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Biomedical subjects

D Hunter

Publications and source records attributed to D Hunter.

At least 19 recordsLinked to original sources
PubMed1995

Consensus methods for medical and health services research.

Health providers face the problem of trying to make decisions in situations where there is insufficient information and also where there is an overload of (often contradictory) information. Statistical methods such as meta-analysis have been developed to summarise and to resolve inconsistencies in study findings--where information is available in an appropriate form. Consensus methods provide another means of synthesising information, but are liable to use a wider range of information than is common in statistical methods, and where published information is inadequate or non-existent these methods provide a means of harnessing the insights of appropriate experts to enable decisions to be made. Two consensus methods commonly adopted in medical, nursing, and health services research--the Delphi process and the nominal group technique (also known as the expert panel)--are described, together with the most appropriate situations for using them; an outline of the process involved in undertaking a study using each method is supplemented by illustrations of the authors' work. Key methodological issues in using the methods are discussed, along with the distinct contribution of consensus methods as aids to decision making, both in clinical practice and in health service development.

Consensus Statements as Topic↗
PubMed1995

Life-threatening alterations in heart rate after the use of adenosine in atrial flutter.

Adenosine has become the preferred treatment for common types of supraventricular tachycardia because it is extremely effective and rarely associated with with serious side effects. It has also been advocated as an intervention for diagnostic use to assess uncommon types of tachycardia. Evidence is shown in this report that adenosine was associated with dangerous worsening of arrhythmia in patients with atrial flutter. In two patients, adenosine precipitated acceleration of ventricular response, in one case necessitating emergent cardioversion. Both patients had atrial flutter with 2 to 1 atrioventricular block that evolved into 1 to 1 atrioventricular conduction. In three other patients, adenosine was associated with prolonged bradyasystole and hypotension. In each of the five patients, adenosine was given in a standard fashion (6 or 12 mg). In summary, adenosine should be recognized as a potentially dangerous intervention in patients with atrial flutter. If it is used for diagnostic purposes, resuscitative equipment should be readily available.

Adenosine↗
PubMed1995

Balanced analgesia with intravenous ketorolac and patient-controlled morphine following lower abdominal surgery.

STUDY OBJECTIVE: To investigate the efficacy, opioid-sparing effects and any reduction in adverse events of a continuous intravenous (i.v.) infusion of ketorolac following lower abdominal surgery. DESIGN: Randomized, double-blind, placebo-controlled, parallel-group study. SETTING: Inpatient elective gynecologic surgical patients. PATIENTS: 60 ASA physical status I or II patients aged 18 to 70 years scheduled for elective abdominal hysterectomy. INTERVENTIONS: Following standardized preparation and anesthesia, continuous i.v. infusions of either ketorolac or placebo were administered for 24 hours postoperatively with a patients' standardized postoperative protocol. Supplementary analgesia was administered by an i.v. patient-controlled analgesia (PCA) system. MEASUREMENTS AND MAIN RESULTS: A significantly lower proportion of the patients in the ketorolac group (6%) rated their pain at 24 hours as moderate or severe compared with patients in the placebo group (34%) (p = 0.04). Mean 24-hour morphine consumption was significantly lower in the ketorolac group (43 mg; SEM 5 mg) compared with the placebo group (55 mg SEM 5 mg) (p = 0.02). There was no significant difference in the incidence of postoperative hypoxemia between the groups with respect to mean times per hour spent with oxygen saturation (SPO2) less than 85%, more than 85% but less than 90%, or more than 90% but less than 94%, mean hourly SPO2, or the incidence and duration of severe hypoxemic episodes. Nausea and vomiting were the only significant adverse events, and they occurred in 30% of patients in both groups. CONCLUSION: Intravenous infusion of ketorolac combined with morphine delivered via a PCA device would appear to be a valuable method of providing balanced analgesia following lower abdominal surgery.

Adolescent↗
PubMed1995

Childhood socioeconomic status and risk of cardiovascular disease in middle aged US women: a prospective study.

OBJECTIVE: To examine prospectively the relationship of childhood socioeconomic status and risk of cardiovascular disease in middle aged women. DESIGN: A prospective cohort of women with 14 years follow up data (1976-90). SUBJECTS: A total of 117,006 registered female nurses aged 30 to 55 years in 1976 and free of diagnosed coronary heart disease, stroke, and cancer at baseline. MAIN OUTCOME MEASURES: Incident fatal coronary heart disease, non-fatal myocardial infarction, and stroke (fatal and non-fatal). RESULTS: Low socioeconomic status in childhood was associated with a modestly increased risk of incident non-fatal myocardial infarction and total cardiovascular disease in adulthood. Compared with middle aged women from white collar childhood backgrounds, the age adjusted risk of total cardiovascular disease for women from blue collar backgrounds was 1.13 (95% CI 1.02, 1.24) and that of non-fatal myocardial infarction was 1.23 (95% CI 1.06, 1.42). No significant increase in risk was observed for stroke or fatal coronary heart disease. Adjustment for differences in family and personal past medical history, medication use, exercise, alcohol intake, diet, birth weight, being breastfed in infancy, and adult socioeconomic circumstance somewhat attenuated the increased risks observed for women from blue collar childhood socioeconomic backgrounds. In multivariate analysis, women whose fathers had been manual labourers had the highest relative risk of total coronary heart disease (RR = 1.53; 95% CI 1.09, 2.16) and non-fatal myocardial infarction (RR = 1.67; 95% CI 1.11, 2.53) when compared with women whose fathers had been employed in the professions. CONCLUSION: In this group lower childhood socioeconomic status was associated with a small but significant increase in the risk of total coronary heart disease as well as non-fatal myocardial infarction. For women from the most socioeconomically disadvantaged childhood backgrounds, the association is not explained by differences in a large number of cardiovascular risk factors, by differences in adult socioeconomic status, or by differences in indices of nutrition during gestation or infancy.

Adult↗
PubMed1995

Increasing incidence of anorexia nervosa in the female population of northeast Scotland.

OBJECTIVE: The aim of the study was to determine whether there has been an increase in the incidence of anorexia nervosa in the female population in the northeast of Scotland since the 1960s. METHOD: Standardized diagnostic criteria were applied to the case records of female subjects who had been diagnosed as suffering from anorexia nervosa and had presented for the first time to psychiatric services between 1965 and 1991 or had been admitted for the first time to a general hospital between 1970 and 1991. Age-standardized annual incidence rates were calculated from 1965 through 1991. As a broad measure of severity, the weights of patients in 3 early years of the study, 1970-1972, were compared with those of patients in the last 3 years, 1989-1991. RESULTS: Over the 27-year period studied, 287 patients received confirmed diagnoses of anorexia nervosa, and the mean annual increase in incidence was 5.3%. The rate of increase was highly statistically significant. Comparison of weights at presentation showed a trend for patients presenting in 1970-1972 to be lighter than those presenting in 1989-1991. CONCLUSIONS: Rates of referral for female subjects with anorexia nervosa have greatly increased since the 1960s. These rates likely reflect a genuine increase in incidence, but the data suggest that less severely ill patients are now being referred.

Adolescent↗
PubMed1995

Energy expenditure of below-knee amputees during harness-supported treadmill ambulation.

Traditional rehabilitation of amputees is primarily aimed at strengthening remaining musculature necessary for prosthetic use and gait training. Available gait training time, however, is often limited by pain, residual limb skin tolerance, and the patient's cardiovascular endurance. Harness-supported treadmill ambulation is a rehabilitation technique being used by physical therapists to decrease an individual's body weight by a given percentage during exercise. This, theoretically, allows an amputee to ambulate on a prosthesis at a lower energy cost. The purpose of this study was to compare the energy expenditure of healthy below-knee amputee volunteers with healthy able-bodied volunteers during harness-supported treadmill ambulation in order to determine if energy conservation is achieved. Subjects were tested on a treadmill, walking at .67 m/sec (1.5 mph) and 1.34 m/sec (3.0 mph) during each of the following randomized harness-supported treadmill ambulation situations: full body weight, 20% body weight supported, and 40% body weight supported. During the last minute of each trial, rate of perceived exertion, heart rate, and standardized indirect calorimetry oxygen consumption (VO2, ml/kg/min) measures were collected. Caloric expenditure (kl/min) was calculated using metabolic conversion equations. Peak heart rate, peak VO2, and peak kl/min were measured after the conclusion of the last walking trial by taking each subject to volitional fatigue. Data were analyzed for each harness-supported treadmill ambulation situation and group using analysis of variance (ANOVA). The researchers identified significantly lower ratings of perceived exertion, heart rates, and VO2s for able-bodied subjects vs. below-knee amputees for all trials. Both groups demonstrated significantly lower heart rates, VO2s, and kl/min at 1.34 m/sec with 40% body weight supported.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Complement factor H mRNA in Epstein-Barr virus-transformed B lymphocytes of a factor H-deficient patient: detection by polymerase chain reaction.

A Spanish family with a hereditary deficiency of factor H was identified in previous studies. The deficiency was subtotal as low amounts of a dysmorphic molecule with partial identity to factor H were detected in her serum. The aim of this study was to obtain further characterisation of her deficiency employing her immortalised lymphocytes. After purification of mRNA from her Epstein-Barr virus (EBV)-transformed lymphocytes and from Raji cells, and cDNA synthesis we succeeded in amplifying cDNA which codes for factor H domains 13-15 from both cell lines, using specific oligonucleotides. The amplified fragments were indistinguishable from the one which was amplified from the control cloned cDNA template. The failure to amplify the 3' end of the patient's factor H mRNA suggests that the mRNA is truncated, which is consistent with the characteristics of the dysmorphic protein. Thus, factor H mRNA was detectable in Raji cells and the patient's EBV-transformed lymphocytes. We suggest that immortalised B lymphocytes can be used for the study of a range of inherited complement deficiencies.

B-Lymphocytes↗
PubMed1994

Validation of the Gail et al. model for predicting individual breast cancer risk.

BACKGROUND: The Gail et al. model is considered the best available means for estimating an individual woman's risk of developing breast cancer. Such estimates are useful in decision making on the part of women, in designing prevention trials, and in targeting screening and prevention efforts. PURPOSE: Our purpose was to evaluate the ability of the model to accurately predict individual breast cancer risk, using a large population independent of the one from which the model was derived. METHODS: We compared the number of cancer cases predicted by the model to the actual number of cases observed in the Nurses' Health Study. The study population was 115,172 women who did not have breast cancer at the beginning of the study. Questionnaires were sent to participants every 2 years, seeking data on risk factors and diagnoses of breast cancer. Follow-up compliance was 95% over the 12-year study period. RESULTS: The model over-predicted absolute breast cancer risk by 33% (95% confidence interval [CI] = 28%-39%), with the overprediction more than twofold among premenopausal women (95% CI = 1.9-2.2), among women with extensive family history of breast cancer (95% CI = 1.1-3.9), and among women with age at first birth younger than 20 years (95% CI = 1.3-4.7). The correlation coefficient between observed and predicted risk was 0.67, indicating that the model is less than satisfactory for ranking individual levels of breast cancer risk. Overprediction occurred at all deciles of predicted risk. CONCLUSIONS: The model's performance is unsatisfactory for estimating breast cancer risk for individual women aged 25-61 years who do not participate in annual screening. Lower mammography screening rates in the Nurses' Health Study may account for some, but not all, of the discrepancy between observed and predicted cases. IMPLICATIONS: A recent modification of the model by the tamoxifen trial investigators is likely to have provided accurate power calculations. This modified form of the model should be useful for planning other large, population-based studies.

Adult↗
PubMed1994

A prospective study of cigarette smoking and risk of colorectal adenoma and colorectal cancer in U.S. women.

BACKGROUND: A positive correlation between smoking and colorectal cancer has been reported for men, but not for women, who began smoking in substantial numbers in the late 1940s and early 1950s. We hypothesized that smoking acts as an initiator of colorectal neoplasia and that an association with cancer in women has been missed because of the long period between initiation and diagnosis of cancer. PURPOSE: Our purpose was to assess the association between smoking and risk of colorectal adenoma and colorectal cancer in women and to estimate the minimum induction period between the onset of smoking and cancer diagnosis. METHODS: Our data came from the ongoing Nurses' Health Study, in which current and lifetime smoking histories and other potential confounding factors were assessed by questionnaire at baseline and at 2-year intervals. We documented 586 new cases of colorectal cancer from 1976 to 1990 from a group of 118,334 women and 564 new cases of adenoma among 12,143 women who had a first colonoscopy or sigmoidoscopy between 1980 and 1990. We then assessed the relative risk (RR) of small adenoma, large adenoma (> or = 1 cm), and colorectal cancer in terms of pack-years of smoking. RESULTS: The amount smoked in the prior 20 years was related to the prevalence of small adenomas (multivariate RR = 1.45; 95% confidence interval [CI] = 1.25-1.68; P < .0001) and less strongly with large adenomas (RR = 1.31; 95% CI = 1.17-1.47; P < .0001), adjusting for age, intake of saturated fat, dietary fiber, folate, and alcohol, body mass, family history of colorectal cancer, and pack-years of cigarettes smoked within the prior 20 years. Pack-years of cigarettes smoked more than 20 years in the past was associated with risk of large adenoma (multivariate RR for a 20 pack-year increment = 1.29; 95% CI = 1.01-1.64; P trend = .04), but not of small adenoma (RR = 1.11; 95% CI = 0.93-1.34). Cigarette smoking was unrelated to colorectal cancer until 35 years after smoking began, but then became progressively more strongly related with time. Among women who had started smoking more than 10 cigarettes per day 35-39 years in the past, the RR for cancer was 1.47 (95% CI = 1.07-2.01), progressing to 1.63 (95% CI = 1.14-2.33) after 40-44 years and 2.00 (95% CI = 1.14-3.49) after 45 years. CONCLUSIONS: Because the minimum induction period for colorectal cancer appears to be at least 35 years, an association between smoking and colorectal cancer in women may just now be showing up. IMPLICATIONS: Our findings suggest that cigarette smoking may be a previously unrecognized, preventable cause of colorectal cancer among women.

Adenoma↗
PubMed1994

Intraureteral metallic self-expanding endoprosthesis (Wallstent) in the treatment of difficult ureteral strictures.

Intractable and recurrent ureteral stricture presents a continuous challenge to the urologist. We report on 5 patients with severe ureteral stricture who were successfully treated with self-expanding metallic stents. Ureteral stricture occurred at ureteroileal anastomotic sites after neoplasm resection in 2 cases, multiple upper ureteral strictures were related to multiple surgical procedures for correction of bladder exstrophy in 1 and a ureteral kink developed in 1. Treatment with transluminal balloon dilation provided poor results but self-expanding metallic stents were used successfully with no major complications. In the last patient the stent and the overlying ureter were removed due to recurrent reflux; the gross and histological ureteral changes are discussed in detail. The technical approach is described, alternative therapeutic options are considered and pertinent literature is reviewed.

Adult↗
PubMed1994

Extradural infusion analgesia for postoperative pain relief.

We describe 4-yr experience providing extradural infusion analgesia in a district hospital for treatment of postoperative pain. A total of 770 patients recovering from major surgery were treated on general surgical wards between April 1989 and March 1993. The results of a retrospective audit showed that pain control, assessed with both a visual analogue scale (VAS score (0-10 cm)) and a verbal rating scale (VRS), was good. At rest, more than 80% of patients scored pain as absent or mild (VAS score 0-3) during the first 24 h, with only 4% experiencing severe pain (VAS score 7-10). On movement, 50% of patients had good pain control (VAS score 0-3) while 20% of patients experienced severe pain (VAS score 7-10). Minor complications such as emetic sequelae and pruritus were common; these conditions were mild and rarely required treatment. Hypotension (< 100 mm Hg) occurred in 34% of patients in the first 24 h. Ventilatory frequencies of 8 b.p.m. or less occurred in 2.6% of patients. Four patients (0.52%) developed severe respiratory depression. These patients demonstrated increased sedation but only one had a low ventilatory frequency. Three patients died while receiving extradural infusion analgesia.

Adolescent↗
PubMed1994

Serologic survey and serum biochemical reference ranges of the free-ranging mountain lion (Felis concolor) in California.

Serum samples from 58 mountain lions (Felis concolor) in California (USA) were collected between April 1987 and February 1990. Nineteen serum samples were used for serum biochemistry determinations; the ranges were similar to reference values in domestic cats, captive exotic felidae and free-ranging mountain lions. A serological survey was conducted to determine whether antibodies were present against selected infectious agents. Fifty-four (93%) of 58 sera had antibodies against feline panleukopenia virus. Fifteen (68%) of 22, 16 (28%) of 58, 11 (19%) of 58, and 10 (17%) of 58 had serum antibodies against feline reovirus, feline coronavirus, feline herpes virus, and feline calicivirus, respectively. Twenty-three (40%) of 58 and 21 (58%) of 36 had serum antibodies against Yersinia pestis and Toxoplasma gondii, respectively. Only one of 22 sera had antibodies against the somatic antigen of Dirofilaria immitis. Feline leukemia virus and feline immunodeficiency virus antigens were not detected in any mountain lion's sera. All 58 sera samples were negative for antibodies to feline immunodeficiency virus and Chlamydia psittaci.

Animals↗
PubMed1994

Neurogenesis in the olfactory epithelium.

The initial step in the recognition of odors occurs when individual odorant molecules enter the nasal cavity and interact with the sensory endings of neurons located in the olfactory epithelium. These neurons are unique in several respects. First, they are directly accessible to the external environment. Second, perhaps because of their exposure to toxic substances in the environment, they degenerate and are replenished continuously from a population of stem cells at the base of the epithelium. Third, the sensory neurons born in the olfactory epithelium of adults retain the ability to differentiate and establish synaptic contact with target cells in the mature olfactory bulb. These unique features, which are conserved phylogenetically (for example, see Blaustein et al), provide substantial rationale for studying neuronal genesis and differentiation in the olfactory epithelium. We will summarize much of what is currently known about the development of the olfactory epithelium, the birth and differentiation of olfactory receptor neurons, and the molecular correlates of these events.

Animals↗
PubMed1994

Pre-emptive analgesia from intravenous administration of opioids. No effect with alfentanil.

Forty patients undergoing total abdominal hysterectomy were randomly allocated to receive either 40 micrograms.kg-1 of alfentanil on induction of anaesthesia or 40 micrograms.kg-1 of alfentanil after the skin incision. Postoperative pain relief was provided with morphine from a patient-controlled analgesia system. The amount of morphine consumed in the operating theatre, while in recovery and for the first 24 h postoperatively was recorded. Pain scores were assessed at 24 h using a visual analogue scale. There were no differences found between the two groups for morphine consumption but the 'pre-emptive' group had significantly higher pain scores at rest. We conclude that there is no clinically useful pre-emptive analgesic effect with this dose of alfentanil and that therefore systemic opioid premedication is unlikely to decrease postoperative analgesic requirements through the mechanism of pre-emptive analgesia.

Adult↗
PubMed1994

A prospective study of the association of serum neopterin, beta 2-microglobulin, and hepatitis B surface antigenemia with death in infants and children with HIV-1 disease.

A high percentage of HIV-1-infected infants and children in Romania are coinfected with hepatitis B virus. Little information is available on the impact of concurrent hepatitis B infection on the course of HIV-1 infection. We conducted a prospective cohort study over 1 year in a group of 68 HIV-1-infected infants and children to determine whether hepatitis B surface antigenemia, neopterin, and beta 2-microglobulin (B2M) predicted death. Among the 44 hepatitis B surface antigen-positive (HBsAg+) subjects at enrollment, 13 (30%) died during 1 year of follow-up. In comparison, two of 24 (8%) HBsAg-negative subjects died (RR = 7.7; p = 0.05). Higher initial serum concentrations of neopterin and B2M were negatively associated with survival. After stratifying by baseline clinical evidence of HIV-related disease, survival was negatively associated with HBsAg+ status (p = 0.04) in 33 children in stage P-2, adjusting for age, serum neopterin, and serum B2M levels. The results of this study suggest that serum neopterin is a marker for severity of clinical illness and that HBsAg+ status increases the mortality rate among children with clinical evidence of HIV infection.

Biopterins↗