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Biomedical subjects

L Morrison

Publications and source records attributed to L Morrison.

At least 19 recordsLinked to original sources
PubMed2006

Lethal consequences.

Explore the source record for details and available documents.

Antibiotic Prophylaxis↗
PubMed2006

Extended storage of platelets in SSP platelet additive solution.

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the effects of extended storage of pooled random platelets in SSP+ additive solution (MacoPharma). MATERIALS AND METHODS: Eight buffy coat-derived, pooled, leucoreduced platelet concentrates were prepared in 75% SSP+, 25% plasma using Fresenius/NPBI Composelect thrombocyte polishing filter (TPF) systems. Platelet concentrates were stored for 19 days in polyolefin storage bags and samples for in vitro analysis were taken at various time-points during storage. RESULTS: Platelet yields were lower than seen routinely when platelets are prepared in 100% plasma. The in vitro quality of the platelets stored in SSP+ was maintained until day 9. Glucose was depleted by day 12 and this was accompanied by a rapid fall in pCO2, a rise in pO2 and a cessation of lactate production. ATP and bicarbonate concentrations fell, the platelets began to swell and the ability to swirl decreased. Soluble P-selectin, glycocalicin, and regulated on activation, normal, T-cell expressed, and secreted (RANTES) concentrations increased, as did P-selectin expression. Loss of platelets and an increase in lacate hydrogenase concentration indicated that lysis had occurred. However, the pH remained between 6.4 and 7.4. CONCLUSIONS: The results suggest that SSP+ could be used for platelet storage for up to 9 days. However, the preparation of platelets in the additive requires some optimization. In vivo studies are required to confirm these in vitro results.

Blood Platelets↗
PubMed2005

Total and nematode-specific IgE responses in intestinal lymph of genetically resistant and susceptible sheep during infection with Trichostrongylus colubriformis.

Total and antigen-specific IgE responses in afferent (AIL) and efferent (EIL) intestinal lymph of sheep with a nematode resistant (R) or susceptible (S) genotype during challenge infection with the intestinal nematode parasite Trichostrongylus colubriformis were examined. Within each sheep line, lambs with a nematode naive or nematode field-primed pre-challenge status were used. Total IgE level in AIL and EIL was dependent on nematode infection and was further influenced by genotype or the immune phenotype (nematode immune mean FEC+/-SDM=77+/-179 or non-immune mean FEC+/-SDM=4016+/-4318) of the animal. During T. colubriformis challenge immune animals had higher levels of total IgE in lymph than non-immune sheep, R line sheep had higher concentrations of total IgE than S line sheep, and field-primed animals had higher total IgE levels than nematode naive animals. Concentrations of total IgE were consistently higher in AIL than EIL or serum and were higher in lymph draining the proximal than the distal jejunum demonstrating that polyclonal IgE in AIL was largely derived from the intestinal mucosa of the anatomical compartment where the nematodes reside. The consistently higher concentration of total IgE in AIL was dependent on phenotype or genotype and in S genotype sheep also on the pre-challenge status. Concentrations of nematode specific IgE were significantly higher in EIL than AIL indicating a preference for the production of IgE reacting with excretory secretory products of the infective T. colubriformis larvae in the regional lymph node.

Animals↗
PubMed2005

Playing conditions, player preparation and rugby injury: a case-control study.

This paper investigates the effect of player preparation, ground conditions and weather conditions upon the injury risk for Rugby Union players. A population-based case-control study was performed using a sample (n= 1043) of New Zealand Rugby Union players aged 16 y and above. Details concerning game preparation (warm-up and usual position), and ground and weather conditions (precipitation, wind and temperature) were obtained from the players. If players were injured during the season (n= 624) they were asked to provide details about the game in which they were last injured. Uninjured players (n= 419) provided details about the last game in which they played. Injuries were more likely to occur when games were played on hard grounds or in calm or warm conditions. Playing out of position and the duration of warming up did not significantly alter the risk of injury. When player preparation, ground and weather conditions, grade, age, playing position and rugby experience were simultaneously controlled for, hard ground and the absence of wind were associated with increased risk. The influence of these factors may be indirect, through adaptation to the conditions in which a game is played.

Adolescent↗
PubMed2005

C1 inhibitor deficiency: consensus document.

We present a consensus document on the diagnosis and management of C1 inhibitor deficiency, a syndrome characterized clinically by recurrent episodes of angio-oedema. In hereditary angio-oedema, a rare autosomal dominant condition, C1 inhibitor function is reduced due to impaired transcription or production of non-functional protein. The diagnosis is confirmed by the presence of a low serum C4 and absent or greatly reduced C1 inhibitor level or function. The condition can cause fatal laryngeal oedema and features indistinguishable from gastrointestinal tract obstruction. Attacks can be precipitated by trauma, infection and other stimulants. Treatment is graded according to response and the clinical site of swelling. Acute treatment for severe attack is by infusion of C1 inhibitor concentrate and for minor attack attenuated androgens and/or tranexamic acid. Prophylactic treatment is by attenuated androgens and/or tranexamic acid. There are a number of new products in trial, including genetically engineered C1 esterase inhibitor, kallikrein inhibitor and bradykinin B2 receptor antagonist. Individual sections provide special advice with respect to diagnosis, management (prophylaxis and emergency care), special situations (childhood, pregnancy, contraception, travel and dental care) and service specification.

Adolescent↗
PubMed2002

Infant-furniture-related injuries among preschool children in New Zealand, 1987-1996.

OBJECTIVE: To describe the epidemiology of infant-furniture-related fatalities and hospitalizations in New Zealand, for children aged 0-4 years. METHODS: Infant-furniture-related deaths and hospitalizations were selected from the New Zealand Health Information Service databases for the 10-year period 1987-1996. Intentional injuries were excluded. RESULTS: Forty-three fatalities were identified. Twenty-two fatalities (51%) occurred in cots, while 13 (30%) occurred in beds. Other products involved were prams, push chairs, high chairs, car seats, portable cots and walkers. A total of 1679 infants were hospitalized through infant-furniture-related injuries. Increasing trends in hospitalizations for baby walkers, beds and bunks were observed. CONCLUSIONS: On average, four infants die each year from injuries related to infant furniture, and hospitalizations from injuries associated with infant furniture use are increasing. Mandatory standards are one measure to reduce these numbers, but education is also necessary.

Bedding and Linens↗
PubMed2002

Personal and situational influences on drink driving and sober driving among a cohort of young adults.

OBJECTIVES: To compare personal and situational influences on incidents involving drink driving with those involving sober driving. METHODS: Information on a range of road safety practices was sought in face to face interviews conducted with 969 members of the Dunedin Multidisciplinary Health and Development Study cohort at age 26 years. A total of 750 study members reported an incident that involved the opportunity to consume alcohol and also travel by motor vehicle. Of these, 87 were classified as "drink drive incidents" and 663 as "sober drive incidents". RESULTS: Study members who were male, of lower socioeconomic status, had no school qualifications, or were dependent on alcohol or marijuana at age 21 were significantly more likely to report a drink drive incident at age 26. Compared with the sober drive incidents, the drink drive incidents were more commonly associated with driving alone, drinking at bars, and no advanced planning. For drink drive incidents the amount of alcohol consumed was influenced by the conviviality of the occasion, whereas for sober drive incidents it was the need to drive. One quarter of those reporting drink drive incidents stated they had used marijuana and/or LSD at the event at which they drank. CONCLUSIONS: Drink drive and sober drive incidents differed, particularly with regard to decisions made before the event. Prevention efforts could usefully be targeted toward these decisions.

Accidents, Traffic↗
PubMed2001

Oculopharyngeal muscular dystrophy in Hispanic New Mexicans.

CONTEXT: Oculopharyngeal muscular dystrophy (OPMD) is a rare myopathy caused by polyalanine triplet repeat expansion in the gene for poly(A) binding protein 2 (PABP2) and is found in isolated cohorts throughout the world. We have observed numerous cases of OPMD in New Mexico. OBJECTIVE: To characterize the clinical, genetic, and demographic features of the OPMD population in New Mexico. DESIGN, SETTING, AND PARTICIPANTS: Cohort study with analysis of outpatient clinic medical records from 1965 to 2001 at the University of New Mexico Hospital and the New Mexico VA Health Care System in Albuquerque, which serve the entire state. MAIN OUTCOME MEASURES: Clinical phenotype, supplemented with genetic confirmation (n = 10 patients) and in-depth clinical evaluations (n = 49 patients). RESULTS: We identified 216 cases of OPMD (99 women and 117 men) from 39 kindreds of New Mexicans spanning up to 4 generations. All patients were Hispanic, and the majority of probands came from northern New Mexico. In patients who had both ocular and pharyngeal muscle weakness, ptosis was just as likely to occur before or concurrent with dysphagia. Proximal limb muscle weakness and gait abnormalities were common and occurred later than ocular or pharyngeal weakness. The clinical expression of OPMD caused marked debility, although life-table analysis showed no decrease in life expectancy compared with unaffected family members (P =.81). Ten individuals from different kindreds were found to have an identical polyalanine triplet repeat expansion ([GCG](9)) in the PABP2 gene. CONCLUSIONS: Individuals in this cohort had clinical and genetic characteristics of classic OPMD. Longevity was not affected, but patients experienced considerable morbidity. The origin of the PABP2 mutation in New Mexican OPMD patients is unclear, although the geographic and genetic isolation of northern New Mexicans with a long ancestry in this region may have contributed to the development of this cohort. This disease cohort represents a large and previously unrecognized health care issue in the state of New Mexico and should serve to raise the awareness of this disorder among clinicians who treat Hispanics in the Southwest and throughout the United States.

Adult↗
PubMed2001

The Canadian C-spine rule for radiography in alert and stable trauma patients.

CONTEXT: High levels of variation and inefficiency exist in current clinical practice regarding use of cervical spine (C-spine) radiography in alert and stable trauma patients. OBJECTIVE: To derive a clinical decision rule that is highly sensitive for detecting acute C-spine injury and will allow emergency department (ED) physicians to be more selective in use of radiography in alert and stable trauma patients. DESIGN: Prospective cohort study conducted from October 1996 to April 1999, in which physicians evaluated patients for 20 standardized clinical findings prior to radiography. In some cases, a second physician performed independent interobserver assessments. SETTING: Ten EDs in large Canadian community and university hospitals. PATIENTS: Convenience sample of 8924 adults (mean age, 37 years) who presented to the ED with blunt trauma to the head/neck, stable vital signs, and a Glasgow Coma Scale score of 15. MAIN OUTCOME MEASURE: Clinically important C-spine injury, evaluated by plain radiography, computed tomography, and a structured follow-up telephone interview. The clinical decision rule was derived using the kappa coefficient, logistic regression analysis, and chi(2) recursive partitioning techniques. RESULTS: Among the study sample, 151 (1.7%) had important C-spine injury. The resultant model and final Canadian C-Spine Rule comprises 3 main questions: (1) is there any high-risk factor present that mandates radiography (ie, age >/=65 years, dangerous mechanism, or paresthesias in extremities)? (2) is there any low-risk factor present that allows safe assessment of range of motion (ie, simple rear-end motor vehicle collision, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness)? and (3) is the patient able to actively rotate neck 45 degrees to the left and right? By cross-validation, this rule had 100% sensitivity (95% confidence interval [CI], 98%-100%) and 42.5% specificity (95% CI, 40%-44%) for identifying 151 clinically important C-spine injuries. The potential radiography ordering rate would be 58.2%. CONCLUSION: We have derived the Canadian C-Spine Rule, a highly sensitive decision rule for use of C-spine radiography in alert and stable trauma patients. If prospectively validated in other cohorts, this rule has the potential to significantly reduce practice variation and inefficiency in ED use of C-spine radiography.

Adult↗
PubMed2001

Double locus analysis of chromosome 21 for preimplantation genetic diagnosis of aneuploidy.

Preimplantation genetic diagnosis (PGD) of numerical chromosome abnormalities significantly reduces spontaneous abortions and may increase pregnancy rates in women of advanced maternal age undergoing in vitro fertilization. However, the technique has an error rate of around 10% and trisomy 21 conceptions have occurred after PGD. To further reduce the risk of transferring trisomy 21 embryos to the patient, we designed a protocol that analyzes chromosome 21 twice by targeting two different loci. This protocol was applied to 388 embryos from 60 cycles of PGD of aneuploidy. The scoring criterion used was based on giving equal importance to both probe results. Of the 242 embryos diagnosed as abnormal, 125 were re-biopsied to assess the rate of false positives and false negatives of the protocol and their clinical relevance. The results of the present study showed no reduction in the overall fluorescent in situ hybridization (FISH) error rate for single cells. However, by using a different scoring criterion, the incidence of false negative can be reduced to 1.6% without missing any trisomy 21. In addition, the present study suggests that if two or more loci from the same chromosome could be simultaneously analyzed in single cells, errors caused by false monosomies could be reduced.

Aneuploidy↗
PubMed2001

Canadian CT head rule study for patients with minor head injury: methodology for phase II (validation and economic analysis).

Prospective validation on a new set of patients is an essential test of a new decision rule. However, many clinical decision rules are not prospectively assessed to determine their accuracy, reliability, clinical sensibility, or potential impact on practice. This validation process is important because many statistically derived rules or guidelines do not perform well when tested in a new population. The methodologic standards for a validation study are similar to those described in the article on phase I for derivation studies in the August 2001 issue of Annals of Emergency Medicine. The goal of phase II is to prospectively assess the accuracy, reliability, and acceptability of the decision rule in a new set of patients with minor head injury. This will determine the clinical utility of the rule and is essential if such a rule is to be widely adopted into clinical practice.

Canada↗
PubMed2001

The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation).

Head injuries are among the most common types of trauma seen in North American emergency departments, with an estimated 1 million cases seen annually. "Minor" head injury (sometimes known as "mild") is defined by a history of loss of consciousness, amnesia, or disorientation in a patient who is conscious and talking, that is, with a Glasgow Coma Scale score of 13 to 15. Although most patients with minor head injury can be discharged without sequelae after a period of observation, in a small proportion, their neurologic condition deteriorates and requires neurosurgical intervention for intracranial hematoma. The objective of the Canadian CT Head Rule Study is to develop an accurate and reliable decision rule for the use of computed tomography (CT) in patients with minor head injury. Such a decision rule would allow physicians to be more selective in their use of CT without compromising care of patients with minor head injury. This paper describes in detail the rationale, objectives, and methodology for Phase I of the study in which the decision rule was derived. [Stiell IG, Lesiuk H, Wells GA, McKnight RD, Brison R, Clement C, Eisenhauer MA, Greenberg GH, MacPhail I, Reardon M, Worthington J, Verbeek R, Rowe B, Cass D, Dreyer J, Holroyd B, Morrison L, Schull M, Laupacis A, for the Canadian CT Head and C-Spine Study Group. The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. August 2001;38:160-169.]

Adolescent↗