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Biomedical subjects

L McCormick

Publications and source records attributed to L McCormick.

At least 19 recordsLinked to original sources
PubMed2004

Rofecoxib administration to paediatric patients undergoing adenotonsillectomy.

BACKGROUND: Rofecoxib is a selective COX-2 inhibitor that does not interfere with platelet function and is associated with fewer bleeding complications than other nonsteroidal anti-inflammatory agents (NSAIDs). Our aims were to evaluate the safety and the efficacy of rofecoxib administration to paediatric patients undergoing adenotonsillectomy (T&A). METHODS: We conducted a double-blind, randomized, placebo-controlled study of rofecoxib in 45 ASA 1-2 patients > or = 4 years of age undergoing outpatient T&A. All patients received midazolam 0.5 mg x kg(-1) (max 15 mg) p.o. and either rofecoxib 1 mg x .kg(-1) (max 25 mg) or placebo p.o. 30 min preoperatively. All patients had a standardized anaesthetic and were extubated awake in the operating room at the conclusion of surgery. The Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores were obtained on arrival in the postanaesthetic care unit (PACU). Morphine 25 microg x kg(-1) i.v. were administered up to six times for pain in the PACU. Wong-Baker FACES Scales were obtained at discharge from the PACU and the day surgery unit (DSU). Outcome measures included intraoperative estimated blood loss (EBL), pain scores, PACU morphine requirements and discharge times. RESULTS: There were 23 patients in the rofecoxib group and 22 patients in the placebo group. There were no differences between the rofecoxib and placebo groups in terms of bleeding, pain scores, PACU morphine requirements, PACU times or DSU times. CONCLUSION: Rofecoxib administration to paediatric patients undergoing T&A did not result in increased bleeding. Rofecoxib, however, was not found to decrease morphine use or improve pain scores prior to hospital discharge in T&A patients who received intraoperative morphine and acetaminophen.

Adenoidectomy↗
PubMed2002

A cross sectional study of water quality from dental unit water lines in dental practices in the West of Scotland.

OBJECTIVE: To determine the microbiological quality of water from dental units in a general practice setting and current practice for disinfection of units. DESIGN: A cross-sectional study of the water quality from 40 dental units in 39 general practices and a questionnaire of the disinfection protocols used in those practices. SETTING: NHS practices in primarydental care. SUBJECTS: Thirty-nine general practices from the West of Scotland. METHODS: Water samples were collected on two separate occasions from dental units and analysed for microbiological quality by the total viable count (TVC) method. Water specimens were collected from the triple syringe, high speed outlet, cup filler and surgery tap. Each participating practitioner was asked to complete a questionnaire. Results Microbial contamination was highest from the high speed outlet followed by the triple syringe and cup filler. On average, the TVC counts from the high speed water lines at 37 degrees C and for the high speed lines, triple syringe and cup filler at 22 degrees C were significantly higher than that from the control tap water specimens. The study included units from 11 different manufacturers with ages ranging from under one year to over eight years. The age of the dental unit analysed did not appear to influence the level of microbial contamination. Five of the practices surveyed used disinfectants to clean the dental units but these had no significant effect on the microbiological quality of the water. The majority of dental units (25 out of 40) were never flushed with water between patients. A number of different non-sterile irrigants were used for surgical procedures. CONCLUSION: The microbiological quality of water from dental units in general dental practice is poor compared with that from drinking water sources. Suitable sterile irrigants should be used for surgical procedures in dental practice. Further work is required for pragmatic decontamination regimens of dental unit water lines in a general dental practice setting

Colony Count, Microbial↗
PubMed2002

[Mild cognitive impairments in the elderly: a critical review].

The aging of the population leads to increased awareness of problems associated with age-related degenerative dementias. Given that these dementias are progressive in onset, many clinicians and researchers have proposed criteria that allow for the identification of older subjects manifesting cognitive impairment, but not responding to the criteria for dementia. Our knowledge of subjects with mild cognitive impairment is limited; it is, however, established that they present a high risk of developing dementia in the future. Although it is essential to increase our comprehension of their cognitive and functional decline, the study of subjects presenting mild cognitive impairment is compromised due to the existence of numerous non-converging classifications. The goal of the present article is to conduct a critical review of the different classifications of mild cognitive impairment in the elderly in order to attempt to identify the optimal criteria, allowing for a distinction to be made between subjects with mild cognitive impairment, who remain in a stable state and those whose condition evolves to a dementia. These criteria may enable us to describe a homogenuous group of individuals presenting with different rates of dementia risk factors. We present the classifications most frequently used in clinical and research settings. After listing them according to categorial, clinical or dimensional approaches, we performed a critical analysis for each one. Depending on the diagnostic criteria applied, major variations are revealed for the prevalence of cognitive impairment and the incidence of dementia. They are explained by methodological and theoretical shortcomings that we point out and discuss (e.g., reference group, lack of diagnostic criteria or exclusion criteria, high level of subjectivity). Beyond these criticisms, we discuss the challenges to be met in order to reach the optimal identification criteria. Notably, the impact of mild cognitive impairment on daily living activities should be tested with the use of more specific questionnaires/tasks. The goal of the objective definition of cognitive impairment should be to minimize subjectivity in the diagnosis. It is also suggested that sensitive cognitive measures would be used on all aspects of cognition, while recognizing and taking into account all confounding factors (e.g., age, education level). Given the nature and consequences of mild cognitive impairment, an inter-disciplinary approach is suggested (e.g., neurobiological, psychiatric, and genetic cues). A consensus on optimal diagnostic criteria is essential to propose cognitive and pharmacological treatments for the effective prevention of ementia.

Age Factors↗
PubMed2001

Mechanisms underlying the sensitivity of neurons in the lateral superior olive to interaural intensity differences.

The initial processing of interaural intensity differences (IIDs), the major cue to the azimuthal location of high-frequency sounds in mammals, is carried out by neurons in the lateral superior olivary nucleus (LSO) that receive excitatory input from the ipsilateral ear and inhibitory input from the contralateral ear (IE neurons). The "latency" hypothesis asserts that it is the effects of intensity differences on the latency, and hence the relative timing, of the synaptic inputs to these neurons that is the basis of their sensitivity to IIDs, while other models assign the major role to changes in the relative amplitude of the inputs. To test the latency hypothesis and to determine the contributions of changes in the relative timing and amplitude of synaptic inputs to the IID sensitivity of LSO neurons, a method was developed of generating sets of stimuli that produced either the same changes in the relative timing of inputs without any change in their amplitude (equivalent interaural time difference stimuli) or the same differences in amplitude without any difference in timing (delay-cancelled IID stimuli) as a given range of IIDs. Data were obtained from a sample of IE neurons in the LSO of anesthetized rats using these stimulus paradigms and click and tone-burst stimuli. For click stimuli, the IID sensitivity of a small proportion of neurons was explained entirely by sensitivity to differences in input timing, but the sensitivity of most neurons reflected either sensitivity to the relative amplitude of inputs or to the joint operation of both factors. In neurons whose sensitivity was tested at a number of different absolute sound pressure levels (SPLs), the relative contributions of the two factors tended to differ at different SPLs. The IID sensitivity of onset responses to tone stimuli could be classified into the same three categories but was explained for a larger proportion of neurons by sensitivity to differences in input timing. The IID sensitivity of the late response component of neurons with sustained responses to tones in all cases reflected sensitivity to the relative amplitude of the inputs. The results confirm the contribution of changes in latency produced by intensity changes to the IID sensitivity of the onset responses of many IE neurons in LSO but require rejection of the strong form of the latency hypothesis, which asserts that this factor alone accounts for such sensitivity.

Acoustic Stimulation↗
PubMed2000

Sleep in right hemispherectomized patients: evidence of electrophysiological compensation.

OBJECTIVES: The goal of this study is to provide a better understanding of the role of the cortex in sleep's macro- and microstructure modulation. METHODS: Sleep architecture and phasic events were investigated in 4 patients having undergone right functional or anatomical hemispherectomy and 8 control subjects. Between-groups differences were assessed using the Wilcoxon-Mann-Whitney test. RESULTS: Findings provide evidence for overall similarity between patients' and control subjects' left hemispheric sleep architecture. In addition, results clearly indicate that it is possible to detect electrical activity over the operated side of a hemispherectomized patient's brain, even when resection of the hemi-cortex has been complete. Finally, findings provide evidence for similar left and right hemispheric relative spectral activities and for an increase in fast activity bands over the intact hemisphere in anatomical hemispherectomized patients. CONCLUSIONS: This study provides evidence that right hemispherectomy does not produce significant sleep architecture alterations as recorded over the intact hemisphere. In addition, residual activity detected over the operated side in anatomical hemispherectomized patients is interpreted as resulting from volume conduction originating from generators located in the intact hemisphere. Finally, there is strong evidence for electrophysiological compensation in the intact hemisphere following complete resection of the contralateral hemi-cortex.

Adolescent↗
PubMed1999

Posttranscriptional regulation of US11 in cells infected with a herpes simplex virus 1 recombinant lacking both 222-bp domains containing S-component origins of DNA synthesis.

The US11 gene of herpes simplex virus 1 maps in the unique sequences of the short component of the HSV-1(F) genome approximately 775 bp from the center of the DNA replication origin (OriS) and encodes a virion protein which binds RNA in sequence- and conformation-specific fashion, negatively regulates the accumulation of a prematurely terminated transcript of UL34, associates in the infected cell with the 60S ribosomal subunit, and, late in infection, accumulates in nucleoli. We report the following: (i) Deletion of a 222-bp sequence including OriS (DeltaOriS) negatively affected the accumulation of the US11 protein without decreasing the accumulation of the US11 transcript. (ii) The defect, observed at all times after infection, was multiplicity independent, was unrelated to US11 protein stability, and apparently resulted from a cis-acting element since a coinfecting virus was unable to complement the DeltaOriS virus. (iii) Transcription from the US11 promoter initiated from three sites on the DeltaOriS virus. Transcripts initiated from two of the three initation sites accumulated similarly in cells infected with the DeltaOriS virus or wild-type parent virus. The low-abundance transcript initiating from the third site was apparently unique to the DeltaOriS virus but was not expected to alter the coding capacity of the mRNA. (iv) Infected cells accumulated RNA derived by antisense transcription of the genome domain containing the US11 gene. One transcript accumulated in larger amounts in cells infected with the DeltaOriS virus than in cells infected with parent or repaired virus.

Autoradiography↗
PubMed1998

Diffusion of CDC's Guidelines to Prevent Tobacco Use and Addiction.

The Center for Disease Control and Prevention's School Guidelines to Prevent Tobacco Use and Addiction were developed, in part, to assist state and local education agencies in adopting and implementing effective school-based tobacco prevention and cessation programs. This project assessed state education agency awareness of and reaction to the Guidelines, and documented efforts to disseminate the Guidelines to local schools. Key informants in 15 state education agencies were interviewed. Respondents reported a fairly high level of receptivity to the Guidelines, numerous benefits and few barriers, and high commitment. Levels of use for the Guidelines varied. Dissemination strategies such as mass mailing or teleconferences are not sufficient to influence the use and integration of Guidelines for school health. The diffusion process requires planned change over time through numerous communication channels and should be monitored at the national, state, and local levels to assess effectiveness and impact.

Centers for Disease Control and Prevention, U.S.↗
PubMed1997

REM sleep dream mentation in right hemispherectomized patients.

Investigations of dream mentation in brain damaged patients have shed some light on the controversial issue of cerebral lateralization of dreaming. To examine further the relationships between brain function and dreaming, we studied REM sleep dream recall and content in four patients having undergone right functional or anatomical hemispherectomy and eight matched control subjects. Patients were found to have the capacity to report dreams to much the same extent as control subjects. Further, the patients' dream content was overall similar to that of the control subjects. The results provide strong evidence that dreaming is not a right-hemisphere function, and that the left hemisphere may be more critical for the generation of dreams. In addition, some characteristics of hemispherectomized patients' dream content (characters, smells) are consistent with the possibility that a history of epilepsy may influence REM sleep imagery over the long term.

Adolescent↗
PubMed1997

Assessing the clinical need for short-term conversion from oral to parenteral angiotensin converting enzyme inhibitor therapy in hypertensive patients. A quinapril to quinaprilat placebo-controlled model.

UNLABELLED: RATIONALE AND STUDY DESIGN: This study assesses safety and efficacy when hypertensive patients convert from an oral angiotensin converting enzyme inhibitor, quinapril, to its intravenous counterpart, quinaprilat, and evaluates the need for short-term conversion from oral to parenteral therapy. Blood pressure was measured by clinical measurements using a sphygmomanometer and by 24-h ambulatory blood pressure monitoring. During a placebo-baseline phase, patients blood pressure had to increase within 3 days in the absence of an angiotensin converting enzyme inhibitor. Responding patients were stabilized on oral quinapril and then randomized to 3 days of double-blind treatment with one 5 ml or 10 ml injection twice daily of quinaprilat or placebo. RESULTS: Overall response to quinaprilat in ambulatory blood pressure monitoring and clinic blood pressure measurements was not statistically or clinically different from the response to oral quinapril therapy during baseline. Withdrawal from quinapril resulted in clinically significant increases in all blood pressure measurements compared with baseline therapy; the differences between placebo and quinaprilat therapy were statistically and clinically significant. Two patients treated with quinaprilat withdrew due to hypotension; one patient required a dosage reduction. Parenteral quinaprilat safely maintained blood pressure control whereas placebo control did not during the 72-h interruption of quinapril.

Administration, Oral↗
PubMed1997

Topographical distribution of spindles and K-complexes in normal subjects.

To assess the topographical distribution of sleep spindles and K-complexes, four 15-minute samples of stage 2 sleep in a group of eight healthy young adults were analyzed. Results show that a majority of spindles generated are detected over central regions, and that K-complexes are markedly predominant over prefrontal and frontal regions. These findings are consistent with the single-spindle generator hypothesis and raise questions concerning the Rechtschaffen and Kales rules for scoring K-complexes.

Adolescent↗
PubMed1996

Use of peripheral nerve stimulators to monitor patients with neuromuscular blockade in the ICU.

BACKGROUND: Neuromuscular blockade is a frequently used therapy in the ICU. However, recent reports of prolonged paralysis and general muscular weakness in patients treated with this procedure have raised concerns about its use in intensive care. OBJECTIVE: The purpose of this study was to assess current monitoring practices of nurses who care for patients treated with neuromuscular blockade. METHODS: In January 1995, questionnaires were mailed to a random national sample of 2000 critical care nurses. Of the 2000 questionnaires mailed, 744 were returned. RESULTS: The number of patients per month who were treated with neuromuscular blockade in ICU settings ranged from 0 to 75 (mean = 6.82, SD = 9.15). For each patient, the average number of days of blockade ranged from less than 1 to 63 (mean = 4.12, SD = 3.36). The most common indications for neuromuscular blockade were to assist in mechanical ventilation, reduce oxygen consumption, and treat agitation. Only 41% of respondents (n = 306) reported using train-of-four stimuli and a peripheral nerve stimulator to monitor patients. Depth of neuromuscular blockade was routinely monitored by using clinical assessment (31%), a peripheral nerve stimulator (16%), or both (52%). CONCLUSIONS: Among the respondents, variations existed in monitoring practices and in the use of peripheral nerve stimulators, including the frequency of monitoring and use of the baseline milliamperage. Appropriate monitoring and titration of neuromuscular blocking agents by ICU nurses may aid in preventing adverse effects, including the potential for prolonged neuromuscular blockade. The existing variations in practice may affect patients' outcomes.

Critical Care↗
PubMed1992

Characterization of a herpes simplex virus sequence which binds a cellular protein as either a single-stranded or double-stranded DNA or RNA.

Earlier we reported that herpes simplex virus 1 DNA contains a sequence which binds a host protein in a sequence-specific manner as either a single-stranded or a double-stranded DNA or RNA and that this sequence is located in a transcriptional unit whose RNA traverses the origin of viral DNA replication (OriSRNA) (R.J. Roller, L. McCormick, and B. Roizman, Proc. Natl. Acad. Sci. USA 86:6518-6522, 1989). The protein reacts with both DNA and RNA in band-shift assays and protects the single-stranded RNA sequence from digestion by RNase. We report that the minimal cognate sequence required for these interactions consisted of [N(GTGGGTGGG)2(N less than or equal to 10)]. The ninemer repeat sequence was located at nucleotides -1 to -18 relative to the transcription initiation of the major species of OriSRNA. The activity of the cognate sequence required at least three guanines between thymines and tolerates the insertion of additional thymines, but it was inactivated by the insertion of adenines or by the substitution of some of the guanines with cytosines in one repeat. Replacement of the 10 3' nucleotides has no effect on binding activity, whereas deletion of these sequences abolished it. Among the related sequences with no demonstrable binding activity were some telomeric sequences which interact with known cognate proteins. The electrophoretic mobility of the herpes simplex virus cognate sequences in nondenaturing gels suggests that they may be able to form higher-order structures, but the conditions under which they were formed were different from the optimal conditions for binding the protein. UV light cross-linking studies of labeled RNA-protein complexes following digestion with RNases indicated that the electrophoretic mobility of the protective activity corresponded to that of a protein with an apparent molecular weight of 100,000.

Base Sequence↗
PubMed1992

Toward integrating qualitative and quantitative methods: an introduction.

Both the qualitative and quantitative paradigms have weaknesses which, to a certain extent, are compensated for by the strengths of the other. As indicated in this article, the strengths of quantitative methods are that they produce factual, reliable outcome data that are usually generalizable to some larger population. The strengths of qualitative methods are that they generate rich, detailed, valid process data that usually leave the study participants' perspectives in tact. This article discusses how qualitative and quantitative methods can be combined and it introduces the articles included in this issue.

Anthropology↗
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↗
PubMedDate not supplied

Openness to discuss cancer in the nuclear family: scale, development, and validation.

OBJECTIVE: To describe the development and validation of a scale for assessing openness to discuss cancer in the family. METHOD: Two studies were conducted. Study 1 was a cross-sectional study designed to test the factor structure of the scale. Four hundred ninety-eight patients with either breast cancer or Hodgkin's disease were interviewed. In Study 2, a longitudinal study, 133 patients with cancer in the head and neck were tested at four points in time: just before treatment, 6 weeks, 13 weeks and 52 weeks after treatment. Study 2 aimed to confirm the factor structure established in Study 1, to test for construct validity in a new population, to test the psychometric properties of the Openness Scale, and to test the scale's sensitivity to change. RESULTS: In Study 1, a one-factor solution was revealed, resulting in a scale of eight items. In Study 2, the factor structure found in Study 1 was confirmed. In line with theoretical expectations, subjects who perceived their communication about cancer as more open showed more positive rehabilitation outcomes especially at 13 weeks after treatment (less uncertainty, fewer negative feelings, more control, higher self-esteem, fewer psychological and physical complaints). Furthermore, more open communication related with more support by family members and more discussion with the partner. The scale was found to be stable over time. CONCLUSIONS: The scale's construction and subsequent analysis show that open discussion of problems (related to cancer) in the family can be measured reliably with an eight-item instrument. Additional validation of the scale is indicated.

Adaptation, Psychological↗