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Biomedical subjects

C E Thompson

Publications and source records attributed to C E Thompson.

At least 19 recordsLinked to original sources
PubMed2003

Evaluation of maternal performance of daughters from high and low milk EPD sires.

Angus bulls (n = 24) were selected for either high or low milk EPD, but with similar growth EPD and mated within location (n = 6) at random to Angus cows. Daughters from these matings were bred to calve first at 2 yr of age to common reference sires across locations. Lactation records for 192 daughters were used to evaluate 12-h milk yield, percentage of milk fat and protein, and weaning weight of offspring. Milk production was measured four times during the lactation at regular intervals within location. Dams were separated from their calves the night before milking and milked with a portable milking machine the next morning to estimate 12-h milk yield. A sample of the milk was collected from each cow and analyzed for percentages of milk fat and protein. Data were analyzed as repeated records of the dam. Fixed effects were location, genetic line of sire, gender of calf within location, and milking period, with postpartum interval used as a covariate. Fixed effects and the random effects of sire of dam nested within line, sire of calf, and year were estimated by REML. Genetic line was an important source of variation for milk yield (P < 0.01) and percentage of milk fat (P = 0.03) but not for percentage of milk protein (P = 0.49). Location was significant for all three milk variables (P < 0.01), but the interactions between line and location were not significant. Gender of calf was significant for milk yield (P = 0.04) but not for percentage of milk fat or protein. Line (P = 0.02), location (P = 0.01), calf gender (P = 0.01), and age at weaning (P = 0.01) were significant sources of variation for weaning weight but the interaction of line and location was not (P = 0.69). The correlation coefficient between the sire's milk EPD and 12-h milk yield was significantly different from zero (r = 0.56). The difference between the least squares means for high and low lines for milk yield was 0.66 kg/12 h and the difference was 15.3 kg for weaning weight. The results indicate that there was not evidence for a genotype by environment interaction in milk production for daughters from divergent sires selected for high or low milk EPD.

Animals↗
PubMed2001

Quantifying the 5-HT1A agonist action of buspirone in man.

RATIONALE: Buspirone is used as a neuroendocrine challenge in which the increase of circulating prolactin is taken as a measure of the sensitivity of central serotonergic (5-HT(1A)) pathways. Interpretation of the test is complicated, however, by the fact that buspirone possesses D(2) antagonist and 5-HT(1A) agonist activity, both of which will result in the release of prolactin. To understand the significance of prolactin secretion in response to buspirone, it is important to measure the differential actions of the two controlling pathways. OBJECTIVE: To characterise the dual action of buspirone in stimulating the secretion of prolactin by blocking the 5-HT(1A) action with the 5-HT1A antagonist action of pindolol. METHODS: Healthy male subjects (n=35) received buspirone (0.5 mg x kg bw(-1) orally) with and without pre-treatment with the 5-HT(1A) receptor antagonist pindolol (40 mg over 2 days, 0.5 mg x kg bw(-1) on test day). Nine subjects underwent two additional trials in which they received a placebo with and without pre-treatment with pindolol. RESULTS: Pindolol alone caused a small but significant reduction (18%) in the tonic release of prolactin. Buspirone alone produced a robust prolactin response which was reduced to approximately half by pindolol pre-treatment. Pindolol pre-treatment also, on average, delayed the onset and peak of the prolactin response. There was wide variation among individuals both in the absolute response to buspirone and in the proportion that could be attributed to the non-serotonergic agonist action of buspirone (22-82% IQ range). CONCLUSIONS: Our results indicate that while serotonergic pathways play a minor role in the tonic release of prolactin, the response to a buspirone challenge alone cannot be used as a simple index of central serotonergic activity. However, if two challenges are carried out, one with buspirone and the other with buspirone plus pindolol, quantitative measures can be made of the sensitivity of both the 5-HT(1A) and the putative D(2) pathways controlling prolactin release.

Adolescent↗
PubMed2000

Epidemiology and optimal foraging: modelling the ideal free distribution of insect vectors.

Existing models of the basic case reproduction number (R0) for vector-borne diseases assume (i) that the distribution of vectors over the susceptible host species is homogeneous and (ii) that the biting preference for the susceptible host species rather than other potential hosts is a constant. Empirical evidence contradicts both assumptions, with important consequences for disease transmission. In this paper we develop an Ideal Free Distribution (IFD) model of host choice by blood-sucking insects, predicated on the argument that vectors must have evolved to choose the least defensive hosts in order to maximize their feeding success. From a re-analysis of existing data, we demonstrate that the interference constant, m, of the IFD can vary between host species. As a result, the predicted distribution of insects over hosts has 2 desirable and intuitively plausible behaviours: that it is heterogeneous both within and between host species; and that the intensity of heterogeneity varies with host and vector density. When the IFD model is incorporated into R0, the relationship with the vector:host ratio becomes non-linear. If correct, the IFD could add considerable realism to models which seek to predict the effect of these ecological parameters on disease transmission as they vary naturally (e.g. through seasonality in vector density or host population movement) or as a consequence of artificial manipulation (e.g. zooprophylaxis, vector control). It raises the possibility of targeting transmission hot spots with greater accuracy and concomitant reduction in control effort. The robustness of the model to simplifying assumptions is discussed.

Animals↗
PubMed2000

Site of administration and duration of feeding oleamide to cattle on feed intake and ruminal fatty acid concentrations.

Two experiments were conducted to determine effects of oleamide on feed intake and ruminal fatty acids when the oleamide was introduced in the feed vs through a ruminal fistula (Exp. 1) or the oleamide was fed for an extended (9-wk) length of time (Exp. 2). In Exp. 1, four nonlactating Holstein cows, each fitted with a ruminal cannula, were fed four diets in a 4 x 4 Latin square design. Each period lasted 2 wk. Diets consisted of 48% corn silage and 52% concentrate on a DM basis. One diet contained no added fat (control) and a second diet contained 4.2% oleic acid. The remaining two diets were designed to expose cows to 4.2% amide (as oleamide) either through the feed (AF) or by administering oleamide into the rumen (AR) each day through the ruminal cannula. The AF diet reduced DMI similarly to results reported previously for lactating dairy cows and sheep. Intake of the oleic acid diet was intermediate between the control and AF diets. Dry matter intake was reduced by AR similarly to the AF diet. The acetate:propionate ratio in samples of ruminal contents was reduced by oleic acid but not by AF or AR. In Exp. 2, 12 steers were divided into three equal groups of two Angus and two Simmental x Angus crosses, and each group was assigned a diet containing either no added fat (control), 4% oleamide, or 4% high-oleic canola oil. All steers had ad libitum access to feed and water. Dry matter intake by steers fed the canola oil diet was not different from that by steers fed the control diet when averaged over the first 3 wk, the last 3 wk, or over the entire 9-wk study. Oleamide reduced DMI 4 kg/d over the first 3 wk of the study. However, DMI of the oleamide diet consistently increased over the 9-wk study, resulting in wk 7 to 9 DMI that was not different from that of steers fed the control diet. These results show that the reduction in feed intake when oleamide is added to cattle rations can be attributed more to physiological responses than to an undesirable unique taste or odor of the oleamide. In finishing beef steers, the decreased intake induced by oleamide was most severe during the first 1 or 2 wk of feeding but gradually lessened over time until it nearly returned to normal by wk 9.

Administration, Oral↗
PubMed2000

The alpha1-adrenergic antagonist prazosin ameliorates combat trauma nightmares in veterans with posttraumatic stress disorder: a report of 4 cases.

BACKGROUND: Central nervous system (CNS) adrenergic hyperresponsiveness may be involved in the pathophysiology of posttraumatic stress disorder (PTSD). Two Vietnam combat veterans with PTSD prescribed the centrally active alpha1-adrenergic antagonist prazosin for symptoms of benign prostatic hypertrophy unexpectedly reported elimination of combat trauma nightmares. This observation prompted an open-label feasibility trial of prazosin for combat trauma nightmares in chronic combat-induced PTSD. METHOD: Four consecutively identified combat veterans with chronic DSM-IV PTSD and severe intractable combat trauma nightmares participated in an 8-week open trial of escalating-dose prazosin. Nightmare severity response was rated using the nightmare item of the Clinician Administered PTSD Scale and the Clinical Global Impressions-Change scale. RESULTS: The 2 patients who achieved a daily prazosin dose of at least 5 mg were markedly improved, with complete elimination of trauma nightmares and resumption of normal dreaming. The 2 subjects limited to 2 mg of prazosin to avoid excessive blood pressure reduction were moderately improved with at least 50% reduction in nightmare severity. CONCLUSION: These clinical observations, together with neurobiological evidence for alpha1-adrenergic regulation of CNS neurobiological systems relevant to PTSD, provide rationale for placebo-controlled trials of prazosin for PTSD combat trauma nightmares.

Adrenergic alpha-Antagonists↗
PubMed1998

Laminin alpha2 muscular dystrophy: genotype/phenotype studies of 22 patients.

OBJECTIVE: To determine the number of primary laminin alpha2 gene mutations and to conduct genotype/phenotype correlation in a cohort of laminin alpha2-deficient congenital muscular dystrophy patients. BACKGROUND: Congenital muscular dystrophies (CMD) are a heterogeneous group of muscle disorders characterized by early onset muscular dystrophy and a variable involvement of the CNS. Laminin alpha2 deficiency has been reported in about 40 to 50% of cases of the occidental, classic type of CMD. Laminin alpha2 is a muscle specific isoform of laminin localized to the basal lamina of muscle fibers, where it is thought to interact with myofiber membrane receptor, such as integrins, and possibly dystrophin-associated glycoproteins. METHODS: Seventy-five CMD patients were tested for laminin alpha2 expression by immunofluorescence and immunoblot. The entire 10 kb laminin alpha2 coding sequence of 22 completely laminin alpha2-deficient patients was screened for causative mutations by reverse transcription (RT)-PCR/single strand conformational polymorphisms (SSCP) analysis and protein truncation test (PTT) analysis followed by automatic sequencing of patient cDNA. Clinical data from the laminin alpha2-deficient patients were collected. RESULTS: Thirty laminin alpha2-negative patients were identified (40% of CMD patients tested) and 22 of them were screened for laminin alpha2 mutations. Clinical features of laminin alpha2-deficient patients were similar, with severe floppiness at birth, delay in achievement of motor milestones, and MRI findings of white matter changes with normal intelligence. Loss-of-function mutations were identified in 95% (21/22) of the patients studied. SSCP analysis detected laminin alpha2 gene mutations in about 50% of the mutant chromosomes; PTT successfully identified 75% of the mutations. A two base pair deletion mutation at position 2,096-2,097 bp was present in 23% of the patients analyzed. CONCLUSIONS: Our data suggest that the large majority of laminin alpha2-deficient patients show laminin alpha2 gene mutations.

Base Sequence↗
PubMed1996

Results of a double-blind placebo-controlled study of the double-stranded RNA drug polyI:polyC12U in the treatment of HIV infection.

In this multicenter, randomized, double-blind study the activity of polyI:polyC12U administered with zidovudine was evaluated in the treatment of HIV infection. Thirty-six HIV-positive, pre-AIDS individuals (100-500 CD4+ cells/mm3) who had had at least six months of zidovudine therapy received polyI:polyC12U (400 or 700 mg) or placebo twice weekly with zidovudine. PolyI:polyC12U subjects with baseline CD4+ counts > or = 300/mm3 showed a trend towards reduced CD4+ loss versus placebo recipients. PolyI:polyC12U subjects were more likely to exhibit positive delayed-type hypersensitivity responses than placebo recipients. Placebo subjects crossing over to polyI:polyC12U therapy demonstrated improved CD4+ and delayed-type hypersensitivity responses. PolyI:polyC12U subjects with baseline CD4+ counts > or = 300/mm3 were less likely to develop AIDS than similar placebo subjects. PolyI:polyC12U therapy of HIV-positive subjects restored or stabilized immune function as indexed by delayed-type hypersensitivity reactivity and, in individuals with CD4+ counts > 300/mm3, abrogated CD4+ loss and reduced disease progression. PolyI:polyC12U was generally well-tolerated in this zidovudine-treated population. No subject discontinued therapy due to an adverse reaction or aberrant laboratory parameter.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Sudden death of a carrier of X-linked Emery-Dreifuss muscular dystrophy.

OBJECTIVE: To report a sudden death in a female carrier of Emery-Dreifuss muscular dystrophy and to describe the cardiac abnormalities associated with this disease. STUDY DESIGN: Case series. SETTING: University hospital. PATIENTS: A 45-year-old carrier who died suddenly and two affected men who also died of cardiac manifestations of Emery-Dreifuss muscular dystrophy. MEASUREMENTS: Post-mortem gross pathologic and histopathologic study of the heart. RESULTS: All three hearts showed a unique pattern of pathologic findings. Marked loss of atrial myocardium had occurred. Myocardium had been replaced by adipose and fibrous tissue. The conduction system showed no significant abnormalities. Varying degrees of interstitial and replacement fibrosis were present in the ventricular myocardium. CONCLUSIONS: Emery-Dreifuss muscular dystrophy is associated with characteristic pathologic changes in the heart that can cause death in female carriers and affected men. Female carriers should be identified and evaluated because of the risk for sudden cardiac death.

Adult↗
PubMed1993

Carcass and meat sensory traits of steers finished on fescue and clover, summer forage, or for different periods in drylot.

During a 3-yr period 184 steers were allotted to five treatment groups. Group 1 steers were pastured on fescue-clover and slaughtered in the spring at approximately 540 d of age. Group 2 steers were pastured on fescue-clover then placed on summer pasture regimens and slaughtered at approximately 620 d of age. Group 3 steers were treated the same as Group 2 then placed in the drylot for 45 d. Group 4 steers were treated the same as Group 2 steers then placed in the drylot for 75 d. Group 5 steers were placed in drylot after weaning and conditioning and were slaughtered at endpoints that corresponded with those for Group 3. Steers selected for slaughter at each endpoint were those evaluated to have reached the most optimum slaughter weight and finish by project personnel. Carcasses of steers from fescue-clover and summer pasture had lower yield grades and a lower quality grade than carcasses of steers from drylot (P < .05). Carcasses of steers from fescue-clover and summer pasture had a more yellow fat covering than carcasses of steers that received a concentrate (Treatments 3, 4, and 5, P < .0001). Fescue-clover- and summer pasture-fed steers had a higher percentage of lean and a lower percentage of fat in the 9-10-11th rib section than did steers that received concentrate (P < .005). Chemical analysis of the lean tissue of the 9-10-11th rib section indicated that summer pasture-fed steers had a lower percentage of ether extract and higher percentage of moisture than the lean tissue from steers that received concentrate (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1992

Thrombotic microangiopathies in the 1980s: clinical features, response to treatment, and the impact of the human immunodeficiency virus epidemic.

We reviewed the medical records of 44 adults with 50 consecutive episodes of thrombotic thrombocytopenia purpura (TTP) or hemolytic uremic syndrome (HUS) seen at the University of California, San Francisco affiliated hospitals during the past decade. Patients were treated according to a uniform plan in which initial therapy included daily large volume plasmapheresis using fresh frozen plasma. Patients not responding completely to initial therapy were treated with a salvage regimen including splenectomy, dextran, and corticosteroids. At the time of diagnosis, the lactate dehydrogenase (LDH) was elevated in 98% of cases, with a median value of 1,208 U/L. Other clinical features were present inconsistently, and only 34% of "TTP" episodes involved the classic pentad of hemolytic anemia, thrombocytopenia, neurologic disorders, noninfectious fever, and renal impairment. Primary treatment with plasma exchange produced complete remission in 56% (27 of 48) of the episodes. Previously splenectomized patients uniformly responded to plasma therapy (12 of 12). In patients not responding completely to primary therapy, salvage splenectomy produced complete responses in 81% (13 of 16) of the cases. The pattern of clinical response to therapy was consistent, with initial resolution of neurologic dysfunction (median, 3 days) followed by normalization of LDH levels (5 days) and platelet count (7 days). Normalization of renal function occurred significantly later (15 days). Although short-term responses to plasma therapy in human immunodeficiency virus (HIV)-seropositive patients did not differ from other patients, no HIV-positive patient survived more than 2 years from diagnosis of thrombotic microangiopathy (TMA). We conclude that the diagnosis of TMA requires a high degree of clinical suspicion and that the diagnostic criteria should consist of microangiopathic hemolytic anemia, thrombocytopenia, and an elevated LDH. Initial therapy with plasma exchange leads to disease control in the majority of cases, but an optimal treatment strategy requires the use of alternative methods if initial remission is transient or not achieved. Salvage therapy with splenectomy, steroids, and dextran is highly effective in this setting.

Adult↗
PubMed1992

Standardization of an enzyme immunoassay for human antibody to Haemophilus ducreyi.

We standardized a serologic enzyme immunoassay (EIA) for human immunoglobulin G and M antibodies against Haemophilus ducreyi. We evaluated the performance of this test with respect to the time from acute chancroid and coinfection with human immunodeficiency virus (HIV). Antibody to a crude, soluble bacterial antigen of one H. ducreyi strain was detected in a panel of serum samples from clinically and microbiologically confirmed cases of chancroid and from controls. Test interpretation was standardized for optimal sensitivity and specificity. Performance of the EIA was enhanced in the period of early convalescence from acute primary chancroid and was not diminished in the presence of HIV coinfection. The EIA performed adequately as a serologic screening test for field evaluation and epidemiologic application in conjunction with sexually transmitted disease and HIV detection and control efforts.

Antibodies, Bacterial↗
PubMed1990

Synchronization of estrus after treatment with Luprostiol in beef cows and in beef and dairy heifers.

Four trials were conducted to study synchronous estrous response in beef cows and in beef and dairy heifers to Luprostiol (13, thia-PG-F(2)alpha analog) in comparison with other prostaglandin products. In Trial 1, 60 virgin beef heifers were observed for estrus for 5 d and artificially inseminated. Heifers not observed in estrus within 5 d were randomly assigned to receive 15 mg Luprostiol or 25 mg Lutalyse. In Trial 2, 75 multiparous, lactating beef cows were randomly assigned to receive either 15 mg Luprostiol, 25 mg Lutalyse or 500 mcg Estrumate. All cows received a second injection of the respective treatment 11 d later. In Trial 3, 96 multiparous, lactating beef cows were randomly assigned to receive 15 mg Luprostiol or 25 mg Lutalyse. All cows received a second injection of the respective treatment 11 d later. In Trial 4, virgin dairy heifers were palpated per rectum. Seventy-seven heifers with a palpable corpus luteum (CL) were randomly assigned to receive 15 mg Luprostiol or 500 mcg Estrumate. In all trials animals were artificially inseminated 12 h following observed estrus. Estrous response during the 5-d synchronized period was 44% for Luprostiol and 42% for Lutalyse treated heifers in Trial 1. It was 52, 56 and 60%, respectively, for Luprostiol, Lutalyse and Estrumate treated cows in Trial 2; 23% for Luprostiol and 19% for Lutalyse treated cows in Trial 3; and 68% for Luprostiol and 70% for Estrumate treated heifers in Trial 4. Treatment with Luprostiol results in a similar synchronous estrous response as with the other prostaglandin products used in these studies.

Journal Article↗
PubMed1990

First-service pregnancy rate in beef heifers as influenced by human chorionic gonadotropin administration before and/or after breeding.

Two experiments were conducted to evaluate whether administration of human chorionic gonadotropin (hCG) before and/or after breeding influences the first-service pregnancy rate in beef heifers. In Experiment 1, 125 yearling and two-year-old heifers were allotted to one of four groups: a control group; a group receiving 3,000 IU hCG on Day 4 of the prebreeding estrous cycle; a group receiving 3,000 IU hCG on Day 4 post breeding; and a group receiving 3,000 IU hCG on Day 4 of the prebreeding estrous cycle and again on Day 4 post breeding (Day 1 = estrus). First-service pregnancy rate was not affected by a single intramuscular (i.m.) injection of 3,000 IU of hCG on Day 4 of the prebreeding estrous cycle and/or post breeding. In Experiment 2, 111 yearling heifers were allotted either to an untreated control group or to a group receiving 3,000 IU hCG on Day 4 post breeding. Administration of a single i.m. injection of hCG on Day 4 post breeding did not affect the first-service pregnancy rate.

Journal Article↗
PubMed1990

The Morgan Recharger: a new horn fly (Diptera: Muscidae) control device for beef cattle.

A 20% diazinon formulation was evaluated for control efficacy against the horn fly, Haematobia irritans (L.), in the Morgan Recharger (Morgan International Products, College Grove, Tenn.). The Morgan Recharger releases insecticide with a wicking system from an insecticide reservoir and can be attached to an animal's ear or tail. This device was most effective against the horn fly when used as an ear tag with two per head; horn fly counts did not exceed five flies per side through 8 wk. The diazinon formulation tested was released from the Morgan Recharger at a decreasing rate. The problems and potential of the Morgan Recharger as an effective horn fly control device are discussed.

Animals↗
PubMed1990

Purification and partial characterization of a mitogenic protein released from preadipocytes of massively obese subjects.

A protein released into the culture medium by omental preadipocytes of massively obese persons, which stimulates the replication of rat perirenal preadipocytes, has been purified to a high degree. By gel filtration chromatography, the molecular mass of the mitogenic protein was approximately 66,000 daltons (Da), while on sodium dodecyl sulfate - polyacrylamide gel electrophoresis, two subunits were obtained, relative masses (Mr) of approximately 31,000 and approximately 35,000. The isoelectric point of the approximately 66,000 Da entity was 5.6 +/- 0.2. By specific radioreceptor assay, the purified protein was related to epidermal growth factor and transforming growth factor alpha. It was not related to insulin-like growth factors I and II by radioimmunoassay and radioreceptor assay. We propose that the approximately 66,000 Mr protein, and other mitogenic proteins released by preadipocytes from massively obese persons, act through paracrine-autocrine mechanisms and may play a role in the development of the hyperplasia of enlarged fat cells characteristic of massive corpulence.

Adipose Tissue↗