Zinc protection of fertilized eggs is an ancient feature of sexual reproduction in animals.

One of the earliest and most prevalent barriers to successful reproduction is polyspermy, or fertilization of an egg by multiple sperm. To prevent these supernumerary fertilizations, eggs have evolved multiple mechanisms. It has recently been proposed that zinc released by mammalian eggs at fertilization may block additional sperm from entering. Here, we demonstrate that eggs from amphibia and teleost fish also release zinc. Using Xenopus laevis as a model, we document that zinc reversibly blocks fertilization. Finally, we demonstrate that extracellular zinc similarly disrupts early embryonic development in eggs from diverse phyla, including Cnidaria, Echinodermata, and Chordata. Our study reveals that a fundamental strategy protecting human eggs from fertilization by multiple sperm may have evolved more than 650 million years ago.

Nature, timing, and severity of complications from ultrasound-guided percutaneous renal transplant biopsy.

We sought to review our kidney transplant biopsy experience to assess the incidence, type, presenting symptoms, and timing of renal transplant biopsy complications, as well as determine any modifiable risk factors for postbiopsy complications. This is an observational analysis of patients at the University of Wisconsin between January 1, 2000, and December 31, 2009. Patients with an INR ≥1.5 or platelet counts less than 50 000 were not biopsied. An 18-gauge needle was used for biopsy. Over the study period, 3738 biopsies were performed with 66 complications (1.8%). No deaths occurred. A total of 0.7% were mild complications, 0.7% were moderate complications, 0.21% were severe complications, and 0.19% were life-threatening. Most complications occurred within the 4-h postbiopsy period, although serious complications were often delayed: 67% of complications requiring surgical intervention presented greater than 4 h after biopsy. Biopsy within 1 week of transplant had a 311% increased risk of a complication. Postbiopsy reduction in hematocrit and hemoglobin at 4 h was associated with a complication. In conclusion, life-threatening complications after renal allograft biopsy occurred in 0.19% of patients. Most complications occurred within 4 h postprocedure; however, many serious complications occurred with a time delay after initially uneventful monitoring. The only clinically significant laboratory predictor of a complication was a fall in the hematocrit or hemoglobin within 4 h. Patients biopsied within a week of transplant were at the highest risk for a complication and should therefore be most closely monitored.

Characterizing the compression-dependent viscoelastic properties of human hepatic pathologies using dynamic compression testing.

Recent advances in elastography have provided several imaging modalities capable of quantifying the elasticity of tissue, an intrinsic tissue property. This information is useful for determining tumour margins and may also be useful for diagnosing specific tumour types. In this study, we used dynamic compression testing to quantify the viscoelastic properties of 16 human hepatic primary and secondary malignancies and their corresponding background tissue obtained following surgical resection. Two additional backgrounds were also tested. An analysis of the background tissue showed that F4-graded fibrotic liver tissue was significantly stiffer than F0-graded tissue, with a modulus contrast of 4:1. Steatotic liver tissue was slightly stiffer than normal liver tissue, but not significantly so. The tumour-to-background storage modulus contrast of hepatocellular carcinomas, a primary tumour, was approximately 1:1, and the contrast decreased with increasing fibrosis grade of the background tissue. Ramp testing showed that the background stiffness increased faster than the malignant tissue. Conversely, secondary tumours were typically much stiffer than the surrounding background, with a tumour-to-background contrast of 10:1 for colon metastases and 10:1 for cholangiocarcinomas. Ramp testing showed that colon metastases stiffened faster than their corresponding backgrounds. These data have provided insights into the mechanical properties of specific tumour types, which may prove beneficial as the use of quantitative stiffness imaging increases.

MRI of pregnancy-related issues: müllerian duct anomalies.

OBJECTIVE: Müllerian duct anomalies can adversely affect pregnancy outcomes and can result in clinical symptoms. This article will review the appropriate management of patients with müllerian duct abnormalities. CONCLUSION: Whereas uterine and vaginal septa, vaginal agenesis, and unicornuate uterus can be managed surgically, other uterine anomalies tend to be managed clinically. Hence, appropriate management depends on a reliable assessment of pelvic anatomy. MRI can accurately display female pelvic anatomy and is, therefore, useful in guiding therapy.

Incidental adnexal masses detected at low-dose unenhanced CT in asymptomatic women age 50 and older: implications for clinical management and ovarian cancer screening.

PURPOSE: To determine the prevalence, work-up, and outcomes of indeterminate adnexal masses identified at low-dose unenhanced computed tomography (CT) in asymptomatic women age 50 and older undergoing colonography screening. MATERIALS AND METHODS: This study was institutional review board approved and HIPAA compliant. Informed consent was waived. The fate of indeterminate adnexal lesions identified at unenhanced CT in 2869 consecutive women (mean age, 57.2 years; age range, 50-97 years) undergoing colonography screening between April 2004 and December 2008 was evaluated. RESULTS: One hundred eighteen women (mean age, 56.2 years), representing 4.1% of the screening cohort, had an indeterminate adnexal mass (108 unilateral, 10 bilateral; mean size, 4.1 cm) at prospective CT interpretation. A total of 80 women underwent some combination of further imaging evaluation (n = 76) (transvaginal ultrasonography [n = 71], pelvic magnetic resonance imaging [n = 7], contrast material-enhanced CT [n = 7]) and/or surgery (n = 26). Mean serum CA-125 level in 33 women was 12.8 U/mL; levels were normal (<35 U/mL) in 32 (97%) cases (range, 3-26 U/mL) and mildly elevated (41 U/mL) in one case. Final pathologic findings of surgically excised lesions were cystadenoma or cystadenofibroma (n = 14; 11 serous, three mucinous); nonneoplastic cysts (n = 5; two endometriomas); mature teratoma (n = 3); hydrosalpinx (n = 2); fibroma (n = 1); and benign Brenner tumor (n = 1). Three additional teratomas were diagnosed at index CT only. No ovarian cancers were prospectively identified, although four cases of ovarian cancer developed subsequent to a negative adnexal finding at CT examination during a 15-44-month interval among the remaining 2751 women. CONCLUSION: Incidental indeterminate adnexal lesions were relatively common at unenhanced CT (4.1%), but subsequent work-up revealed no ovarian cancers. Furthermore, a normal finding at CT was not protective against short-term development of ovarian cancer. More sophisticated risk factor assessment is needed to identify women at higher risk.

Colorectal and extracolonic cancers detected at screening CT colonography in 10,286 asymptomatic adults.

PURPOSE: To retrospectively determine the detection rates, clinical stages, and short-term patient survival for all unsuspected cancers identified at screening computed tomographic (CT) colonography, including both colorectal carcinoma (CRC) and extracolonic malignancies. MATERIALS AND METHODS: From April 2004 through March 2008, prospective colorectal and extracolonic interpretation was performed in 10,286 outpatient adults (5388 men, 4898 women; mean age, 59.8 years) undergoing screening CT colonography at two centers in this institutional review board-approved, HIPAA-compliant study. For all histologically proved, clinically unsuspected cancers detected at CT colonography that were identified at retrospective review of the medical records, the stage of disease, treatment, and clinical outcome were analyzed. Benign neoplasms (including advanced colorectal adenomas), symptomatic lesions, and tumors without pathologic proof were excluded. Statistical analysis was performed with Fisher exact test and two-sample z test. RESULTS: Unsuspected cancer was confirmed in 58 (0.56%) patients (33 women, 25 men; mean age, 60.8 years), which included invasive CRC in 22 patients (0.21%) and extracolonic cancer in 36 patients (0.35%). Extracolonic malignancies included renal cell carcinoma (n = 11), lung cancer (n = 8), non-Hodgkin lymphoma (n = 6), and a variety of other tumors (n = 11). Cancers in 31 patients (53.4%) were stage I or localized. At the most recent clinical follow-up (mean, 30.0 months +/- 11.8 [standard deviation]; range, 12-56 months), three patients (5.2%) had died of their cancer. CONCLUSION: The overall detection rate of unsuspected cancer is approximately one per 200 asymptomatic adults undergoing routine screening CT colonography, including about one invasive CRC per 500 cases and one extracolonic cancer per 300 cases. Detection and treatment at an early presymptomatic stage may have contributed to the favorable outcome.

CT colonography: performance and program outcome measures in an older screening population.

PURPOSE: To evaluate computed tomographic (CT) colonography performance and program outcome measures in an older cohort (65-79 years) of an established large-scale colorectal cancer screening program. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the institutional review board; informed consent waived. Retrospective analysis of the 65-79-year-old cohort (n = 577) from the University of Wisconsin CT colonography screening program (n = 5176) was undertaken. Performance and outcome measures including advanced neoplasia prevalence and colonoscopy referral, extracolonic finding, extracolonic work-up, and complication rates were obtained by using a CT colonography database and review of medical records. Comparisons between the older cohort and the general screening population were made by using the Student t, Pearson chi(2), and Fisher exact tests. A P value

Unsuspected extracolonic findings at screening CT colonography: clinical and economic impact.

PURPOSE: To evaluate the frequency and estimated costs of additional diagnostic workup for extracolonic findings detected at computed tomographic (CT) colonography in a large screening cohort. MATERIALS AND METHODS: This retrospective HIPAA-compliant study, which had institutional review board approval, evaluated extracolonic findings in 2195 consecutive asymptomatic adults (1199 women, 996 men; age range, 40-90 years; mean age, 58.0 years +/- 8.1 [standard deviation]) undergoing low-dose CT colonographic screening performed without contrast material at a single institution over a 20-month period. All diagnostic workups generated because of extracolonic findings were reviewed. Associated costs were estimated by using 2006 Medicare average reimbursement. Testing for statistical significance was performed by using the chi(2) and t tests. RESULTS: Further diagnostic workup for unsuspected extracolonic findings was performed in 133 (6.1%) of 2195 patients, including 18 patients in whom additional workup was not recommended by the radiologist. Additional testing included ultrasonography (n = 64), CT (n = 59), magnetic resonance imaging (n = 11), other diagnostic imaging tests (n = 19), nonsurgical invasive procedures (n = 19), and surgical procedures (n = 22). Benign findings were confirmed in the majority of cases, but relevant new diagnoses were made in 55 (2.5%) patients, including extracolonic malignancies in nine patients. The mean cost per patient for nonsurgical procedures was $31.02 (95% confidence interval: $23.72, $38.94); that for surgical procedures was $67.54 (95% confidence interval: $38.62, $101.55). CONCLUSION: Detection of relevant unsuspected extracolonic disease at CT colonographic screening is not rare, accounting for a relatively large percentage of cases in which additional workup was recommended. Judicious handling of potential extracolonic findings is warranted to balance the cost of additional workup against the potential for early detection of important disease, because many findings will prove to be of no clinical consequence.

Anatomic factors predictive of incomplete colonoscopy based on findings at CT colonography.

OBJECTIVE: Reasons for failure to reach the cecum at optical colonoscopy are multifactorial. The purpose of this study was to compare CT colonography (CTC) findings in patients with complete versus those with incomplete optical colonoscopy. MATERIALS AND METHODS: The clinical data and CTC examinations were reviewed in 100 patients who underwent CTC after incomplete optical colonoscopy. The findings were compared with a control group of 100 patients who underwent complete optical colonoscopy after CTC. The interactive 3D colon map and 2D multiplanar reconstruction images from CTC were reviewed independently by two experienced gastrointestinal radiologists for colorectal length (total, sigmoid colon, and transverse colon), number of acute angle flexures (reflecting tortuosity), and advanced diverticular disease. Discrepancies were resolved by secondary consensus review. RESULTS: Significant differences existed between the complete and incomplete optical colonoscopy groups, respectively, for age (mean, 58.2 vs 63.4 years; p < 0.001), sex (60 men and 40 women vs 41 men and 59 women; p < 0.01), and prior abdominal surgery (26.0% vs 48.0%; p < 0.01). Significant differences were seen between the complete and incomplete optical colonoscopy groups, respectively, for all the CTC factors that were evaluated: total colorectal length (mean, 167.0 vs 210.8 cm; p < 0.0001), sigmoid colon length (mean, 48.7 vs 66.8 cm; p < 0.0001), transverse colon length (mean, 49.2 vs 66.3 cm; p < 0.0001), number of flexures (mean, 9.6 vs 11.9; p < 0.0001), and advanced diverticular disease (22.0% vs 34.0%; p <0.05). CONCLUSION: Anatomic features associated with failure to reach the cecum at optical colonoscopy included colonic elongation, tortuosity, and advanced diverticular disease. These predictive factors may have implications for optical colonoscopy training and performance and for patients sent to optical colonoscopy for polyps prospectively detected at CTC.