Echo-Doppler ultrasonographic assessment of resistance and velocity of blood flow in the ductus venosus throughout gestation in fetal lambs.

It has been postulated that during fetal hypoxia, the blood flow shunted through the ductus venosus increases and may account for upto 70% of the total umbilical flow. The objectives of the present study were to use ultrasonography to determine the velocities and waveform indices of blood flow in the ductus venosus in the fetal lamb. The ductus venosus of 15 lamb fetuses was evaluated weekly from Days 45 to 143 of gestation (Day 0=day of AI). The Doppler indices measured were: S/D, the systole/diastole ratio; RI, the resistance index; and PI, the pulsatility index. The velocity waveforms studied were: SV, the peak velocity during ventricular systole; D, the peak velocity during ventricular diastole; aV, the lowest forward velocity during atrial contraction; and TAMV, the time-averaged maximum velocity. Doppler indices from Days 52 to 143 were highly correlated: S/D versus PI (r=0.96, P<0.0001), and versus RI (r=0.93, P<0.0001); and PI versus RI (r=0.97, P<0.0001). Velocity indices were also positively correlated: velocity SV versus D (r=0.87, P<0.0001), versus aV (r=0.79, P<0.05), and versus TAMV (r=0.98, P<0.0001); D versus aV (r=0.88, P<0.05), and versus TAMV (r=0.87, P<0.05); and aV versus TAMV (r=0.82, P<0.05). Doppler indices were negatively correlated with SV (r=-0.22, P<0.03); D (r=-0.37, P<0.0001); TAMV (r=-0.32, P<0.05) and with aV (r=-0.67, P<0.05). The mean value of each Doppler index decreased 40% from Days 52 to 73 (e.g., PI from 0.82+/-0.08 to 0.51+/-0.10; P<0.05), with no significant changes thereafter. Mean (+/-S.E.M.) values of velocity indices SV, D, aV, and TAMV rose twofold from Days 60 to 115 of gestation (e.g., SV from 54.4+/-8.8cm/s to 104.9+/-19.7 and aV from 24.8+/-6.9 to 54.9+/-5.9; P<0.05). In conclusion, Doppler ultrasonography facilitated assessment of the blood flow pattern in the ductus venosus in lamb fetuses between Days 52 and 143.

How healthy are clones and their progeny: 5 years of field experience.

There is considerable concern regarding the health of cloned cattle and their safety as a source of food. The objective was to summarize 5 years of commercial experience with cloning in three countries (United States, Argentina and Brazil). Overall, only 9% of transferred embryos resulted in calves; efficiency ranged from 0 to 45% (most were from 1 to 10%, but 24% of cell lines never produced live calves). There was no significant difference in pregnancy rate following transfer of one versus two embryos. Before 90 days of gestation, two ultrasound markers for embryo death were found, either crown rump length (CRL) or heart beat less than 7.5mm and 150bpm, respectively, were observed alone or together in 27% of clones that died. In addition, after 100 days of pregnancy, placental edema, hydrops fetalis and increased abdominal circumference size were used as ultrasound findings of a fetus at risk of loss. At 114 days of gestation, abdominal circumference in clones that died was statistically larger than in clones that survived alive to term and from MOET- and IVF-derived pregnancies (P<0.05). Since elective cesarean section (C-section) was partially replaced by natural or assisted parturition, C-section rates decreased from 100% in 2000 to 54% in 2005. On average, 42% of cloned calves died between delivery and 150 days of life; the most common abnormalities were: enlarged umbilical cord (37%), respiratory problems (19%), calves depressed/prolonged recumbency (20%) and contracted flexor tendons (21%). From 11 blood parameters evaluated during the first week of life, lactate decreased twice and glucose doubled its original value from 24h to 7 days. Adult cloned females had normal breeding and calving rates and cloned bulls produced good quality semen and had normal fertility when used for AI or natural mating. In conclusion, cloning had no risks qualitatively different from those encountered in animals involved in modern agricultural practices, although the frequency of the risks appeared to be increased in cattle during the early portions of the life cycle of cattle clones.

Effectiveness of the Michigan splint in reducing functional cervical disturbances: a preliminary study.

There is controversial evidence for a functional link between the masticatory apparatus and the cervical spine. The aim of this work was to perform a preliminary study to evaluate the effectiveness of the Michigan splint for the treatment of functional cervical disturbances. Forty patients with functional cervical disturbances were randomly organized into test and control groups. The patients in each group were examined by a physiologist to ascertain the extent of functional changes. The test group underwent splint therapy (Michigan type) during a two-month period. The other patients were sent home and did not receive active treatment. After two months, all patients were reassessed physiologically. Cervical pain and pain induced by epispinal or paraspinal pressure were reduced to a statistically significant extent in the treated group, compared with those in the control group.

The New Zealand accreditation programme: not "re-inventing the wheel".

In some nine months, a remarkable development has occurred in New Zealand. During this period, a pilot Accreditation Programme has been established, four hospitals have been selected and their staff introduced to the programme and a co-ordinating framework has been developed. The ACHS has and will be supportive of these and subsequent developments. The ACHS expects to gain valuable information from this well-formulated pilot project.

Further evidence for behaviorly induced hypoxic conditions in subordinate mice.

When two male mice fight to establish social rank, the subordinate exhibits marked splenomegaly, reticulocytosis and decreased hematocrit. Individuals were isolated at weaning, paired 3 weeks later for two 30-min encounter periods daily for up to 3 weeks. After 2 days and 1 week encounter periods, subordinates had significantly decreased levels of hemoglobin in the kidney compared to dominants and controls. Subordinates had increased ATP levels in blood after 1, 2 and 3 weeks of encounter, bone marrow erythroid hyperplasia, as well as a substantial increase in the erythropoietin titre and Fe99 incorporation in spleen and blood.