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PubMed1991

Ovine luteinizing hormone. VI. Analysis of the misclassification errors in the separation of intrapituitary isohormones by chromatofocusing.

Luteinizing hormone (LH) in extracts of the ovine (o) anterior pituitary gland elutes as eight or more distinct peaks when analyzed by chromatofocusing on pH 10.5-7 gradients [Keel et al., Biol. Reprod., 36 (1987) 1102]. In order to examine the efficacy of this approach to identify the distinct charge isomers of oLH, a pool of pituitary extracts was de-salted by flow dialysis and chromatofocused on a pH 10.5-7 gradient. The immunoreactive oLH eluted in nine distinct peaks which were coded with letters beginning with the most basic form. The fractions corresponding to each peak were pooled, dialyzed and lyophilized. Each peak was then re-chromatofocused on a pH 10.5-7 gradient except for the immunoreactive oLH eluting in peak A' because of the small amount present in this peak. Each peak, except for F and H, also consisted of a small percentage of immunoreactive oLH associated with adjacent peaks. This was plausible because chromatofocusing does not generally yield baseline resolution of peaks. Peak H eluted in a broad manner and was contaminated with significant amounts of isohormones F, G and Z. In contrast, peaks B, E, F, G and Z almost completely eluted in the anticipated regions. Thus, it appears that analysis of oLH charge isomers by chromatofocusing yields minimal misclassification errors and that the misclassification errors observed are associated with molecular forms which comprise a relatively small percentage of the oLH in pituitary extracts.

Animals↗

PubMed2003

Test-retest reliability of an abbreviated self-report overall health status measure.

STUDY DESIGN: Test-retest reliability study. OBJECTIVE: To assess test-retest reliability and estimate minimal detectable change of an overall measure and 2 summary measures of patient self-report of health status. BACKGROUND: Change in patient self-report of health status is a common outcome measure following rehabilitation. Because collection of health status data takes time and clinicians are required to be productive, selected items from reliable instruments were used to form a new, abbreviated instrument of health status relevant to patients in outpatient rehabilitation. There are no test-retest reliability statistics of these health status measures in this population. METHODS AND MEASURES: A convenience sample of 71 patients (mean age +/- SD, 41.9 +/- 17.9 years; age range, 15-83 years; sex, 35% male), with a variety of orthopaedic diagnoses, seeking rehabilitation in 2 outpatient facilities, volunteered. Patients completed health status questionnaires at initial evaluation and at 24 to 72 hours following evaluation. Intraclass correlation coefficients (ICC2.1) were used to estimate test-retest reliability and to estimate measurement error and minimal detectable changes. RESULTS: ICCs with a 1-sided lower limit 95% confidence intervals (CI) of the Overall Health Status measure and the Physical and Mental Component Summary measures for patients with chronic symptoms were 0.92 (0.85), 0.82 (0.68), and 0.85 (0.74), respectively. Minimal detectable changes (90% CI) were +/-12 (scale range, 100), +/- 9 (scale range, 60), and +/- 9 (scale range, 60) scale points, respectively, for the same measures. CONCLUSIONS: Results support the test-retest reliability of the Overall Health Status measure and summary measures for patients with chronic symptoms and demonstrate ability of the Overall Health Status and Physical Summary Scale measures to detect improvement of patient self-report of health status within the first few days of rehabilitation.

Adolescent↗

PubMed1999

Anastomosis to the wrong vessel during off-pump bypass surgery via mini-thoracotomy.

Recently, minimally invasive coronary artery bypass graft operation has been established as a new treatment strategy for cardiac surgeons. We report on a patient who underwent off-pump coronary artery bypass graft operation through a mini-thoracotomy to the wrong coronary artery (first diagonal) with consecutive successful percutaneous transluminal coronary angioplasty of the vessel involved (left anterior descending coronary artery) to demonstrate a special risk that is associated with this kind of operation.

Adult↗

PubMed1996

Simultaneous enumeration of chromosomes 13, 18, 21, X, and Y in interphase cells for preimplantation genetic diagnosis of aneuploidy.

A fluorescence in situ hybridization (FISH) protocol to simultaneously enumerate chromosomes 13, 18, 21, X, and Y in interphase cell nuclei for application in preimplantation genetic diagnosis (PGD) of aneuploidy was tested. Strict scoring criteria were developed to minimize recording errors. The protocol used optimized probes for chromosome-specific DNA repeat and single-copy loci and showed a significantly higher efficiency (95%) than previously published protocols. The other purpose of this study was to differentiate between two signals originating from a single split target or from two targets in close proximity. These criteria were based on the FISH results obtained from the analysis of all or most of the cells from 50 chromosomally normal or mosaic human embryos, 20 aneuploid embryos, and five polyploid embryos donated for research. Subsequently, 183 human embryos underwent PGD of aneuploidy in one of their cells. In 64 embryos that were not transferred back to the uterus, the rest of cells were also analyzed, and the previous results were confirmed in 91% of these embryos, with 0% (0/21) of the embryos classified as normal embryos being abnormal and 14% (6/43) of the embryos classified as abnormal being normal. Compared to previous protocols, these criteria minimize the risk of transferring abnormal embryos after PGD analysis.

Aneuploidy↗

PubMed1991

The relative accuracies of two automated noninvasive arterial pressure measurement devices.

We compared the accuracies of two types of noninvasive blood pressure devices. Thirty-two patients requiring an intraarterial catheter for anesthetic management underwent simultaneous monitoring with Dinamap 1846SX and Ohmeda Finapres 3700 devices. For the first 10 minutes of recording, new Dinamap determinations were performed every 60 seconds; subsequent recordings were made at 3-minute intervals. Data were obtained at the time of new Dinamap readings, and twice between new readings to approximate the real-time performance of the two monitors. We defined superior accuracy as a statistically significant difference in mean absolute error greater than 5 mm Hg. With these criteria, pooled data from all patients revealed no difference in performance, even in real time. Pooled data can be misleading since there was a significant amount of variation in accuracy for both monitors. Therefore, we used nonparametric analysis to determine how many individual patients were monitored better by either device. When we compared only data from new Dinamap readings, the Finapres monitor showed superior performance for systolic readings in 13 patients, versus 6 patients for the Dinamap (P less than 0.05, chi-square test). Similar analysis for diastolic and mean pressure performance did not reach statistical significance. However, in real time, the Finapres unit monitored more patients more accurately for systolic (14 Finapres versus 3 Dinamap), diastolic (11 Finapres versus 3 Dinamap), and mean (10 Finapres versus 3 Dinamap) pressure determinations. The magnitude of these differences were, however, less dramatic than expected. This was probably due to stabilization of arterial pressure during the anesthetic, which minimized the error due to intermittent sampling. We conclude that continuous Finapres readings and new Dinamap determinations are equally accurate for diastolic and mean arterial pressures. The accuracy of Finapres appears to be slightly superior for systolic pressure. The intermittent sampling of oscillometric devices compromises their performance relative to the Finapres in many, but not all, cases.

Adult↗

PubMed2000

[Mistaken grafting to diagonal branch in minimally invasive direct coronary artery bypass: a case required reoperation].

The patient was a 75 year-old male who was admitted with recurrent chest pain during hemodialysis one year after PTCA to the right coronary artery and left circumflex branch (LCX). He had the history of cerebral infarction and chronic renal insufficiency. Coronary angiography showed severe stenosis from the left main trunk to left anterior descending artery (LAD) and restenosis at the PTCA site of LCX. The LCX lesion was dilated with PTCA. Minimally invasive coronary artery bypass (MIDCAB) with left internal thoracic artery (LITA) to LAD was carried out uneventfully. However, chest pain appeared on 1 POD. LITA angiography revealed that LITA was anastomosed to the diagonal branch that had occluded completely in the preoperative angiography. Off-pump CAB to LAD using inferior epigastric artery was carried out through median sternotmy on the same day. He recovered smoothly, and LITA angiography before discharge demonstrated that both grafts to LAD and diagonal branch are patent.

Aged↗

PubMed2001

Input minimization: a model of cerebellar learning without climbing fiber error signals.

The cerebellum is critical for motor learning. Current cerebellar learning models follow the Marr/Albus paradigm, in which climbing fibers provide error signals that shape plastic synapses between parallel fibers and Purkinje cells. However, climbing fibers have slow and largely random discharge, and seem unlikely to provide error signals with resolution sufficient to guide cerebellar learning. Parallel fibers carry error signals and could direct the plasticity of their own synapses, but the error signals are carried along with other signals. This report presents the new input minimization (InMin) model, in which Purkinje cells reduce error by minimizing their overall parallel fiber input. The slowly, randomly firing climbing fiber provides only synchronization pulses. InMin offers an alternative that can unify cerebellar findings.

Action Potentials↗

PubMed1987

Comparative study of colorimetric method using diazotization reaction and high-performance liquid chromatographic method in determination of para-aminohippuric acid.

In this study, colorimetric method and high-performance liquid chromatographic (HPLC) method were improved and established, respectively, in order to minimize analytical errors in determination of para-aminohippuric acid (PAH) in rat urine and plasma. In terms of the colorimetric method, an operative step following addition of Tsuda reagent was modified as follows: after the addition of Tsuda reagent, reaction mixture was kept at 40 degrees C for 70 min before spectrophotometry. Linearities were observed both in the higher range of 0 and 2.5 to 12.5 micrograms and in the lower range of 0 and 100 to 1,000 ng per test tube, and its practical detection limit was 100 ng per test tube. In terms of HPLC method, using a reversed-phase column (Nucleosil 5 C18), PAH was separated by a mobile phase of acetonitrile/50 mM KH2PO4 (pH 2.8) = 9/95. Linearities were observed in the higher range of 0 and 10 ng to 2 micrograms and in the lower range of 0 and 1 to 10 ng per injection, and its practical detection limit was 1 ng per injection. These results denote that the above two methods are applicable to routine PAH determination. In addition, our HPLC method is considered to be applicable to microassay of PAH, because its sensitivity is more sensitive and minimization of volume system is more easily achieved as compared with the colorimetric method.

Aminohippuric Acids↗

PubMed1987

[Noninvasive measurement of cardiac output using two-dimensional Doppler echocardiography and analysis of sources of error].

The purpose of this study was (1) to analyze the factors responsible for errors in the two-dimensional Doppler echographic measurements of cardiac output (C.O.) and (2) to establish a noninvasive method for measuring C.O. The subjects were 50 cardiac patients who had neither aortic valve disease nor intracardiac shunts. The C.O. was calculated using the following formula: C.O. (l/min) = mean flow velocity (cm/sec) x pi(aortic ring diameter/2)2 (cm2) x 60/10(3) Left ventricular ejection flow velocity was recorded in the center of the aortic ring from the apical approach. Mean velocity was calculated by integration of instantaneous mean velocity in the ejection phase divided by the cardiac cycle length, and was corrected by the Doppler incident angle. The inner diameter of the aortic ring was measured in the parasternal long-axis view at the time of the maximum ejection flow velocity. The following results were obtained: 1. Sources of error in the measurement of cardiac output. 1) Accuracy of instantaneous mean velocity calculating circuit: This calculating circuit was accurate in model experiments using pulsatile flow. 2) Effect of high-pass filter: In model circuits, application of high-pass filter overestimated flow velocity. The higher the cut-off frequency of the high-pass filter, the larger the overestimation. This was probably due to the parabolic flow velocity profile in the circuit. 3) Flow velocity profile in the aortic ring: The flow velocity profile seemed to be flat in the aortic ring except near the anterior aortic wall. Therefore, the effect of the high-pass filter was considered to be negligible in case of clinical application. 4) The effects of shift and size of sample volume: The location of sample volume relative to the aortic valve ring shifted about 7 mm during systole. However, the shift and size of sample volume seemed to have little effect on the measured C.O., because the flow velocity profile was nearly flat in the aortic ring. 5) Ultrasound beam incident angle: From a practical viewpoint, it was necessary to set an incident angle of less than 50 degrees for minimizing the error. We were able to set the angle within 50 degrees in all but one of patients. 6) Diameter of the aortic ring: Two-dimensional echographic measurement of the aortic ring diameter was not so accurate; it seemed to become a major source of error in the calculation of C.O.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed2000

Effects of brain oedema in the measurement of ischaemic brain damage in focal cerebral infarction.

In a model of focal cerebral ischaemia, enlargement of ischaemic tissue by ischaemic brain oedema is one of the major problems in the measurement of infarction volume. To minimize an error of this overestimation, several methods have been proposed. However, there has been no attempt to compare these methods to elucidate their eligibility in the measurement of ischaemic area. The authors used three different morphometric analyses in the measurement of infarction volume to assess the antiischaemic affects of a competitive NMDA antagonist, D-CPPene in MCA occlusion model of the rat: a direct measurement, the Swanson's method, and a measurement using a diagram. Post-occlusion treatment of D-CPPene (4.5 mg/kg, i.v. +3 mg/kg/h, i.v.) produced reduction of infarction volume to about 40% compared to the control (P < 0.05). The volume of infarction determined by the direct measurement was much larger than that by Swanson's or diagram method (P < 0.05), about 70% larger in the control and by two times in the treated. However, there was no significant difference in the measured volume between the Swanson's and diagram methods. The protection rate, which was calculated as % = (infarct volume of the control--that of the treated/infarct volume of the control) x 100%, was larger in the Swanson's and diagram methods than in the direct measurement. In conclusion, it is confirmed that the direct measurement at the peak time of ischaemic brain oedema brings about not only an overestimation of infarction volume but lower protection rate also, compared to the methods designed to minimize the overestimation. Our results also demonstrate the diagram method is useful in reducing overestimation of infarct volume that may be caused by ischaemic brain oedema, though this method was not designed for the purpose of avoiding oedema at first.

Animals↗

PubMed2000

Input respiratory impedance measured by head generator in preschool children.

The upper airway wall motion represents a serious problem when measuring the input impedance of the respiratory system (Zrs) by the forced oscillation technique, particularly in young children. To minimize this error, it has been proposed to vary transrespiratory pressure around the head rather than directly at the mouth, using the head generator technique (HGT). The aim of this study was to collect normative data in preschool children in whom the technique may prove most useful. Zrs was measured using HGT and 4-32-Hz pseudorandom noise input in 127 healthy children. Age ranged from 2. 8 to 7.4 years and height (H) from 0.89 to 1.29 m. The fast Fourier transforms of pressure and flow allowed us to calculate respiratory system resistance (Rrs(f)) and reactance (Xrs(f)) at each frequency (f). Resonant frequency (fn), respiratory system inertance (Irs), and compliance (Crs) were derived from the Xrs(f) data. The technique was accepted by more than 95% of the children. A coherence function </=0.95 required us to reject Zrs values in the lower frequency spectrum. These missing data did not allow reliable estimation of fn, Irs, and Crs in 44% of children. Regression equations of Zrs on growth parameters were obtained. H was the only significant predictive variable. The decrease of Rrs with growth was best described by a multiplicative model [e.g., ln (Rrs(20)) = 2. 5301 - 2.3837. ln (H)]. The slope of the regression lines of Xrs on H was dependent on f: positive between 4 and 16 Hz, negative at high frequency (e.g., 32 Hz), and nonsignificant in the intermediate range (e.g., 20 Hz). Irs and fn decreased significantly and Crs increased as H increased. The current study provides reference values for input impedance of the respiratory system in preschool children with upper airway artifacts minimized. HGT should be particularly helpful at or around 20 Hz, where the signal to noise ratio is larger than at lower frequencies but where upper airway artifacts may significantly corrupt measurements with the standard generator.

Airway Resistance↗

PubMed1975

Ureteral catheterization studies.

It is apparent that the split function study and renal vein renin determination are complementary and afford valuable information for selecting patients with potentially curable renovascular hypertension. The split function study, when interpreted with the recently defined split function ratio, offers the clinician a highly accurate means of diagnosing significant renal ischemia. Because the split function ratio shows the disparity between the ischemic and contralateral kidney to a greater degree, the chance of misdiagnosis due to laboratory or physician error is minimized. The split function study, however, is of limited value in patients with pyelonephritis since the water- and salt-losing characteristics of the pyelonephritic kidney may mask significant renal ischemia. In these patients, as well as those with a nonfunctioning kidney or hydronephrosis, the renal vein renin determination is the test of choice. In addition, the added morbidity of the split function study is not warranted in a patient with an elevated peripheral renin which, for interpretation, requires an accurate 24 hour urine for sodium, a renal vein renin ratio outside the range of patients with essential hypertension (renal vein renin ratio greater than 1.7) and evidence of suppression of renin secretion from the contralateral kidney. If, however, the renin determination does not afford convincing evidence of significant renal ischemia in a patient with radiographic evidence of renal arterial stenosis, a split function ratio definitely should be determined to more completely define the pathology. The attendant morbidity of a carefully performed split renal function study does not approach the morbidity and mortality associated with unnecessary surgery or inadequately treated hypertension.

Adult↗

PubMed1975

Diagnostic error in breast disease.

Fifty-six breast biopsies, incorrectly assessed by preoperative clinical or mammographic examination, were reviewed to define the characteristics in the tumor or patient that caused the clinician and mammographer to be diagnostically inaccurate. The most important patient characteristic associated with error was the use of hormones. Failure to recognize that oral contraceptive use significantly reduces the incidience of benign breast disease contributed to the frequent misdiagnosis of lesions in those patients. Twelve of 16 masses in oral contraceptive users were malignant. In seven, their resemblance to cysts or fibroadenomas resulted in treatment delay of two weeks or 18 months. Because benign disease is uncommon in women who have used contraceptives two or more years, all new lesions in those women should be studied by biopsy promptly. Neither clinical nor mammographic evaluation of lesions in postmenopausal women who used estrogens was accurate. Twelve postmenopausal patients with carcinoma had used estrogens. Three of these lesions were considered benign clinically and four, by mammogram. In one, treatment was delayed four years. In women over 50 not using hormones, clinical diagnosis of malignancy was accurate. Ten carcinomas in those women were missed by mammogram. Eight had negative nodes; thus a negative mamogram when the clinical diagnosis is correct may be an effective guide in predicting the status of axillary nodes. Paget's disease was not recognized clinically in two of eight patients with that disease, and an additional two were not recognized on mammography. The initial examiner did not identify three of six inflammatory carcinomas. Ten percent of benign lesions were intraductal hyperplasia or papillomatosis with atypia and were the benign lesions most often misdiagnosed clinically and by mammogram. No microscopic lesions were noted on mammography without an associated palpable mass. Twenty-five per cent of the lesions in women aged 40-49 were incorrectly assessed by mammography or clinical examination. Four (15%) of the 27 carcinomas in this age group were not recognized by either modality. Mammography helped delineate the characteristics of masses in premenopausal women. With recognition that any mass that appears in a woman using oral contraceptives must be studied by biopsy, combined clinical and mammographic study in primenopausal women should minimize diagnostic error. Unfortunately, neither clinical nor mammographic evaluation of the women with irregular periods approaching menopause or within three years past menopause is accurate. It is in that age group that new diagnostic modalities are needed and when reported their efficacy in that age group should be stressed.

Adult↗

PubMed2003

Terminal digit bias in a specialty hypertension faculty practice.

Traditional blood pressure (BP) methodology is subject to observer error such as terminal digit preference and single number preference leading to inaccuracies in measurement. A high percentage (60-90%) of terminal BP readings digit being zero has been reported from general medical- and hospital-based clinics. This study examined terminal digit preference in a hypertension specialty practice and assessed clinical factors that may be associated with zero preference in this setting. A retrospective chart review of patients presenting to the hypertension clinic at the University of Connecticut Health Center during the month of September 2001 was performed. Data were extracted on age, gender, height, weight, treatment status, and systolic and diastolic BP measurements taken by nursing staff and attending physicians. Terminal digit preference was apparent in BP readings taken by both nursing staff and physicians. Zero was the terminal systolic BP digit in 40% of readings taken by the nursing staff and 31% of readings taken by physicians. For diastolic BP readings, the percentages were 23 and 36%, respectively. Nurses also recorded 43% of diastolic BP readings with terminal digit 2. Age was significantly higher in those persons in whom the physician diastolic BP terminal digit was zero than in those with nonzero terminal digits (67+/-14 vs 59+/-18 years, P=0.008). Body mass index was lower in the patient group with diastolic terminal digit zero bias compared to those with nonzero terminal digits (28+/-5 vs 32+/-6 kg/m(2), P=0.02). In conclusion, although the frequency of zero digit preference did not reach the 60-80% levels found in previous studies, there was evidence of terminal digit preference in the systolic and diastolic measurements taken by nursing staff and attending physicians in a specialist hypertension clinic. We believe that the lower levels of terminal digit preference observed are an effect of increased training in proper BP measurement and technique. However, the observed bias in measurement even in a hypertension unit argues for regular monitoring and feedback to minimize such errors.

Aged↗

PubMed2004

Surgical video systems.

A surgical video system (SVS) is an integration of components used to perform minimally invasive surgery (MIS). In the operating room, an SVS consists of an endoscope, an attached video camera, a light source, a video processor, and one or more video displays. A single SVS can generally be used in any type of MIS procedure (e.g., general, orthopedic, urologic), provided that it is equipped with the appropriate type of endoscope. In this Evaluation, we tested seven systems from six manufacturers. We found that, on average, three-chip systems provide better overall image quality than one-chip systems. Three systems were judged as providing image quality slightly superior to that of all the other systems; however, the level of subjectivity involved in judging performance suggests that users should perform in-house trials before purchase. All the evaluated systems performed relatively well in performance testing, but most systems were rated Fair or Poor in several human factors and safety tests. In fact, only two systems did not receive any Poor ratings in the Light Source Safety Features tests. Although users bear much of the responsibility for ensuring that light sources are used safely, most manufacturers have not made simple design changes that would make unintentional misuse less likely. We would be more likely to rate systems that still exhibit these safety issues in the future as Not Recommended or Unacceptable.

Costs and Cost Analysis↗

PubMed2000

Age-related changes in muscle fiber regeneration in the human thyroarytenoid muscle.

BACKGROUND: Muscle fiber regeneration is essential to maintain normal muscle fiber populations and muscle mass by continuous replacement of fibers lost to acute muscle injury or overuse. However, the extent of ongoing muscle fiber regeneration in the laryngeal muscles is unknown. OBJECTIVE: The present study provides statistically unbiased, quantitative estimates of the content of regenerating fibers in the human thyroarytenoid muscle over the adult lifespan. DESIGN: In the adult, only regenerating muscle fibers express the developmental myosin isoform. Therefore, regenerating fibers were identified using immunohistochemical techniques. The content of regenerating muscle fibers in the entire muscle volume was then estimated using stereological techniques. Through the use of a computer-automated sampling protocol, stereological data were collected from sets of isotropic uniform random cryostat sections. Overprojection error was minimized by using a confocal laser-scanning microscope to image thin optical sections for use as sample fields. SUBJECTS: Eight autopsy cases, subjects ranging in age from 19 to 81 years. RESULTS: The summed length of fibers expressing developmental myosin increased significantly (P=.02) with age when compared with the overall muscle fiber length. CONCLUSIONS: This finding indicates that muscle fibers maintain the capability for spontaneous regeneration, and that the proportion of regenerating fibers increases as the thyroarytenoid muscle ages. This increase is possibly a compensatory response to an age-related increase in muscle fiber injury or death.

Adult↗

PubMed1983

Vectorelectronystagmography. A new analysis technique.

We propose herein a new system of derivation for vectorelectronystagmography that minimizes the errors in interpretation of eye movement from the experimental data. The conventional three-point analysis may result in errors as large as 35% in comparison with the proposed technique.

Electronystagmography↗

PubMed1999

Allocation of inner cell mass and trophectoderm cells to the preimplantation blastocyst of the domestic ferret, Mustela putorius furo.

The growth of ferret preimplantation blastocysts in vivo, collected between 156 and 240 hr post coitum, was investigated. A technique, combining immunosurgery and differential fluorochrome staining, was used to discriminate between inner cell mass (ICM) and trophectoderm (TE) cells. Using the stains propidium iodide and bisbenzimide (Hoechst 33342), the ICM was stained blue and the TE was stained pink. The ICM and TE counts for 90 blastocysts, respectively, averaged 25 and 63 at 156 hr and increased exponentially to 2077 and 4137 at 240 hr. The Box-Cox procedure was used for choosing a transformation that minimized the error sum of squares for a linear regression of Y (cell count) on X (time in hr). Logarithmic transformations of the ICM, TE and total cell count gave a good fit, but the following equations obtained by the Box-Cox procedure provided the best fit, where Y is cell count and X is time in hours. For inner cell mass: Y = [(176.06 + 2.45X)/-899.44 + 1]-3.33; trophectoderm: Y = [(301.38 + 14.48X)/-6863.42 + 1]-10; and total: Y = [(2266.97 + 17.0X)/-7837.21 + 1]-5. The R2 values were 0.73, 0.84, and 0.84, respectively. The exponential growth of the ferret embryo during the time interval that measurements were made fits the general pattern described for other mammalian embryos. This report is the first to characterize the pattern of cell allocation and growth in preimplantation blastocysts of the ferret, and the first such report for a carnivore. The pattern of in vivo development provides a standard for judging the quality of in vitro produced and matured ferret embryos and, concomitantly, a means to evaluate culture systems.

Animals↗