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Biomedical subjects

M Knox

Publications and source records attributed to M Knox.

At least 19 recordsLinked to original sources
PubMed2000

Pea Ty1-copia group retrotransposons: transpositional activity and use as markers to study genetic diversity in Pisum.

The variation in transposition history of different Ty1-copia group LTR retrotransposons in the species lineages of the Pisum genus has been investigated. A heterogeneous population of Ty1-copia elements was isolated by degenerate PCR and two of these (Tps12 and Tps19) were selected on the basis of their copy number and sequence conservation between closely related species for further in-depth study of their transpositional history in Pisum species. The insertional polymorphism of these elements and the previously characterised PDR1 element was studied by sequence-specific amplification polymorphism (SSAP). Each of these elements reveals a unique transpositional history within 55 diverse Pisum accessions. Phylogenetic trees based on the SSAP data show that SSAP markers for individual elements are able to resolve different species lineages within the Pisum genus. Finally, the SSAP data from all of these retrotransposon markers were combined to reveal a detailed picture of the intra and interspecies relationships within Pisum.

Amino Acid Sequence↗
PubMed2000

The effect of fetal fibronectin testing on admissions to a tertiary maternal-fetal medicine unit and cost savings.

OBJECTIVE: Fetal fibronectin bedside testing has been proposed as a diagnostic tool for the accurate diagnosis of preterm labor. The study objective was to determine whether the introduction of routine fetal fibronectin bedside testing affected costs and transfer rates from referral district hospitals to a tertiary obstetric hospital, as well as direct admissions to a tertiary referral hospital. STUDY DESIGN: We performed an 18-month prospective audit of fetal fibronectin use in 9 referral hospitals and one university maternal-fetal medicine unit. Data collected were delivery details and cervical dilatation at admission. Cost savings in terms of transport costs for patients with a negative fetal fibronectin result who were not transferred or admitted to the tertiary center were calculated for interhospital transfer (road ambulance or fixed-wing retrieval). RESULTS: One hundred fifty-one patients had a presumptive diagnosis of threatened preterm labor. Forty-five patients had a positive fetal fibronectin result and 106 had a negative fetal fibronectin result (3 with cervical dilatation >/=3 cm). Eleven (24%) patients with a positive fetal fibronectin result were delivered within 7 days, and 5 (5%) with a negative fetal fibronectin result were delivered within 7 days. One patient was delivered at 34 weeks, and the remaining patients were delivered at or after 36 weeks' gestation. All 3 patients with negative fetal fibronectin results with cervical dilatation of >/=3 cm were delivered within 5 days, leaving 2 (1.9%) patients (with closed cervices and negative fetal fibronectin results) being delivered 5 days after the fetal fibronectin testing. Ninety percent of the patients admitted to a referral hospital with threatened preterm labor who had a negative fetal fibronectin result were not transferred; thus an unnecessary transfer was avoided, with cost savings ranging from $30,297 for road and fixed-wing transport. CONCLUSION: A negative fetal fibronectin result is not helpful if cervical dilatation is present, and these patients should be treated as having a high risk of preterm delivery. The use of a fetal fibronectin test was associated with a 90% reduction in maternal transfer and can substantially reduce the costs and inconvenience associated with unnecessary transfer.

Antibodies, Monoclonal↗
PubMed2000

Aggressive behavior in clinically depressed adolescents.

OBJECTIVE: To investigate the prevalence and characteristics of aggressive behavior in adolescent inpatients and outpatients with major depressive disorder (MDD). Differences between males and females in prevalence and type of aggression, and level of parent-child agreement in report of aggression, were analyzed. METHOD: Participants were 74 adolescents with MDD, aged 13 to 17 years. The Structured Clinical Interview for DSM-IV Axis I Disorders was used to identify MDD. Adolescents' aggressive behavior was assessed using an adapted version of the Brown-Goodwin Assessment for Lifetime History of Aggression; the Measure of Aggression, Violence, and Rage in Children; and the Buss-Durkee Hostility Inventory-Adapted Version. RESULTS: Results indicate high levels of aggressive behavior in adolescents with MDD. Amount and type of aggression did not differ by gender. Results indicate poor correspondence between parent and adolescent reports of aggression, which was most marked for females. CONCLUSIONS: Aggressive behaviors are highly prevalent in depressed youths, with similar types and levels evident in males and females. Parents tend to under-report and may not be cognizant of aggressive behavior that occurs outside the home, particularly for females.

Adolescent↗
PubMed2000

Advanced practice 101: a "PERLL" for practice.

As advanced practice nursing students begin and continue their programs of study, they are often asked, "What is an advanced practice nurse, and what are the distinguishing characteristics?" For many students, articulating an answer is somewhat difficult, and some even fumble. Therefore, we have developed an acronym to help students organize their thinking in answering these questions. This acronym is a useful tool to help students discuss the characteristics of advanced practice nurses in an organized and well-thought-out manner, keeping in mind that some of these talking points should be customized to the individual state or regional requirements for advanced practice nursing.

Abbreviations as Topic↗
PubMed1999

Mediastinitis after cardiac surgery--epidemiology and current treatment.

Mediastinal infection is a feared complication observed after 0.4%-5% of cardiac operations. Even today the mortality remains as high as 20%-40%. We discuss the aetiology, mechanisms, prevention, diagnosis, and medical management. The staging system for mediastinal wound infections developed at a joint conference of German cardiac surgical centres is presented. The use of parenteral polyvalent immunoglobulins is also discussed.

Cardiac Surgical Procedures↗
PubMed1997

Recent implementations of electronic medical records in four family practice residency programs.

Electronic medical records (EMRs) are increasingly replacing paper records, and many residency program directors are interested in incorporating EMR systems into their clinics. The authors describe their experiences implementing EMRs in their family practice residency programs; the four programs are the Eau Claire Family Practice Residency Program, the Galveston Family Practice Residency Program, the Mayo-Scottsdale Residency Program, and the Wyoming Valley Family Practice Residency. The authors provide background information about each program and an overview of the EMR systems; they then describe the implementation processes, addressing training, integration with other software- and paper-based systems, security, costs, and effects on patient volume and staffing levels. Finally, they discuss the general benefits of and barriers to EMR-system implementations, and make recommendations for other programs considering implementing EMRs.

Attitude to Computers↗
PubMed1995

Sexual harassment in health care: implications for medical radiation technology training programs.

In May 1993, the Council on Education--Radiation Therapy of the Canadian Association of Medical Radiation Technologists (CAMRT) decided to include two new items in its curriculum guide: components of sexual abuse prevention; and legal requirements of consent to treatment and specific procedures (especially those related to gender-sensitive procedures). In order to design a lecture or workshop that would cover these subjects, the committee undertook a review of current literature on sexual harassment and abuse. A two-hour workshop was then given to the 12 students in the Radiation Therapy Program at the Cross Cancer Institute in Edmonton, Alberta. This article attempts to give an overview of the literature as well as the author's recommendations on the format and content for presenting this subject to students. A summary of the students' comments is also included.

Alberta↗
PubMed1994

Structure of the Pisum sativum seed lipoxygenase gene lox1:Ps:3.

We have isolated the Pisum sativum (pea) lox1:Ps:3 gene which encodes a lipoxygenase that is 84% identical in coding sequence to the LOX-3 gene from Glycine max (soybean). The 10028 bp sequence includes 5895 bp 5' to the transcription start site and 707 bp 3' to the stop codon. The coding region of lox1:Ps:3 contains eight introns, at positions equivalent to those in the soybean LOX-3 and L-4, the Phaseolus vulgaris (Frenchbean) LOX1, and the Pisum sativum lox1:Ps:2 genes. The first intron is unusually small. The 5'-flanking sequence contains two regions that have the potential to form hairpin structures, but few motifs known to interact with transcription factors. Despite their similarity in terms of expression, the lox1:Ps:3 and lox1:Ps:2 genes have little similarity within their 5'-flanking regions.

Genes, Plant↗
PubMed1994

Residual sedating effects of ethanol.

To test for dose and duration effects of residual sedation, ethanol (0.0, 0.5, and 0.9 g/kg) was administered (at 0830, 1030, and 0730 hr, respectively) to 10 healthy, normal-sleeping men, aged 21-35 years. The Multiple Sleep Latency Test was conducted at 0930, 1130, 1330, 1530, 1730, 1930, and 2130 hr, and a divided attention performance assessment was done at 1400, 1600, 1800, and 2000 hr. Breath ethanol concentration for both doses was 0.04% at 1130 hr, 0.01% at 1330 hr, and 0 at 1530 hr. A significant reduction in sleep latency was observed from 0930 to 1530 hr, but not thereafter. Divided attention performance overall was significantly impaired on the 1400-hr test only. These data again showed residual sedation and suggest residual sedation is time limited and not affected in duration or intensity by dose.

Adult↗
PubMed1994

Correction of intramyocardial hypercarbic acidosis with sodium bicarbonate.

Although it has been hypothesized that exogenously administered bicarbonate can exacerbate intramyocardial acidosis and compromise contractile function, this phenomenon has not been demonstrated in an intact model in which intramyocardial pH (pH(int)), regional venous pCO2, and regional contractile function have been simultaneously monitored. In 20 anesthetized dogs, we studied the effects of intracoronary infusions of sodium bicarbonate NaHCO3 30 mEg over 15 min, on regional pH(int), (glass electrode) and regional stroke work (SW, sonomicrometry) before and after creating systemic hypercarbic acidosis by hypoventilation. During NaHCO3 administration, regional coronary venous pCO2 increased rapidly during the first minute (eucapnea; 34 +/- 7 to 55 +/- 18 mm Hg; hypercapnea: 70 +/- 15 to 98 +/- 23 mm Hg, P < 0.05 for both increases). Regional venous pH rose from 7.36 +/- .04 to 7.55 +/- .06 (P < 0.05) after the first minute of NaHCO3 infusion during eucapnea and from 7.09 +/- .09 to 7.22 +/- .09 (P < 0.05) during hypercapnea. During the first minute of NaHCO3 infusion, pH(int) declined minimally. However, during the remaining 14 min of each infusion, pH(int) increased significantly (eucapnea: 7.19 +/- 0.10 to 7.43 +/- 0.12; hypercapnea: 6.86 +/- 0.14 to 7.02 +/- 0.15, P < 0.05 for both changes). Regional SW decreased significantly during the first minute of infusion, both during eucapnea (23,400 +/- 7,400 to 18,000 +/- 6,300 ergs/cm2, P < 0.05) and hypercapnea (27,000 +/- 9,100 to 25,000 +/- 10,000 ergs/cm2, P < 0.05). The first minute of contractile dysfunction was followed by recovery and ultimately supranormal contractile function during the remainder of each bicarbonate infusion. To test the hypothesis that transient intracellular acidosis during bicarbonate infusions was underestimated by measurements of pH(int), measurements of intracellular pH using the pH-sensitive dye, BCECF, were performed in isolated guinea pig papillary muscles incubated in vitro. These measurements confirmed the presence of transient intracellular acidosis during bicarbonate infusion. In conclusion, (1) the intracoronary administration of sodium bicarbonate causes a transient depression in myocardial contractile function that is related to transient intracellular acidosis; and (2) despite exacerbating hypercarbia, sodium bicarbonate ultimately neutralizes intracellular acid and augments myocardial contractile function.

Acidosis↗
PubMed1993

Effects of ethanol, diphenhydramine, and triazolam after a nap.

This study assessed the capacity of a 60-minute nap to reverse the sedating and performance-disruptive effects of ethanol, triazolam, and Diphenhydramine. Twelve healthy, young men received (at 0800 to 0830) .6 g/kg ethanol and a placebo pill, .25 mg triazolam and ethanol placebo, 50 mg Diphenhydramine and ethanol placebo, and a placebo pill and ethanol placebo on each of 2 days in a Latin Square design. On one treatment day (at 0900 hour) subjects were allowed a 60-minute nap and on the other a sleep latency test (no nap). Then, sleep latency was tested (by Multiple Sleep Latency Test [MSLT] at 1100, 1300, 1500, and 1700) and divided attention performance assessed (at 1130). The nap reversed the sedative effects of ethanol and Diphenhydramine and reduced those of triazolam (on MSLT). The nap reduced the performance-disruptive effects of ethanol and Diphenhydramine but not those of triazolam. Given the differing neurobiological mechanisms of these drugs, the data suggest that some of their effects are nonspecific and result from activation of sleep mechanisms that a nap can reverse.

Adult↗
PubMed1993

Social networks and support mechanisms for people with mild intellectual disability in competitive employment.

Participant observation techniques were used to examine the social networks and the social support mechanisms of nine subjects with a mild intellectual disability working in competitive employment settings. Results indicated that the social networks of this group of people lacked complexity with few interconnections among the network nodes. The major sources of social support emanated from the family and from organizations catering for people with disabilities. While subjects perceived considerable social support within the workplace, this support was restricted to the workplace and in general did not extend beyond it. Implications of the findings of the study for ensuring the adequacy of social support both within and beyond the workplace for this group of people are discussed. Additionally, the need for the development of a theory or model of social support as it pertains to people with a mild intellectual disability employed in competitive employment settings is advocated.

Activities of Daily Living↗
PubMed1993

Retrograde coronary sinus perfusion provides non-homogeneous myocardial blood flow.

The ability of retrograde cardioplegia to protect the right ventricle has been questioned. Canine myocardial circulation was assessed by infusing colored microspheres through the coronary sinus. The relative flow index (RFI), a normalized measure of tissue blood flow, was determined for 76 sections of myocardium. Three distinct flow regions were evident from these measurements. A paucity of blood flow through some basal sections of the right ventricle (RFI = 0.23 +/- 0.19) was found to be significantly different (p < 0.005) from regions of the heart with normal flow (RFI = 1.12 +/- 0.06). Sections from the right ventricular apex demonstrated augmented flow (RFI = 3.72 +/- 1.18). These data indicate that retrograde coronary perfusion provides nonuniform flow and under some conditions may provide inadequate perfusion to portions of the right ventricle.

Animals↗
PubMed1992

Patient tolerance of ioxaglate and iopamidol in internal mammary artery arteriography.

To compare discomfort caused by ioxaglate and iopamidol, 25 patients scheduled for coronary angiography including internal mammary arteriography were studied. Each patient received both agents. Data were available on 22 randomly selected patients who completed the protocol. Two patients were withdrawn because of unsuccessful internal mammary artery cannulation and one because of idiosyncratic reaction to diazepam. After the internal mammary artery injections, the short-form McGill Pain Questionnaire (SF-MPQ) was completed to evaluate the patient response. Ioxaglate caused significantly less discomfort than iopamidol. Word scale (WS) p less than .05; visual analog scale (VAS) p less than .05. We conclude that ioxaglate is much better tolerated than iopamidol in internal mammary arteriography.

Adult↗
PubMed1992

Sedating effects of ethanol and time of drinking.

Ethanol (0.5 g/kg) was administered to 12 healthy, normal-sleeping men, aged 21 to 45, at two different times of the day (0900 and 1700 hr). The Multiple Sleep Latency Test (MSLT) was conducted at 1000, 1200, 1400, and 1600 hr in the day drinking condition and at 1800, 2000, 2200, and 2400 hr in the evening drinking condition. On placebo, sleepiness was greater in the daytime testing hours than in the evening, replicating findings on the circadian rhythm of sleepiness/alertness. There was a time of drinking (day versus evening) by ethanol interaction. An ethanol effect on sleep latency was found in the daytime hours, when alertness was relatively low. Ethanol failed to have a significant effect on sleep latency during the evening hours when alertness levels were increasing. Performance on a divided attention task, administered 1 hr postconsumption, was impaired by ethanol consumption, but did not vary as a function of time of drinking (day versus evening). However, at 5 hr postconsumption, mean reaction time on the first 20 min of a 40-min auditory vigilance task was slowed by ethanol to a greater extent after day drinking then after evening drinking.

Adult↗
PubMed1992

Left ventricular systolic and diastolic dysfunction after infusion of tumor necrosis factor-alpha in conscious dogs.

We used a load-insensitive index of systolic left ventricular (LV) function and an analysis of diastolic pressure-dimension relationships to test the hypothesis that recombinant human (rh) tumor necrosis factor-alpha (TNF alpha) impairs LV function in dogs. Animals were studied 7-10 d after aseptic implantation of instrumentation to monitor cardiac output, external anterior-posterior LV diameter, and LV and pleural pressures. Data were analyzed from seven dogs that received active rhTNF alpha (100 micrograms/kg over 60 min) and from five dogs that received heat-inactivated rhTNF alpha. At 24 h after infusion of active rhTNF alpha, the slope of the LV end-diastolic dimension-stroke work relationship decreased significantly, indicating a decrement in LV systolic contractility. Simultaneously, LV unstressed dimension increased significantly, suggesting diastolic myocardial creep. The end-diastolic relationship between LV transmural pressure and normalized LV dimension (strain) was markedly displaced to the left, suggesting increased diastolic elastic stiffness. Despite these changes in LV performance, cardiac index was maintained by tachycardia. The abnormalities in LV function were resolved by 72 h. We conclude that rhTNF alpha reversibly impairs LV systolic and diastolic function in unanesthetized dogs. Because dysfunction occurs greater than 6 h after the infusion of rhTNF alpha and persists for 24-48 h, the mechanism underlying this phenomenon may involve secondary mediators or a change in myocardial gene expression.

6-Ketoprostaglandin F1 alpha↗