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Biomedical subjects

B Reynolds

Publications and source records attributed to B Reynolds.

At least 19 recordsLinked to original sources
PubMed1998

Photosensitizing effects of m-tetrahydroxyphenylchlorin on human tumor xenografts: correlation with sensitizer uptake, tumor doubling time and tumor histology.

The photodynamic effects of m-tetrahydroxyphenylchlorin (mTHPC) were assessed on human malignant mesothelioma, squamous cell carcinoma and adenocarcinoma xenografts grown in nude mice and were correlated with mTHPC uptake, histology and doubling time of the tumors. Non-thermal laser light was delivered to the tumor as surface radiation 4 days after intraperitoneal administration of 0.1 and 0.3 mg mTHPC/kg body weight, respectively. The extent of tumor necrosis was measured by histomorphometry. The mTHPC concentration in non-irradiated tumors was assessed by high-performance liquid chromatography (HPLC). The tumors were graded according to their doubling time and their vascular architecture as assessed by histology. The 0.1 mg/kg dose of mTHPC resulted in an equal uptake for all 3 tumor types but revealed a larger extent of photosensitized necrosis for adenocarcinoma, which displayed a delicate tumor stroma with numerous small capillary vessels, than for mesothelioma and squamous cell carcinoma, which were both poor in stroma and vessels. The 0.3 mg/kg dose of mTHPC resulted in a 2-fold higher tumor uptake for all 3 tumor types and in a larger extent of necrosis for mesothelioma and squamous cell carcinoma, but not for adenocarcinoma xenografts, compared with the lower drug dose. Our results demonstrate that different tumor xenografts respond differently to mTHPC-PDT for a given drug-light condition. In this setting, the photosensitizing effect was more closely related to the vascular architecture of the tumors than to the sensitizer uptake and doubling time of the different tumors

Adenocarcinoma↗
PubMed1998

Analgesic efficacy and safety of (R)- ketoprofen in postoperative dental pain.

This double-blind, randomized, parallel-group study compared the analgesic efficacy and safety of single doses of (R)- ketoprofen 25 mg and 100 mg to that of acetaminophen 1,000 mg and placebo in 177 patients experiencing moderate to severe pain after surgical removal of their impacted third molars. Both (R)- ketoprofen 100 mg and acetaminophen 1,000 mg were significantly (P < 0.05) more efficacious than placebo for all summary analgesic measures. Other than a more rapid analgesic onset (45 minutes versus 60 minutes) for acetaminophen 1,000 mg, (R)- ketoprofen 100 mg and acetaminophen 1,000 mg were statistically equivalent to each other. The 25 mg dose of (R)- ketoprofen appeared to approach the analgesic threshold dose, being numerically but not statistically superior to placebo for all summary measures. There were no serious adverse events observed in this study, with the overall incidence of side effects being somewhat less in the (R)- ketoprofen groups than in the acetaminophen 1,000 mg group. (R)- Ketoprofen possesses analgesic activity and an acceptable side-effect profile in the oral surgery pain model.

Acetaminophen↗
PubMed1998

Percutaneous placement of tracheal T tube.

Tracheal T tubes provide effective palliation of unresectable benign and malignant tracheal obstruction, but placement may be difficult when previous operation, radiation, or tumor limits surgical exposure of the cervical trachea. Percutaneous placement using commercially available percutaneous tracheostomy kits may provide an alternative approach in these cases.

Female↗
PubMed1998

A Canadian survey of cancer patients' experiences: are their needs being met?

Cancer patients (n = 913) who received treatment within the previous 2 years were interviewed to quantify reports of symptoms associated with cancer, measure the impact of symptoms on lifestyles, document experiences with accessing information and treatment for cancer and its symptoms, and record attitudes about the level of care received. Cancer patients were primarily recruited through newspaper ads placed throughout Canada and asked to complete a self-report questionnaire. Patients called a toll-free number and were interviewed to ensure eligibility. Most respondents were female (66%) with breast cancer (64%). Prostate cancer (40%) was the most common diagnosis among males. Almost all respondents (94%) reported experiencing one or more symptoms. Fatigue and anxiety were the most frequently reported symptoms (78% and 77%, respectively). Fatigue was most likely to be self-rated as moderate to severe and was most likely to interfere in normal daily activities. Respondents who experienced fatigue reported a more frequent use of healthcare services (including complementary therapies) than those who did not experience fatigue. Half of the respondents reported trying to find information on fatigue, but only half of these said they had obtained information. The most helpful sources of information were nurses, specialists, and other cancer patients. Respondents were more likely to be dissatisfied with their treatments for their symptoms than for their cancer. This survey indicates that most cancer patients experience symptoms related to the disease and its treatment. The most prevalent symptoms are fatigue and anxiety; fatigue is the most debilitating.

Adult↗
PubMed1997

Quality of life and sexuality following radical prostatectomy in patients with prostate cancer who use or do not use erectile aids.

OBJECTIVES: It is well established that prostate cancer patients undergoing radical prostatectomy may experience disruptive side effects, most notably urinary incontinence and erectile dysfunction. The purpose of this study is to compare relevant outcomes between patients awaiting radical prostatectomy for prostate cancer and patients who already underwent the surgery, taking into account type of prostatectomy and use of erectile aids. METHODS: We compared self-reports of global quality of life, sexuality, urinary continence, and physical capabilities in 86 nerve-sparing patients, 89 standard-prostatectomy patients, 74 prostatectomy patients who used erectile aids, and a comparison group of 45 patients awaiting radical prostatectomy. RESULTS: Regardless of type of surgery, use of erectile aid, or preoperative status, most patients reported good quality of life. The best outcomes in sexuality were reported by patients who used erectile aids, who appeared similar in sexuality to patients awaiting surgery. When differences were detected, standard prostatectomy patients who did not use erectile aids scored worse in most areas of sexuality than nerve-sparing patients who did not use erectile aids. There were no differences in frequency of urinary leakage among the three surgery subgroups. CONCLUSIONS: Although most patients reported problems in sexual and urinary function, global quality of life does not appear to be compromised following radical prostatectomy. Findings suggest that postsurgical sexuality differs depending on type of prostatectomy and use of erectile aids, while urinary function is similar across surgery groups. We conclude that erectile aids should be offered routinely to patients who are ineligible for nerve-sparing surgery or experience erectile difficulties following the nerve-sparing procedure.

Aged↗
PubMed1997

The effect of electrode size on transvenous defibrillation energy requirements: a prospective evaluation.

Recent technological advances have resulted in high success rates for implantation of nonthoracotomy defibrillation lead systems. Further decreases in defibrillator size, facilitating pectoral placement, will depend in part on lowering defibrillation energy requirements. The purpose of this study was to determine if endocardial defibrillation energy requirements are influenced by electrode size. Thirteen adult mongrel dogs were studied under general anesthesia. A 9 Fr integrated bipolar pace/sense/defibrillation electrode (cathode) was positioned transvenously at the RV apex. The second defibrillation electrode (anode) was positioned at the junction of the RA and SVC. Two diameters of the proximal electrode, 7 Fr and 11 Fr, were sequentially tested in random order in each animal. The DFT for each electrode was determined using a 50-V up-down method. Energy, leading edge voltage, and current, current distribution, and total resistance were measured. The mean defibrillation voltage threshold with the 11 Fr proximal electrode was significantly less than with the 7 Fr proximal electrode (551.1 +/- 76.5 V vs 588.5 +/- 54.6 V, P < 0.01). Similarly, the mean DFT with the 11 Fr electrode was less than with the 7 Fr electrode (20.7 +/- 5.7 J vs 23.3 +/- 4.4 J, P < 0.01). Lower DFTs were found using the larger electrode in 11 of the 13 animals studied. However, there was no difference in defibrillation lead impedance between the two electrode systems. Endocardial defibrillation energy requirements may be lowered with a larger diameter proximal electrode. The mechanism by which this occurs may be due to a more even distribution of current gradients with the larger electrode. Determination of the optimal electrode size requires evaluation in humans, as this may allow further reduction in defibrillation energy requirements and defibrillator size.

Animals↗
PubMed1997

The level of lipopolysaccharide-binding protein is significantly increased in plasma in patients with the systemic inflammatory response syndrome.

Currently, there is no way to predict with a high degree of sensitivity and specificity which patients are likely to develop systemic inflammatory response syndrome (SIRS) following systemic infection, trauma, organ rejection, or blood loss. The level of human lipopolysaccharide-binding protein (LBP) was determined in the plasma of 22 patients with a clinical diagnosis of early SIRS. Twenty-nine plasma samples from healthy volunteers were used as controls. The mean level of LBP in the plasma of healthy volunteers was 7.7 micrograms/ml (standard deviation, 6.2 micrograms/ml). Twenty-one of 22 patients (95%) with SIRS had an LBP level on admission at least 2 standard deviations above the mean LBP level for a healthy volunteer control group (range, 4.9 to 114.2 micrograms/ml; mean, 36.6 micrograms/ml; standard deviation, 22.2 micrograms/ml; P < 0.0001). The level of LBP in the plasma of the majority of patients with early SIRS is significantly increased compared to that in healthy controls. The sensitivity, specificity, and predictive value of elevated plasma LBP levels in patients with SIRS remain to be determined.

Acute-Phase Proteins↗
PubMed1997

Power scalers: the new boom in contemporary periodontics.

The choice of which type of instrumentation to use remains the decision of the practitioner. It all depends on what goal the clinician hopes to achieve, the resources, and the physical set up within which they work. While speed in debridement, coupled with ease of use and comfort to the patient and practitioner are all important, the primary goal must always remain the optimal healing and success of the dental procedure. With improved tip designs and efficiency, power scaling has the ability to improve dental hygiene and periodontal care in the future.

Crystallography↗
PubMed1994

The influence of clients' perceptions of the helping relationship in the development of an empathy scale.

The paper includes a discussion about the origins of items on a measure of cognitive-behavioural empathy. This scale was originally produced by the author as a teaching tool for an empathy education programme (for RNs) and subsequently developed into a quantitative measure of empathy. The instrument is being used as part of a triangulated approach for data collection on research into the effectiveness of an educational programme about registered nurses' empathy. Antecedents of the initial item pool for the scale stem from theoretical views about empathy, the professional experience of others, and the researcher's experience with clients. While this scale has undergone some investigation for reliability and validity, this work will only be summarized briefly. The major focus for the paper is clients' reports of interpersonal conditions which they perceive as being helpful, or unhelpful, in respect of building therapeutic nurse-client relationships.

Attitude to Health↗
PubMed1994

A critique: Watson's caring ideology. The proper focus of psychiatric nursing?

1. Watson's (1989) conceptualization of care possesses limited clinical utility in psychosocial contexts, given that there already exists an extensive lineage of human concepts of helping, within various psychotherapeutic traditions. 2. Watson's (1989) use of language delimits any utility that the "caring" construct might possess, Watson's conceptualization of caring is an inappropriate focus for psychiatric nursing, and historical precedents exist for many of the propositions upon which the science of caring is based. 3. Four decades of psychiatric nursing practice research and education render Watson's notion of a "science of caring" redundant.

Empathy↗
PubMed1994

The T alpha 1 alpha-tubulin promoter specifies gene expression as a function of neuronal growth and regeneration in transgenic mice.

We have previously demonstrated that one member of the alpha-tubulin multigene family, termed T alpha 1 in rats, is regulated as a function of neuronal growth and regeneration. To elucidate the molecular mechanisms responsible for coupling gene expression to morphological differentiation, we have isolated the T alpha 1 gene, have fused 1.1 kb of the 5' flanking region to a nuclear lacZ reporter gene, and have generated transgenic mice. Analysis of these transgenic mice demonstrated that marker gene expression was specific to the CNS and PNS, with expression in vivo at embryonic day 13.5 being similar to expression of the endogenous gene. Moreover, the induction of transgene expression was correlated temporally with neuronal commitment in developing neural crest-derived peripheral neurons and in the developing retina. Immunocytochemical analysis of mixed primary embryonic brain cultures confirmed that transgene expression was specific to neurons, with the majority of neurons, but not astrocytes or oligodendrocytes, expressing beta-galactosidase. Transgene expression in vivo was maintained in developing neurons until early in postnatal life, subsequent to which its expression decreased coincident with neuronal maturation. The transgene was then reinduced in regenerating facial motoneurons following unilateral axotomy of the facial nerve. Thus, 1.1 kb of 5' flanking sequence from the T alpha 1 gene contains the sequence elements responsible for specifying gene expression to embryonic neurons and for subsequently regulating gene expression in both developing and mature neurons as a function of morphological growth.

Animals↗
PubMed1994

Topoisomerase II mediated DNA lesions induced by acridine-4-carboxamide and 2-(4-pyridyl)quinoline-8-carboxamide.

Acridine-4-carboxamide and 2-(4-pyridyl)quinoline-8-carboxamide represent a new generation of antitumor intercalators related to amsacrine (m-AMSA), a classic topoisomerase II-targeted drug. We examined the ability of these tricyclic carboxamides to induce DNA lesions that reflect the stabilization of topoisomerase II cleavage complexes. DNA-protein cross-links (DPC) and DNA double-strand breaks (DSB) were assessed in mouse fibrosarcoma cells (line 935.1). DPC were rapidly formed and readily reversible. A bell-shape concentration dependence suggested a self-inhibition of DPC at higher drug levels. In isolated nuclei, DPC formation by 2-(4-pyridyl)quinoline-8-carboxamide required ATP and was inhibited by novobiocin, a topoisomerase II inhibitor. Acridine-4-carboxamide and 2-(4-pyridyl)quinoline-8-carboxamide were also potent inducers of DSB. In contrast to DPC, however, DNA breaks continued to increase with drug concentration. These DSB were masked (presumably by non-covalently associated proteins) when analyzed by nucleoid sedimentation. Thus, while both DPC and DSB seemed to be topoisomerase mediated, at least some DSB appeared to lack the enzyme bound covalently. DNA lesions by tricyclic carboxamides occurred, in general, at drug concentrations comparable to those needed to inhibit cell survival. Also, the tricyclic carboxamides inhibited the catalytic activity of isolated topoisomerase II. The results indicate that tricyclic carboxamides interfere with the action of topoisomerase II. However, the mechanisms of enzyme inhibition by these drugs differ from the classical trapping of topoisomerase in covalent cleavage complex m-AMSA.

Acridines↗
PubMed1993

A case of deletion 14(q22.1-->q22.3) associated with anophthalmia and pituitary abnormalities.

An interstitial deletion of the region q22.1-->q22.3 of chromosome 14 is described in a child with bilateral anophthalmia, dysmorphic features including micrognathia, small tongue, and high arched palate, developmental and growth retardation, undescended testes with a micropenis, and hypothyroidism. Interstitial deletions of the long arm of chromosome 14 are extremely rare, but this case seems to confirm that the region q22 is specifically concerned with pituitary and eye development.

Abnormalities, Multiple↗