Design of a handheld and portable fluorescence imaging system for quantitative detection of pregnancy-specific biomarkers in cattle.

Reproductive management significantly impacts dairy farm productivity, necessitating accurate timely pregnancy detection in cattle. This paper presents a novel handheld and portable fluorescence imaging system designed for quantitative assessment of pregnancy-specific biomarkers, addressing the limitations of current detection methods. The objective was to develop a cost-effective, at-farm solution for detecting pregnancy-specific protein B (PSPB) in bovine plasma samples. The system integrates an imaging module and a custom software application, enabling image capture, data processing, and PSPB concentration determination. Calibration utilizing known PSPB concentrations achieved a 0.6 ng/mL limit of detection. Validation encompassed a comparison with a standard ELISA method using 100 bovine plasma samples; minimal bias and good agreement were observed within the linear range of the calibration curve for both methods. The system offers portability, user-friendliness, and potential for multiplex detection, promising real-time, at-farm reproductive management. This study demonstrates the successful development and validation of a portable fluorescence imaging system, offering an efficient and accurate approach to detecting pregnancy-specific biomarkers in cattle. Its implications extend to improving dairy farm productivity by enabling timely and reliable reproductive management practices.

Comparison of analytical sensitivity and women's interpretation of home pregnancy tests.

BACKGROUND: Internationally there are no defined standards for expressing the performance of home-based pregnancy tests, nor any pre-defined accuracy standard requirements. The aim of this study was to evaluate the accuracy of a selection of home-based pregnancy tests relative to their packaging/product insert claims. METHODS: Eight home-based pregnancy tests were evaluated using human chorionic gonadotrophin (hCG) urine standards (0, 15, 25 mlU/mL). Testing was performed by a technician and results were read by a technician and a panel of consumer volunteers (each blinded to the expected result) and compared with the expected result based on the manufacturer's claimed accuracy. Volunteers also completed questionnaires relating to various device attributes. RESULTS: The overall agreement between the technician reading and expected reading from the hCG concentration was >90% for the Clearblue® DIGITAL, Clearblue® PLUS, Confirme® Plus, David® and Haus™ tests, and approximately 80% for Predictor® Early; agreement was <50% for Femitest® Jet Ultra and Cyclotest® Early tests. RESULTS were available from 72 volunteers (aged 18-45 years). Overall the percentage agreement between volunteer result and expected result was >95% for Clearblue DIGITAL and Clearblue PLUS tests; agreement for all other tests was <75% (lowest were Cyclotest Early and Femitest Jet Ultra, 33.0% and 39.4%, respectively). The Clearblue DIGITAL test was scored most highly by volunteers in the questionnaires. CONCLUSIONS: Many home-based pregnancy tests commonly used by women are not as accurate as their packaging information claims. International test standards which define appropriate performance characteristics for home pregnancy tests are urgently required.

Screening method to evaluate point-of-care human chorionic gonadotropin (hCG) devices for susceptibility to the hook effect by hCG ß core fragment: evaluation of 11 devices.

BACKGROUND: The predominant hCG variant in urine, hCG ß core fragment (hCGßcf), has been demonstrated to cause false-negative results in qualitative point-of-care (POC) hCG devices. This is a major concern for healthcare professionals using POC pregnancy tests. We developed a screening method to evaluate qualitative POC hCG devices for their susceptibility to inhibition by hCGßcf. Using this method, we evaluated the performance of 11 commonly used devices. METHODS: A wide range of purified hCG and hCGßcf concentrations were mixed and tested on 2 POC devices. By use of those results, a screening method was defined and 9 additional POC devices were evaluated. Two solutions containing (a) 500 pmol/L (171 IU/L) intact hCG with 0 pmol/L hCGßcf and (b) 500 pmol/L intact hCG with 500 000 pmol/L hCGßcf were used to screen all POC devices. RESULTS: The OSOM and Cen-Med Elite devices were found to be most susceptible to false-negative results due to hCGßcf. The BC Icon 20 and the Alere were the least susceptible. The remaining 7 were moderately affected. Devices that gave the strongest signal with hCGßcf alone were those that were least likely to show a hook effect. CONCLUSIONS: The screening method put forth here can be used by device users and manufacturers to evaluate POC devices for inhibition by hCGßcf. Of 11 devices evaluated, only 2 have been identified that exhibit minimal to no susceptibility to hCGßcf.

Evaluation of Nischay scheme in improving antenatal care in a northern state of India.

OBJECTIVE: To evaluate Nischay scheme (provision of pregnancy detection kit) in improving antenatal care. METHODOLOGY: A natural experiment design was conducted during September 2011 to April 2012 in a randomly selected district of Haryana state of India. Community Health Center (CHC), Primary Health Center (PHC), sub-center and villages were selected using random sampling technique. The retrospective record analysis of antenatal data pertaining to 6 months before (April to September 2008) and after (October 2008 till March 2009) the launch of Nischay scheme was compared in the study. Only those centers were included in the study which have timely and adequate supply of the kits so that pregnant women would not have been missed (to be diagnosed as pregnant). The training status of ANMs and ASHA of selected sub-centers along with their knowledge about usage of kits was assessed. Besides this, beneficiaries were interviewed from selected sub-centers about their awareness and utilization of Nischay scheme. RESULTS: Before 6 months of a launch of Nischay scheme, the median of ANC registration per sub-center per month was in the range of 18-25.5, whereas after 6 months it was 16-22.5. The difference in key ANC parameters (ANC registration, ANC < 12 weeks and completed three ANC) before and after introduction of the scheme was not found to be statistically significant. Only 15.6 % of beneficiaries were aware about Nischay scheme. The primary source of the information is either ANM (60 %) or ASHA (40 %). Those who were aware of this scheme had utilized this kit from the nearby sub-center. All (100 %) ANMs and 93 % of ASHAs had been adequately trained about using Nischay kit and interpreting the result. CONCLUSIONS: There was no significant change in ANC registration in the period of 6 months after the launch of the scheme despite trainings to the frontline health workers. Further research is required to understand the bottlenecks so that corrective actions can be taken.

Pregnancy detection and monitoring in cattle via combined foetus electrocardiogram and phonocardiogram signal processing.

BACKGROUND: Pregnancy testing in cattle is commonly invasive requiring manual rectal palpation of the reproductive tract that presents risks to the operator and pregnancy. Alternative non-invasive tests have been developed but have not gained popularity due to poor specificity, sensitivity and the inconvenience of sample handling. Our aim is to present the pilot study and proof of concept of a new non invasive technique to sense the presence and age (limited to the closest trimester of pregnancy) of the foetus by recording the electrical and audio signals produced by the foetus heartbeat using an array of specialized sensors embedded in a stand alone handheld prototype device. The device was applied to the right flank (approximately at the intercept of a horizontal line drawn through the right mid femur region of the cow and a vertical line drawn anywhere between lumbar vertebrae 3 to 5) of more than 2000 cattle from 13 different farms, including pregnant and not pregnant, a diversity of breeds, and both dairy and beef herds. Pregnancy status response is given "on the spot" from an optimized machine learning algorithm running on the device within seconds after data collection. RESULTS: Using combined electrical and audio foetal signals we detected pregnancy with a sensitivity of 87.6% and a specificity of 74.6% for all recorded data. Those values increase to 91% and 81% respectively by removing files with excessive noise (19%).Foetus ageing was achieved by comparing the detected foetus heart-rate with published tables. However, given the challenging farm environment of a restless cow, correct foetus ageing was achieved for only 21% of the correctly diagnosed pregnant cows. CONCLUSIONS: In conclusion we have found that combining ECG and PCG measurements on the right flank of cattle provides a reliable and rapid method of pregnancy testing. The device has potential to be applied by unskilled operators. This will generate more efficient and productive management of farms. There is potential for the device to be applied to large endangered quadrupeds in captive breeding programs where early, safe and reliable pregnancy diagnosis can be imperative but currently difficult to achieve.

The utility of six over-the-counter (home) pregnancy tests.

BACKGROUND: The home pregnancy market is rapidly evolving. It has moved from detection of pregnancy on the day of missed menstrual bleeding, to detection claims 4 days prior. It is moving from all manual tests to digital tests, with a monitor reading the bands and informing women they are pregnant. A thorough study is needed to investigate the validity of claims and evolving usefulness of devices. METHODS: Studies were proposed to examine the sensitivity and specificity of home tests and their abilities to detect pregnancy. Methods examined the abilities of tests to detect human chorionic gonadotropin (hCG), hyperglycosylated hCG, free ß-subunit, a mixture of these antigens in 40 individual early pregnancy urines. RESULTS: Using a mixture of hCG, hyperglycosylated hCG and free ß-subunit typical for early pregnancy, the sensitivity of the First Response manual and digital tests was 5.5 mIU/mL, while the sensitivities of the EPT and ClearBlue brand manual and digital tests was 22 mIU/mL. On further evaluation, the First Response manual and digital tests both detected 97% of 120 pregnancies on the day of missed menstrual bleeding. The EPT manual and digital devices detected 54% and 67% of pregnancies, respectively, and the ClearBlue manual and digital devices detected 64% and 54% of pregnancies, respectively. CONCLUSIONS: First Response manual and digital claim >99% detection on the day of missed menses. The results here suggest similar sensitivity for these two tests. The EPT and ClearBlue manual and digital test make similar >99% claims, the data presented here disputes their elevated claim.

Quantitative analysis of various targets based on aptamer and functionalized Fe3O4@graphene oxide in dairy products using pregnancy test strip and smartphone.

Pregnancy test strips are one of the most mature and widely used commercial lateral flow devices used to determine pregnancy. Being a simple and rapid detection method, human chorionic gonadotropin (hCG) was used with different aptamers (hCG-apt) as probes for the detection of metal ions, small organic molecules, and proteins. Quantitative detection of target analytes was achieved using a smartphone app and a portable device developed in our laboratory. The results showed detection ranges of 1 nM-1 µM, 0.1 nM-10 µM and 32 nM-500 nM for Pb2+, chloramphenicol, and ß-lactoglobulin, respectively, and the corresponding visual detection limits in dairy products were 5 nM, 1 nM and 50 nM, respectively. Based on these results, rapid detection of multiple analytes can be realized through aptamer modification, thereby broadening the application range of commercial lateral flow devices for analysis of food chemistry.

Early conception factor lateral flow assays for pregnancy in the mare.

The ECF lateral flow assay test is marketed to detect non-pregnancy in mares. The objectives of the present study were to determine the accuracy of the ECF test, the accuracy of the electronic reader accompanying the ECF test, and agreement between two human readers and the electronic reader. Serum samples were collected from anestrus, cycling but not inseminated, and inseminated mares, and were evaluated with the ECF test (EDP Biotech Company, Knoxville, TN, USA) at The Ohio State University and at the EDP Biotech Laboratory. Specificity ranged from 0.07 to 0.16, the negative predictive value ranged from 0.15 to 0.33, and accuracy ranged from 0.43 to 0.52. The electronic reader did not add improve the accuracy or predictive values of the test. Based on the electronic reader, 80.0% of the serum samples collected from the anestrus mares were false positives; Readers 1 and 2 had 60.0 and 33.3% false positives, respectively. For samples collected during the estrous cycle, 83.9% were false positives by the electronic reader, whereas Readers 1 and 2 had 43.7 and 26.4% false positives. We concluded that, regardless of whether the test strips were evaluated by a human or electronic reader, this assay was not accurate for determination of the non-pregnant mare.

Diving deep to detect manta ray pregnancies.

Georgina Mills explains how researchers have used cutting-edge technology to learn more about reproduction in manta rays in the Maldives.

Accuracy of pregnancy diagnosis in swine by ultrasonography.

Early and accurate diagnosis of nonpregnant sows and gilts has the potential to increase reproductive efficiency and the financial income in pig production by reducing non-productive days per sow per year. The objectives of this study were to compare the efficiency of pregnancy diagnosis between Doppler Echo+ and real time ultrasonography (RTU) and to compare the efficiency by using RTU at different days post-mating (days 17 to 24) under commercial conditions. In the 1st study, using crossbreed sows and gilts (n=107), pregnancy diagnoses were done with Doppler Echo+ and then with RTU. Between 28 and 65 days of gestation, Doppler Echo+ had 85% sensitivity and 32% specificity, and efficiency was 73%. In the 2nd study, sows (n=142) were scanned for pregnancy diagnosis between 17 and 24 d post-mating (PD1) and reconfirmed between 38 and 45 days of gestation (PD2). After 21 days of gestation, RTU had over 90% sensitivity and 45% specificity, and 70% efficiency. Accuracy between PD1-farrowing was 75.5% and between PD1 and PD2 was 80.6%. In the 3rd study, sows were diagnosed pregnant by RTU (n=151) at 17 to 24 days of gestation or A-mode ultrasound (n=172) at 28 to 30 days of gestation. There were no significant differences in conception rate (P > 0.09) and farrowing rate (P > 0.67) between both groups. Hence, there was no improvement in fertility and farrowing rate by using RTU instead of A-mode ultrasound under commercial conditions.

Characterizing urinary hCGßcf patterns during pregnancy.

OBJECTIVE: Elevated concentrations of hCG beta core fragment (hCGßcf) are known to cause false-negative results in qualitative urine pregnancy test devices, but the pattern of urinary hCGßcf during normal pregnancy has not been well characterized. Here, we evaluate the relationship between urine hCG, hCGßcf, and hCG free ß subunit (hCGß) during pregnancy. DESIGN AND METHODS: Banked second trimester urine specimens from 100 pregnant women were screened for high concentrations of hCGßcf using a qualitative point-of-care device known to demonstrate false-negative results in the presence of elevated hCGßcf concentrations. Additional first and third trimester specimens from the same pregnancy were obtained from 10 women who generated negative/faint positive results, 5 women who generated intermediate positive results, and 10 women who generated strong positive results on the point-of-care device. Intact hCG, hCGßcf, hCGß, and specific gravity were quantified in these 75 specimens. RESULTS: Urinary hCGßcf concentrations were greater than intact hCG concentrations at all times. A strong correlation (r(2)=0.70) was observed between urine intact hCG and hCGßcf concentrations. A poor correlation was observed between specific gravity and intact hCG (r(2)=0.32), hCGß (r(2)=0.32), and hCGßcf (r(2)=0.32). The highest hCGßcf concentrations were observed between 10 and 16weeks gestation but individual women demonstrated very different patterns of hCGßcf excretion. CONCLUSIONS: Urine specimens with elevated hCGßcf are frequently encountered during pregnancy but hCGßcf excretion patterns are unpredictable. Manufacturers and clinicians must appreciate that hCGßcf is the major immunoreactive component in urine during pregnancy and must design and interpret qualitative urine hCG test results accordingly.

Evaluation of a semi-quantitative pregnancy device for susceptibility to interference caused by hCGßcf.

OBJECTIVE: Previous work has documented the ability of the Clearblue Advanced Test with Weeks Estimator, a new over-the-counter (OTC) urine hCG device, to accurately estimate weeks since ovulation in early pregnancy. In this study, the performance of this device in more advanced pregnancy was assessed. METHODS: The Clearblue Advanced Test with Weeks Estimator device was used to test solutions containing purified intact hCG and hCGßcf at concentrations consistent with early, middle and late pregnancy. Urine samples from three normal pregnant patients 9-13 weeks of gestation and from a patient 12 weeks of gestation known to generate false negative results on qualitative urine test devices due to excess hCGßcf were also evaluated. RESULTS: The Clearblue Weeks Estimator device gave expected results using solutions containing purified intact hCG and hCGßcf at concentrations observed throughout pregnancy. The device generated expected results using urine from three of four patients tested between 9 and 13 weeks of gestation. However, when urine from a patient with elevated concentrations of hCGßcf was used, the device correctly indicated pregnancy although the estimate for the date was incorrect. CONCLUSION: This device gave expected "pregnant" results using all samples tested. However, the "Weeks Estimator" should be interpreted with caution when used by patients after seven weeks of pregnancy.

Performances of urine pregnancy tests on College of American Pathologists Survey specimens.

The participant performances on the College of American Pathologists (CAP) Urine Survey specimens distributed during 1979 and 1980 for pregnancy testing are reviewed. Almost all the reagent methods used by the participants performed well on the negative specimens. Prominent differences in results on the positive specimens were found. Awareness by laboratorians of the reagent sensitivity, limitations, and capabilities of commercial tests for determining human chorionic gonadotropin in urine is recommended.

PIP: Pregnancy tests for human chorionic gonadotropins (hCG) in urine has yielded false-positive and false-negative results. The technical error rate in performing pregnancy tests is 1-4%. This paper presents the results of participant tests on the CAP (College of American Pathologists) Survey specimens. In 1979 and 1980, the CAP prepared 22 urine survey specimens for hCG testing. Radioimmunoassay was used to determine reference levels of hCG in these specimens. 8 negative specimens contained no hCG, 8 low-level specimens contained 0.6-1.0 U/ml, and 6 high-level specimens contained 2.2-3.8 U/ml. Laboratories participating in the CAP Urine Survey Program received and tested these specimens for the presence of hCG using their reagent products of choice and recorded their results as positive or negative. The CAP Computer Center tabulated the results as correct or incorrect according to the assayed levels of hCG within the specimens. 35,014 hCG tests were performed. 58.9% were determined by slide procedures, and 41.1% were determined by tube procedures. Correct results were obtained in 88.2-99.3% of participant tests. Correct results were obtained in 70.8-100% of participant tests on urine specimens containing high levels of hCG (2.2-3.8 U/ml), and in 2.2-96.4% of participant tests on urine specimens containing low levels of hCG (0.6-1.0 U/ml). This study shows that almost all the reagent methods used by participants performed well on the negative specimens. 2 major factors affect the performance of results with various urine pregnancy tests: 1) the sensitivity of the test for hCG detection, and 2) the level of hCG in the specimen. Laboratory workers should develop a high level of awareness of the reagent's sensitivity, limitations, and capabilities of commercial tests for urine hCG.

Pregnancy diagnosis in sheep using a rectal probe.

A total of 1823 ewes in three flocks was examined for pregnancy using a rectal-abdominal palpation technique. A correct diagnosis was made in 97 per cent of ewes with no evidence of ewe mortality or abortion. Ewes can be examined at the rate of 120 or more per hour. It is concluded that the technique is a simple, safe and reliable method of pregnancy diagnosis in sheep from 70 days of gestation.