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Biomedical subjects

P C Young

Publications and source records attributed to P C Young.

At least 19 recordsLinked to original sources
PubMed2002

Destructive osteoarthritis after delayed diagnosis of tuberculosis.

Osteoarticular tuberculosis rarely occurs in developed countries. Initial symptoms are often overlooked and the diagnosis is frequently delayed for several months. Thus, despite available diagnostic tools and accessible treatment, destruction of affected joints remains a complication of non-vertebral osteoarticular tuberculosis even in industrialized countries. We report a patient from Cleveland, Ohio, USA, in whom the delayed diagnosis of tuberculous osteoarthritis led to severe destruction of the left knee and finally, after superinfection with Staphylococcus aureus, to an above-the-knee amputation. The epidemiology, presentation, diagnosis and treatment of nonvertebral tuberculous osteoarthritis are discussed.

Aged↗
PubMed2001

Significance of grunting respirations in infants admitted to a well-baby nursery.

OBJECTIVES: (1) To determine the frequency and duration of grunting in term and near-term newborns; (2) to determine the peripartum characteristics associated with grunting; and (3) to compare the short-term outcomes of newborns with and without grunting. DESIGN: Medical record review of all newborns admitted to a well-baby nursery during a 2-month period. SETTING: University well-baby nursery for term infants, with more than 2700 deliveries annually. MAIN OUTCOME MEASURES: Frequency and duration of grunting, maternal and newborn clinical characteristics, clinical course, and length of stay. RESULTS: Grunting respirations beginning during the first 4 hours of life were recorded for 81 (17.4%) of 466 newborns. Fifty-five (68%) stopped grunting within 30 minutes of birth, 69 (85%) by 1 hour, and 75 (93%) by 2 hours. More mothers of grunting infants received intrapartum antibiotics than mothers of nongrunters (33% vs 20%; P =.03). More grunting infants than nongrunters received bag and mask resuscitation (15% vs 5%; P =.01). More chest radiographs, blood cell counts, and blood cultures were ordered for grunting infants, and antibiotics were more often given to grunting than nongrunting infants (11.1% vs 4.6%; P =.04). Grunters' length of stay exceeded that of nongrunters (72 vs 55 hours; P =.01), but only 3 were transferred to a neonatal intensive care unit. CONCLUSIONS: All grunting infants should be carefully observed, but because nearly all otherwise healthy term or near-term infants will stop grunting and have a benign course, other interventions can be postponed for 1 or 2 hours to give the newborn a chance to stop grunting or show other signs of respiratory illness.

Anti-Bacterial Agents↗
PubMed2001

Exposures and outcomes of children with urticaria seen in a pediatric practice-based research network: a case-control study.

OBJECTIVES: (1) To determine the duration, outcome, and associated findings of urticaria in children seen by general pediatricians; (2) to compare the exposure to foods, medications, insect stings or bites, and the presence of other symptoms in children with urticaria with controls; (3) to determine general pediatricians' management of urticaria. DESIGN: Case-control. PARTICIPANTS: Children with urticaria seen by Utah Pediatric Practice Based Research Network members between August 1, 1999, and August 31, 2000. Control patients were matched for age and sex. MAIN OUTCOME MEASURES: Duration of urticaria; associated symptoms; personal and family history of atopy; medications; ingestion of peanuts, nuts, shellfish, tomatoes, strawberries, or eggs; being stung by an insect; suspected cause, diagnostic studies; treatment. RESULTS: Fifty-two cases and 47 controls were enrolled. The mean duration of urticaria was 8.9 days (range, 1-50 days). Seventeen patients (33%) and 1 control patient were taking antibiotics (odds ratio [OR], 22.3; 95% confidence interval [CI], 2.8-176; chi(2), P<.001). Fourteen patients and 5 controls had gastrointestinal symptoms (OR, 3.1; 95% CI, 1.02-9.4; chi(2), P =.04). There were no differences between cases and controls for other symptoms, personal or family history of atopy, ingestion of the foods listed, insect sting, or other medications. A cause was suspected in 28 patients (54%): a "viral illness" (19%), antibiotics (15%), or a combination (35%). CONCLUSIONS: Patients were more likely than controls to be taking an antibiotic and were more likely to have a personal or family history of atopy or to report ingesting foods commonly associated with urticaria. A viral illness was the most common cause suspected by pediatricians.

Adolescent↗
PubMed2001

High-resolution analysis of tomato leaf elongation: the application of novel time-series analysis techniques.

This paper demonstrates the use of a novel suite of data-based, recursive modelling techniques for the investigation of biological and other time-series data, including high resolution leaf elongation. The Data-Based Mechanistic (DBM) modelling methodology rejects the common practice of empirical curve fitting for a more objective approach where the model structure is not assumed a priori, but instead is identified directly from the data series in a stochastic form. Further, this novel approach takes advantage of the latest techniques in optimal recursive estimation of non-stationary and non-linear time-series. Here, the utility and ease of use of these techniques is demonstrated in the examination of two time-series of leaf elongation in an expanding leaf of tomato (Lycopersicon esculentum L. cv. Ailsa Craig) growing in a root pressure vessel (RPV). Using this analysis, the component signals of the elongation series are extracted and considered in relation to physiological processes. It is hoped that this paper will encourage the wider use of these new techniques, as well as the associated Data-Based Mechanistic (DBM) modelling strategy, in analytical plant physiology.

Algorithms↗
PubMed2001

Data-based modelling and proportional-integral-plus (pip) control of nitrate in an activated sludge benchmark.

This paper presents the result of an investigation into the Proportional Integral Plus (PIP) control of nitrate in the second zone of an activated sludge benchmark. A data-based reduced order model is used as the control model and identified using the Simplified Refined Instrumental Variable (SRIV) identification and estimation algorithm. The PIP control design is based on the Non Minimum State Space (NMSS) form and State Variable Feedback (SVF) methodology. The PIP controller is tested against dynamic load disturbances and compared with the response of a well tuned PI controller.

Benchmarking↗
PubMed2000

Strain differences in vaginal responses to the xenoestrogen bisphenol A.

Bisphenol A (BPA) is the monomer component of polycarbonate plastics and epoxy resins; human exposure derives from leachate in foodstuffs packaged in certain plastics or from epoxy-based dental appliances. BPA stimulates prolactin secretion in Fischer 344 (F344) rats but not in Sprague-Dawley (S-D) rats. The present studies were performed to determine if another classic estrogen target tissue, the rat vagina, responds to BPA in a strain-specific manner. In F344 rats BPA increased DNA synthesis in vaginal epithelium with a median effective dose (ED(50)) of 37.5 mg/kg body weight; DNA synthesis was not stimulated in S-D rats by any dose tested. Clearance of (3)H-BPA from blood followed the same time course in both strains of rats, with a half-life of 90 min. Scatchard analysis of [(3)H]estradiol binding showed no strain differences in concentration or affinity of the vaginal estrogen receptor. BPA increased the level of mRNA for the immediate early gene, c-fos, with similar dose-response curves in both rat strains. Thus, F344 and S-D rats exhibit differences in sensitivity to BPA at the level of cell proliferation in the vaginal epithelium. However, metabolic clearance of BPA and the early events that lead to the proliferative response, receptor-ligand interaction and induction of immediate early genes, show no strain differences. These observations suggest that differences in intermediate effects must account for the difference in sensitivity of the proliferative response to the xenoestrogen. Furthermore, these results point to the need for caution in choosing a suitable end point and animal model when seeking to test the estrogenic effects of xenobiotics.

Animals↗
PubMed1999

Acute generalized exanthematous pustulosis induced by chromium picolinate.

A case of acute generalized exanthematous pustulosis (AGEP) due to chromium picolinate is described. This supplemental form of chromium has received a great deal of interest recently because of its possible beneficial effects on both muscle strength and body composition. There have been no previous reports to our knowledge of adverse cutaneous reactions to this agent. Various aspects of AGEP are reviewed.

Acute Disease↗
PubMed1999

Ask, advise, assist: pediatricians and passive smoke exposure.

The objectives of this study were to determine: (1) how frequently pediatricians obtain a history of passive smoke exposure (PSE), (2) what type of advice regarding PSE they offer and how frequently they offer it, and (3) what methods and what assistance they believe would be useful to reduce PSE. A random sample of 1,000 US members (GEN) of the American Academy of Pediatrics (AAP) and all 724 members of the AAP sections of pulmonology, otolaryngology, and allergy (SPECS) were sent a questionnaire. Seven hundred fifty-five usable questionnaires were returned. Ninety-six percent of 321 general pediatricians obtained a PSE history at least "sometimes" but were much more likely to "always" do so when seeing a patient with asthma (87%) or recurrent otitis media (56%) than during well-child visits (41%) (p < 0.0001). Ninety-eight percent of pulmonologists and 95% of allergists "always" obtained a PSE history from parents of their asthmatic patients as compared with generalists who reported doing so 87% of the time (p = 0.0004). Fifteen percent of GEN gave specific assistance to parents with smoking cessation such as referral to an internist or family practitioner or a community agency or initiating a smoking cessation program themselves, whereas 85% gave only nonspecific advice such as, "don't smoke around the child," or "quit smoking." Reasons for not initiating a cessation program included lack of skills (38%) or time (36%) or a belief that it was "not their responsibility" (13%). Pediatricians indicated that brochures for parents that describe the hazards of PSE and contain specific information regarding how to refer to community smoking cessation programs would be of most use to them in helping parents reduce PSE to their children. Pediatricians frequently ask about PSE and advise reducing it but seldom assist parents with specific advice regarding effective methods to quit smoking.

Child↗
PubMed1999

Panic disorder in schizophrenia.

OBJECTIVE: To determine the frequency of panic attacks and panic disorder in patients with chronic schizophrenia or schizoaffective disorder. METHOD: Fifty-three male outpatients meeting Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for chronic schizophrenia or schizoaffective disorder were administered sections of the Structured Clinical Interview for DSM-IV (SCID). If panic attacks were reported, patients were queried about treatment and about onset relative to psychotic symptoms. RESULTS: Forty-nine patients were sufficiently organized to participate in the evaluation. Twenty-one (43%) experienced panic attacks, and 16 (33%) had current or past panic disorder. Eight (50%) of the 16 with panic disorder had been treated for panic. Substance dependence was not associated with having panic attacks or current or past panic disorder. Patients with paranoid schizophrenia were more likely than patients with schizoaffective or undifferentiated schizophrenia to have experienced panic attacks (57% versus 20%, chi 2 = 6.0, P < 0.02) or panic disorder (47% versus 10%, chi 2 = 6.9, P < 0.01). CONCLUSION: Panic attacks and panic disorder are common in men with schizophrenia or schizoaffective disorder. Panic disorder may be an overlooked comorbid diagnosis in patients with schizophrenia.

Chronic Disease↗
PubMed1999

Kawasaki disease: more patients are being diagnosed who do not meet American Heart Association criteria.

OBJECTIVE: To determine the frequency of Kawasaki disease (KD) diagnosis in patients who did and did not meet American Heart Association (AHA) diagnostic criteria and to examine the clinical findings, the time to treatment, and the outcomes of the two groups. DESIGN: Retrospective review of all patients with a discharge diagnosis of KD at a tertiary care children's hospital (1991-1997). RESULTS: A total of 127 patients were identified. All received intravenous immune globulin (IVIG) and had complete echocardiographic studies. AHA criteria were met in 81 (63.8%). More patients who did not meet criteria (9 of 46, 20%) had coronary artery abnormalities (CAA), compared with those who had the complete clinical picture (6 of 81, 7%). The 15 patients with CAA received IVIG later (12.4 +/- 7.4 days) from onset of symptoms compared with those with no CAA (8.2 +/- 4.6). The time period was the same for patients with CAA who met the criteria, (11.8 +/- 5.8 days) as for patients who did not meet AHA criteria (12.8 +/- 8.6 days). Infants were more likely than were older children to develop CAA, to receive IVIG later, and to be diagnosed with an incomplete clinical picture. CONCLUSION: Physicians are increasingly likely to diagnose KD in patients who do not meet complete AHA criteria. Despite the potential risks of overdiagnosis and overtreatment, this practice seems justified because the complete criteria are an insensitive indicator of having or developing CAA.

Adolescent↗
PubMed1999

MR imaging of the traumatized lumbar spine.

MR imaging is the imaging modality of choice for evaluation of the traumatized lumbar spine, providing critical information for determination of appropriate therapy. It is superior to other modalities for evaluating the supporting ligaments, disc, spinal cord, and the cauda equina. Major fracture patterns are readily discernable. Canal compromise caused by osseous fragments, epidural hemorrhage, or disc fragments is well visualized.

Cauda Equina↗
PubMed1998

Usefulness of echocardiography for detection of coronary artery thrombi in patients with Kawasaki disease.

To evaluate the role of echocardiography for predicting and accurately detecting thrombi in patients with abnormal coronary arteries after Kawasaki disease, we reviewed the echocardiograms of 40 consecutive patients and compared echocardiographic findings with angiographic findings when available. Patients with Kawasaki disease who had coronary artery aneurysms > or =5 mm had significantly greater multivessel involvement, thrombi, and persistent coronary abnormalities than those with diameters <5 mm.

Child, Preschool↗
PubMed1998

Felodipine-induced gingival hyperplasia.

Felodipine is a calcium channel blocking agent used in the management of hypertension and angina. We report a case of gingival hyperplasia in a patient with chronic use of this drug. Gingival changes occurred soon after initiation of felodipine and improved upon its discontinuation. The clinical characteristics, inciting agents, proposed pathogenetic mechanisms, as well as prevention and treatment of drug-induced gingival hyperplasia are briefly reviewed.

Aged↗
PubMed1997

A comparison of intercuff and single cuff techniques of intravenous regional anaesthesia using 0.5% prilocaine mixed with technetium 99m-labelled BRIDA.

Intravenous regional anaesthesia of the upper limb is a widely used technique first described by Bier in 1908. The exact site of action of injected local anaesthetic has not been determined. We have performed intravenous regional anaesthesia on volunteers using prilocaine mixed with technetium 99m-labelled 2,4,6 trimethyl-3-bromo iminodiacetic acid. Two different techniques of intravenous regional anaesthesia (the 'normal' cuff and the intercuff techniques) were combined with gamma camera tracking of the radiolabel to determine the site of local anaesthetic action. The onset of action was similar for both techniques. The local anaesthetic was mainly retained in the antecubital fossa in both techniques but in the 'normal' technique, the local anaesthetic subsequently showed some retrograde spread. This would suggest that the main site of action of local anaesthetic used for intravenous regional anaesthesia is the larger nerves in the vicinity of the antecubital fossa.

Adult↗
PubMed1997

Aeromedical evacuation in Bosnia.

The objective of this study was to assess the value of aeromedical evacuation when compared to road ambulance transportation in predominantly trauma patients in a rural area. Uniquely, trauma was the most common presenting condition (75%), distances to secondary care facilities were long and road routes were poor with a risk of being mined. Data were collected of all British aeromedical flights in Multi-National Division Southwest, Bosnia-Herzegovina, over a six-month period, and benefit to the patient was assessed by a panel of experts when compared to calculated road ambulance evacuation. Sixty-nine patients were evacuated by air on 57 flights and transported to a secondary care facility for further management. The panel of experts found that only 15 of the 69 patients (22%) had benefited from aeromedical evacuation. This study again shows the low benefit to the patient from indiscriminate use of aeromedical evacuation, despite the air ambulance being operated in apparently ideal conditions of a high percentage of trauma, a rural setting and poor road communications. Crew safety and the high costs further highlight the need to devise a system that can screen out unnecessary flights and identify those patients who would benefit most.

Adult↗
PubMed1996

Novel estrogenic action of the pesticide residue beta-hexachlorocyclohexane in human breast cancer cells.

The estrogenic action of some persistent organochlorine pesticide residues may play a role in the progression of hormonally responsive tumors of the breast and uterus. The prototypical xenoestrogen o,p'-dichlorodiphenyltrichloroethane (o,p'-DDT) acts by binding and activating the estrogen receptor (ER). The present study focuses attention on the mechanisms through which another organochlorine compound, beta-hexachlorocyclohexane (beta-HCH), exerts estrogen-like effects in human breast cancer cells. Both o,p'DDT and beta-HCH stimulated proliferation in a dose-dependent manner in the ER-positive cell lines MCF-7 and T47D but not in the ER-negative lines MDA-MB231, MDA-MB468, and HS578T. Both compounds produced an increase in the steady state level of pS2 mRNA in MCF-7 cells. These responses were equal in magnitude to the maximal effect of estradiol, and they were inhibited by inclusion of the antiestrogen ICI164384. On the other hand, when tested in a competitive binding assay, beta-HCH did not displace 17beta-[3H]estradiol from the ER even at a concentration that was 40,000-fold higher than the tracer steroid. Furthermore, nuclear retention of the ER during homogenization procedures was induced by a 2- or 24-h treatment of MCF-7 cells with o,p'-DDT and 17beta-estradiol but not by treatment with beta-HCH; this indicates that beta-HCH nether activates the ER, nor is it converted intracellularly to an ER ligand. Transcriptional activation by beta-HCH occurs in estrogen-responsive GH3 rat pituitary tumor cells transfected with a luciferase reporter construct driven by a complex 2500-bp portion of the PRL gene promoter; this trans-activation response is inhibited by inclusion of ICI164384. However, beta-HCH is ineffective in stimulating a reporter construct driven only by a consensus estrogen response element and a minimal promoter derived from the herpes simplex virus thymidine kinase gene. Thus, beta-HCH cannot act on a simple, single estrogen response element; rather, it requires the combinatorial regulation found in a complex promoter. These data are consistent with the notion that beta-HCH stimulation of cell proliferation and gene expression is ER dependent, but its action is not through the classic pathway of binding and activating the ER. beta-HCH may represent a new class of xenobiotic that produces estrogen-like effects through nonclassic mechanisms and, therefore, may be of concern with regard to breast and uterine cancer risk.

Adenocarcinoma↗