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Biomedical subjects

G McCracken

Publications and source records attributed to G McCracken.

15 recordsLinked to original sources
PubMed2005

Assessing adherence with toothbrushing instructions using a data logger toothbrush.

OBJECTIVES: To evaluate patient compliance with toothbrushing instructions using a data logger and a brushing diary. METHODS: Dental patients were provided with powered toothbrushes modified to carry electronic data loggers. Demonstration of the most effective way to use the toothbrush was provided with instructions to brush for 2 minutes morning and evening. Data logger brushes were supplied for two episodes of 8 weeks. Brushing time was also recorded in a diary during episode 1. RESULTS: Data from 14 brushes (2,287 recordings) were used to evaluate compliance in episode 1 Nine brushes (1,526 recordings) were used in episode 2 A total of 2,333 brushing events were reported manually in the diaries. Data logger records during episode 1 showed that only 34% of events were compliant with the instruction of a 2 minute brushing time, 20% were partially compliant (within +/-30s of 2 minutes), and 46% of events were non-compliant (>30s from 2 minutes). The respective proportions for episode 2 were 24%, 24% and 52%. Diary data reported 58% of events as compliant with 42% non-compliant. CONCLUSIONS: Manually completed brushing diaries do not provide an accurate reflection of subjects' compliance with toothbrushing instructions.

Data Collection↗
PubMed2004

Antenatal HIV testing: evaluation of uptake and women's attitudes in a low risk population.

The number of HIV-positive heterosexuals in the UK is increasing, with a resultant increase in the number of pregnant women who are HIV-positive. The benefits of diagnosing an HIV-positive woman antenatally are well established. The Department of Health of England issued guidelines recommending named voluntary antenatal testing, with a view to achieving a maternal diagnosis rate of 90% by December 2002. In Northern Ireland the policy was distributed in 2003. The screening programme in our hospital had an uptake rate of 98.7 %. Responses to a questionnaire to evaluate the process indicate that HIV testing was associated with low levels of anxiety and that patients were well satisfied with the counselling they received.

Female↗
PubMed2001

Coexistent cutaneous Aspergillus and cytomegalovirus infection in a liver transplant recipient.

Cutaneous infections are a significant cause of morbidity in solid organ recipients. These infections may be complex with multiple pathogens occurring in the same lesion. We describe the unusual association of cutaneous Aspergillus and cytomegalovirus (CMV) infections in a liver transplant recipient. Cutaneous CMV infection is rare and often indicates severe systemic involvement, whereas Aspergillus is a frequent cause of opportunistic cutaneous fungal infection. Seven weeks after liver transplantation, our patient had hemorrhagic, eroded plaques develop on his arms. The results of routine histology, immunoperoxidase staining for CMV antibody, and fungal culture revealed coexistent cutaneous Aspergillus flavus and CMV infections. The patient was treated with ganciclovir, amphotericin B, and topical terbinafine cream; however, 2 weeks after the development of the cutaneous lesions, the patient died.

Antifungal Agents↗
PubMed2000

An ovine model of chronic stable heart failure.

BACKGROUND: Chronic stable large animal models of heart failure are difficult to establish. We report an ovine model of chronic stable heart failure achieved by a technique of repetitive myocardial infarctions (one of the most common causes of cardiac failure) with catheter-based techniques. METHODS AND RESULTS: Ejection fraction (EF) was assessed by echocardiography. A perfusion catheter was positioned in either the left anterior descending or circumflex artery by using standard angioplasty techniques. Myocardial infarction was induced by a Gelfoam embolism via this catheter and was confirmed by electrocardiographic (ECG) changes and new segmental abnormalities. The procedure was repeated at 2 weekly intervals until the EF was less than 40%. Target EF was achieved in 15 animals, with a mean of 3.4 embolizations (range 2 to 8). Baseline EF was 68%, with a mean final EF of 33%. This resulted in a 54% reduction in EF (range 44% to 68%) from baseline values. Two animals developed late symptomatic heart failure and died, whereas EF was stable at 3-month follow-up echocardiography in the remaining animals with no significant spontaneous improvement. CONCLUSION: Chronic stable heart failure can be established in sheep with catheter-based skills and a microembolization technique that causes repetitive myocardial infarctions.

Animals↗
PubMed2000

Serum levels of vascular endothelial growth factor in preeclamptic and normotensive pregnancy.

The purpose of these studies was first to determine if vascular endothelial growth factor (VEGF), a vascular permeability agent, is increased in the serum of women with preclinical and clinical preclampsia (PE), and second to determine how these levels change after delivery. Twenty preeclamptic and 25 normotensive women at term consented to have blood taken pre- and post-delivery. Ten preeclamptic, 10 gestational hypertensive, and 28 normotensive women had blood collected respectively at 12, 20, and 30 weeks gestation and predelivery. Serum was extracted from all samples, and VEGF concentrations were determined by radioimmunoassay. Predelivery, the median serum VEGF concentration in the preeclamptic group was 51.7 ng/mL, and in the control group the concentration was 13.9 ng/mL (P<0.0001). Serum VEGF concentrations fell within 24 hours of delivery in both groups, which resulted in median values of 3.8 ng/mL and 3.2 ng/mL respectively (P<0.3). At 12 and 20 weeks, there was no significant difference between the serum VEGF concentrations in the 3 groups (P<0.3, 0.052 respectively). At 30 weeks, prior to the onset of clinical PE, the serum VEGF levels in the eventual preeclamptic group were elevated significantly compared with the gestational hypertensive and normotensive groups (P<0.001). Predelivery serum VEGF concentrations were significantly elevated in the preeclamptic group and were similar to those in the first study (P<0.0001). These findings suggest that VEGF may be important in the pathophysiology of PE and has the potential to act as a preclinical marker for the condition.

Adult↗
PubMed1999

Emergency department observation of poisoned patients: how long is necessary?

OBJECTIVE: To compare the emergency physician disposition decisions after observation periods of two, four, and six hours in a single cohort of ED patients with acute intentional ingestion to determine the accuracy of disposition decisions at two and four hours relative to the six-hour period of observation. METHODS: This was a prospective observational study at two university hospital EDs. Study participants were patients with potentially toxic oral ingestions occurring less than six hours prior to ED presentation. Patients with isolated recreational drug or ethanol use were excluded. Structured data forms were completed at presentation, and two, four, and six hours later. Data included signs and symptoms consistent with toxic ingestion, physical examination, laboratory determinations, medications ingested, treatment, and suicide risk. At two and four hours, physicians were asked to determine whether they thought the patient was safe for medical clearance. These patients continued to be observed for six hours. The main outcome was whether patients initially thought to be appropriate for early medical clearance were ultimately cleared at six hours. RESULTS: There were 260 patients enrolled: 28 were immediately admitted to the hospital and 17 were immediately discharged; 215 entered ED observation. Patients had a mean age of 24 years; 55% were female; 50% were suicidal; 17% had toxidromes. Of the 215 observed patients, 106 (49%) were deemed safe for early medical clearance at two hours. All 106 were ultimately cleared at six hours (100%, 95% CI = 97% to 100%). Of the 109 not safe for early medical clearance at two hours, 61 (56%) were deemed safe for early medical clearance at four hours; all 61 were subsequently discharged at six hours (100%; 95% CI = 95% to 100%). Overall, 167 of 215 (77%) observed overdose patients were deemed safe for early medical clearance after two or four hours of observation. All 167 were ultimately cleared at six hours (100%; 95% CI = 98.2% to 100%). CONCLUSIONS: A large subset of overdose patients who are medically cleared after six hours of observation can be identified within two to four hours of presentation. No patient who was believed to be safe for medical clearance at either two or four hours had a complication within the six-hour time period (95% CI = 0% to 1.8%). These data suggest that asymptomatic patients with selected acute intentional ingestions can be released from medical observation in less than six hours.

Adolescent↗
PubMed1996

Correlation among clinical, laboratory, and hepatobiliary scanning findings in patients with suspected acute cholecystitis.

STUDY OBJECTIVE: To assess the ability of various clinical and laboratory parameters to predict the results of hepatobiliary scintigraphy (HBS) in patients with suspected acute cholecystitis. METHODS: This was a retrospective chart review of all patients referred from the emergency department for an HBS in 1993 to exclude acute cholecystitis. The setting was a university-affiliated tertiary care hospital with an annual census of approximately 42,000. The participants were 100 consecutive patients who were seen in the ED and had an HBS and obtainable medical records. Medical records of all patients referred from the ED for an urgent HBS in 1993 were retrospectively reviewed for the following information: demographics, historical information, physical findings, laboratory findings, biliary scintigraphic findings, and surgical pathologic findings. Comparisons were made between patients with a positive or negative HBS. Sensitivities, specificities, and positive and negative predictive values were calculated for dichotomous variables with a positive HBS as a control standard. A separate analysis was performed for patients with pathologically confirmed acute cholecystitis. RESULTS: Fifty-three patients had a positive HBS, and 47 had a negative HBS. A history of fever had a positive predictive value of 100% and a sensitivity of 14.6%. The presence of Murphy's sign was both sensitive (97.2%) and highly predictive (93.3%) of a positive HBS yet was not documented in 35 cases. All other variables were not found to be helpful in predicting the results of HBS. Pathologic diagnoses were available in 44 patients. Of 40 patients with pathologically confirmed acute cholecystitis, fever and leukocytosis were absent at the time of presentation in 36 (90%) and 16 (40%) of the cases, respectively. Murphy's sign was absent in 3 (10%) of 29 of these patients. A stepwise analysis failed to identify any combination of clinical variables that was associated with a higher probability of a positive HBS. CONCLUSION: No single or combination of clinical or laboratory findings at the time of ED presentation identified all patients with a positive HBS. Murphy's sign had the highest sensitivity and positive predictive value yet was poorly documented. Liberal use of biliary scintigraphy or ultrasound is encouraged to avoid underdiagnosis of acute cholecystitis.

Acute Disease↗
PubMed1991

Metabolic tolerance to arginine: implications for the safe use of arginine salt-aztreonam combination in the neonatal period.

Two similar cohorts of low birth weight infants whose size was appropriate for gestational age randomly received either aztreonam-arginine plus ampicillin (n = 15) or gentamicin plus ampicillin (n = 15) for empiric treatment of neonatal sepsis. The regimens were infused together with glucose at greater than 5 mg/kg per minute, and immediate (4 hours) and cumulative (3 days) effects were assessed. Serum arginine and insulin values rose immediately after administration of aztreonam (containing 0.15 mmol of arginine per kilogram), but there were no changes in the gentamicin-treated cohort; no differences occurred in either cohort in serum concentrations of glucose, ammonia, potassium, creatinine, and bilirubin. After 3 days of antibiotic therapy (n = 13), the baseline serum arginine concentration was almost twice as high in the aztreonam group and showed a similar further rise and fall during the 4 hours after infusion; arginine urinary fractional excretion (normalized to creatinine clearance) decreased in the gentamicin group. The indirect bilirubin concentration rose more (p less than 0.001) in the aztreonam-treated infants (5.1 to 11.5 mg/dl (87 to 196 mumol/L] than in the gentamicin-treated infants (5.5 to 8.1 mg/dl (94 to 138 mumol/L)). Thus a modest differential bilirubin response and modestly elevated baseline serum arginine level occurred after the 3-day low-arginine doses of this study; serum ammonia and glucose concentrations were not affected. Aztreonam-arginine in neonates was well tolerated metabolically, and we believe that it can be used safely in conjunction with attention to glucose and bilirubin metabolism.

Ammonia↗