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C J Morrow

Publications and source records attributed to C J Morrow.

At least 37 records · Page 2Linked to original sources
PubMed1994

In vivo formation of 25-hydroxycholesterol from endogenous cholesterol after a single meal, dietary cholesterol challenge.

The role of oxysterols as regulatory molecules in the suppression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity was investigated in the intact rat in response to an acute dietary cholesterol challenge. When rats were fed highly purified cholesterol as a single meal at a level of 5% of the diet, maximal inhibition of enzyme activity (66%) occurred 120 min after the completion of the meal. Furthermore, when nonsaponifiable liver extracts were chromatographically resolved and analyzed by high performance liquid chromatography (HPLC) and capillary gas chromatography-mass spectrometry (GC-MS), 25-hydroxycholesterol was identified in the livers of rats 120 min after the completion of the single cholesterol meal. Significantly, only barely detectable amounts of 25-hydroxycholesterol were observed in the livers from control rats fed a sterol-free diet. The biosynthetic origin of 25-hydroxycholesterol was investigated with the use of deuterated water. Rats were fed deuterium oxide (33%) ad libitum for 3 days and then killed 120 min after the completion of a single cholesterol meal. As before, 25-hydroxycholesterol was detected in the livers from cholesterol-fed rats, but not to a significant extent in livers from control-fed rats receiving a sterol-free diet. Isotope ratio mass spectrometry revealed that the fractional incorporation of deuterium into 25-hydroxycholesterol (21%) was less than that observed for cholesterol (24%) isolated from the same livers, indicating that 25-hydroxycholesterol was produced endogenously from exogenous cholesterol and not from autoxidation of cholesterol. In a separate experiment it was also shown that [3H]mevalonate was incorporated into 25-hydroxycholesterol after a single meal cholesterol challenge, but was barely detected in the livers of control rats. The evidence obtained in the present article supports the hypothesis that 25-hydroxycholesterol is endogenously produced from cholesterol at early time intervals after an acute dietary cholesterol challenge. In addition, rat liver HMG-CoA reductase was inhibited by the administration of a single intragastric dose (1 microgram/kg) of an aqueous solution of 25-hydroxycholesterol. Thus, the results provide strong support for the conclusion that 25-hydroxycholesterol plays a significant role in the in vivo regulation of rat liver cholesterol biosynthesis after an acute dietary cholesterol challenge.

Animals↗
PubMed1992

Laparoscopic intra-uterine insemination of fallow deer with frozen-thawed or fresh semen after synchronisation with CIDR devices.

This study investigated the efficacy of fixed-time laparoscopic intra-uterine insemination of farmed fallow deer (Dama dama) with frozen-thawed or fresh semen. In the trials with frozen-thawed semen, a total of 547 mature non-lactating does across five New Zealand farms were used. For oestrous synchronisation and artificial insemination, a standard control regimen was applied to at least 30% of the does on each farm, involving the insertion of single CIDR type-G devices intravaginally for 14 days, deposition of 50 x 10(6) frozen-thawed spermatozoa at 65 hours after withdrawal of the CIDR device and the continuous presence of vasectomised bucks from the insertion of the CIDR device until 10 days after insemination. Various aspects of this protocol were changed for the remaining does on each farm, including inseminations at 60 or 70 hours, the absence of vasectomised bucks, insemination with 25 x 10(6) or 10 x 10(6) spermatozoa, synchronisation with CIDR type-S devices and synchronisation with prostaglandin. The conception rate, based on rectal ultrasonography at 45 days after insemination, was 67% across all treatments (n=547). Corrected conception rates (+/-s.e.), calculated following between-farm adjustments, were 67+/- 3% for the control regimen, 67+/- 9% and 73 +/- 8% for inseminations at 60 and 70 hours respectively, 61 +/- 9% for absence of bucks, 80 +/- 8% and 74 +/- 9% for inseminations with 25 x 10(6) and 10 x 10(6) spermatozoa respectively, 62 +/- 10% for CIDR type-S device synchronisation, and 49 +/- 10% for prostaglandin synchronisation. Despite apparent differences, none of the treatments resulted in adjusted conception rates that were significantly different from the control regimen (P>0.01). In the trials with fresh semen, 216 does in the USA were inseminated at 69-71 hours after withdrawal of the CIDR device using either cryopreserved semen from New Zealand (n=158; 25 x 10(6) spermatozoa per inseminate) or fresh semen (n=58; 7.5 x10(6) to 20 x 10(6) spermatozoa per inseminate) collected less than 10 hours earlier. The overall conception rates were 77% and 81% respectively, with no significant differences between semen type (frozen v. fresh) or fresh spermatozoa number per inseminate (P>0.01). A further 102 does in New Zealand similarly received fresh semen from 3/4 Mesopotamian buck. Doses of 10 x 10(6) (n=35), 5 x 10(6) (n=32) or 2.5 x 10(6) (n=35) spermatozoa per inseminate were delivered at 69-71 hours after withdrawal of the CIDR device. The conception rates were 77%, 66% and 51% respectively, reflecting a dose effect (P<0.05). However, 1/4 Mesopotamian does in the group (n=19) exhibited higher conception rates (95% overall) irrespective of semen dose, possibly indicating a semen/recipient genotype interaction. It is concluded that laparoscopic intra-uterine insemination of fallow deer with frozen-thawed or fresh semen at fixed intervals after removal of a CIDR device can give acceptable conception rates under a range of on-farm management options and semen doses.

Journal Article↗
PubMed1992

Effect of progesterone and oestradiol benzoate on oestrous behaviour and secretion of luteinizing hormone in ovariectomized fallow deer (Dama dama).

Eighteen ovariectomized fallow deer does and two adult bucks were used to investigate the effect of exogenous progesterone and oestradiol benzoate on oestrous behaviour and secretion of luteinizing hormone (LH). In Expts 1 and 2, conducted during the breeding season (April-September), does were treated with intravaginal Controlled Internal Drug Release (CIDR) devices (0.3 g progesterone per device) for 12 days and differing doses of oestradiol benzoate administered 24 h after removal of the CIDR device. The dose had a significant effect on the proportion of does that exhibited oestrus within the breeding season (P less than 0.001), the incidence of oestrus being 100% with 1.0, 0.1 and 0.05 mg, 42% for 0.01 mg and 0% for 0.002 mg oestradiol benzoate. There was a significant log-linear effect of dose on the log duration of oestrus, which was 6-20, 2-14, 2-12 and 2 h after treatment with 1, 0.1, 0.05 and 0.01 mg of oestradiol benzoate, respectively. Dose had a significant effect on the peak plasma LH concentration (P less than 0.01), mean (+/- s.e.m.) surge peaks of 27.7 +/- 2.3, 25.9 +/- 1.8 and 18.6 +/- 3.4 ng/ml being observed following treatment with 1, 0.1 and 0.01 mg oestradiol benzoate respectively. In Expt 3, also conducted during the breeding season, progesterone treatment (0 vs. 6-12 days) before the administration of 0.05 mg oestradiol benzoate had a significant effect on the incidence of oestrus (0/6 vs. 10/12, P less than 0.05), but not on LH secretion. The duration of progesterone treatment (6 vs. 12 days) had no effect on oestrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Relationship between the onset of oestrus, the preovulatory surge in luteinizing hormone and ovulation following oestrous synchronization and superovulation of farmed red deer (Cervus elaphus).

The timing of ovulation relative to the onset of oestrus and the preovulatory surge in luteinizing hormone (LH) was studied in red deer following treatments to synchronize oestrus and induce either a monovulatory or superovulatory response. Mature hinds (n = 36) were allocated randomly to two mating groups (n = 16 + 20), with respective treatments staggered by 4 weeks during the 1990 rut (March-April). Each hind was treated with an intravaginal controlled internal drug releasing (CIDR)-type S device for 14 days. Treatments to induce a monovulatory response included CIDR device alone (treatment A; n = 4 + 8) and additional injection of 200 iu pregnant mares' serum gonadotrophin (PMSG) at device removal (treatment B; n = 4 + 4). Treatments to induce a superovulatory response included injections of 200 iu PMSG and 0.5 units ovine follicle-stimulating hormone (FSH) at about time of removal of CIDR devices (treatment C; n = 4 + 4) and further treatment with gonadotrophin-releasing hormone (GnRH) analogue 18 h after removal of CIDR devices (treatment D; n = 4 + 4). The hinds were run with crayon-harnessed stags from insertion of CIDR devices (12 March or 9 April) and blood samples were taken every second day to determine plasma progesterone. Further blood samples were collected for determination of plasma LH and progesterone via indwelling jugular cannulae every 2 h for 72 h from removal of CIDR devices. Hinds were allocated randomly to an initial ovarian examination by laparoscopy at either 16 or 20 h (A and B), or 12 or 16 h (C and D) after the onset of oestrus, with laparoscopy repeated at intervals of 8 h until either ovulation was recorded (A and B), or for four successive occasions (C and D). All hinds received cloprostenol injections 15 days after device removal. A total of 28 hinds (78%) exhibited oestrus and a preovulatory LH surge, with mean (+/- SEM) times to onset of oestrus of 44.6 +/- 1.0 h (A; n = 7), 37.4 +/- 2.0 h (B; n = 7), 16.3 +/- 1.7 h (C; n = 6) or 14.0 +/- 1.7 h (D; n = 8). Failure to exhibit oestrus or LH surge was most prevalent among hinds in treatment A early in the rut.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Comparison of Haemophilus paragallinarum isolates by restriction endonuclease analysis of chromosomal DNA.

Chromosomal DNA from Haemophilus paragallinarum was examined by restriction endonuclease analysis (REA) using the enzymes BamHI, EcoRI, HindIII, or SmaI. The enzyme SmaI had no apparent effect upon the DNA from eight representative H. paragallinarum isolates. The remaining enzymes cut the H. paragallinarum DNA to varying degrees, with the most useful patterns for distinguishing isolates being given by HindIII. The REA patterns given by HindIII were stable under both in vitro and in vivo conditions. The use of the enzyme HindIII showed that eight Australian isolates of H. paragallinarum were genetically similar. In contrast, 14 isolates of H. paragallinarum from outside Australia were markedly different from each other and the Australian isolates. A plasmid of approximately 6 kilobase pairs in size was found in one isolate of H. paragallinarum.

Animals↗
PubMed1990

Temporal relationship between the onset of oestrus, the preovulatory LH surge and ovulation in farmed fallow deer, Dama dama.

A study was conducted to determine the timing of ovulation relative to the onset of oestrus and the preovulatory LH surge in fallow deer. Mature fallow does were randomly allocated to two treatments (N = 10 per treatment) designed to synchronize oestrus on or about 17 May. Does assigned to Group 1 (prostaglandin-induced oestrus) each initially received single intravaginal CIDR [Controlled Internal Drug Release] devices for 13 days followed by an i.m. injection of 750 mg cloprostenol on Day 12 (15 May) of the subsequent luteal cycle. Does assigned to Group 2 (progesterone-induced oestrus) each received CIDR devices for 13 days, with withdrawal occurring on 15 May. All does were run with crayon-harnessed bucks (10:1 ratio) from the start of synchronization (18:00 h 15 May). Ten does (5 per group) were blood sampled via indwelling jugular cannulae every 2 h for 72 h from cloprostenol injection or CIDR device withdrawal and the plasma was analysed for concentrations of progesterone and LH by radioimmunoassay. Does within each treatment were randomly allocated to an ovarian examination time of 12, 16, 20 or 24 h after the onset of oestrus. Laparoscopy was repeated at 12-h intervals until ovulation was recorded. The ovaries of does failing to exhibit oestrus were examined 72 and 86 h after cloprostenol injection or CIDR device withdrawal. A total of 17 does were observed to exhibit oestrus at a mean (+/- s.e.m.) interval from treatment of 44.6 +/- 3.6 h for Group 1 (N = 9) and 34.1 +/- 2.5 h for Group 2 (N = 8).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Transcutaneous oxygen tension in preterm neonates during neonatal behavioral assessments and heelsticks.

This study evaluates the effects of neonatal behavioral assessments and heelsticks on transcutaneous oxygen tension (TcPO2) in 37 preterm neonates from a neonatal intensive care unit. Two behavioral assessments were evaluated, the Brazelton Neonatal Behavioral Assessment Scale (BNBAS) and the Neurobehavioral Assessment for Preterm Infants (NAPI). TcPO2 during heelsticks was used as a comparison because reliable decreases have typically been noted during heelsticks. Although the heelsticks resulted in significant declines in TcPO2, the behavioral assessments led to only negligible changes in TcPO2. Observed changes during the behavioral assessments occurred in a small number of infants, primarily during the few test procedures administered to the infants outside of their isolettes. Accordingly, it is suggested that time outside the isolette and associated temperature changes may be more critical variables than the assessments per se.

Arousal↗
PubMed1990

Isolation of Mycoplasma synoviae from infectious synovitis of chickens.

This report describes the first isolations of Mycoplasma synoviae from the synovial sheaths and joints of commercial chickens affected with synovitis in Australia. Over 4 years 3 separate outbreaks were investigated in which up to 20% of birds exhibited clinical signs of poor growth and "hot foot" syndrome (swollen inflamed footpads). Once an outbreak occurred, chronic infection of the farm usually ensued. Grossly the hocks and footpads were swollen by a purulent exudate and associated inflammatory changes with histological features of a severe acute synovitis. Seroconversion of the flocks occurred at the time of the development of lesions. M. synoviae specific antibodies were demonstrated by ELISA in the joint fluid of affected birds. It is concluded that the cases described are similar to avian infectious synovitis syndrome caused by M. synoviae previously described overseas.

Animals↗
PubMed1987

Holoprosencephaly in Border Leicester lambs.

Holoprosencephaly in Border Leicester lambs is described. This defect is characterised by lack of the longitudinal cerebral fissure, fusion of the cerebral hemispheres and a single lateral ventricle. Facial defects are also associated with this condition. Results of a breeding experiment suggest that it is inherited in an autosomal recessive manner. Results from a survey indicate that the condition is widespread in Border Leicester sheep.

Abnormalities, Multiple↗
PubMed1985

Isoprenoid synthesis in isolated embryonic Drosophila cells. Sterol-independent regulatory signal molecule is distal to isopentenyl 1-pyrophosphates.

Embryonic Drosophila cells (Kc cells) were used to further characterize sterol-independent modulation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity. 3-Methyl-3-5-dihydroxyvalerate (mevalonate), 3-fluoromethyl-3,5-dihydroxyvalerate (fluoromevalonate), and 3-ethyl-3,5-dihydroxyvalerate (homomevalonate) were tested as modulators. Although mevalonate caused a rapid, reversible suppression of reductase activity, fluoro- and homomevalonate increased activity; fluoromevalonate was more effective than homomevalonate. Mevalonate, added simultaneously with fluoromevalonate, blocked the analogue's effect on Kc cell reductase activity. However, mevalonate did not suppress an established fluoromevalonate increase in HMG-CoA reductase activity. Fluoromevalonate blocked [1-14C, 5-3H]mevalonate conversion to 14CO2- and 3H-labeled lipids and [3H] mevalonate 5-pyrophosphate accumulated. Neither protein nor RNA synthesis were required for mevalonate-mediated suppression of reductase activity. However, fluoromevalonate's effect on reductase activity required protein synthesis. Furthermore, in the absence of protein synthesis, fluoromevalonate-stabilized Kc cell HMG-CoA reductase activity. We have concluded that mevalonate, fluoromevalonate, homomevalonate, and compactin (mevinolin) modulated HMG-CoA reductase activity because they altered isoprenoid carbon flow to a post-isopentenyl 1-pyrophosphate regulatory, signal molecule.

Animals↗
PubMed1985

Cardiomyopathy associated with a curly hair coat in Poll Hereford calves in Australia.

Fifteen newborn Poll Hereford calves from five farms died over a three-and-a-half year period. From birth all calves had a tight, curly hair coat which was not observed on any other calves on these properties. All calves with this phenotype died before reaching six months of age. Seven of the 15 calves were noticed to have exercise intolerance, hyperpnoea and dyspnoea for one to seven days before death. The incidence of additional features of the curly hair coat phenotype is also described. Post mortem examinations conducted on the calves revealed focal, diffuse and pale fibrous streaking of the entire myocardium and vascular congestion of the livers, spleens and lungs. A primary cardiomyopathy was diagnosed on the basis of the clinical and pathological findings. Analysis of the pedigrees of seven affected calves from one farm demonstrated a common ancestor for all sires and dams of affected calves and suggested a simple autosomal recessive mode of inheritance of the syndrome as a reasonable hypothesis for future experimental testing.

Animals↗
PubMedDate not supplied

Implementation of a family-centered treatment program for substance-abusing women and their children: barriers and resolutions.

Recent federal health financing and health care delivery programs have increased access to alcohol and other drug abuse treatment programs for low-income women, and have provided intervention and prevention services for their children and families. The Village South Families in Transition (FIT) in Miami, Florida, implemented a residential treatment program for women and their children that aims to decrease alcohol and other drug use, reduce reliance on social and health welfare systems, improve functioning in specific life-skill and vocational areas, improve parenting techniques and maternal/child relations, and provide intervention and prevention services for the clients' children in a safe and supportive environment. Program implementation required resolutions to numerous barriers, including securing a facility for women and children; recruiting, hiring and training of staff; establishing and maintaining community linkages; treatment considerations; balancing treatment versus evaluation/research; and critical decisions faced by treatment staff as they modify client-centered programs to incorporate gender-specific and family-centered programs.

Adult↗