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J McKenzie

Publications and source records attributed to J McKenzie.

At least 19 recordsLinked to original sources
PubMed2002

Compatibility of ropivacaine with morphine, sufentanil, fentanyl, or clonidine.

BACKGROUND: Ropivacaine hydrochloride (HCl) ('Naropin') is a long-acting local anaesthetic agent, administered epidurally to patients undergoing various surgical procedures. A combination of local anaesthetic and opioid is often administered for the management of severe pain to ensure that a minimal dose of each is used. Ropivacaine might be used in combination with an alpha2-adrenergic agonist for the management of visceral pain. Stability data have shown that ropivacaine is compatible with the systemic narcotic opioid analgesics morphine sulphate, sufentanil citrate and fentanyl citrate for 14 days in a Polybag (AstraZeneca-AB, Sweden), but no data have been obtained for the longer-term compatibility of ropivacaine with these opioids or with the alpha2-adrenergic agonist clonidine HCl. OBJECTIVE: This study used the Mark II Polybag (AstraZeneca-AB, Sweden) to test the physical and chemical compatibility of these products for up to 30 days. METHODS: Ropivacaine HCl solution for epidural infusion, 2 mg/mL, in 200 mL Mark II Polybag and commercially available additives in glass ampoules or vials were used as starting material. Appropriate admixtures were made and their appearance, pH, and drug concentrations were monitored on days 0, 7, 14, and 30. The appearance of the admixtures was examined with the aid of a stereomicroscope (Olympus, no. 220186, New York, USA) at 10x magnification. Drug concentration and enantiomeric purity were determined using high-performance liquid chromatographic analysis. RESULTS: All combinations at all doses stayed within the compatibility criteria (if no visible signs of physical changes in the admixture appeared throughout the 30 days of storage, and if pH and drug concentrations in each admixture did not vary by more than 10% between day 0 and days 7, 14, or 30 in storage). In addition, there were no important differences in the enantiomeric purity of ropivacaine with each combination. CONCLUSION: The study demonstrated that ropivacaine was suitable for use in combination with the opioids morphine sulphate, sufentanil citrate, and fentanyl citrate, or with the alpha2-adrenergic agonist clonidine HCl, for up to 30 days of storage before the management of severe or visceral pain. From a microbiological point of view, combinations not prepared under aseptic conditions should be used immediately. 'Naropin' is a trade mark of the AstraZeneca group of companies.

Adrenergic alpha-Agonists↗
PubMed2001

The acetylcholinesterase gene and organophosphorus resistance in the Australian sheep blowfly, Lucilia cuprina.

Acetylcholinesterase (AChE), encoded by the Ace gene, is the primary target of organophosphorous (OP) and carbamate insecticides. Ace mutations have been identified in OP resistants strains of Drosophila melanogaster. However, in the Australian sheep blowfly, Lucilia cuprina, resistance in field and laboratory generated strains is determined by point mutations in the Rop-1 gene, which encodes a carboxylesterase, E3. To investigate the apparent bias for the Rop-1/E3 mechanism in the evolution of OP resistance in L. cuprina, we have cloned the Ace gene from this species and characterized its product. Southern hybridization indicates the existence of a single Ace gene in L. cuprina. The amino acid sequence of L. cuprina AChE shares 85.3% identity with D. melanogaster and 92.4% with Musca domestica AChE. Five point mutations in Ace associated with reduced sensitivity to OP insecticides have been previously detected in resistant strains of D. melanogaster. These residues are identical in susceptible strains of D. melanogaster and L. cuprina, although different codons are used. Each of the amino acid substitutions that confer OP resistance in D. melanogaster could also occur in L. cuprina by a single non-synonymous substitution. These data suggest that the resistance mechanism used in L. cuprina is determined by factors other than codon bias. The same point mutations, singly and in combination, were introduced into the Ace gene of L. cuprina by site-directed mutagenesis and the resulting AChE enzymes expressed using a baculovirus system to characterise their kinetic properties and interactions with OP insecticides. The K(m) of wild type AChE for acetylthiocholine (ASCh) is 23.13 microM and the point mutations change the affinity to the substrate. The turnover number of Lucilia AChE for ASCh was estimated to be 1.27x10(3) min(-1), similar to Drosophila or housefly AChE. The single amino acid replacements reduce the affinities of the AChE for OPs and give up to 8.7-fold OP insensitivity, while combined mutations give up to 35-fold insensitivity. However, other published studies indicate these same mutations yield higher levels of OP insensitivity in D. melanogaster and A. aegypti. The inhibition data indicate that the wild type form of AChE of L. cuprina is 12.4-fold less sensitive to OP inhibition than the susceptible form of E3, suggesting that the carboxylesterases may have a role in the protection of AChE via a sequestration mechanism. This provides a possible explanation for the bias towards the evolution of resistance via the Rop-1/E3 mechanism in L. cuprina.

Acetylcholinesterase↗
PubMed2001

Eye color and cutaneous nevi predict risk of ocular melanoma in Australia.

Ethnicity, cutaneous nevi and eye color are generally accepted risk factors for melanoma of the eye, although case-control studies have produced conflicting results. We sought to determine the constitutional risk factors for melanomas of the choroid, ciliary body, iris and conjunctiva in Australia. A population-based case-control study was conducted, with case ascertainment from a prospective national incidence survey and randomly selected community controls. Two hundred and ninety cases aged 18-79 years and diagnosed between 1st January 1996 and 31st July 1998 were enrolled with 916 controls frequency matched by age, sex and State or Territory of residence. Risk of choroidal and ciliary body melanoma (n = 246) was increased in people with grey (OR 2.9, 95% CI 1.5-5.5), hazel (OR 2.2, 95% CI 1.4-3.7) and blue eyes (OR 1.7, 95% CI 1.0-2.7) compared with brown eyes. Risk was also increased in those with 4 or more nevi on their back, those unable to tan, and those who squinted when outdoors as a child. Risk was reduced in people born other than in Australia and New Zealand (OR 0.7, 95% CI 0.5-1.0). Non-brown eye color was a risk factor for iris melanoma (n = 25). No risk factors were identified for conjunctival melanoma (n = 19). Eye color is the strongest constitutional predictor of choroidal and ciliary body melanoma, and may indicate a protective effect of melanin density at these sites. An independent association with cutaneous nevi suggests a role for other genetic factors.

Adolescent↗
PubMed2001

Declining levels of total serum cholesterol in adult New Zealanders.

AIM: To measure the average serum concentration of total cholesterol and high density lipoprotein cholesterol in a representative sample of New Zealanders. METHODS: Serum total and high density lipoprotein cholesterol levels were measured in a representative sample of 1,412 men and 1,741 :women aged 15 years or older who participated in the National Nutrition Survey (1997) of New Zealanders. RESULTS: The average serum total cholesterol concentration in men was the same as in women (5.7 mmol/L); however, younger women (44 years and under) tended to have lower levels and older women (55 years and over) higher levels of total cholesterol than men. Women in all age groups had higher average levels of high density lipoprotein cholesterol (1.4 mmol/L) than men (1.2 mmol/L). Ethnic differences were apparent with Maori men having significantly higher average levels of total cholesterol than their New Zealand European counterparts. CONCLUSIONS: Mean serum total cholesterol concentration in women has declined by 0.3 mmol/L from 6.0 mmol/L (p<0.05) since the previous representative survey of New Zealanders (Life in New Zealand Survey, 1989), but by only 0.1 mmol/L in men, despite a similar reduction amongst men and women in the proportion of dietary energy derived from total and saturated fat. It is possible that weight gain in men and women during the last nine years is having a differential effect on serum cholesterol concentrations.

Adolescent↗
PubMed2001

Dietary iron intakes and biochemical iron status of 15-49 year old women in New Zealand: is there a cause for concern?

AIM: To assess dietary iron intakes and biochemical iron status of a nationally representative sample of nonpregnant 15-49 year old women (n=1,751) in New Zealand. METHODS: A cross-sectional national survey was conducted in 1996/97. Women were selected via a multistage stratified cluster sampling procedure with increased sampling of Maori and Pacific women. Dietary iron intakes were estimated using a 24-hour diet recall. Biochemical iron status was assessed on a non-fasting venipuncture blood sample (n=1,047) via haemoglobin, mean cell volume, erythrocyte zinc protoporphyrin, transferrin receptors and serum ferritin. RESULTS: Average daily dietary iron intakes ranged from 9.6 mg/day among Pacific women to 10.5 mg/day among Maori women; 41% of 20-49 year olds and 45% of adolescents were at risk of low dietary iron intakes. The estimated percentage of 15-49 year old women with iron deficiency anaemia ranged from 1.4-5.5%, and for iron deficiency without anaemia from 0.7-12.6% depending on the age group and criteria used. CONCLUSIONS: The overall estimated prevalence of suboptimal biochemical iron status among 15-49 year old women in New Zealand ranged from 7-13%, which compared favourably with premenopausal women living in other western countries. This situation is, however, a public health concern given the potential negative functional consequences associated with even mild iron deficiency.

Adolescent↗
PubMed2001

Food security: is New Zealand a land of plenty?

AIM: To explore the concept of food security (when there is enough, appropriate and acceptable food available) in the adult New Zealand population using the National Nutrition Survey (NNS97). METHODS: The stepwise development of indicators of food security included a literature search and focus groups with low income women and men. Key issues surrounding the procurement and provision of food were determined and eight indicator statements prepared for inclusion in NNS97, to be addressed by each participant on behalf of their household. RESULTS: Prevalence was significantly higher (p<0.05) for females compared to males for the majority of indicator statements among New Zealand European & Others and Maori. New Zealand European & Others reported the most food security; Pacific people reported the least and Maori fell between the two. There was a significant increasing linear trend of food security with age (p<0.001), after adjusting for gender. "Food runs out in my/our household due to lack of money" was cited more often by female compared to male New Zealand European & Others in NZDep96 quartiles III and IV. CONCLUSION: The issue of 'not having enough food' may be more prevalent in New Zealand than US or Australia. Among New Zealand European & Others the higher prevalence of insufficient food due to lack of money among females from NZDep96 quartiles III and IV suggests that males may be protected from this by their female partners. Food security needs to be improved among young adults, women, Maori and Pacific people in order to prevent longer term nutritional health consequences.

Adolescent↗
PubMed2000

Bioethics for clinicians: 18. Aboriginal cultures.

Although philosophies and practices analogous to bioethics exist in Aboriginal cultures, the terms and categorical distinctions of "ethics" and "bioethics" do not generally exist. In this article we address ethical values appropriate to Aboriginal patients, rather than a preconceived "Aboriginal bioethic." Aboriginal beliefs are rooted in the context of oral history and culture. For Aboriginal people, decision-making is best understood as a process and not as the correct interpretation of a unified code. Aboriginal cultures differ from religious and cultural groups that draw on Scripture and textual foundations for their ethical beliefs and practices. Aboriginal ethical values generally emphasize holism, pluralism, autonomy, community- or family-based decision-making, and the maintenance of quality of life rather than the exclusive pursuit of a cure. Most Aboriginal belief systems also emphasize achieving balance and wellness within the domains of human life (mental, physical, emotional and spiritual). Although these bioethical tenets are important to understand and apply, examining specific applications in detail is not as useful as developing a more generalized understanding of how to approach ethical decision-making with Aboriginal people. Aboriginal ethical decisions are often situational and highly dependent on the values of the individual within the context of his or her family and community.

Aged↗
PubMed2000

Gender differences in the presentation of depressed outpatients: a comparison of descriptive variables.

BACKGROUND: Gender differences in the clinical manifestation of depression and related variables were examined in 170 depressed outpatients. METHOD: Age of onset of depression, chronicity, recurrence, subtype of depression, self-harm history and prior treatment history were assessed with structured clinical interviews. Depression symptom profile, family psychiatric history and social, occupational and interpersonal functioning were assessed with self-report and clinician ratings. RESULTS: Overall, males and females were remarkably similar. Significant findings were that depressed females reported significantly more appetite increase, weight gain and carbohydrate craving, and in general, expressed their depression in a more emotional manner, than depressed males. CONCLUSION: Psychosocial and biological explanations for these results are explored. LIMITATIONS: Descriptive study and multiple testing

Adult↗
PubMed2000

Diet quality of young children who received nutrition education promoting lower dietary fat.

OBJECTIVE: : To evaluate the impact of nutrition education promoting lower dietary fat on the overall diet quality in children using a multidimensional index that measures nutrient and food intakes in relation to US dietary recommendations. DESIGN: : Prospective cohort study with two intervention and two control groups. Children with elevated low density lipoprotein (LDL) cholesterol were randomized to one of two intervention groups or an at-risk control group. The intervention children received either the parent-child autotutorial (PCAT) programme, a 10-week home-based self-instruction nutrition education programme, or nutrition counselling from a registered dietitian. Children with non-elevated plasma cholesterol formed the not-at-risk control group. Dietary and blood data were collected at baseline and at 3 months. SETTING: : Paediatric practices in suburbs north of Philadelphia, PA. SUBJECTS: : Two hundred and twenty-seven 4-10-year-old children with elevated LDL cholesterol between the 80th and 98th percentiles, and 76 age- and gender-matched children with non-elevated plasma cholesterol, were studied. RESULTS: : Children who received PCAT or counselling significantly improved their overall diet quality (-0.6 and -0.4 change in diet quality index (DQI) scores) compared with at-risk control children. Children who received either form of nutrition education were more likely to meet the recommendations for three components of the DQI (total fat, saturated fat, sodium) (OR >1.7), but did not improve their intakes of three components of the DQI (vegetables and fruits, complex carbohydrates, calcium) at 3 months. CONCLUSIONS: : Nutrition education promoting lower dietary fat improved children's overall diet quality. However, several dietary behaviours important for long-term health remained unchanged.

Analysis of Variance↗
PubMed2000

ICD waveform optimization: a randomized, prospective, pair-sampled multicenter study.

The theoretical tissue model-based estimates of phase 1 and phase 2 duration of biphasic waveforms are considerably shorter than the pulse widths currently used in ICDs with standard tilt. This study used a tissue resistance/capacitance (RC) model to identify optimal biphasic pulse widths. By paired step-down defibrillation threshold (DFT) testing, the efficacy of standard versus "tuned" biphasic waveforms was evaluated in 91 patients. Standard waveforms consisted of a phase 1 set to 65% tilt and phase 2 = phase 1. The tuned waveform was based on an RC model of membrane characteristics with a time constant of 3.5 ms. The optimal phase 1 truncation point is at the peak of membrane response. The optimal phase 2 duration ends with a membrane response near or just below 0. In paired analysis, no significant differences were found in DFT or impedance between standard and tuned waveforms. In patients with DFTs > 400 V, the tuned waveform lowered the DFT by an average of 38 V (P < 0.05). Multivariate analyses showed a significant inverse relationship between DFT and impedance (P < 0.001). As impedance increased, the tuned waveform was associated with DFTs comparable to the standard waveform with shorter pulse duration and lower delivered energy. No single tilt value allowing an easy calculation of delivered energy was related to ICD waveform efficacy. The use of ICDs with tuned optimal pulse durations offer a greater flexibility of choice for patients with high DFTs.

Aged↗
PubMed1999

The lifetime value of donors: gaining insight through CHAID.

Techniques such as regression and CHAID can greatly aid fund raisers in developing an understanding of the behavior of their donors. They can offer particular utility in allowing fund raisers to gain a detailed picture of the LTV of their donors. As organizations begin to employ LTV analyses to inform the targeting of their donor recruitment activity and to use them as the basis for segmenting their donor development mailings, both the efficiency and effectiveness of their fund raising will be greatly enhanced as a result.

Database Management Systems↗
PubMed1998

Adjunctive intra-operative local anaesthesia in paediatric strabismus surgery: a randomized controlled trial.

PURPOSE: The aim of the present study was to test the hypothesis that adjunctive local anaesthesia decreases postoperative pain, vomiting or length of stay in children having strabismus repair METHOD: A prospective, randomized, triple-armed clinical trial involving a treatment comparison between topical amethocaine, sub-conjunctival bupivacaine and, as a placebo, topical normal saline was performed. All treatments were given at the end of surgery before emergence from the anaesthetic. RESULTS: Overall, there was no statistically significant difference between outcome measures in the three trial groups. Using post hoc analysis there was a statistically significant difference between the groups receiving amethocaine and bupivacaine compared with the saline group in terms of the pain score at 120 min postoperatively. This difference has little clinical significance. CONCLUSIONS: Neither topical amethocaine nor subconjunctival bupivacaine makes a clinically significant difference to postoperative pain, emesis or length of stay. Moderate dose paracetamol per rectum alone appears to be effective analgesia for strabismus surgery, although it probably masked any small adjunctive effect of the topical anaesthesia used in the present trial.

Adolescent↗
PubMed1997

Vagal control of left ventricular contractility is selectively mediated by a cranioventricular intracardiac ganglion in the cat.

Activation of the vagus nerve leads to decreases in sinoatrial (SA) rate, atrioventricular (AV) conduction, and myocardial contractility. Previous data are consistent with the hypothesis that vagal control of cardiac rate and AV conduction are mediated by two anatomically separated and physiologically independent parasympathetic intracardiac ganglia located in fat pads on the surface of the right and left atria, respectively. These data suggested that vagal control of ventricular contractility might be mediated through another intracardiac ganglion. We examined the ventricles of cat hearts histologically for the presence of ganglia. Multiple small basophilic ganglia composed of a few neurons, and an occasional larger ganglion were found embedded in the epicardial fat surrounding the cranial margin of the anterior surface of the left ventricle, near the juncture with the right ventricle, which we refer to as the CV ganglion. In anesthetized cats, right cervical vagal stimulation decreased SA rate by 44 +/- 5%, decreased the rate of AV conduction by 68 +/- 14%, and reduced ventricular contractility by 19.5 +/- 5.7%. Vagally induced negative inotropism was almost completely prevented by microinjection of a ganglionic blocking drug into the CV ganglion. However, these injections into the CV ganglion did not significantly effect vagally induced decreases in either SA rate or AV conduction. We conclude: (1) that ganglia are found in a fat pad on the surface of the left ventricle of the cat heart and (2) that the CV ganglion selectively mediates the negative inotropic effect of vagal stimulation on the left ventricle. Greater understanding of the physiological functions of intracardiac neuronal circuits may help in developing new strategies to treat disorders of cardiac contractility such as congestive heart failure.

Animals↗
PubMed1997

Radial scars: a review of 30 cases.

Radial Scars/Complex Sclerosing Lesions are benign breast lesions that are seen more frequently now with the advent of screening mammography. These lesions need to be excised surgically in the absence of classical diagnostic features.

Breast↗
PubMed1997

The effect of changes in dietary fat on the food group and nutrient intake of 4- to 10-year-old children.

OBJECTIVE: To determine how young children changed their overall diet when they changed their fat intake after 3 months of participating in a nutrition education demonstration study designed to lower low-density lipoprotein cholesterol and cardiovascular risk. METHODS: Three 24-hour dietary recalls were collected from 303 4- to 10-year-old children at baseline and 3 months later. At both times, mean number of servings from food groups, grams of fat contributed from food groups, and intake of calories and nutrients were calculated and compared among quartiles of children formed according to change in their percent of calories from total fat after 3 months. RESULTS: Children who reduced their percent of calories from total fat most (ie, by an average of 8.5%) after 3 months consumed fewer servings from meats, eggs, dairy, fats/oils, and breads but tended to increase their number of servings from lower-fat foods within those food groups, particularly from dairy foods. These children also increased their mean intake of fruits, vegetables, and desserts, and maintained average intakes of all nutrients (except vitamin D) in excess of two thirds of the respective recommended dietary allowance. CONCLUSIONS: Young children who reduced their percent of calories from total fat in accordance with the current National Cholesterol Education Program recommendations accomplished this by reducing their overall intake of higher-fat foods, replacing higher-fat foods with lower-fat foods within several food groups, particularly within the dairy group (eg, drinking skim milk instead of whole milk) and by consuming more servings of fruits, vegetables, and very-low-fat desserts. These behaviors did not compromise their mean calorie or nutrient intakes, showing that it is possible for young children to lower their fat intake safely to reduce their risk of future heart disease.

Child↗
PubMed1996

Change in nutrient intakes, number of servings, and contributions of total fat from food groups in 4- to 10-year-old children enrolled in a nutrition education study.

OBJECTIVE: To determine change in nutrient intakes, number of servings, and contributions of total fat from food groups in children who lowered their dietary fat intake. DESIGN: A research and demonstration study designed to lower plasma low-density lipoprotein cholesterol level. There were four study groups: two intervention and two control groups. All children had hypercholesterolemia except for those in one control group. There 24-hour dietary recalls were collected on randomly assigned days over a 2-week period at baseline and 3 months after the intervention. SUBJECTS: Three hundred three 4-to 10-year old children from suburbs north of Philadelphia, Pa. INTERVENTIONS: One intervention involved a home-based, parent-child autotutorial program (PCAT group) with audiotaped stories and print materials for the children and their families; the other intervention involved one face-to-face counseling session with a registered dietitian (counseling group). OUTCOME MEASURES: Change in mean nutrient intakes compared with the Recommended Dietary Allowance (RDA); change in number of servings and mean grams of total fat contributed from 10 different food groups. STATISTICAL ANALYSES PERFORMED: Analyses of variance and chi 3 analyses. RESULTS: Children in every study group had mean intakes of all nutrients (except vitamin D) greater than 67% of the RDA 3 months after the baseline measurement. Several food groups (ie, meats, dairy products, fats/oils, and desserts) provided less total fat to the diets of children who reduced their dietary lipid intake after 3 months (i.e., PCAT and counseling groups). These children also reduced the mean number of servings selected from these food groups. Within these same food groups, some children consumed fewer servings of higher fat foods and more servings of lower fat foods. APPLICATIONS/CONCLUSIONS: Children who lowered their dietary fat intake after intervention reported both quantitative and qualitative changes in food choices from several food groups. These choices did not significantly reduce their nutrient intakes.

Aging↗