Fertilization and early embrology: Monozygotic twinning in the human is associated with the zona pellucida architecture

Six cases of identical twin pregnancies which occurred in 2163cycles of in-vitro fertilization during a 3 year period arereported. Monozygosity was confirmed when the number of fetusesexceeded the number of embryos replaced (n = 4) or when twoconcepti were observed in a single amniotic sac (n = 2). Eachof the reported pregnancies resulted from replacement of embryoseither with naturally thin zonae pellucida or embryos whosezonae had been breached during micromanipulation for assistedfertilization (subzonal sperminsertion) or assisted hatching.That such cases exclusively gave rise to monozygosity suggestsa link between the physical state of the zona pellucida, hatching,and generation of identical twins.     

Endogenous and recombinant erythropoietin levels decline in human amniotic fluid and fetal plasma in vitro at 37 degrees C.

OBJECTIVE: To determine the in vitro stability of endogenous and recombinant erythropoietin (EPO) incubated at 37 degrees C in amniotic fluid (AF) and fetal plasma. STUDY DESIGN: Endogenous and recombinant EPO in AF, fetal plasma and phosphate buffer were incubated in vitro for 21 days at 37 degrees C. Serial aliquots were analyzed for EPO and the rates of EPO decline were compared within and between groups. RESULTS: Endogenous and recombinant EPO declined significantly in plasma and AF at 37 degrees C. Endogenous EPO displayed a similar linear rate of decline in AF and plasma, with nearly 70% of the initial hormone concentration remaining at 21 days. Recombinant EPO incubated in buffer did not change. CONCLUSIONS: Using the rate of decline in endogenous EPO we observed, EPO levels measured in AF or plasma within 21 days of fetal demise can be extrapolated back to the level likely present at fetal death.     

Fast method for 1D non-cartesian parallel imaging using GRAPPA.

MRI with non-Cartesian sampling schemes can offer inherent advantages. Radial acquisitions are known to be very robust, even in the case of vast undersampling. This is also true for 1D non-Cartesian MRI, in which the center of k-space is oversampled or at least sampled at the Nyquist rate. There are two main reasons for the more relaxed foldover artifact behavior: First, due to the oversampling of the center, high-energy foldover artifacts originating from the center of k-space are avoided. Second, due to the non-equidistant sampling of k-space, the corresponding field of view (FOV) is no longer well defined. As a result, foldover artifacts are blurred over a broad range and appear less severe. The more relaxed foldover artifact behavior and the densely sampled central k-space make trajectories of this type an ideal complement to autocalibrated parallel MRI (pMRI) techniques, such as generalized autocalibrating partially parallel acquisitions (GRAPPA). Although pMRI can benefit from non-Cartesian trajectories, this combination has not yet entered routine clinical use. One of the main reasons for this is the need for long reconstruction times due to the complex calculations necessary for non-Cartesian pMRI. In this work it is shown that one can significantly reduce the complexity of the calculations by exploiting a few specific properties of k-space-based pMRI.     

Cervical metastases of microcystic adnexal carcinoma in an otherwise healthy woman

Microcystic adnexal carcinoma is a rare cutaneous neoplasm characterized by slow but locally aggressive growth, which normally does not lead to systemic metastasis. Frequent local recurrences are reported, which are most likely due to insufficient operative technique. We present the fourth case of cervical ipsilateral metastatic microcystic adnexal carcinoma in an otherwise healthy woman. The patient presented with a previously diagnosed but not completely resected microcystic adnexal carcinoma in the area of the right posterior scalp and two palpable ipsilateral lymph nodes. The tumor was resected using intraoperative snap frozen histological evaluation of the resection borders. In the same procedure two lymph nodes were resected from the right neck. The lymph nodes were histologically assessed and showed infiltration by small strains of tumor cells. After exclusion of a second primary tumor, e.g., mammary carcinoma, as the cause for cervical lymph node metastases, we performed a modified radical neck dissection with resection of the sternocleidomastoid muscle and the accessory nerve, which was histologically proven to be perineurally infiltrated by tumor cells. In this second procedure the histological evaluation of the specimen showed no sign of remaining tumor infiltration. After exclusion of distant metastasis the patient was irradiated with 60 Gy. The patient is well 1 year after the initial treatment without signs of recurrence.     

Sex,stress, and health: Does stress predict health symptoms differently for the two sexes?

Objectives: Previous studies have been inconsistent with regard to the extent to which stress perception, rather than stressor exposure, predicts negative health symptoms. Because sex differences have been observed in all three of these variables, in this study the possibility that sex differences also exist in the relationships between them is investigated. Methods: Self‐report inventories of perceived stress, stressor exposure, and negative health symptoms were given to 107 young‐adult participants (65 females, 42 males). Results: Sex differences were observed in the associations among perceived stress, stressor exposure, and negative health symptom rates. Specifically, while higher perceived stress and higher stressor exposure rates independently predicted higher negative health symptoms rates in females, only higher stressor exposure rates independently predicted higher negative health symptoms in males. Indeed, unexpectedly, after controlling for exposure to stressors there was a trend towards higher perceived stress predicting lower negative health symptoms in males. Conclusions: While exposure to stress was a significant negative predictor of health for both sexes, perception of stress was predictive only for females. One implication of this finding is that different psychological models are needed to predict health symptoms in the two sexes. Copyright © 2005 John Wiley & Sons, Ltd.     

Decreases in arterial oxygen saturation in paediatric outpatients during transfer to the postanaesthetic recovery room

Arterial oxygen saturation was measured by pulse oximetry in two groups of paediatric outpatients breathing room air during transport from the operating room to the postanaesthetic recovery room. In Group I (n = 60) readiness for transfer from OR to PARR was decided clinically. In Group II (n = 50) additional criteria of oxygen saturation (SaOe) greater than or equal to 98 per cent with end-tidal gas N2O less than or equal to 10 per cent and CO2 less than or equal to 45 mmHg were met. A higher incidence of desaturation (SaO2 less than or equal to 90 per cent) occurred in Group I (27 per cent) than in Group II (eight per cent) (P less than 0.05). More children under 2 yr desaturated in Group I (50 per cent) than Group II (17 per cent) (P greater than 0.05 less than 0.10). Twenty-two patients in each group had a recent history of upper respiratory tract infections. In these patients, desaturation was more marked in those in Group I (32 per cent) than in Group II (five per cent) (P less than 0.05). Within each group, the incidence of desaturation during transport was similar in patients with or without a recent URI.     

Translational crossroads for biomarkers.

A group of investigators met at a Specialized Programs of Research Excellence Workshop to discuss key issues in the translation of biomarker discovery to the development of useful laboratory tests for cancer care. Development and approval of several new markers and technologies have provided informative examples that include more specific markers for prostate cancer, more sensitive tests for ovarian cancer, more objective analysis of tissue architecture and an earlier indication of response to treatment in breast cancer. Although there is no clear paradigm for biomarker development, several principles are clear. Marker development should be driven by clinical needs, including early cancer detection, accurate pretreatment staging, and prediction of response to treatment, as well as monitoring disease progression and response to therapy. Development of a national repository that uses carefully preserved, well-annotated tissue specimens will facilitate new marker development. Reference standards will be an essential component of this process. Both hospital-based and commercial laboratories can play a role in developing biomarkers from discovery to test validation. Partnering of academe and industry should occur throughout the process of biomarker development. The National Cancer Institute is in a unique position to bring together academe, industry, and the Food and Drug Administration to (a) define clinical needs for biomarkers by tumor type, (b) establish analytic and clinical paradigms for biomarker development, (c) discuss ways in which markers from different companies might be evaluated in combination, (d) establish computational methods to combine data from multiple biomarkers, (e) share information regarding promising markers developed in National Cancer Institute-supported programs, and (f) exchange data regarding new platforms and techniques that can accelerate marker development.     

Body composition of patients on a very low-protein diet: a two-year survey with DEXA.

BACKGROUND: It has been reported that patients on a very-low-protein diet (VLPD) maintain a satisfactory nutritional status because of a conserved adaptive metabolic response. However, only few studies have examined the course of nutritional status and body composition in the long term (2 years). METHODS: Thirteen stable patients (8 men; age, 55 +/- 12 years; glomerular filtration rate (GFR), 15 +/- 5 mL/min) receiving a VLPD (0.3 g/kg/day protein) supplemented with amino acids and ketoanalogues (SVLPD) were studied for 2 years. A joint visit with a physician and a dietitian and routine blood and urine analyses were performed every month. Dual-energy x-ray absorptiometry (DEXA), which was used to assess modification of body composition, and GFR (urinary 51Cr-EDTA) and urinary urea and creatinine excretion, which were used to assess nutritional status and compliance to the diet, were assessed every 3 months. RESULTS: GFR, albumin, and prealbumin levels remained stable. Urea urinary excretion decreased at 3 months and then slightly increased at 2 years, but the calculated protein intake remained low at 0.38 +/- 0.1 g/kg/day. Energy intake remained close to 30 kcal/kg/day. No significant change was observed for total fat mass or percent fat mass. After an initial decrease, lean body mass stabilized at 6 months and then increased significantly from 6 to 24 months (P =.02, paired t-test); the mean increase during this period was of 2 kg, that is, 4.6%. Urinary creatinine excretion showed the same profile. Total bone mass, lumbar or hip site bone mass, and Z-score significantly decreased from T0 to 1 and 2 years (P <.05). CONCLUSION: This study confirms that a supplemented VLPD is nutritionally safe for a long period, but attention must be paid to bone mass.