystals, which we call a "hybrid columnar Bragg glass," can be achieved by confining a columnar liquid crystal in an anisotropic random environment of, e.g., strained aerogel. Long-ranged orientational order in this phase makes single-domain x-ray scattering possible, from which a wealth of information could be extracted. We give detailed quantitative predictions for the scattering pattern in addition to exponents characterizing anomalous elasticity of the system.

Endometrial receptivities after leuprolide suppression and gonadotropin stimulation: histology, steroid receptor concentrations, and implantation rates.

The effect of markedly supraphysiologic levels of E2 and P4 on the endometrium was assessed by examining endometrial histology, E2 and P4 receptor concentrations, and embryo implantation rates in IVF cycles with and without leuprolide use. Results suggest that 1) the high ovarian response common in leuprolide pretreated cycles can advance endometrial histology, but only up to a certain limit, 2) P4 greater than 25ng/ml or E2 greater than 200pg/ml on the day of transfer was associated with non-lagging endometria, 3) implantation rate in high response cycles is not impaired and may be increased, 4) earlier P4 supplementation in low response cycles may be beneficial, 5) extraordinarily high response (E2 greater than 5000pg/ml) may be detrimental to implantation, and 6) the optimal histology for implantation appears to be at least day 16.

Detection of mutated K12-ras in histologically negative lymph nodes as an indicator of poor prognosis in stage II colorectal cancer.

Stage II colorectal carcinoma is characterized by negative lymph node pathology as determined by conventional microscopic examination. These patients generally do not receive adjuvant therapy although 20%-30% will die from metastatic disease. To determine whether K-ras mutations at codon 12 could be used as a sensitive indicator of occult lymph node metastasis in stage II colon carcinoma, a retrospective study was performed using restriction endonuclease-mediated selective polymerase chain reaction (REMS-PCR) amplification. Of 106 colonic tumors analyzed, 46 were identified as positive for a K12-ras mutation in the primary tumor. Multiple lymph node samples from 38 of these 46 patients were examined by a sensitive nested PCR protocol for the presence of a K12-ras mutation. Of these 38 patients, 14 had 1 or more positive lymph nodes by PCR (37%) and 24 were negative for the mutation (63%). Of the 14 patients with a K12-ras mutation detected in lymph nodes, 8 died of the disease within 5 years (57%) compared to only 4 of the 24 patients with ras-negative lymph nodes (17%). The difference in time to death from disease, stratified using K12-ras status of lymph nodes, was statistically significant (P = 0.036; log-rank test). These results suggest K-ras mutation status of lymph nodes in patients with stage II colon cancer might identify a subgroup of patients who are more likely to develop recurrent and/or metastatic disease and benefit from adjuvant therapy. Larger studies are indicated to determine whether detection of K-ras mutation positivity in histologically negative lymph nodes portends a poor prognosis and to determine whether more aggressive use of adjuvant therapy is warranted.

High doses of gonadotropins have no detrimental effect on in vitro fertilization outcome in normal responders.

OBJECTIVE: To examine the effect of high doses of gonadotropins on IVF outcome in normal (intermediate) responders. DESIGN: Retrospective analysis of patients undergoing IVF therapy from 1990 to 1994 at our institution. SETTING: Academic tertiary center. PATIENTS: A homogeneous group of women that consisted of intermediate responders examined in their initial attempt and who received differing amounts of gonadotropins were examined. INTERVENTIONS: All patients were stimulated using a combination of a GnRH-agonist and FSH and hMG and were allocated into two groups, based on the amount of gonadotropin administered initially (four or six ampules). MAIN OUTCOME MEASURES: Implantation and pregnancy (clinical and ongoing) rates were compared. RESULTS: There were no significant differences between patients receiving high doses versus those patients receiving lower doses of gonadotropins with regard to implantation and pregnancy rates. CONCLUSIONS: We conclude that high doses of gonadotropins have no detrimental effect on IVF outcome in normal (intermediate) responders.

Outcome of twin, triplet, and quadruplet in vitro fertilization pregnancies: the Norfolk experience.

OBJECTIVE: To review the maternal morbidity and neonatal morbidity and mortality associated with in vitro fertilization (IVF) multiple pregnancies. DESIGN: Retrospective analysis of data collected from office and hospital records and from questionnaires sent to patients, their obstetricians, and pediatricians. SETTING: Patients (all with private insurance carriers) enrolled in an academic IVF program (The Jones Institute for Reproductive Medicine). PATIENTS, PARTICIPANTS: All IVF pregnancies resulting in one or more gestational sacs on the initial ultrasound at 6 to 7 weeks were reviewed. MAIN OUTCOME MEASURES: The frequency and severity of obstetrical and neonatal complications and the perinatal mortality of IVF twins, triplets, and quadruplets were compared. These were also compared with non-IVF multiple pregnancies. RESULTS: From 1982 to 1990, 629 IVF pregnancies progressed beyond 20 weeks; 115 twins (18.3%), 15 triplets (2.4%), and 4 quadruplets (0.6%). There was a high incidence of antenatal complications such as abortions (30.3%, 42%, and 20%), premature labor (41.5%, 92.3%, and 75%), pregnancy-induced hypertension (17.0%, 38.6%, and 50%), and gestational diabetes mellitus (3.1%, 38.5%, and 25%) for twins, triplets, and quadruplets, respectively. The mean gestational age at delivery was 35.5 +/- 3.7, 31.8 +/- 2.7, and 31.0 +/- 1.7 weeks, respectively. There was also a proportionate progressive increase in neonatal complications. The mean weights were 2,473 +/- 745, 1,666 +/- 441 and 1,414 +/- 368 g, respectively. Twins (22.7%), 64.1% of triplets, and 75% of quadruplets needed admission to the neonatal intensive care unit and remained for an average of 12.0 +/- 2.3, 17.4 +/- 14.0, and 57.8 +/- 17.9 days, respectively. There was no difference in the mean Apgar scores or the incidence of congenital malformations in the three groups. The corrected perinatal mortality rates were 38.5, 0.0, and 0.0 per thousand live births, respectively. CONCLUSION: Triplet and quadruplet IVF pregnancies have increased obstetrical and neonatal complications compared with IVF twins. The perinatal mortality and the incidence of congenital malformations are, however, comparable in all three groups.

Significance of basal follicle-stimulating hormone levels in women with one ovary in a program of in vitro fertilization.

OBJECTIVE: To understand the impact of having a single ovary on basal follicle-stimulating hormone (FSH) level and its diagnostic and prognostic usefulness in in vitro fertilization (IVF). DESIGN: All IVF cases from July 1987 to June 1990 with known basal FSH (n = 1,272) were divided into those with one and those with two ovaries to compare outcomes based on basal FSH levels. SETTING: Tertiary care academic center with a large IVF practice. MAIN OUTCOME MEASURES: Basal FSH, age, and IVF outcomes including peak estradiol, numbers of follicles aspirated, oocytes retrieved, fertilized, and transferred, and pregnancies (clinical and ongoing). RESULTS: In women with only one ovary, basal FSH was increased, and IVF outcomes were poorer. The rise in FSH was able, in large part, to account for the diminished performance in the single ovary cases. CONCLUSIONS: Women with only one ovary have higher basal FSH levels than those with two ovaries, and this rise can be used to predict their IVF performance.

Basal follicle-stimulating hormone level and age affect the chance for and outcome of pre-embryo cryopreservation.

All IVF cycles in which subsequent transfers of thawed pre-embryos occurred were studied. Both age and basal (cycle day 3) FSH level are important determinants of the chance for cryopreservation and the performance of cryopreserved pre-embryos. Although there was no age or FSH level above which pregnancy with frozen pre-embryos was not possible, the chances clearly decline. Thus, consideration to transferring larger numbers of pre-embryos fresh should be given to women in the fifth decade and those with basal FSH > 15 IU/L.

Superior analytic characteristics of an immunometric assay for gonadotropins also provides useful clinical prediction of in vitro fertilization outcomes.

OBJECTIVE: To determine whether an analytically superior gonadotropin assay, the monoclonal, two-site immunometric assay, also provided superior prediction of clinical outcomes when compared with conventional RIA methodology. DESIGN: Methods comparison study. SETTING: Tertiary academic center. PATIENTS: One hundred fifty-seven consecutive IVF patients. INTERVENTION: Comparisons of FSH and LH levels on cycle day 3 were made using paired RIA and immunometric assay procedures. The ability of day 3 LH, FSH, and their ratio in predicting IVF performance was determined using regression analyses. RESULTS: The predictive ability of FSH as assayed by immunometric assay at least equaled that obtained by RIA for both peak E2 levels and the number of mature oocytes retrieved. CONCLUSION: Results from this study indicate that gonadotropin levels as measured by immunometric assay represent an effective clinical tool in predicting IVF outcomes that may prove superior to RIA.

Experience with a novel vaginal progesterone preparation in a donor oocyte program.

OBJECTIVE: To compare the efficacy of a vaginal progesterone preparation with our standard IM preparation within a donor egg program. DESIGN: Prospective randomized trial. SETTING: Donor egg program at a university assisted reproductive therapy program (Jones Institute for Women's Health). PATIENT(S): Couples accepted into the donor egg program because of either premature ovarian failure or evidence of diminished ovarian reserve. INTERVENTION(S): Women were randomized into either a group receiving IM progesterone replacement or a group receiving vaginal progesterone replacement. Both groups underwent Estraderm patch/progesterone treatment in a mock cycle leading to an endometrial biopsy on day 26 followed by a second cycle in which ET was performed. Subjects with residual ovarian function received a GnRH agonist. In the IM treatment group, 100 mg was administered from cycle days 15 to 27. In the vaginal treatment group, Crinone 8%, a polycarbophil-based gel preparation containing 90 mg of micronized progesterone, was administered twice daily from the evening of day 14. MAIN OUTCOME MEASURE(S): Endometrial histology, serum levels of progesterone (on days 13, 17, 20, 24, and 26), the occurrence of pregnancy, implantation rate, and pregnancy outcome. RESULT(S): Fifty-four women randomized into the vaginal progesterone treatment group and 18 women in the IM treatment group achieved ET. Mean serum progesterone levels were higher in the IM treatment group than in the Crinone group. Endometrial histology was "in phase" for all subjects in both groups. Clinical pregnancies were observed in 26 of 54 women and 5 of 18 women in the Crinone and IM progesterone groups, respectively. The ongoing pregnancy rate (PR) of 31% (17/54) and implantation rate of 23% in the subjects receiving Crinone was not statistically different from the IM progesterone group's ongoing PR of 22% (4/18) and implantation rate of 18%. CONCLUSION: Vaginal progesterone replacement with the polycarbophil gel preparation was as effective as IM progesterone in producing clinical and ongoing pregnancies within our donor egg program in the dosages administered.

Crinone 8% (90 mg) given once daily for progesterone replacement therapy in donor egg cycles.

OBJECTIVE: To determine whether once-daily dosing of Crinone 8% (90-mg progesterone vaginal gel; Serono Laboratories, Inc., Norwell, MA) is sufficient for normal endometrial development and pregnancy support. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): Eighty-six women who required complete progesterone replacement for a donor egg cycle. INTERVENTION(S): Crinone 8% (90 mg) once daily or IM progesterone (100 mg) once daily was administered from day 15 onward. Both groups underwent an endometrial biopsy on day 26 of a mock cycle, followed by a second cycle in which ET was performed. MAIN OUTCOME MEASURE(S): Endometrial development, serum progesterone levels, pregnancy rates, implantation rates, and bleeding patterns. RESULT(S): Mean (+/-SD) serum progesterone levels on day 26 were 11.3+/-6.5 ng/mL in the Crinone group and 65.2+/-12.5 ng/mL in the IM progesterone group. At histologic examination, endometrial biopsy specimens were found to be "in phase" for 100% (42/42) of women in the Crinone group and 95.5% (42/44) of women in the IM progesterone group. Although 8 of 42 patients had serum progesterone levels of <6 ng/mL, there was no correlation with endometrial development. Only 1 patient bled before the 14th day of progesterone therapy, and she went on to be delivered of twins. Clinical pregnancy, ongoing pregnancy, implantation, and miscarriage rates were not statistically different for the Crinone and IM progesterone groups: 45.6% (21/46) versus 52.3% (23/44); 39.1% (18/46) versus 40.9% (18/44); 21.5% (34/158) versus 19% (30/158), and 14.3% (3/21) versus 22% (5/23), respectively. Power was sufficient to detect a 25% difference in clinical pregnancy rates. CONCLUSION(S): Crinone 8% administered once daily appears to produce the same endometrial development and pregnancy rates as IM progesterone in women who require complete progesterone replacement, and it does not cause early bleeding.

Histochemical localization of endometrial insulin-like growth factor binding protein-1 and -3 during the luteal phase in controlled ovarian hyperstimulation cycles: a controlled study.

OBJECTIVE: To determine if controlled ovarian hyperstimulation (COH) affects the endometrial expression of IGFBP-1 and IGFBP-3. DESIGN: Prospective, controlled study. SETTING: Tertiary infertility clinic. PATIENT(S): Eighteen oocyte donors undergoing COH cycles and 17 natural cycle controls. INTERVENTION(S): Controlled ovarian hyperstimulation, endometrial biopsies. MAIN OUTCOME MEASURE(S): Immunohistochemical scoring of endometrial IGFBP-1 and -3 expression, morphological endometrial dating, and serum estradiol (E(2)), LH, and progesterone (P(4)) concentrations. RESULT(S): No statistically significant difference was observed between natural and stimulated cycles in change in IGFBP-1 or -3 over standardized cycle days throughout the window of embryo implantation (days 17-24). The IGFBP-1 and -3 expression was zero or near zero for both the natural and COH cycles until day 12-13. Both IGFBPs showed increased production throughout the secretory phase. Advanced endometrial histology (>/=1 day) in glands and stroma was noted in COH cycles. Significant positive correlations of E(2) and P(4) were noted with IGFBP-1 and -3 but not with advanced endometrial morphology in the COH cycles. CONCLUSION(S): The COH cycles have no significantly increased endometrial IGFBP-1 or -3 expression throughout the implantation phase of the luteal cycle compared with normal menstrual cycles. Both IGFBPs were absent in the proliferative phase and increased throughout the secretory portion of the embryo implantation window.

Detection of endometrial pinopodes by light microscopy.

OBJECTIVE: To study the value of light microscopy (LM) in the assessment of endometrial pinopodes. DESIGN: Comparative histologic study. SETTING: Outpatient infertility clinic in an academic teaching institution. PATIENT(S): Eighteen oocyte donors undergoing controlled ovarian hyperstimulation. INTERVENTION(S): Endometrial biopsies on days 14-24 of the cycle. MAIN OUTCOME MEASURE(S): Assessment of pinopodes by scanning electron microscopy (SEM) and of endometrial surface projections by LM. RESULT(S): The luminal surface was identified by LM in 36 of 38 endometrial specimens obtained. Although apical projections could be recognized in all, they were few, moderate, and abundant in 20, 12, and 4 cases, respectively. Pinopodes were detected by SEM in all 4 samples with abundant projections, but in only 14 of 32 samples with lesser quantities of these surface features. No predictive value could be ascribed to apical projections viewed by LM for the developmental stage of pinopodes as defined by SEM. CONCLUSION(S): The LM of routine endometrial specimens can serve as a preliminary tool in the evaluation of surface morphology. Although abundant apical projections by LM are compatible with the presence of pinopodes by SEM, the latter modality remains as the definitive method in cases with few or moderate projections and for the evaluation of the stage of pinopode development.

Predictive value of pregnancy during original in vitro fertilization cycle on implantation and pregnancy in subsequent cryothaw cycles.

OBJECTIVE: To understand the homogeneity of oocyte quality within a cohort. DESIGN: All women (n = 367) that had cryopreserved pre-embryos subsequently thawed were studied. Pregnancy and implantation rates in the in vitro fertilization (IVF) and cryothaw transfers were examined. SETTING: Tertiary care academic center. RESULTS: Pregnancy in original IVF cycle predicted higher implantation rates at subsequent cryothaw transfers. Similarly, pregnancy in cryothaw cycles was associated with higher implantation and ongoing pregnancy rates at the initial IVF cycle. CONCLUSIONS: Within a cohort of oocytes, pregnancy with some of the pre-embryos in a cohort predicts pregnancy with the remaining oocytes in the cohort. Thus, oocytes within a cohort have similar pregnancy potential.

Basal follicle-stimulating hormone level is a better predictor of in vitro fertilization performance than age.

A study of 1,478 consecutive in vitro fertilization (IVF) cycles was made to determine if basal follicle-stimulating hormone (FSH) levels and age were independent predictors of IVF performance. Regression analyses indicated independent contributions of both basal FSH and age in predicting cancellation rate, peak estradiol, number of oocytes retrieved, fertilized, and transferred, and total and ongoing pregnancy rates. Miscarriage rate was unrelated to both age and basal FSH. Follicle-stimulating hormone level was a better predictor than age for all outcome variables examined and remained a significant predictor after accounting for age, etiology of infertility, and semen quality. The combined use of age and basal FSH in counseling patients improves the accuracy of prognosis, and may provide an index of functional ovarian reserve ("ovarian age").