Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
1.
Anim Reprod Sci ; 148(3-4): 245-50, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25015846

ABSTRACT

This study provides standard information on the attributes of sperm and describes the surface structure of normal and abnormal spermatozoa of Rusa timorensis. Two fertile stags were used as the source of semen collected during the first breeding season commencing from April 5 to July 2, 2012. Another five stags were used as the source of semen collected during the second breeding season commencing from April 1 to June 27, 2013. Semen samples were collected from the stags using an electro-ejaculator. The ejaculate was processed and samples prepared for light and scanning electron microscopy (SEM) according to standard methods. No significant difference (P>0.05) was found between sperm attributes in comparison between different stags and different months of the fertile seasons. The results of this study have also demonstrated that there are no differences in size, shape and surface structure between spermatozoa of the different stags and different months of the fertile seasons. Sperm attributes (volume, pH, sperm concentration, general motility, progressive motility and viability) were 2.2±0.29 ml, 7.2±0.17, 886.3±39.7×10(6) spermatozoa/ml, 78.7±2.01%, 80.8±1.85% and 83.2±0.85%, respectively. Morphological analysis showed low percentage of abnormal spermatozoa 13.9±2.88%. Scanning electron microscopy revealed spermatozoa which consisted of a flat paddle-shaped head, short neck and a tail, which was subdivided into midpiece, principal piece and endpiece. The average spermatozoon was 66.2±0.69 µm in total length. The flat paddle-shaped head was 7.8±0.28 µm long, 4.2±0.15 µm at its widest width, 2.4±0.18 µm basal width and 0.7±0.0 2µm thick. As for the tail, the midpiece length was 13.2±0.14 µm, 0.6±0.04 µm in diameter; the principal piece was 42.6±0.04µm, and 2.8±0.06 µm for the endpiece. Abnormal spermatozoa such as tapered head, microcephalic head, decapitated spermatozoa and bent tails were observed. Results provide standard information useful for development of strategies for semen cryopreservation and assisted reproductive technology in this species.


Subject(s)
Deer , Semen Analysis , Spermatozoa/cytology , Spermatozoa/ultrastructure , Animals , Male , Microscopy, Electron, Scanning , Microscopy, Polarization , Semen Analysis/veterinary , Sperm Head/ultrastructure , Sperm Midpiece/ultrastructure , Spermatozoa/abnormalities
3.
Anim Reprod Sci ; 141(3-4): 148-53, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24012278

ABSTRACT

A study was conducted to profile the plasma progesterone (P4) concentrations and establish the length of oestrous cycle in the Rusa timorensis during the breeding season. Five healthy hinds were selected for peripheral blood sampling twice weekly to gauge the P4 levels by radioimmunoassay, at the start of the breeding season indicated by rutting behaviours of sexually active males. The hinds were polyestrous as proven by the cyclic trend of P4 levels. After the presumptive oestrus indicated by the lowest P4 concentrations (0.20±0.09ng/ml), this ovarian hormone was markedly elevated on day 7 of the cycle (0.78±0.20ng/ml), reached its peak (2.61±0.23ng/ml, P<0.05) on day 14, and then declined to the basal level in the subsequent oestrus. The mean oestrous cycle length in R. timorensis during the breeding season was 19.2 days with a range of 18-21 days, and the pattern of circulating progesterone during the oestrous cycle of the R. timorensis is similar to those of other deer species. It was also observed that the length of oestrous cycle of R. timorensis determined by gauging the progesterone levels and observation of the oestrous behaviours as well as changes in the cellular pattern of vaginal epithelial cells are highly consistent.


Subject(s)
Deer/blood , Deer/physiology , Estrous Cycle/blood , Estrous Cycle/physiology , Progesterone/blood , Animals , Estrus/physiology , Female , Time Factors
4.
Clin Radiol ; 68(9): e502-10, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23706826

ABSTRACT

AIM: To investigate the diagnostic accuracy of single-voxel proton magnetic resonance spectroscopy (SV (1)H MRS) by quantifying total choline-containing compounds (tCho) in differentiating malignant from benign lesions, and subsequently, to analyse the relationship of tCho levels in malignant breast lesions with their histopathological subtypes. MATERIALS AND METHODS: A prospective study of SV 1H MRS was performed following dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in 61 women using a 3 T MR system. All lesions (n = 57) were analysed for characteristics of morphology, contrast-enhancement kinetics, and tCho peak heights at SV (1)H MRS that were two-times above baseline. Subsequently, the tCho in selected lesions (n = 32) was quantified by calculating the area under the curve, and a tCho concentration equal to or greater than the cut-off value was considered to represent malignancy. The relationship between tCho in invasive ductal carcinomas (IDCs) and their Bloom & Richardson grading of malignancy was assessed. RESULTS: Fifty-two patients (57 lesions; 42 malignant and 15 benign) were analysed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), of predicting malignancy were 100, 73.3, 91.3, and 100%, respectively, using DCE-MRI and 95.2, 93.3, 97.6, and 87.5%, respectively, using SV (1)H MRS. The tCho cut-off for receiver operating characteristic (ROC) curve was 0.33 mmol/l. The relationship between tCho levels in malignant breast lesions with their histopathological subtypes was not statistically significant (p = 0.3). CONCLUSION: Good correlation between tCho peaks and malignancy, enables SV (1)H MRS to be used as a clinically applicable, simple, yet non-invasive tool for improved specificity and diagnostic accuracy in detecting breast cancer.


Subject(s)
Breast Neoplasms/diagnosis , Carcinoma, Ductal, Breast/diagnosis , Protons , Adult , Aged , Aged, 80 and over , Breast/chemistry , Choline/analysis , Early Detection of Cancer/methods , Female , Humans , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy/methods , Middle Aged , Prospective Studies , Sensitivity and Specificity , Young Adult
5.
Phys Med Biol ; 56(6): 1743-53, 2011 Mar 21.
Article in English | MEDLINE | ID: mdl-21346279

ABSTRACT

The objective of this work was to propose and demonstrate a novel technique for the assessment of tumour pharmacokinetic parameters together with a regionally estimated vascular input function. A breast cancer patient T2*-weighted dynamic contrast enhanced MRI (DCE-MRI) dataset acquired at high temporal resolution during the first-pass bolus perfusion was used for testing the technique. Extraction of the lesion volume transfer constant K(trans) together with the intravascular plasma volume fraction v(p) was achieved by optimizing a capillary input function with a measure of cardiac output using the principle of intravascular indicator dilution theory. For a region of interest drawn within the breast lesion a v(p) of 0.16 and a K(trans) of 0.70 min(-1) were estimated. Despite the value of v(p) being higher than expected, estimated K(trans) was in accordance with the literature values. In conclusion, the technique proposed here, has the main advantage of allowing the estimation of breast tumour pharmacokinetic parameters from first-pass perfusion T2*-weighted DCE-MRI data without the need of measuring an arterial input function. The technique may also have applicability to T1-weighted DCE-MRI data.


Subject(s)
Breast Neoplasms/pathology , Cardiac Output/physiology , Contrast Media , Magnetic Resonance Imaging/methods , Breast Neoplasms/metabolism , Contrast Media/pharmacokinetics , Coronary Circulation , Female , Humans , Middle Aged , Models, Biological , Pilot Projects
6.
Phys Med Biol ; 55(1): 121-32, 2010 Jan 07.
Article in English | MEDLINE | ID: mdl-20009182

ABSTRACT

The purpose of this work is to quantify the accuracy of pharmacokinetic parameter measurement in DCE-MRI of breast cancer at 3 T in relation to three sources of error. Individually, T1 measurement error, temporal resolution and transmitted RF field inhomogeneity are considered. Dynamic contrast enhancement curves were simulated using standard acquisition parameters of a DCE-MRI protocol. Errors on pre-contrast T1 due to incorrect RF spoiling were considered. Flip angle errors were measured and introduced into the fitting routine, and temporal resolution was also varied. The error in fitted pharmacokinetic parameters, K(trans) and v(e), was calculated. Flip angles were found to be reduced by up to 55% of the expected value. The resultant errors in our range of K(trans) and v(e) were found to be up to 66% and 74%, respectively. Incorrect T1 estimation results in K(trans) and v(e) errors up to 531% and 233%, respectively. When the temporal resolution is reduced from 10 to 70 s K(trans) drops by up to 48%, while v(e) shows negligible variation. In combination, uncertainties in tissue T1 map and applied flip angle were shown to contribute to errors of up to 88% in K(trans) and 73% in v(e). These results demonstrate the importance of high temporal resolution, accurate T1 measurement and good B1 homogeneity.


Subject(s)
Breast Neoplasms/metabolism , Breast/metabolism , Contrast Media/pharmacokinetics , Magnetic Resonance Imaging/methods , Algorithms , Breast Neoplasms/diagnosis , Computer Simulation , Female , Humans , Time Factors
7.
Australas Phys Eng Sci Med ; 30(4): 288-91, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18274069

ABSTRACT

Percutaneous image-guided needle biopsy is typically performed in highly vascular organs or in tumours with rich macroscopic and microscopic blood supply. The main risks related to this procedure are haemorrhage and implantation of tumour cells in the needle tract after the biopsy needle is withdrawn. From numerous conducted studies, it was found that heating the needle tract using alternating current in radiofrequency (RF) range has a potential to minimize these effects. However, this solution requires the use of specially designed needles, which would make the procedure relatively expensive and complicated. Thus, we propose a simple solution by using readily available coaxial core biopsy needles connected to a radiofrequency ablation (RFA) generator. In order to do so, we have designed and developed an adapter to interface between these two devices. For evaluation purpose, we used a bovine liver as a sample tissue. The experimental procedure was done to study the effect of different parameter settings on the size of coagulation necrosis caused by the RF current heating on the subject. The delivery of the RF energy was varied by changing the values for delivered power, power delivery duration, and insertion depth. The results showed that the size of the coagulation necrosis is affected by all of the parameters tested. In general, the size of the region is enlarged with higher delivery of RF power, longer duration of power delivery, and shallower needle insertion and become relatively constant after a certain value. We also found that the solution proposed provides a low cost and practical way to minimizes unwanted post-biopsy effects.


Subject(s)
Biopsy, Needle/instrumentation , Radiofrequency Therapy , Animals , Biopsy, Needle/adverse effects , Biopsy, Needle/economics , Cattle , Costs and Cost Analysis , Hot Temperature/therapeutic use , Humans , Neoplasm Seeding , Neoplasms/diagnosis , Postoperative Hemorrhage/prevention & control , Surgery, Computer-Assisted
8.
Australas Phys Eng Sci Med ; 29(3): 278-80, 2006 Sep.
Article in English | MEDLINE | ID: mdl-17058591

ABSTRACT

Illuminance level in the softcopy image viewing room is a very important factor to optimize productivity in radiological diagnosis. In today's radiological environment, the illuminance measurements are normally done during the quality control procedure and performed annually. Although the room is equipped with dimmer switches, radiologists are not able to decide the level of illuminance according to the standards. The aim of this study is to develop a simple real-time illuminance detector system to assist the radiologists in deciding an adequate illuminance level during radiological image viewing. The system indicates illuminance in a very simple visual form by using light emitting diodes. By employing the device in the viewing room, illuminance level can be monitored and adjusted effectively.


Subject(s)
Environmental Monitoring/instrumentation , Lighting/instrumentation , Photometry/instrumentation , Radiology/instrumentation , Transducers , Environmental Monitoring/methods , Equipment Design , Equipment Failure Analysis , Photometry/methods , Radiology/methods
SELECTION OF CITATIONS
SEARCH DETAIL
...