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Biomedical subjects

J Sexton

Publications and source records attributed to J Sexton.

At least 19 recordsLinked to original sources
PubMed2006

Oscillometric brachial mean artery pressures are higher than intra-radial mean artery pressures in intensive care unit patients receiving norepinephrine.

BACKGROUND: Norepinephrine is frequently used in intensive care unit (ICU) patients to raise and maintain an adequate mean arterial pressure (MAP). Conflict arises as to which MAP should guide vasopressor dose, as oscillometric MAP in the brachial artery often diverges from intra-radial MAP. We wanted to estimate the magnitude of this difference in ICU patients receiving norepinephrine, and to see whether the patient age, norepinephrine dose, age of radial catheter, ventilation treatment or severity of illness influenced the difference. METHODS: Prospective observational study comparing oscillometric MAP and intra-radial MAP performed in a central hospital-based surgical ICU during the period from February 2002 through to October 2003. Sixty-eight consecutive patients who received a norepinephrine infusion to maintain MAP above 70 mmHg were included. The mean arterial blood pressure was measured both oscillometrically and in the ipsilateral radial artery. RESULTS: Oscillometric MAP was on average 6.6 mmHg higher (95% CI 5.3-7.9) than intra-radial MAP in the 134 sets of measurements (P < 0.001). The patient's age (P = 0.319), norepinephrine dosage (P = 0.959) the age of the radial catheter (P = 0.992) were not significant. The difference in MAP was marginally greater in ventilated patients (P = 0.061) and significantly greater as the simplified acute physiology score (SAPS) score increased (P = 0.022). CONCLUSIONS: MAP measured oscillometrically over the brachial artery directly in the radial artery gave different results in an ICU population receiving norepinephrine. In more than one of four patients this difference is so large, and increases with illness severity, that the selection of any one method would influence treatment.

Adolescent↗
PubMed2003

Design, development and validation of software for modelling dietary exposure to food chemicals and nutrients.

The Monte Carlo computational system for stochastic modelling of dietary exposure to food chemicals and nutrients is presented. This system was developed through a European Commission-funded research project. It is accessible as a Web-based application service. The system allows and supports very significant complexity in the data sets used as the model input, but provides a simple, general purpose, linear kernel for model evaluation. Specific features of the system include the ability to enter (arbitrarily) complex mathematical or probabilistic expressions at each and every input data field, automatic bootstrapping on subjects and on subject food intake diaries, and custom kernels to apply brand information such as market share and loyalty to the calculation of food and chemical intake.

Diet↗
PubMed2001

Evaluation of methods for subtyping Campylobacter jejuni during an outbreak involving a food handler.

In October 1998, the Centers for Disease Control and Prevention (CDC) assisted in an investigation of an outbreak of campylobacteriosis at a school in Salina, Kansas. Twenty-two isolates were submitted from the Kansas state public health laboratory to CDC, 9 associated with the outbreak and 13 epidemiologically unrelated sporadic isolates. Pulsed-field gel electrophoresis (PFGE) using SmaI and SalI was initially used to validate the epidemiologic data. We then tested the ability of other subtyping techniques to distinguish the outbreak-associated isolates from unrelated sporadic isolates. The methods employed were somatic O serotyping, PCR-restriction fragment length polymorphism (RFLP) analysis of flaA, DNA sequence analysis of 582 bp of flaA that included the short variable region (SVR), and sequencing of the entire flaA gene. PFGE was the most discriminatory technique, yielding 11 SmaI and 10 SalI restriction profiles. All outbreak isolates were indistinguishable by PFGE, somatic O serotyping, and sequencing of the 582-bp region of the flaA gene. fla typing by PCR-RFLP grouped one sporadic isolate with the outbreak strain. Analysis of the DNA sequence of a 582-bp segment of flaA produced strain groupings similar to that generated by PCR-RFLP but further differentiated two flaA PCR-RFLP types (with a 1-bp difference in the 582-bp region). Two sporadic strains were distinct by flaA PCR-RFLP but differed only by a single base substitution in the 582-bp region. The entire flaA gene was sequenced from strains differing by a single base pair in the 582-bp region, and the data revealed that additional discrimination may in some cases be obtained by sequencing outside the SVR. PFGE was superior to all other typing methods tested for strain discrimination; it was crucial for understanding the Kansas outbreak and, when SmaI was used, provided adequate discrimination between unrelated isolates.

Bacterial Typing Techniques↗
PubMed2000

Commentary

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Journal Article↗
PubMed2000

Ensuring seamless care at hospital discharge: a national survey.

AIM: To identify the services that hospital pharmacies were providing in 1999 to facilitate seamless care upon patient discharge. DESIGN: Postal questionnaire containing closed and open questions. SUBJECTS AND SETTING: U.K. Trust hospitals. Questionnaire addressed to Chief Pharmacists to be completed by themselves or most appropriate deputy, then returned anonymously in prepaid envelope. RESULTS: The response rate was 73.4% (163/222). 71.2% of responses came from general hospitals and 23.3% from teaching hospitals. Junior medical staff members were responsible for preparing virtually all discharge prescriptions, which were checked against the ward prescription chart by pharmacists in three-quarters of U.K. Trusts. Hospitals used a wide variety of methods to communicate information about medicine regimens to GPs. There was also wide variation in the provision of discharge counselling, telephone 'help-lines' and clear medication records to patients. Few hospitals involved community pharmacies routinely in the discharge process. CONCLUSION: There is still wide variation within hospital pharmacy practice in meeting the medicines-related needs of patients at discharge.

Communication↗
PubMed1999

Neuromuscular disease and hypoventilation.

Alveolar hypoventilation associated with neuromuscular disease can occur in acute and chronic forms. In the acute form, progressive weakness of respiratory muscles leads to rapid reduction in vital capacity followed by respiratory failure with hypoxemia and hypercarbia. Symptoms are those of acute respiratory failure, including dyspnea, tachypnea, and tachycardia. In the chronic form, impairment of the respiratory muscles affects mechanical properties of the lungs and chest wall, decreases the ability to clear secretions, and eventually may alter the function of the central respiratory centers. Symptoms include orthopnea, fatigue, disturbed sleep, and hypersomnolence. Treatment and outcome of the disease's chronic form are dependent on the underlying clinical cause of the alveolar hypoventilation. For chronic but stable diseases such as old polio, quadriplegia, or kyposcoliosis, mechanical support of minute ventilation can reverse symptoms. For chronic and progressive disease such as muscular dystrophy and amyotrophic lateral sclerosis, mechanical support of minute ventilation provides only symptomatic relief and is usually associated with deterioration to the point of complete ventilator dependency for survival. For the chronic progressive forms of alveolar hypoventilation, there is currently a need for quality randomized controlled clinical trials to define physiologic indicators and appropriate timing for mechanical support of minute ventilation.

Acute Disease↗
PubMed1998

Emergency department presentation of an unusual pleural effusion.

Pleural effusion as a manifestation of malignancy is commonly encountered in clinical practice; most are transudates or exudates of endogenous body fluids. We report a case of pleural effusion that is directly related to the inadvertent infusion of chemotherapeutic agents into the hemithorax of a patient with ovarian carcinoma. With the increasingly common use of outpatient intravenous therapy, emergency department presentations of unusual pleural effusions should be considered.

Aged↗
PubMed1998

Low level CO2 effects on pulmonary function in humans.

The purpose of the study was to determine whether chamber exposure to low levels of CO2 results in functional alterations in gas mixing and closing volume in humans. Four healthy volunteer subjects were exposed to 0.7% CO2 and to 1.2% CO2. Spirometry, lung volumes, single breath nitrogen washout, diffusing capacity for carbon monoxide (DLCO) by two methods, and cardiac output were measured in triplicate. Values were obtained over two non-consecutive days during the training period (control) and on days 2 or 3, 4, 6, 10, 13, and 23 of exposure to each CO2 level. Measurements were made during the same time of day. There was one day of testing after exposure, while still in the chamber but off carbon dioxide. The order of testing, up until measurements of DLCO and cardiac output, were randomized to avoid presentation effects. The consistent findings were a reduction in diffusing capacity for carbon monoxide and a fall in cardiac output, occurring to a similar degree with both exposures. For the group as a whole, there was no indication of major effects on spirometry, lung volumes, gas mixing or dead space. We conclude that small changes may occur in the function of distal gas exchanging units; however, these effects were not associated with any adverse health effects. The likelihood of pathophysiologic changes in lung function or structure with 0.7 or 1.2% CO2 exposure for this period of time, is therefore, low.

Breath Tests↗
PubMed1994

Vaccination of sheep with purified cysteine proteinases of Fasciola hepatica decreases worm fecundity.

There has been some evidence from several parasite systems that proteinases might have potential as protective antigens against parasitic infection. A cysteine proteinase complex identified in the regurgitant of adult F. hepatica was examined in this context. The thiol-cathepsin-related proteinases of M(r) 28,000 were purified and tested in vaccine trials of sheep infected with liver fluke. Ten animals were immunised with the purified proteinases and developed antibodies to the cysteine proteinases prior to challenge with F. hepatica metacercariae. Infection appeared to cause a boost in antibody response by Week 4 into infection, and antibody levels were generally sustained throughout infection. The cysteine proteinases are not novel antigens, since low-level antibody titres were also detected in nonimmunised controls by late infection. On completion of the trial, there was no difference in worm burden between the two groups. However, faecal egg counts and therefore worm fecundity were significantly decreased.

Animals↗
PubMed1994

Job marketability survey for athletic trainers in selected midwestern States.

This study was conducted to determine job availability for athletic trainers in school and/or clinic settings in western Kansas, western Nebraska, western Oklahoma, and eastern Colorado. A survey was sent to 109 physical therapy (PT) clinics and 194 public schools to determine the major factors associated with job marketability. Of the 194 questionnaires mailed to the public schools, 119 were returned for a 61% response rate. Of the 109 questionnaires mailed to PT clinics, 57 were returned for a 52% response rate. Very few school districts (13%) hired their own trainer due to financial restrictions; therefore, the National Athletic Trainers' Association (NATA) athletic trainer would increase his/her likelihood of being hired if he/she was also teacher-certified. Most of the clinics responding would hire an NATA-certified athletic trainer if that individual was also licensed as a physical therapist, whereby, the trainer without PT licensure could be used for outreach programs for the local high schools. Essential factors identified by both the public school and clinic personnel for increasing the marketability of athletic trainers were: 1) NATA certification, 2) acquisition of an additional certification such as a teaching endorsement or a PT degree, and 3) willingness to provide services jointly to the schools and/or clinic with either being the primary hiring agent.

Journal Article↗
PubMed1993

Simplified treatment of vascular lesions using the argon laser.

Treatment of mucosal lesions and abnormalities using the carbon dioxide laser is well documented in the dental literature; however, use of the argon laser for the ablation of intraoral vascular malformations is not. This article discusses the argon laser-soft tissue interaction and illustrates by case reports its application in the treatment of vascular lesions.

Adult↗
PubMed1993

Permethrin-impregnated bed nets for malaria control in northern Guatemala: epidemiologic impact and community acceptance.

Permethrin-impregnated bed nets were evaluated as a control measure for malaria in northern Guatemala. Twelve hundred forty participants were allocated to one of three experimental groups (impregnated bed nets [IBN], untreated bed nets [UBN], and controls) and followed up for a period of 13 months. The incidence density of malaria was significantly lower in both IBN (86 cases/1,000 person-years) and UBN groups (106/1,000) compared with that in controls (200/1,000). No difference in malaria incidence was noted between the IBN and UBN groups. Complaints of fever and chills were less frequent in the IBN group compared with controls. The participants were enthusiastic about the nets, which they saw as a means for avoiding nuisance insects more than for preventing malaria. Most (85%) wanted to wash their nets every 4-12 weeks, a practice known to shorten the duration of residual insecticide action. Larger studies are needed to determine whether or not impregnated bed nets offer an advantage over untreated nets in this setting.

Adult↗