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Biomedical subjects

J E Palmer

Publications and source records attributed to J E Palmer.

At least 19 recordsLinked to original sources
PubMed2007

Retrospective study of dystocia in mares at a referral hospital.

REASONS FOR PERFORMING STUDY: The period between the onset of dystocia and its resolution has an important bearing on fetal outcome. There are few published data on which to base decisions regarding optimum management of cases in practice. OBJECTIVES: To evaluate and compare the effects of a coordinated dystocia management protocol (CDMP) with that of a previous protocol of random management on time to resolution and outcome in both an emergency dystocia referral population of mares (referred emergency cases: EM) and in a population of mares residing in hospital due to high risk pregnancy (HRP) concerns that then experience dystocia at parturition. METHODS: Retrospective study performed at a university hospital referral centre of cases presenting from 1991-2004 divided into Group 1 (pre-CDMP) and Group 2 (CDMP). RESULTS: Medical records of 71 cases with dystocia were retrieved and data recorded. For referred emergency cases (EM), time from hospital presentation to resolution decreased significantly by 32 min (P = 0.03) after institution of CDMP. Survival rate of mares at discharge was 86%. Survival of EM foals was low, with 10% in Group 1 and 13% in Group 2, surviving to discharge. For EM foals delivered alive, survival to discharge was 30% and 43% in Groups 1 and 2, respectively. Median Stage II was significantly (P < 0.001) different at 71 and 282 min for EM foals delivered alive vs. those not alive at delivery, respectively. Median duration of Stage II was also significantly (P < 0.001) different between EM foals surviving and not surviving to discharge, at 44 and 249 min, respectively. Survival of HRP dystocia foals to discharge was 79%. CONCLUSIONS: Although CDMP reduced the time from presentation at the hospital to resolution significantly for EM, total duration of Stage II for EM was unchanged, as was foal outcome. POTENTIAL RELEVANCE: Very early referral of mares with dystocia to referral centres with dystocia management protocols may improve fetal outcome as increased duration of Stage II in the horse affects fetal outcome negatively.

Animals↗
PubMed2003

Acquisition and loss of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia over a 5-year period: effect of a triclosan/copolymer dentifrice.

OBJECTIVES: The present study describes the natural history of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia over a 5-year period and the effect of a triclosan/copolymer dentifrice on these organisms in a normal adult population. MATERIAL AND METHODS: Subgingival plaque samples were collected from 504 adult volunteers. Probing pocket depths (PPD) and relative attachment levels were measured using an automated probe. Participants were matched for disease status (CPI), plaque index, age and gender, and allocated to receive either a triclosan/copolymer or placebo dentifrice. Re-examination and subgingival plaque sampling was repeated after 1, 2, 3, 4 and 5 years. P. gingivalis, A. actinomycetemcomitans and P. intermedia were detected and quantitated using an enzyme linked immunosorbent assay. Logistic regression and generalised linear modelling were used to analyse the data. RESULTS: This 5-year longitudinal study showed considerable volatility in acquisition and loss (below the level of detection) of all three organisms in this population. Relatively few subjects had these organisms on multiple occasions. While P. gingivalis was related to loss of attachment and to PPD >/=3.5 mm, there was no relationship between A. actinomycetemcomitans or P. intermedia and disease progression over the 5 years of the study. Smokers with P. gingivalis had more PPD >/=3.5 mm than smokers without this organism. There was no significant effect of the triclosan dentifrice on P. gingivalis or A. actinomycetemcomitans. Subjects using triclosan were more likely to have P. intermedia than those not using the dentifrice; however this did not translate into these subjects having higher levels of P. intermedia and its presence was uniform showing no signs of increasing over the course of the study. CONCLUSION: The present 5-year longitudinal study has shown the transient nature of colonisation with P. gingivalis, A. actinomycetemcomitans and P. intermedia in a normal adult population. The use of a triclosan-containing dentifrice did not lead to an overgrowth of these organisms. The clinical effect of the dentifrice would appear to be independent of its antimicrobial properties.

Adolescent↗
PubMed2003

The effect of a triclosan-containing dentifrice on the progression of periodontal disease in an adult population.

OBJECTIVES: The aim of the present study was to determine the effect of unsupervised, long-term use of a 0.3% triclosan/2% copolymer dentifrice on the progression of periodontal disease in a general adult population. METHODS: Five hundred and four volunteers were enrolled in a double-blind, controlled clinical trial. Participants were matched for disease status, plaque index, age and gender. At the baseline examination, probing pocket depths and relative attachment levels were recorded and participants were assigned to either the test or control group. Re-examinations took place after 6, 12, 24, 36, 48 and 60 months. Subgingival plaque samples were collected at each examination and assayed for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia. A generalised linear model was used to analyse the data, with a number of covariates thought to influence the responses included as the possible confounding effects. RESULTS: The triclosan/copolymer dentifrice had a significant effect in subjects with interproximal probing depths > or =3.5 mm, where it significantly reduced the number of sites with probing depths > or =3.5 mm at the following examination, when compared with the control group (p<0.001). Furthermore, this effect increased with increasing numbers of affected sites. There was no effect of the triclosan/copolymer dentifrice in individuals without probing depths > or =3.5 mm at the previous examination. Other factors significantly affecting probing pocket depths (PPD) included increasing age, smoking and presence of P. gingivalis. PPD > or =3.5 mm were positively associated with loss of attachment some 2 years later. CONCLUSION: This study showed that in a normal adult population, unsupervised use of a triclosan/copolymer dentifrice is effective in slowing the progression of periodontal disease.

Adult↗
PubMed2002

Increased visual after-effects in migraine following pattern adaptation extend to simultaneous tilt illusion.

Much previous research into visual processing in migraine supports a model of abnormal cortical processing, in between the headache attacks, that is characterised by hyperexcitability, heightened responsiveness, a lack of habituation and/or a lack of intra-cortical inhibition. Shepherd (2001) reported two adaptation studies that challenged this view, one using the tilt after-effect, the second using the motion after-effect. Models of cortical function in migraine based on hyperexcitability and a lack of inhibition lead to specific predictions in an adaptation study: there should have been smaller after-effects in people with migraine than in people without. Both experiments, however, revealed larger after-effects in the migraine group than in the control group. Here, these results are extended to the simultaneous tilt illusion and an identical pattern of results was obtained: there were consistently larger effects in the migraine group than in the control group. The results from the three experiments are not consistent with a lack of inhibition in migraine. The results are discussed in terms of alternative models of cortical function, including a lack of excitation and reduced central energy reserves.

Adaptation, Ocular↗
PubMed2001

Bacterial isolates from blood and their susceptibility patterns in critically ill foals: 543 cases (1991-1998).

OBJECTIVE: To assess microorganisms isolated from blood specimens obtained from critically ill neonatal foals and to evaluate their antimicrobial susceptibility patterns. DESIGN: Retrospective study. ANIMALS: 543 neonatal foals. PROCEDURE: Medical records of foals that were < 1 month old and were admitted to a referral neonatal intensive care unit were reviewed for results of bacteriologic culture of blood and antimicrobial susceptibility patterns. RESULTS: At least 1 microorganism was isolated from 155 of 543 (28.5%) foals. Escherichia coli was the most commonly isolated bacterium. A single gram-positive organism was detected in 49 foals. Although 90% of the E coli isolates were susceptible to amikacin, some gram-negative and gram-positive organisms had resistance against multiple antimicrobials. CONCLUSIONS AND CLINICAL RELEVANCE: Gram-negative bacteria remain the most common isolates from blood of neonatal foals; however, gram-positive organisms were also found, and with greater prevalence than reported elsewhere. Susceptibility patterns may vary, and resistance to multiple antimicrobials may develop. This is especially true for organisms such as Enterobacter spp and Enterococcus spp. Prudent empirical treatment for neonatal sepsis should include broad-spectrum antimicrobials.

Animals↗
PubMed2001

Suppression of perception in migraine: evidence for reduced inhibition in the visual cortex.

BACKGROUND: Results from transcranial magnetic stimulation (TMS) studies of visual cortex have confirmed visual cortical hyperexcitability in patients with migraine. It has been speculated that this may be due to deficient intracortical inhibitory tone. However, the TMS induction of phosphenes relies on the reporting of a subjective experience, and may thus be subject to bias. METHODS: Seven migraineurs with visual aura and seven sex- and age-matched controls were studied. Fifty-four different three-letter combinations were briefly displayed and followed by a magnetic pulse at 40, 70, 100, 130, 160, and 190 msec. Subjects were required to report as many letters as they thought they had recognized. RESULTS: In the migraine group, the mean proportion of correctly identified letters was significantly higher at 100 msec, as was the proportion of trials with two or three letters correctly reported. The time window in which perceptual suppression could be introduced was narrower in migraineurs compared to controls. CONCLUSION: These findings suggest that inhibitory systems are activated to a lesser extent by TMS pulses in patients. This observation is in agreement with the hypothesized deficiency of intracortical inhibition of the visual cortex, at least in migraineurs with aura.

Adolescent↗
PubMed2001

A longitudinal study of interleukin-1 gene polymorphisms and periodontal disease in a general adult population.

BACKGROUND: Cross-sectional studies have demonstrated that a specific polymorphism (allele 2 of both IL-1A +4845 and IL-1B +3954) in the IL-1 gene cluster has been associated with an increased susceptibility to severe periodontal disease and to an increased bleeding tendency during periodontal maintenance. The aim of the present study was to investigate the relationship between IL-1 genotype and periodontitis in a prospective longitudinal study in an adult population of essentially European heritage. METHODS: From an ongoing study of the Oral Care Research Programme of The University of Queensland, 295 subjects consented to genotyping for IL-1 allele 2 polymorphisms. Probing depths and relative attachment levels were recorded at baseline, 6, 12, 24, 36, 48 and 60 months using the Florida probe. Periodontitis progression at a given site was defined as attachment loss > or =2 mm at any observation period during the 5 years of the study and the extent of disease progression determined by the number of sites showing attachment loss. Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia were detected using ELISA. RESULTS: 38.9% of the subjects were positive for the composite IL-1 genotype. A relationship between the IL-1 positive genotype and increased mean probing pocket depth in non-smokers greater than 50 years of age was found. Further, IL-1 genotype positive smokers and genotype positive subjects with P. gingivalis in their plaque had an increase in the number of probing depths > or =3.5 mm. There was a consistent trend for IL-1 genotype positive subjects to experience attachment loss when compared with IL-1 genotype negative subjects. CONCLUSION: The results of this study have shown an interaction of the IL-1 positive genotype with age, smoking and P. gingivalis which suggests that IL-1 genotype is a contributory but non-essential risk factor for periodontal disease progression in this population.

Adult↗
PubMed2001

Visual cortex excitability in migraine with and without aura.

OBJECTIVES: Previous research using transcranial magnetic stimulation has produced equivocal findings concerning thresholds for the generation of visual phosphenes in migraine with aura. These studies were methodologically varied and did not systematically address cortical excitability in migraine without aura. We therefore studied magnetophosphene thresholds in both migraine with aura and migraine without aura compared with headache-free controls. METHODS: Sixteen subjects with migraine with aura and 12 subjects with migraine without aura were studied and compared with 16 sex- and age-matched controls. Using a standardized transcranial magnetic stimulation protocol of the occipital cortex, we assessed the threshold stimulation intensity at which subjects just perceived phosphenes via a method of alternating course and fine-tuning of stimulator output. RESULTS: There were no significant differences across groups in the proportion of subjects seeing phosphenes. However, the mean threshold at which phosphenes were reported was significantly lower in both migraine groups (migraine with aura=47%, migraine without aura=46%) than in controls (66%). Moreover, there was no significant correlation between individual phosphene threshold and the time interval to the closest migraine attack. CONCLUSION: Our findings confirm that the occipital cortex is hyperexcitable in the migraine interictum, both in migraine with and without aura.

Adolescent↗
PubMed2001

A Brassica oleracea gene expressed in a variety-specific manner may encode a novel plant transmembrane receptor.

The species Brassica oleracea includes several agricultural varieties characterized by the proliferation of different types of meristems. Using a combination of subtractive hybridization and PCR (polymerase chain reaction) techniques we have identified several genes which are expressed in the reproductive meristems of the cauliflower curd (B. oleracea var. botrytis) but not in the vegetative meristems of Brussels sprouts (B. oleracea var. gemmifera) axillary buds. One of the cloned genes, termed CCE1 (CAULIFLOWER CURD EXPRESSION 1) shows specific expression in the botrytis variety. Preferential expression takes place in this variety in the meristems of the curd and in the stem throughout the vegetative and reproductive stages of plant growth. CCE1 transcripts are not detected in any of the organs of other B. oleracea varieties analyzed. Based on the nucleotide sequence of a cDNA encompassing the complete coding region, we predict that this gene encodes a transmembrane protein, with three transmembrane domains. The deduced amino acid sequence includes motifs conserved in G-protein-coupled receptors (GPCRs) from yeast and animal species. Our results suggest that the cloned gene encodes a protein belonging to a new, so far unidentified, family of transmembrane receptors in plants. The expression pattern of the gene suggests that the receptor may be involved in the control of meristem development/arrest that takes place in cauliflower.

Amino Acid Sequence↗
PubMed2000

Cortical hyperexcitability is cortical under-inhibition: evidence from a novel functional test of migraine patients.

Recent studies of the visual cortex in patients with migraine have generally concluded that migraine (particularly migraine with aura) is associated with a state of functional cortical hyperexcitability. The mechanisms giving rise to this hyperexcitability have hitherto been unclear. This paper reports two studies that used a novel investigative technique, derived from basic research in vision science, to examine specific deficits of inhibitory processing in primary visual cortex. The technique is termed the metacontrast test, and it examines visual masking under highly specified conditions. In Study 1, 12 migraine with aura patients (MA), 12 age-matched migraine without aura patients (MO) and 12 age- and sex-matched headache-free control subjects (C) were compared using the metacontrast test. MA patients were significantly less susceptible to visual masking in the metacontrast test than both MO and C groups: this result is highly consistent with a deficit in cortical inhibitory processing in MA patients. Study 2 examined MA patients taking a variety of migraine prophylactics, again using the metacontrast test. Test results normalized in those MA patients taking sodium valproate, but not in those taking other prophylactics. Sodium valproate is a GABA-A agonist that is known to cross the blood-brain barrier: GABA-ergic networks act as the primary inhibitory mechanism in visual cortex. Taken together, the results of these studies argue that cortical hyperexcitability, at least in MA patients, is likely to be a result of deficient intracortical inhibitory processes.

Adult↗
PubMed2000

Ante-dependence modeling in a longitudinal study of periodontal disease: the effect of age, gender, and smoking status.

BACKGROUND: It is generally accepted that periodontal disease progresses by a series of bursts that are interspersed by periods of stability or even gain of attachment. In order to analyze longitudinal data on a patient's disease experience, it is necessary to use models which accommodate serial dependence. Ante-dependence between the results of a series of periodontal examinations over time can be modeled using a Markov chain. This model describes temporal changes in patients' levels of disease in terms of transition probabilities, which allow for both regression and progression of the disease. The aim of the present study was to demonstrate the use of a Markov chain model to analyze data from a longitudinal study investigating the progression of periodontal disease in an adult population. METHODS: The study population consisted of 504 volunteers; however, only 456 were included in the analysis because the remaining 48 subjects did not give consecutive data. Subjects were examined at baseline, 6 months, and 1, 2, and 3 years. Probing depths (PD) were recorded using an automated probe. Disease was defined as four or more sites with PD > or = 4 mm. Markov chain modeling was used to determine the effect of age, gender, and smoking on the natural progression and regression (healing) of periodontal disease. RESULTS: Smoking and increasing age had no effect on the progression of disease in this population, but did have a significant effect (P values < or = 0.05) in reducing the regression of disease; i.e., their effect on disease appears to be inhibition of the natural healing process. Gender had no significant effects. CONCLUSIONS: These results demonstrate how ante-dependence modeling of longitudinal data can reveal effects that may not be immediately apparent from the data, with smoking and increasing age being seen to inhibit the healing process rather than promote disease progression.

Adolescent↗
PubMed1999

Prevalence of Clostridium perfringens enterotoxin and Clostridium difficile toxin A in feces of horses with diarrhea and colic.

OBJECTIVE: To determine prevalence of clostridial enterotoxins in feces of horses with diarrhea and colic, and to determine whether an association exists between detection of clostridial enterotoxins in feces and development of diarrhea as a complication of colic. DESIGN: Prospective case series and case-control study. ANIMALS: 174 horses with diarrhea, colic, or problems not related to the gastrointestinal tract. PROCEDURE: Horses were assigned to 1 of 4 groups: colic with diarrhea (group 1; n = 30); colic without diarrhea (group 2; 30); diarrhea without colic (group 3; 57); and control (group 4; 57). Feces were evaluated by use of ELISA to detect Clostridium perfringens enterotoxin (CPE) and C difficile toxin A (TOXA). Frequency of detection of CPE or TOXA in groups 1 and 3 was compared with that in groups 2 and 4, respectively. RESULTS: Prevalence of enteric clostridiosis in horses in group 3 was 25%. Clostridium perfringens enterotoxin was detected in 9 of 57 (16%), TOXA in 8 of 57 (14%), and both toxins in 3 of 57 (5%) fecal samples collected from these horses. Neither toxin was detected in feces of the age-matched horses in group 4. Clostridial enterotoxins were detected in feces of 7 of 60 (12%) horses with colic (groups 1 and 2), however, a significant association was not found between detection of enterotoxins in feces and development of diarrhea as a complication of colic. CONCLUSIONS AND CLINICAL RELEVANCE: Clostridia are important etiologic agents of diarrhea in horses. Additionally, changes in intestinal flora of horses with colic may allow for proliferation of clostridia and elaboration of enterotoxins regardless of whether diarrhea develops.

Animals↗
PubMed1998

Cognitive processing in migraine: a failure to find facilitation in patients with aura.

Recent interest in cognitive processing in migraine has been based on the assumption that cortical hyperexcitability in migraine with aura may manifest itself in the form of response time advantages in migraine as compared to controls. The study reported here attempted to replicate and extend the findings of Wray and colleagues (Brain 1995;118: 25-35). Using identical cognitive tasks, three experiments failed to find differences between migraine with aura patients and controls: furthermore, an additional group of patients without aura were also statistically indistinguishable from controls with respect to response times. Error rates were consistently high across experiments, indicating that subjects were responding at or near chance levels. These findings cast doubt on the utility of straightforward cognitive psychological methods for the study of cortical hyperexcitability in migraine. Some theoretical difficulties concerning the interpretation of response times in the context of migraine pathophysiology are discussed.

Adult↗
PubMed1996

Ankle and thigh skin surface temperature changes with repeated ice pack application.

OBJECTIVE: Most of the research on cold applications has been performed on nonexercising supine subjects during a single cold pack application. Most athletic injuries occur during exercise, which increases skin temperature. Exercise before ice application will also increase ankle skin temperature during the rewarming phase. The purpose of this study was to examine the effects of activity on subsequent ice pack applications and rewarming using standard immediate care procedures. DESIGN AND SETTING: Three experimental conditions (20-, 30-, and 40-minute ice pack applications) were applied to 12 subjects in a repeated measures design. Subjects rode a bicycle ergometer for 15 minutes before ice application to the ankle and opposite thigh, and were active (walking with crutches, simulated showering and dressing) for 20 minutes following application. Subjects rested with the limb elevated for an additional 40 minutes. Ice packs were then reapplied for the appropriate time (20, 30, or 40 minutes) followed by 60 minutes of rest with the limb elevated. SUBJECTS: Twelve (8 males, 4 females) college-aged volunteers. Only subjects with good-to-high fitness levels were accepted for this study. MEASUREMENTS: Ankle skin, thigh skin, and atmospheric temperatures were measured every minute using an Isothermex (Columbus Instruments, Columbus, OH). RESULTS: Thigh temperature changes during the first ice application were greater during the 30- and 40-minute conditions than the 20-minute condition. Ankle and thigh temperature changes during the first ice application and rewarming, and for the entire trial were greater during the 40-minute condition than the 20-or 30-minute conditions. Throughout the first ice application and rewarming, and the entire trial, thigh temperature changes were greater during the 30-minute condition than the 20-minute condition. CONCLUSIONS: During immediate care procedures following injury, ice packs should be reapplied immediately following showering, changing clothes, and returning home.

Journal Article↗
PubMed1995

Evidence for a high rate of false-positive results with the indirect fluorescent antibody test for Ehrlichia risticii antibody in horses.

OBJECTIVE: The original objective was to determine seroprevalence of Ehrlichia risticii antibody among horses in California. On the basis of the unexpected results of the survey, an investigation into the accuracy and reproducibility of results of the indirect fluorescent antibody (IFA) test for E risticii was carried out. DESIGN: Prospective, seroprevalence study. ANIMALS: Healthy horses (n = 655) and horses with clinical signs of equine monocytic ehrlichiosis (EME; n = 514) from various regions of California. PROCEDURE: The IFA test was performed. Results were compared with results of an ELISA and with results of western immunoblot analysis. RESULTS: Overall, 104 of 655 (15.9%) healthy horses had evidence of an antibody response. However, 84 of 514 (16.3%) horses with clinical signs of EME also had positive test results, and of the 8 seropositive diseased horses for which paired (acute and convalescent) samples had been submitted, only 1 had a rise in antibody titers between the acute and convalescent samples. Comparison of results for the IFA test, ELISA, and western immunoblot analysis revealed a high rate of false-positive results for the IFA test. Subsequent studies suggested that routine vaccination of horses with non-E risticii vaccines may have contributed to the false-positive reactions. CLINICAL IMPLICATIONS: The data failed to provide conclusive evidence of E risticii infection among California horses. Owing to the high percentage of false-positive test results, caution is advised when using the IFA test to diagnose EME in horses or to determine the necessity for E risticii vaccination.

Animals↗
PubMed1995

Hyperlipidemia, hyperlipemia, and hepatic lipidosis in American miniature horses: 23 cases (1990-1994).

The medical records of 23 American Miniature Horses with hyperlipidemia, hyperlipemia, or hepatic lipidosis were reviewed. The most common clinical signs were anorexia and lethargy. The mean duration of clinical signs was 2.4 days. A primary disease was identified in 19 cases. Enterocolitis was the most common primary disease (n = 10). Intentional feed restriction, as part of treatment for colic, resulted in hyperlipemia in 2 horses and hyperlipidemia in 1. Four horses had primary hyperlipemia, 3 of which had signs of hepatoencephalopathy secondary to hepatic lipidosis. Dextrose, heparin, and insulin were the most common treatments. The overall survival was 61% (14/23). All horses with peak serum triglyceride concentrations > 1,200 mg/dl died or were euthanatized, whereas all but 1 with peak serum triglyceride concentrations < 1,200 mg/dl survived. These findings suggest that when American Miniature Horses, like other ponies and donkeys, are in a negative energy balance, they can rapidly develop hyperlipidemia or hyperlipemia. Early detection and treatment may improve survival.

Animal Feed↗