Ultrasonographic evaluation of fetal development in the rat.

The study objectives were to measure gestational sac (GS) diameter and crown-to-rump (CR) length in conscious pregnant rats and to determine the chronological ultrasonographic appearance of heart beat and fetal organogenesis. The study formed part of a unilateral surgical salpingectomy trial with 16 female Sprague-Dawley rats (Rattus norvegicus). Ten rats were operated on while the other six served as controls. After surgery all were mated at 8-10 weeks of age. Gestational length was taken as 22 days. Rats were manually restrained for abdominal ultrasonography and were scanned daily from day 7 until day 19 or 20 post-mating followed by immediate euthanasia. Measurements' were taken from two GSs per rat. The presence of several early GSs in a row were described as a "string of pearls". As a fetus developed features of organogenesis were recorded. There was no significant difference in GS diameters and CR length between the test and control groups. Mean GS diameters ranged from 2.9 mm (day 7) to 18.1 mm (day 20). A string of pearls was seen on days 8-11. The CR length ranged from 1.6 mm (day 11) to 26.4 mm (day 20). A heart beat was first seen on day 11 and the echogenic vertebral column at day 14-15. From day 16, ribs, feet and the isoechoic lungs and liver were seen. The lungs became hyperechoic to the liver from day 18-19. The tail and mandible were visible on day 18 and the aorta and caudal vena cava were seen on day 19, as well as an occasional bladder. These measurements and staged in utero ultrasonographic appearance of various organ and skeletal structures will assist in a reasonably accurate prediction of the day of impending parturition by laboratory personnel and researchers.

Ultrasonographic and laparoscopic evaluation of the reproductive tract in older captive female cheetahs (Acinonyx jubatus).

The study uniquely described the clinical value of transabdominal ultrasonography for monitoring features characterizing the estrous cycle in female cheetahs (Acinonyx jubatus). The reproductive tracts of 21 female, nulliparous, and relatively aged (median: 11 and interquartile range: 9.25-14 years) captive cheetahs resident on two sites in Namibia were assessed by transabdominal ultrasound. Subsequently, the ovarian findings on ultrasound were compared with direct visualization while performing laparoscopic sterilization. A combination of these observations supported by concurrent sampling for vaginal cytology and serum progesterone concentrations defined the estrous status of individual animals. At one site, six cheetahs had been implanted with the GnRH agonist, deslorelin as a contraceptive at least once within the preceding 11 years. On ultrasound, 31 uterine horns and 35 ovaries with discernible structures on 28 (86%) were visualized in the 21 cheetahs. The uterine body was difficult to visualize because of its intrapelvic location. Eleven of 19 uteri (58%) visualized showed endometrial edema suggestive of estrogenization. The uteri of four cheetahs (19%) showed evidence of mild cystic endometrial hyperplasia. Paraovarian cysts were seen on ultrasound (n = 21) and laparoscopy (n = 26) in 16 (76.2%) and 18 (85.7%) cheetahs, respectively. Ovarian volumes obtained from ultrasonographically determined dimensions predicted cyclic activity. Laparoscopy showed that 19 ovaries had discernible follicular structures. In the study population, 10 (47.6%) cheetahs were in proestrus or estrus; none in the luteal phase; and 11 (52.4%) in anestrus. Transabdominal ultrasound, in combination with serum progesterone concentrations and vaginal cytology, was used with acceptable accuracy to assess cyclic ovarian activity in captive cheetahs. A considerable proportion of this aged population showed ovarian activity and the prevalence of paraovarian cysts was notable. A history of prior deslorelin treatment was not associated with either reproductive activity or uterine pathology.

Congenital pyloric mucosal fold resulting in an antral valve outflow obstruction in a bull terrier.

An under-sized three-month-old female bull terrier was referred with a history of regurgitation since three days of age. Thoracic radiographs were unremarkable, while abdominal radiographs showed a distended stomach, despite a 12 hour fast. Abdominal ultrasonography revealed gastric outflow obstruction of unclear aetiology. Coeliotomy was performed, during which an excessive mucosal fold at the pyloric antrum was excised. Histopathology of the pyloric fold revealed mild oedema and fibrosis of the mucosal tissue. The dog made a complete recovery, with resolution of regurgitation and grew to within the expected breed size. In the authors' opinion, this is the first canine report of congenital antral mucosal valve resulting in gastric outflow obstruction, and only the second report in any species.

Inter-individual variability among the mechanomyographic and electromyographic amplitude and mean power frequency responses during isometric ramp muscle actions.

The purpose of this study was to examine the inter-individual variability in the patterns of responses for mechanomyographic (MMG) and electromyographic (EMG) amplitude and mean power frequency (MPF) of the vastus lateralis (VL) and rectusfemoris (RF) muscles during isometric ramp muscle actions of the leg extensors. Fifteen participants (mean +/- SD age = 24 +/- 4 years) performed two or three 6-s isometric ramp muscle actions with linear increases in torque from 15% to 90% of the highest maximal voluntary contraction (MVC) torque. Surface MMG and EMG signals were simultaneously recorded from the VL and RF muscles. The composite (averaged across subjects) and individual patterns of responses for the normalized MMG and EMG amplitude and MPF vs. isometric torque relationships were analyzed. The composite patterns for MMG amplitude for the VL and RF muscles were fit with cubic models, although, only 87% of the individual patterns (13 of 15 subjects) exhibited the same cubic pattern as the composite. For MMG MPF, the composite relationships were also cubic, but only 27% (4 subjects) and 40% (6 subjects) of the individuals exhibited the same patterns for the VL and RF respectively. 60% (8 subjects) of the individual EMG amplitude patterns of responses matched the same curvilinear composite patterns for the VL and RE, while only 7% (1 subject) and 27% (4 subjects) of the EMG MPF responses were similar to the composite models for the VL and RF muscles, respectively. Therefore, since the individual patterns did not always match the composite relationships (i.e., inter-individual variability), these findings suggested that the MMG and EMG amplitude and MPF vs. isometric torque relationships should be examined on a subject-by-subject and muscle-by-muscle basis during isometric ramp muscle actions.

Frequency and CT findings of recurrent disease after lung transplantation.

PURPOSE: To determine the frequency and computed tomographic (CT) findings of recurrence of the primary disease after lung transplantation at six North American lung transplantation centers. MATERIALS AND METHODS: Medical records of 1,394 lung transplant recipients were reviewed to identify patients with recurrent primary disease. Their CT scans and pathologic specimens were reviewed. RESULTS: The frequency of disease recurrence in the six transplantation centers was 1% (15 of 1,394 patients), including six previously reported cases. Sarcoidosis recurred in nine (35%) of 26 transplants and was the most common disease to recur. Three (33%) of nine patients with recurrent sarcoidosis had correlative findings at CT. When present, CT findings were usually different at recurrence compared with pretransplantation CT findings. CONCLUSION: A relatively small percentage of patients are at risk for recurrence of primary disease following lung transplantation. Sarcoidosis is the most common disease to recur.

Anatomic site and immune function correlate with relative cytokine mRNA expression levels in lymphoid tissues of normal rhesus macaques.

Reverse transcriptase real-time polymerase chain reaction was used to determine pro-inflammatory, anti-viral and immunoregulatory cytokine mRNA expression levels in peripheral blood mononuclear cells (PBMC) of healthy juvenile, adolescent and adult rhesus macaques. Few age-related changes in cytokine mRNA expression levels were observed. Expression of interleukin 2 and Mx, a type I interferon-inducible gene, decreased with age, whereas interleukin 4 and macrophage inflammatory protein 1 (MIP-1) alpha and beta mRNA levels increased in older monkeys. Independent of age, the pro-inflammatory cytokines [tumour necrosis factor alpha (TNF-alpha) and chemokines] were expressed at higher mRNA levels in PBMC than the immunoregulatory cytokines (interleukins 2, 4, 12). Pro-inflammatory cytokine mRNA expression levels were highest in lymphoid tissues draining mucosal surfaces. Thus, a correlation exists between cytokine mRNA levels in lymphoid tissues and the anatomical site.

Evaluation of intraoperative nerve-monitoring during insertion of an iliosacral implant in an animal model.

BACKGROUND: The use of continuous electromyographic and somatosensory-evoked-potential monitoring systems has been advocated to assist in avoiding nerve-root injury during operations on the pelvic ring. More recently, it was suggested that stimulus-evoked electromyographic monitoring may further decrease the risk of iatrogenic nerve-root injury during posterior pelvic fixation by enabling the surgeon to determine the actual distance of an implant from a nerve root. The purpose of the current study was to evaluate the relative efficacy of these three methods of monitoring for minimizing the risk of neural injury during the placement of iliosacral implants. METHODS: While the function of the first sacral nerve root was monitored with the use of stimulus-evoked electromyographic, continuous electromyographic, and somatosensory-evoked-potential monitoring techniques, a 2.0-millimeter stainless-steel Kirschner wire was progressively inserted, guided by a high-speed computerized tomographic scanner, into the first sacral body of seventeen hemipelves in nine dogs. The end point was contact with the nerve as demonstrated by the computerized tomographic images. It was expected that this end point would be heralded by a burst of spontaneous electromyographic activity and an abnormal somatosensory-evoked-potential signal. Anatomical dissection at the completion of the study documented the final position of the Kirschner wire. RESULTS: Anatomical dissection demonstrated compression or penetration of the nerve root in sixteen of the seventeen specimens. A spontaneous burst of electromyographic activity was not recorded for any specimen on continuous electromyographic monitoring; this finding was significantly different from what had been expected (p<0.001). Because of technical problems, somatosensory evoked potentials could be recorded for only twelve hemipelves that had nerve-root compression or penetration, and abnormal somatosensory evoked potentials were recorded for only one of the twelve; this finding was significantly different from what had been expected (p<0.001). A total of 113 stimulus-evoked electromyographic data points were obtained. The correlation coefficient for the relationship between the current threshold recorded with stimulus-evoked electromyographic monitoring and the distance of the wire from the nerve was 0.801 (p<0.001). The actual measured current thresholds were of an observed proportion not different from what had been expected (p = 0.48). CONCLUSIONS: Continuous electromyographic and somatosensory-evoked-potential monitoring techniques failed to indicate contact with the nerve root reliably in this animal model. However, stimulus-evoked electromyographic monitoring consistently provided reliable information indicating the proximity of the implant to the nerve root.

A two-dimensional YAC pooling strategy for library screening via STS and Alu-PCR methods.

We have developed a simple two-dimensional YAC pooling strategy to facilitate YAC library screening via STS and Alu-PCR approaches. The method has been implemented using the human total genomic YAC library of Olson and coworkers, and its validity tested by isolation of many chromosomes 19- and 21-specific YACs. The Alu-PCR approach is notable in that it is hybridization-based, such that PCR primer pairs do not need to be repeatedly synthesized and tested for each screening step.