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Biomedical subjects

D Hood

Publications and source records attributed to D Hood.

At least 19 recordsLinked to original sources
PubMed2006

Elevated procalcitonin as a diagnostic marker in meningococcal disease.

Patients with meningococcal disease who seek medical attention can create a diagnostic dilemma for clinicians due to the nonspecific nature of the disease's presentation. This study assesses the diagnostic accuracy of procalcitonin levels in the setting of meningococcal disease. Two emergency department cohorts (A and B) were studied between 2002 and 2005, during the current epidemic of serogroup B meningococcal disease in New Zealand. Cohort A consisted of 171 patients, all with confirmed meningococcal disease (84 children, 87 adults). Cohort B consisted of a large (n=1,524) consecutively recruited population of febrile patients who presented to the emergency department, 28 of whom had confirmed meningococcal disease. Within the meningococcal disease cohort (cohort A), the geometric mean procalcitonin level was 9.9 ng/ml, with levels being higher in children than in adults (21.6 vs. 4.6 ng/ml, p=0.01). The overall sensitivity of elevated procalcitonin, using a cutoff of 2.0 ng/ml in children and 0.5 ng/ml in adults, was 0.93 (95%CI: 0.88-0.96). Despite the higher cutoff level for paediatric patients, a trend towards greater sensitivity existed in children (0.96 vs. 0.90; p=0.08). Elevated procalcitonin was correlated with whole blood meningococcal load (r=0.50) and Glasgow Meningococcal Sepsis Prognostic Score (r=0.40). Within the cohort of patients who were febrile on presentation (cohort B), the specificity of elevated procalcitonin in meningococcal disease was 0.85 (95% CI: 0.83-0.87), the positive and negative likelihood ratios were 6.1 and 0.08, respectively, and the sensitivity of elevated procalcitonin (0.93; 95% CI: 0.76-0.99) was corroborated. Measurement of procalcitonin is a useful tool in patients with nonspecific febrile illnesses when the possibility of meningococcal disease is present. The diagnostic accuracy surpasses that of current early laboratory markers, allowing results to be used to guide decisions about patient management.

Adolescent↗
PubMed2005

Making electronic mail accessible: perspectives of people with acquired cognitive impairments, caregivers and professionals.

The primary objective of this study was to better understand the technology needs, barriers and strategies of individuals with acquired cognitive impairments (ACI) in order to design and modify technologies with potential for alleviating the diminished independence and social isolation common in this population. The authors hypothesized that (1) higher rates of computer use would be reported by younger, more highly educated individuals with ACI, those with less severe injuries and those with previous computer experience; (2) A low percentage of survey respondents would own their own computers; and (3) People with ACI would experience social isolation and report low frequency of connecting with important people who live far away. A total of 133 individuals with ACI, professionals and care providers completed the survey. To gain more specific information, seven focus groups were conducted with 66 individuals with ACI and 20 care providers. Finally, 10 current email users participated in structured conversations, detailing their strategies for using email. The survey revealed that 80% of subjects with ACI reported owning a computer. Age and education were not predictors of computer use, but individuals whose ACI was the result of more severe injuries were less likely to use computers. As expected, respondents reported that maintaining contact with distant loved ones is problematic. The focus groups and conversations provided more detail about the communication needs of the population and the relative advantages and disadvantages of email compared with telephone and mail. Participants also identified barriers to email use they had encountered or feared they would encounter when using email. A number of accommodations to overcome these barriers were suggested. The results of the survey, focus groups and conversations confirmed the utility of email and other technologies for people with ACI and the need to make these technologies more accessible. The results and suggestions provided by the focus groups and interviews are being used in the design of Think and Link, an email interface for use by individuals with ACI.

Adult↗
PubMed2004

The changing face of tuberculosis control in a rural district of New Zealand.

SETTING: Waikato Health District (WHD), New Zealand. OBJECTIVE: To describe the changing epidemiology of TB in the WHD and the factors responsible for this. DESIGN: Descriptive epidemiological study of all notified TB cases from the WHD from 1 January 1992 to 31 December 2001. Major outcome measures were delay of diagnosis and treatment outcome. RESULTS: There were 244 cases included. Over the 10-year period, TB incidence has remained stable in the WHD. There has been a significant reduction of TB in the Maori population (from 30.3 to 12.5/100,000, P = 0.03). This has been matched by a rise in the overseas-born population (from 4.6 to 21.2/100,000, P = 0.04). Tuberculosis became a predominantly urban disease during the study period. Delay in diagnosis (>4 weeks) occurred in 85% of cases, with significantly more delays in older age groups. Use of directly observed therapy (OR 3.65, 95%CI 1.24-10.76), and being a migrant (OR 3.52, 95%CI 1.74-7.09), were significantly associated with improved treatment outcome. CONCLUSION: A significant change in the epidemiology of TB has occurred over the last decade. Tuberculosis control strategies need to be developed to effectively diagnose and treat patients from diverse cultural backgrounds.

Adult↗
PubMed2002

Series of incidents of Listeria monocytogenes non-invasive febrile gastroenteritis involving ready-to-eat meats.

AIMS: A series of cases and outbreaks of febrile noninvasive gastrointestinal disease involving 31 identified cases was investigated in terms of the numbers and types of Listeria monocytogenes present in the suspect foods (ready-to-eat meats) and clinical samples from cases. METHODS AND RESULTS: Foods and faecal samples involved in the incidents were tested for the presence and number of L. monocytogenes. Isolates were typed by macrorestriction analysis using pulsed-field gel electrophoresis. The foods contained high levels of L. monocytogenes, in one case 1.8 x 10(7) g-1. Faecal samples contained L. monocytogenes for up to 15 d after the contaminated food was consumed. All isolates from the food and faecal samples were of serotype 1/2 and were indistinguishable from one another by macrorestriction typing. CONCLUSIONS: It is likely that the meats were contaminated either during their manufacture after they had been cooked or by underprocessing. The long shelf lives on these products would have allowed the contaminating L. monocytogenes to grow to the high numbers measured in this study, causing food poisoning as described. SIGNIFICANCE AND IMPACT OF THE STUDY: Outbreaks of febrile noninvasive listeriosis are relatively rare. This report adds ready-to-eat meats to the range of foods that have acted as vehicles for such outbreaks.

Bacterial Typing Techniques↗
PubMed2001

A multicenter, matched case-control study of risk factors for equine laminitis.

Risk factors for equine laminitis were examined in a prospective case-control study of the 258 cases seen at six collaborating veterinary teaching hospitals over a 32-month period. Case-control pairs were matched on institution, clinician, and season of diagnosis. The 90% of case-control pairs (78 acute, 155 chronic) that had complete data for age, gender, and breed were used in separate conditional logistic-regression models for acute and chronic laminitis. There was an increase in risk for horses with acute laminitis from 5 to 7 years of age (OR 4.7, 95% CI 1.3-16) and from 13 to 31 years of age (OR 3.9, 95% CI 1.3-12) (both compared to <5 years); risk was increased for chronic laminitis from 10 to 14 years (OR 3, 95% CI 1.4-6.8) and from 15 to 38 years (OR 2.9, 95% CI 1.4-6.1) (both compared to <6 years). Mares - but not stallions - were more likely than geldings to develop acute laminitis (OR 2.6, 95% CI 1.1-6.2) and chronic laminitis (OR 2.0, 95% CI 1.1-3.6). In the small acute-laminitis data set, the breed variable was collapsed into three categories: Thoroughbred (THB, reference), the Quarter Horse (QH), and other (non-QH-THB). The non-QH-THB group was at increased risk of acute laminitis (OR 3.8, 95% CI 1.2-11.8). For the seven breed-group categories used in the chronic-laminitis model, however, all non-THB breed groups appeared significantly at risk as compared to the THB, with odds ratios ranging from 3.3 (95% CI 1.3-8.30) for the QH to 9.1 (95% CI 2.1-39.3) for ponies.

Acute Disease↗
PubMed1999

Contribution of genomics to bacterial pathogenesis.

Genomics is changing the landscape of modern biology. The impact is far-reaching because it provides both the most economical means of acquiring large amounts of information and because it has forced the creation of new technologies to exploit this information. Five of the six genomes published in the year from August 1998 to August 1999 were human pathogens, all of which are highly host-adapted. Four of these are obligate intracellular pathogens and the study of these genomes is providing novel insights into the intricacies of pathogen-host interactions and co-evolution. These genomes are also significant because they mark the beginning of an important trend in the sequencing of closely related genomes, including the sequencing of more than one strain from a single pathogenic species. As comparative genomics truly comes of age, the ability to compare the genomes of pathogenic and non-pathogenic organisms will hopefully provide insight into what makes certain bacterial strains and species pathogens.

Bacteria↗
PubMed1997

Separate and joint effects of arginine and glucose on ovine fetal insulin secretion.

To determine separate and joint effects of increases (delta) in fetal plasma concentrations of arginine (Af) and glucose (Gf) on fetal insulin (If) secretion (delta If), 15 late-gestation fetal sheep were given 5-min arginine bolus infusions (40, 86, 144, 201, and 402 mumol/kg estimated fetal wt) at 90 min of 120 min steady-state glucose clamps (basal Gf, basal + 0.6 mM Gf, and basal + 1.1 mM Gr), producing absolute and percent increases above basal Af of 25.8 +/- 1.3 microM (+33%), 50.9 +/- 6.3 microM (+66%), 83.8 +/- 7.1 microM (+108%), 122.1 +/- 9.4 microM (+156%), and 302.2 +/- 28.2 microM (+386%), respectively. Acute hyperglycemia alone produced an increase above basal If of 9 +/- I microU/ml (+80%) and 19 +/- 2 microU/ml (+170%) after basal + 0.6 mM Gf and basal + 1.1 mM Gf, respectively. Increasing values of delta Af showed separate but lesser effects on delta If, which were significant only at very high values of Af (> 100% above mean normal Af) unless marked hyperglycemia (1.5- to 2-fold normal) was also present, demonstrating joint effects of delta Af and delta Gf on delta If according to a best-fit inverse polynomial response surface. We conclude that physiological increases in Af at normal glucose concentrations are not a potent-stimulus to insulin secretion in fetal sheep.

Animals↗
PubMed1996

Experimental evaluation of a modular approach to mobilizing antitobacco influences of peers and parents.

The experimental evaluation of two components of a community intervention to prevent adolescent tobacco use are described. Youth antitobacco activities (e.g., peer quizzes, sidewalk art, poster and T-shirt giveaways, etc.) and family communications activities (pamphlets to parents and student quizzes of parents) were evaluated in two time-series experiments, each of which was conducted in two experimental and one control community. Students in Grades 6 and 8 and their parents were assessed in a series of four phone surveys in the first experiment and six phone surveys in the second. Implementation of the youth antitobacco and family communications activities led to significantly greater exposure of young people to antitobacco information. They led to increases in parent and youth knowledge about tobacco use and more negative attitudes toward tobacco. In Experiment 2, youths in intervention communities had significantly lower rated intentions to smoke. The findings suggest the value of a modular approach to community interventions for influencing the social context relevant to the onset of adolescent tobacco use.

Adolescent↗
PubMed1994

Neonatal laryngoceles. A cause for airway obstruction.

The neonatal laryngocele is a congenital pathologic entity originating in the saccule of the laryngeal ventricle. This entity may present as an uncommon cause of neonatal airway obstruction. We present two cases of this condition and the management undertaken. Both patients demonstrated significant airway distress. Evaluation of each patient included either plain x-ray films of the neck, ultrasound, or computed tomography of the neck. A cystic mass, containing air and fluid, was identified causing external compression of the airway in each case. Surgical intervention required airway endoscopy and an external approach to excise the mass. Tracheotomy was avoided in both cases; however, one infant required further surgery for laryngomalacia. Both children have done well in follow-up.

Airway Obstruction↗
PubMed1994

Analysis of intrabolus forces in patients with Zenker's diverticulum.

This report presents 10 patients with Zenker's diverticulum who were evaluated with simultaneous solid-state manometry and fluoroscopy. With this method, intrabolus forces are determined. Each patient had abnormal intrabolus forces regardless of the size of the diverticulum and cricopharyngeal muscle dysfunction. In the literature, there has been conflicting manometry results when studying Zenker's diverticulum. The use of analysis of intrabolus forces increases the sensitivity of manometric evaluation. This study establishes pressure abnormality in the pharyngoesophageal segment of patients with Zenker's diverticulum. The pathogenesis of Zenker's is presented based on these findings.

Deglutition↗
PubMed1994

Peripheral blood stem cell collection after mobilization with intensive chemotherapy and growth factors.

Peripheral blood has become an alternative to bone marrow as a source of stem cells for transplantation. One of the major disadvantages of peripheral blood as a source is the low concentration of stem cells. For successful engraftment, the infusion of at least 6 x 10(8) nucleated cells per kg is required, a cell number obtained by 6-8 cell pheresis sessions. This cell number contains approximately 0.1% CD34 cells equivalent to 600,000 CD34 cells. It is known that chemotherapy and hematopoietic growth factors increase the concentration and total number of progenitor cells in the peripheral blood. In breast and lung cancer patients we are using two cytoreductive regimens: cytoxan 2 g/m2 + platinol 90 mg/m2, and VP-16 600-900 mg/m2+ platinol 90 mg/m2, respectively, in conjunction with G-CSF for stem cell mobilization. At the time of hematopoietic recovery, between day 13 and 16, the absolute number of CD34+ cells increases in 75% of the patients more than 20-fold, from 5,000 to at least 100,000/ml blood, and to more than 40-fold, to 200,000/ml, in 54% of the patients. Therefore, 3.4-7.5 ml blood contains up to 750,000 CD34+ cells, the minimum number of CD34 cells/kg body weight infused when steady-state collected peripheral blood cells are used. Since we use a minimum of 3 x 10(6) CD34+ cells/kg body weight, 15,000 ml of mobilized blood are required. This amount can often be obtained by collecting 500 ml blood by phlebotomy in 2-3 separate sessions, which is an easy and cost-effective method for the patient.

Antigens, CD↗
PubMed1993

Control of epidemic group A meningococcal disease in Auckland.

AIM: To study group A meningococcal vaccine delivery to infants less than 2 years of age in Auckland in 1987 to control epidemic disease. METHODS: Mechanisms of vaccine delivery and its facilitation are described. A detailed audit of delivery of vaccine to children less than two years using signed consent forms determined delivery source. This was the age group at highest risk, and poorly covered by routine childhood vaccines. Primary health care source of children presenting with disease was determined by telephone. RESULTS: The epidemic of group A meningococcal disease in the winters of 1985 and 1986 abated most likely due to the vaccination of high risk children (3 months-13 years) in 1987. 90% of the target population were vaccinated. In south Auckland the majority (92%) of vaccine doses for children less than two years of age was delivered by the Plunket Society with Department of Health backing aided by community health workers. By contrast delivery by, general practitioners was greater in north-west and central Auckland (approximately 25%, of dose 1), especially after the publicity over possible side effects (approximately 50% of dose 2). Coverage for dose 1 of children < 2 years was similar (89%) in south Auckland. Of children presenting with meningococcal disease 1 in 4 did not have an identifiable general practitioner. CONCLUSIONS: Vaccines to prevent serious paediatric illness are known to be highly cost effective. The best method of delivery of vaccinations may vary from area to area. Major community involvement including community health workers for the Maori and Pacific Island communities may have facilitated the dissemination of information in this campaign.

Adolescent↗
PubMed1993

Hemodynamic and analgesic actions of epidurally administered clonidine.

BACKGROUND: alpha 2-Adrenergic agonists such as clonidine produce behavioral analgesia and cardiovascular depression in animals, but clonidine's site of action in clinical analgesia and cerebrospinal fluid (CSF) pharmacokinetics have not been defined. METHODS: Clonidine was administered in the lumbar epidural space to nine volunteers while monitoring blood pressure, heart rate, finger and toe blood flow, and response to cold pain testing, and while sampling CSF and arterial plasma for clonidine analysis. Effects were correlated to plasma and CSF clonidine concentrations. Ten other volunteers received stepped intravenous infusions of the opioid alfentanil with similar testing. RESULTS: Clonidine decreased pain report in the foot but not the hand, and this effect correlated stronger with CSF than with plasma clonidine, suggesting a spinal site for analgesia. Extrapolation of CSF clonidine pharmacokinetics suggests the minimum effective CSF clonidine concentration for postoperative pain relief is 76 +/- 15 ng/ml. Clonidine increased finger and toe blood flow, decreased blood pressure and heart rate, produced sedation, and mildly increased arterial PCO2, in most cases correlating better with plasma than CSF clonidine concentrations, suggesting actions at central sites. In 10 other volunteers, intravenous infusion of the opioid alfentanil produced analgesia of similar intensity to clonidine but was accompanied by significant respiratory depression. CONCLUSIONS: These data support previous studies in animals and provide the scientific rationale for this novel analgesic therapy. In comparison to the potent opioid alfentanil, epidural clonidine produces a similar degree of analgesia but less respiratory depression.

Alfentanil↗