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Biomedical subjects

M H Adams

Publications and source records attributed to M H Adams.

At least 19 recordsLinked to original sources
PubMed1999

Identification and initial characterization of calcyclin and phospholipase A2 in equine conceptuses.

For development to proceed normally, the appropriate genes must be expressed in the correct tissues and in the correct time frame. Knowledge of gene expression during development provides information about the changes taking place within the conceptus as well as possible reasons for pregnancy failure. However, little is known about gene expression during development in the equine conceptus. In this study, we examined differences in gene expression between day 12 and day 15 equine conceptuses by suppression subtractive hybridization. This technique was used to isolate transcripts that are more abundantly expressed in day 15 conceptuses compared to day 12 conceptuses. Between day 12 and 15 of pregnancy in horses, maternal recognition of pregnancy occurs, gastrulation is taking place, and mesoderm is beginning to form. Fifty cDNA clones were isolated, sequenced, and compared to known sequences in the GenBank database. Two cDNA clones identified that were of primary interest were calcyclin and phospholipase A2. Calcyclin is a calcium-binding protein of the S-100 protein family that has been found in mouse decidua and trophoblast. Calcyclin was found to be expressed in both day 12 and 15 equine conceptuses, with approximately a 30-fold increase in transcript abundance between days 12 and 15. Phospholipase A2 is an enzyme that cleaves phospholipids to release fatty acids and is involved in arachidonic acid release needed for prostaglandin, thromboxane, and leukotriene synthesis. Multiple forms of PLA2, that appear to be differentially regulated in day 12 and 15 conceptuses, were detected by northern blotting.

Amino Acid Sequence↗
PubMed1999

Oxytocin-neurophysin I mRNA abundance in equine uterine endometrium.

A positive-feedback loop between luteal oxytocin and uterine prostaglandin F2 alpha (PGF) is a major signal for luteolysis in ruminants. Likewise, uterine PGF causes luteolysis in mares, but the involvement of oxytocin in this process is unclear. We wanted: 1) to determine if the oxytocin-neurophysin I (OT-NP I) gene is transcribed into mRNA in the endometrium of mares; and, if so, 2) to analyze relative changes in abundance of endometrial OT-NP I mRNA throughout the estrous cycle and during early stages of pregnancy. Endometrial biopsies were obtained from nonbred mares during estrus, and 5, 10, and 15 d after ovulation (n = 3/d). Biopsies were also obtained from pregnant mares 10, 15, and 20 d after ovulation (n = 3/d). Relative amounts of OT-NP I and glyceraldehyde-3-phosphate dehydrogenase mRNA in endometrium were assessed by reverse transcription-polymerase chain reaction and Southern blotting. Endometrial OT-NP I mRNA abundance changed with day of the cycle or pregnancy, and levels at estrus were higher than at any other days examined. The OT-NP I mRNA levels were negatively correlated with serum progesterone across all days examined and positively correlated with serum estradiol in nonbred mares. The reverse transcription-polymerase chain reaction products for both OT-NP I and glyceraldehyde-3-phosphate dehydrogenase were cloned into vectors and sequenced. Each shared greater than 89% nucleotide and predicted amino acid identities with the respective human, bovine, ovine, and rat products. Uterine oxytocin may be involved in regulation of reproductive tract function during the estrous cycle and/or establishment of pregnancy in horses.

Amino Acid Sequence↗
PubMed1999

Changes in equine endometrial oestrogen receptor alpha and progesterone receptor mRNAs during the oestrous cycle, early pregnancy and after treatment with exogenous steroids.

Two experiments were performed to determine changes in the abundance of oestrogen and progesterone receptor (ER alpha and PR) mRNAs in equine endometrium during the oestrous cycle and early pregnancy, and under the influence of exogenous steroids. In Expt 1, endometrial biopsies were obtained from non-mated mares during oestrus and at days 5, 10 and 15 after ovulation, and from pregnant mares at days 10, 15 and 20 after ovulation. There were overall effects of day on the abundance of ER alpha (P = 0.0001) and PR (P = 0.0014) mRNAs. The amount of ER alpha mRNA decreased at day 10 of pregnancy, and PR mRNA was reduced at day 5 in non-mated mares and at day 15 of pregnancy, compared with oestrous values. Experiment 2 was conducted to determine the effects of exogenous steroids on endometrial ER alpha and PR mRNAs. Endometrial biopsies were obtained from 19 anoestrous mares that had been treated with vehicle, oestradiol, progesterone, or oestradiol followed by progesterone for either a short or a long duration. The steroid treatment affected the abundance of ER alpha mRNA (P = 0.0420), which was higher (P < 0.05) in the oestradiol group than in the group treated with oestradiol followed by long duration progesterone. The steroid treatment did not affect the abundance of PR mRNA. These results demonstrate that the amount of steroid receptor mRNA changes with the fluctuating steroid environment in the uterine endometrium of cyclic and early pregnant mares, and that the duration of progesterone dominance may affect ER alpha gene expression. In addition, factors other than steroids may regulate ER alpha and PR gene expression in equine uterine endometrium.

Analysis of Variance↗
PubMed1998

Pharmacokinetics of minoxidil in patients with cirrhosis and healthy volunteers.

OBJECTIVES: To determine the effect of reduced hepatic function on the pharmacokinetics of minoxidil. The pharmacokinetics of antipyrine, lorazepam, and indocyanine green were included as indicators of hepatic function. METHODS: Eight mild cirrhotics and eight healthy subjects received antipyrine (po), lorazepam (IV), indocyanine green (IV) and minoxidil 5 mg (po). Blood and urine were sampled for up to 72 h after each drug, and drug concentrations were measured by validated HPLC methods. Blood pressure and heart rate were measured for safety. RESULTS: For unchanged minoxidil, the serum elimination rate constant was significantly smaller and mean residence time was significantly longer in cirrhotic patients. Urinary elimination rate constant for minoxidil glucuronide was significantly smaller and fraction of dose excreted in urine was significantly higher in cirrhotic patients. Antipyrine elimination was significantly slower for cirrhotic patients. No differences were observed in lorazepam pharmacokinetic parameters. CONCLUSION: Pharmacokinetic analysis suggests a longer dosage interval may be appropriate in patients with hepatic impairment. In the absence of multiple-dose minoxidil pharmacodynamic studies in this population, minoxidil should be used as in other populations: begin with a modest dose, and adjust the dose based on clinical response.

Adult↗
PubMed1997

Evaluation of National Research Council amino acid recommendations for large white turkeys.

Two trials of identical experimental design were conducted to evaluate the NRC (1994) amino acid requirements for growing turkeys. Diets were formulated for 4-wk age intervals using intact ingredients and amino acid supplements to provide 85, 90, 95, 100, 105, 110, 115, and 120% of the suggested requirements. Formulation was done in a manner to minimize excess levels of as many essential amino acids as possible. Day-old male poults of a commercial Large White strain were grown to 20 wk on the test diets with body weight and feed conversion determined at intervals throughout the test; representative samples of birds were processed to determine carcass composition and parts yield. Results suggested that diets formulated to provide 105% of the suggested NRC requirements were needed to provide maximum body weight gain, feed conversion, and breast meat yield. Ambient temperatures in the present study frequently exceeded 27 C and may have contributed to the need for somewhat greater amino acid needs than the present NRC (1994) suggestions.

Aging↗
PubMed1996

Characterisation of proteins in the seminal plasma of stallions, geldings and supplemented with testosterone.

The major proteins in stallion seminal plasma were characterised by two-dimensional polyacrylamide gel electrophoresis, and compared with the patterns of proteins in normal geldings (castrated males) and geldings supplemented with testosterone. The major proteins or groups of proteins identified according to their approximate relative molecular weight in kilodaltons (kDa) and apparent isoelectric point (pl) were: 1) 60 kDa. pl 7; 2) 23 kDa, pl 4-5; 3) 25-30 kDa, pl 5.5-6; 4) 23 kDa, pl 7-8; and 5) 15-20 kDa, pl 6-7.5. Protein groups 1 and 2 were more prominent in the seminal plasma from the stallions and supplemented geldings than that from the unsupplemented geldings, while protein groups 3, 4 and 5 were more prominent in the seminal plasma from the unsupplemented geldings.

Animals↗
PubMed1995

Changes in equine endometrial retinol-binding protein RNA during the estrous cycle and early pregnancy and with exogenous steroids.

A cDNA library was constructed from poly(A) RNA obtained from Day 14 nonbred equine endometrium. A cDNA probe for porcine retinol-binding protein (RBP) was used to screen the library, and a complete cDNA sequence (1133 bp, excluding the poly(A) tail) was obtained. Endometrial biopsies were obtained from cycling, nonbred mares at Days 0, 1, 4, 8, 10, 11, 13, and 15 and from pregnant mares at Days 11, 13, 15, and 17 after ovulation (n = 2 mares each day). Endometrial biopsies were also taken from 18 noncycling anestrous mares after the following treatments: C (vehicle control for 1 day, n = 3), E (estradiol-17 valerate, 5 mg/day for 6 days, n = 3), P (progesterone, 250 mg/day for 6 days, n = 4), ESP (E for 6 days followed by, P for 6 days, n = 4), and ELP (E for 6 days followed by P for 12 days, n = 4). Northern blot analyses were performed on total RNA (30 micrograms) using cDNA probes to equine (e) RBP and human glyceraldehyde-3 phosphate dehydrogenase (G3PDH). The RBP RNA levels (normalized to G3PDH) from nonbred mares were low during early diestrus and increased after Day 10, and RBP RNA levels from pregnant mares were similar to those of nonbred mares for corresponding days. E tended to decrease endometrial RBP RNA; and P, ESP, and ELP increased it compared to C. There were no significant differences among P, ESP, and ELP RBP RNA levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

The effect of co-administered drugs on oxaprozin binding to human serum albumin.

The binding of the non-steroidal anti-inflammatory drug oxaprozin to human serum albumin was studied by bioaffinity high-performance liquid chromatography using a column based on immobilized human serum albumin. Displacement studies using marker compounds for the major drug binding sites showed that oxaprozin has a high affinity for the benzodiazepine/indole site and binds to the warfarin site but with a significantly lower affinity. Biochromatography and ultrafiltration techniques were used to screen for possible competition and allosteric interactions between oxaprozin and potential co-administered drugs including non-steroidal anti-inflammatory drugs, antipyretics, hypoglycaemics, inhibitors of angiotensin-converting enzyme, anaesthetics, metal ions and anticancer agents. Competition occurred mainly with drugs bound at the benzodiazepine site (benzodiazepines, various non-steroidal anti-inflammatories).

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Utilization of hydrolyzed sucrose polyester (olestra) in broiler diets.

Three experiments were conducted in which hydrolyzed olestra (HO) and hydrolyzed olestra manufacturing by-product (HBP) were compared with corn oil (CO) and a feed-grade hydrolyzed animal-vegetable fat blend (AVF) as fat supplements in diets for broilers. Various blends of HO and HBP with AVF and other fat sources were also evaluated. Results of these experiments indicate that HO or HBP may be used as energy sources in broiler diets. Use of these materials as the sole source of supplemental fat often reduced body weight gain and impaired feed utilization as compared with CO or AVF; however, when used as a component of a blended fat product typical of industry supplements, there was little if any adverse effect on live performance. Carcass fatty acid content was a reflection of dietary fat content. If the blend of fats containing HO or HBP contains a suitable ratio of unsaturated and saturated fatty acids, the product should be an acceptable source of supplemental energy in broiler diets.

Animal Feed↗
PubMed1994

Stability of indocyanine green in human serum stored at -20 and -70 degrees C.

The stability of indocyanine green (ICG) in human serum after storage at -20 and -70 degrees C for an extended time was studied. Serum samples were fortified with ICG at 6.5, 2.0 and 0.3 microgram ml-1, aliquoted, and frozen at -20 or -70 degrees C. The analytic methodology used an internal standard and separation on a reverse phase liquid chromatographic column with UV detection at 240 nm. Samples were prepared for analysis by protein precipitation with acetonitrile. The assay was stability indicating as shown by the complete loss of the ICG peak upon storage at -20 degrees C for 8 weeks. ICG was not stable, as determine by a t test, for 1 week in human serum when stored at -20 degrees C. Storage at -70 degrees C improved stability but the ICG concentration began to fall steadily after 4 weeks of storage.

Blood↗
PubMed1993

Characterization of equine oviductal proteins synthesized and released at estrus and at day 4 after ovulation in bred and nonbred mares.

Proteins synthesized and released in vitro by oviducts collected from horse mares during estrus and at day 4 after ovulation for bred and nonbred mares were examined by two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (2-D SDS PAGE) and fluorography. Ampullary and isthmic regions both produced a wide array of nondialyzable proteins in culture. Major proteins or groups of proteins identified according to relative molecular weight (kDa) and apparent isoelectric point (pI) were at 100 kDa, pI 8; 100-200 kDa, pI 6; 150 kDa, pI 4.5; 60-100 kDa, pI 4; and an array of polypeptides at 21-22 kDa, pI 5-6. Oviductal secretory activity, measured by incorporation of radiolabeled amino acids into nondialyzable macromolecules released into incubation medium, was greater (P < .01) for the ampullary than the isthmic oviductal region. No consistent differences were observed in fluorograms between estrus vs. day 4 after ovulation, ampulla vs. isthmus, ipsilateral vs. contralateral to the corpus luteum or largest follicle, oviducts from bred vs. nonbred mares, or mare ages. Dialyzed medium from ampullary and isthmic regions of oviducts was subjected to 1-D or 2-D SDS PAGE followed by western blotting utilizing an antiserum directed against human retinol binding protein (RBP). The family of 21-22 kDA polypeptides was identified as immunoreactive RBP.

Animals↗
PubMed1993

Effects of amino acid restriction during starter and grower periods on subsequent performance and incidence of leg disorders in male large white turkeys.

Male Nicholas Large White turkeys were fed diets formulated to meet a minimum of 100, 110, or 120% of NRC (1984) amino acid recommendations. There were three periods when 75% of recommended standards were fed: 0 to 3 wk, 0 to 6 wk, or 6 to 12 wk. A fourth (control) group was not restricted at any time. Four pens of 12 males were fed each amino acid by restriction combination. At 18 wk, leg scores were assigned to all birds and representative samples of birds processed for parts yield. All birds fed restricted diets had significantly lower BW at 18 wk than unrestricted controls but did not differ in feed utilization. Dietary amino acid levels significantly influenced BW and feed utilization, but there was no interaction with restriction times. There were no significant effects of amino acid levels or restriction times on incidence of leg disorders. Breast meat yields (quantity and percentage of carcass) were significantly influenced by both restriction time and amino acid levels. There seemed to be little if any compensatory gain following amino acid restriction in these studies.

Amino Acids↗
PubMed1991

Effects of sodium bicarbonate and potassium chloride drinking water supplementation. 2. Meat and carcass characteristics of broilers grown under thermoneutral and cyclic heat-stress conditions.

Two broiler trials were conducted to investigate the effect on post-mortem carcass and meat quality of NaHCO3 and KCl drinking water supplementation under thermoneutral and cyclic heat-stress climatic conditions. Water chill carcass weight change, water- and oven-cooked breast filled yields, and breast meat tenderness were measured. In Trial 1, neither environmental regimen, nor water treatments, nor their interaction was a significant (P less than .05) source of variation for the parameters measured. In Trial 2, environmental regimen was a highly significant (P less than .01) source of variability for chilled carcass weight change; the cyclic heat-stressed broiler carcasses gained more weight than the thermoneutral (control) broiler carcasses during ice-water chilling. Oven-cooked fillet yield was significantly (P less than .05) affected by environmental regimen; fillets from cyclic heat-stressed broilers had lower yields than thermoneutral (control) broiler fillets. Drinking water treatments were a significant (P less than .05) source of variation for breast meat tenderness in Trial 2. Broilers given .5% NaHCO3 from 5 to 8 wk of age had higher shear resistance values than broilers given a combination of .5% NaHCO3 and .5% KCl or tap water-fed controls. Breast meat shear values were negatively correlated (P less than .05) with 8-wk broiler body weight and 5- to 8-wk gain.

Analysis of Variance↗
PubMed1991

Comparison of different anticoccidials on processing characteristics and parts yield of broiler chickens.

Broilers were grown to 42 days of age on diets supplemented with salinomycin (60 mg/kg), monensin (99 mg/kg), or halofuginone (3 mg/kg) and continued on unmedicated diets to 49 days of age. There were no significant (P greater than .05) differences among anticoccidials in final body weight, feed conversion, or mortality rates. Samples of birds were processed for dressing percentage and parts yield. Both males and females fed salinomycin had significantly higher breast meat yield as a percentage of postchill weight than those fed halofuginone but not those fed monensin; differences were not significant for breast meat yield of males or females fed monensin or halofuginone. Males fed halofuginone had significantly heavier leg quarters than those fed salinomycin but not those fed monensin. Females fed salinomycin had significantly higher water uptake during chill than those fed monensin or halofuginone. Results of the present study indicate that the anticoccidial used in growing broilers may influence some carcass yield parameters.

Animals↗