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Biomedical subjects

L Yates

Publications and source records attributed to L Yates.

At least 19 recordsLinked to original sources
PubMed2006

Radioligand binding and functional responses of ligands for human recombinant adenosine A(3) receptors.

The binding and functional properties of adenosine receptor ligands were compared in Chinese hamster ovary cells transfected with human adenosine A(3) receptors. Inhibition of [(125)I]-aminobenzyl-5'-N-methylcarboamidoadenosine ([(125)I]-AB-MECA) binding by adenosine receptor ligands was examined in membrane preparations. Inhibition of forskolin-induced cAMP accumulation by agonists was measured using a cAMP enzyme immunoassay. The rank order of agonist potency for both assays was N(6)-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) > 5'-N-ethylcarboxamidoadenosine (NECA) > (-)-N(6)-[(R)-phenylisopropyl] adenosine (R-PIA) > 4-aminobenzyl-5'-N-methylcarboxamidoadenosine (AB-MECA) > N(6)-cyclopentyl adenosine (CPA) > adenosine. The radioligand binding rank order of antagonist potency was N-[9-chloro-2-(2-furanyl)[1,2,4]-triazolo[1,5-c]quinazolin-5-benzeneacetamide (MRS1220) > 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) > 8-phenyltheophylline (8-PT) > 8-(p-sulfophenyl)-theophylline (8-SPT). MRS1220 competitively inhibited the effect of IB-MECA on cAMP production, with a K(B) value of 0.35 nm. These data are characteristic of adenosine A(3) receptors. The absence of Mg(2+) and presence of guanosine 5'-(gamma-thio)triphosphate (GTPgammaS) significantly reduced agonist binding inhibition potency, indicating binding to high- and low-affinity states. The IB-MECA, NECA and R-PIA IC(50) values were greater for the cAMP assay than for radioligand binding, suggesting an efficient stimulus-response transduction pathway.

Adenosine↗
PubMed2005

The non-motor symptom complex of Parkinson's disease: a comprehensive assessment is essential.

Parkinson's disease (PD) is a progressive disease that usually affects the motor system but is also associated with a non-motor symptom (NMS) complex that ranges from dribbling saliva, constipation, depression, sleep disorders, apathy, hallucinations, and dementia. These features contribute significantly to morbidity and institutionalization, more than quadrupling the cost of care. Furthermore, recent evidence suggests that NMS such as constipation, olfaction, rapid eye movement behavior disorder, fatigue, and depression may be markers of a preclinical stage of PD. PD-NMS are not well recognized in clinical practice and part of the reason is the lack of any instrument that aims to assess the complex range of NMS of PD in a unified and integrated manner. Recently, an international, multidisciplinary PD-NMS group has developed an integrated questionnaire and scale to assess NMS of PD in a comprehensive manner. This will help improve care and treatment of PD in the future.

Brain↗
PubMed2002

An evaluation of the beta-1 adrenergic receptor Arg389Gly polymorphism in individuals at risk of coronary events. A WOSCOPS substudy.

AIMS: The Glycine389 variant of the beta-1 adrenergic receptor generates markedly less cAMP when stimulated in vitro than the more prevalent Arginine389 variant and may confer protection against coronary events similar to that observed with beta-blockers. The aim of this study was to ascertain whether this Glycine389 variant protects against coronary events. METHODS AND RESULTS: We identified the genotype at position 389 of the beta1AR in 1554 individuals taken from men enrolled in the West of Scotland Coronary Prevention Study. Men with a coronary event (event group) were each matched for age and smoking status with two control subjects from the same cohort who had not had a coronary event (control group). We compared the distribution of genotypes in the event and control groups. Conditional logistic regression was used to calculate odds ratios for each of the genotypes. The prevalence of the three genotypes in the entire cohort was ArgArg 53.5%, ArgGly 39.6%, GlyGly 6.9%. The Arg389Gly beta-1 adrenergic receptor polymorphism was not associated with coronary events. Using the ArgArg genotype as the reference, the odds ratio for the ArgGly genotype was 1.1 (95% CI, 0.88-1.38) and for the GlyGly genotype it was 1.05 (95% CI, 0.68-1.62). CONCLUSION: Our longitudinal case-control study demonstrates that the Glycine389 variant of the beta-1 adrenergic receptor does not protect against coronary events.

Adult↗
PubMed1998

Relation of endometriosis and neuromuscular disease of the gastrointestinal tract: new insights.

OBJECTIVE: To investigate the neuromuscular activity of the gastrointestinal tract by antroduodenal manometry in women with endometriosis documented by laparoscopy, to assess the effects of diet and drug therapy on symptoms, and to assess the bacterial overgrowth that is commonly associated with these nerve diseases. DESIGN: Prospective, open-label study. SETTING: A clinical center for the care of women's health. PATIENT(S): Fifty women with endometriosis documented by laparoscopy and gastrointestinal tract symptoms characterized by chronic abdominal pain, nausea, vomiting, early satiety, bloating and distention, and altered bowel habits. INTERVENTION(S): Motility of the gastrointestinal tract was recorded and bacterial overgrowth was assessed. Treatment consisted of dietary changes, including reduction of glycemic carbohydrates, balancing with omega 9 oils, elimination of foods with caffeine and tyramine, and addition of omega 3 fatty acids, as well as drug therapy with clonazepam (0.25 mg 3 times per day). RESULT(S): All 50 women showed a characteristic motility change (ampulla of Vater-duodenal wall spasm, a seizure equivalent of the enteric nervous system). Forty of the women showed bacterial overgrowth. There was a significant reduction in the total symptom score after 8 weeks of treatment. CONCLUSION(S): This study suggests that endometriosis and gastrointestinal tract symptoms are a result of the dysfunction of hollow organs. Correction of the biochemical imbalance of the eicosanoid system and the hypersecretion of insulin that results from excessive intake of glycemic carbohydrates and lack of essential fatty acids significantly decreases symptoms in patients with endometriosis and associated neuromuscular disease of the gastrointestinal tract.

Adult↗
PubMed1998

Use of the bispectrum to analyse properties of the human electrocardiograph.

The bispectrum and bicoherence spectrum have been shown to be powerful techniques for identifying different types of nonlinear system responses. This paper presents an introduction to bispectral techniques applied to biomedical signals and examines the bispectral properties of the human electrocardiograph (ECG). The bispectrum proves to be an effective tool for representing and distinguishing different ECG response types. Bispectral ECG analysis is non-invasive and may prove to be a useful discriminant diagnostic.

Electrocardiography↗
PubMed1996

Splinting and local steroid injection for the treatment of ulnar neuropathy at the elbow: clinical and electrophysiological evaluation.

OBJECTIVE: To compare the effects of splinting alone in the treatment of ulnar nerve lesion at the elbow with the effects of applying a local steroid injection in addition to splinting. DESIGN: Twelve nerves of 10 patients were randomly assigned into two groups: 5 nerves in Group A were treated with elbow splinting only; 7 nerves in Group B were treated with local steroid injection in addition to splinting. Therapeutic effects were assessed 1 and 6 months after treatment. SETTING: Patients were selected from an outpatient clinic of a VA Medical Center. PATIENTS: Ten patients (12 nerves) with ulnar neuropathy at the elbow confirmed by electrodiagnostic tests. INTERVENTIONS: Elbow splint was given to patients of both Groups A and B. A single dose of 40 mg triamcinolone plus 1 mL of 1% lidocaine was injected around the ulnar nerve at the elbow of Group A patients. MAIN OUTCOME MEASURES: Clinical evaluation of symptoms and signs, and ulnar motor and sensory nerve conduction studies were performed before, 1 month after, and 6 months after treatment. RESULTS: There was significant improvement in symptoms in both groups at 1 and 6 months after treatment. Ulnar motor nerve conduction velocity across the elbow improved at 1 month in Group A only, but showed improvement at 6 months in both groups. There was no significant change in the other parameters either at 1 or 6 months in both groups. In comparing the differences between Groups A and B regarding the changes at 1 or 6 months after treatment, there was no significant difference between the two groups in all parameters. CONCLUSIONS: Splint application alone is adequate to improve the symptoms and ulnar nerve conduction across the elbow. The addition of a steroid injection did not provide further benefit in the treatment of cubital tunnel syndrome.

Adult↗
PubMed1996

Major vascular injury from high-pressure water jet.

High-pressure water jets are used in industry as a cleaning and cutting tool. Penetrating injuries by these devices can produce minimal external evidence of extensive internal damage. We report a literature review and the case of a limb-threatening injury to the lower extremity caused by such a device.

Accidents, Occupational↗
PubMed1993

Seroepidemiology of Coxiella burnetii among wildlife in Nova Scotia.

We used an indirect immunofluorescence assay to determine antibody titers to phase I and phase II Coxiella burnetii antigens in serum samples from a variety of wild animals in Nova Scotia. Forty-nine percent of the hares, 16.5% of the moose, 7.1% of the raccoons, and 1.5% of the white-tailed deer tested had antibodies to phase I antigen. We conclude that there is extensive infection of the hare population by C. burnetii, with lesser degrees of infection of the moose, raccoon, and deer population.

Animals↗
PubMed1990

Effects of neuro-developmental treatment and orthoses on knee flexion during gait: a single-subject design.

The interactive effects of neuro-developmental treatment and inhibitive ankle-height orthoses on gait were examined via a single-subject research design. Knee flexion during gait at initial contact, mid-stance, heel-off, and mid-swing were measured in a 2-year-old girl with diplegia by use of a goniometer and freeze-frame videography. During the treatment and treatment/orthoses phases, a decrease in excessive knee flexion was noted. Changes in trend over time were greater in the 3-week treatment phase than in the 3-week treatment/orthoses phase. Changes in level at the initiation of the treatment/orthoses phase were greater than in the treatment phase. The described neuro-developmental treatment activities were conducted correctly 92% of the time according to an independent observer. The interrater reliability of goniometric data measured by videography was .93 using intraclass correlation coefficients. The results of this study suggest that both methods of treatment can be used to decrease excessive knee flexion during gait in a child with diplegia.

Biomechanical Phenomena↗
PubMed1990

Incidence of Q fever: pilot studies in two areas in Nova Scotia.

We carried out two pilot studies to determine the incidence of Q fever in Nova Scotia. The first study involved 199 people from the Annapolis Valley region. The first set of blood samples was collected between May and September and the second three to five months later. Two subjects had titers greater than or equal to 1:256 (by the indirect immunofluorescence test), suggesting recent infection. The second group studied consisted of 95 residents of Baddeck. Nova Scotia. Their first serum samples were collected between March and October 1987 and their second samples 18 months later. Two (2%) had fourfold rises in titer and one had a high stable titer. We conclude that the incidence of Q fever in these two areas of Nova Scotia is high.

Aged↗
PubMed1990

Q fever in Sokoto, Nigeria.

There is very little information available about the prevalence of Coxiella burnetii in Africa. We obtained blood from 75 Nigerians hospitalized in Sokoto for a variety of acute medical conditions. Their age range was 7 months to 50 years; there were 39 males and 36 females. Antibody titers were determined to phase I and phase II C. burnetii antigens using a microimmunofluorescence test. Thirty-three (44%) had an antibody titer of greater than or equal to 1:8 to phase II C. burnetii. We conclude on the basis of this limited survey that Q fever is common in Nigeria.

Adolescent↗
PubMed1989

Truckin' pneumonia--an outbreak of Q fever in a truck repair plant probably due to aerosols from clothing contaminated by contact with newborn kittens.

We describe an outbreak of Q fever affecting 16 of 32 employees at a truck repair plant. None of the cases were exposed to cattle, sheep or goats, the traditional reservoirs of Q fever. The cases did not work, live on, or visit farms or attend livestock auctions. One of the employees had a cat which gave birth to kittens 2 weeks prior to the first case of Q fever in the plant. The cat owner fed the kittens every day before coming to work as the cat would not let the kittens suckle. Serum from the cat had high antibody titres to phase I and phase II Coxiella burnetii antigens. The attack rate among the employees where the cat owner worked, 13 of 19 (68%), was higher than that of employees elsewhere, 3 of 13 (28%) [P less than 0.01]. The cat owner's wife and son also developed Q fever. None of the family members of the other employees with Q fever was so affected. We conclude that this outbreak of Q fever probably resulted from exposure to the contaminated clothing of the cat owner.

Adult↗
PubMed1988

An outbreak of Q fever probably due to contact with a parturient cat.

Thirty-three cases (24 definite, nine probable) of Q fever were diagnosed in Victoria County, Cape Breton, Nova Scotia from May to August, 1985. Twenty-six of the cases occurred in residents of Baddeck (population 900, attack rate 2.8 percent), and 21 of the cases occurred during the month of June. There was geographic clustering of the cases: 14 of the 33 (42 percent) lived or worked in four buildings located side by side in the center of town. A case control study revealed that 25 of 29 cases were exposed to a cat that gave birth to stillborn kittens on June 8, 1985 and had bled per vaginum for three weeks prior to delivery. The cat lived in one of the buildings where geographic clustering occurred and frequently visited the other buildings. None of the 40 control subjects was so exposed (p less than 0.001). This cat had an antibody titer of 1:512 to Coxiella burnetii phase 1 antigen and a titer of 1:1024 to phase 2 antigen. Exposure to cattle, sheep and goats, the traditional reservoirs of Q fever, was uncommon among patients and control subjects and none of eight cattle tested had antibodies to C burnetii phase I antigen. We conclude that the infected parturient cat was probably responsible for this outbreak of Q fever affecting 2.8 percent of the population of the town of Baddeck.

Adolescent↗
PubMed1986

Q fever pneumonia associated with exposure to wild rabbits.

4 patients with atypical pneumonia and a history of exposure to wild rabbits were found to have antibodies to Coxiella burnetii but not to the other organisms also commonly associated with atypical pneumonia. 10 (45%) of 22 snowshoe hares caught in the area where 1 of the patients snared his rabbits had antibodies to Coxiella burnetii. Q fever ought to be included in the differential diagnosis of pneumonia acquired following exposure to wild rabbits.

Animal Population Groups↗
PubMedDate not supplied

Community-acquired pneumonia requiring hospitalization: 5-year prospective study.

We studied all patients with community-acquired pneumonia who were admitted to our 800-bed adult acute care hospital from 1 November 1981 to 15 March 1987. The 719 patients had a mean age of 63.2 years; 18% were admitted from nursing homes, and 18% required ventilatory assistance as part of the therapy for pneumonia. Patients with nursing home-acquired pneumonia were significantly older; had a higher mortality (40% vs. 17%); were more likely to be admitted in January; were less likely to complain of cough, fever, anorexia, chills, headache, nausea, sore throat, myalgia, or arthralgia; and were more likely to be confused than those admitted from the community. Pneumonia of unknown etiology and aspiration pneumonia were more common and Mycoplasma pneumoniae infection less common among those with nursing home-acquired pneumonia. Streptococcus pneumoniae accounted for 58% of the 48 cases of bacteremia. None of the bacteremic patients received antibiotics before admission, compared with 34% of the nonbacteremic patients. Aerobic gram-negative rod bacteremia was not more frequent among nursing home patients than among those from the community. The overall mortality was 21% (8.5% for those less than 60 years of age and 28.6% for those greater than 60 years old). By multivariate analysis the following variables were significant predictors of mortality: number of lobes involved by the pneumonic process, number of antibiotics used to treat the pneumonia, age, admission from a nursing home, ventilatory support, and the number of complications that occurred while the patient was in the hospital.

Aged↗