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Biomedical subjects

J R Robinson

Publications and source records attributed to J R Robinson.

At least 37 records · Page 2Linked to original sources
PubMed1997

Reliability of the Manitoba Mental Health Management Information System for Research.

OBJECTIVES: To determine the accuracy of data contained in Manitoba's Mental Health Management Information System (MHMIS) as compared with client charts and to determine which factors influence completeness and accuracy. METHODS: Data on diagnosis, open date and close date, demographic information, and contact information were obtained from client charts and compared with data extracted from the MHMIS. Semistructured interviews were conducted with individuals who contribute data to the MHMIS. RESULTS: Data on required demographic variables, primary diagnosis, and open and close dates are highly similar in the 2 sources. The correlation between data sources on the number of client contacts is also good. CONCLUSION: This study establishes the reliability of MHMIS data. MHMIS data, in combination with hospital abstracts and physician claims data, provide the information needed to serve as a psychiatric case register (PCR) and can be used for psychiatric epidemiology as well as for planning, monitoring, and evaluating mental health services.

Cross-Sectional Studies↗
PubMed1996

Vaginal permeability and enzymatic activity studies in normal and ovariectomized rabbits.

PURPOSE: This study was initiated to develop an animal model, using ovariectomized rabbits, for the post-menopausal human, based on in vitro vaginal tissue permeability and aminopeptidase activity. METHODS: An enkephalin derivative [D-ala(2),N-methyl-phe(4)-glycol(5)][tyrosyl-3,5-(3)H] enkephalin {[(3)H] RX 783006), which has relative enzymatic stability to aminopeptidases and dipeptidyl peptidase, was used as a model peptide drug for permeability experiments. Aminopeptidase activity in vaginal homogenates, as well as in tissue pieces, was determined using 4-methoxy-2-naphthylamides of leucine, alanine, arginine, and glutamic acid as specific substrates. In addition, histological examination of normal and ovariectomized vaginal tissues was performed. RESULTS: Vaginal permeability of the drug was significantly increased in the ovariectomized compared to the intact animal. The full vaginal tissue became thinner and mucosal epithelial thickness was reduced about two-fold after ovariectomization and vaginal cells from the castrated rabbit were typically immature. Aminopeptidase activity, leucine aminopeptidase, aminopeptidase B and A, was the same in vaginal tissue homogenates and whole-tissue specimens in both normal and ovariectomized rabbits whereas the activity of aminopeptidase N was significantly decreased in ovariectomized as compared to normal rabbits. CONCLUSIONS: Based on the present data, the ovariectomized rabbit may be useful as an animal model for postmenopausal vaginal studies.

Aminopeptidases↗
PubMed1996

Quality of attachment as a predictor of maternal visitation to young hospitalized children.

Tested a comprehensive model of factors predicting maternal visitation with hospitalized children. Subjects were 86 mothers who completed the Spielberger State-Trait Anxiety Inventory, a 12-item attachment measure derived from the Waters and Deane Attachment Q-sort, and a demographic questionnaire. Children were 10 months to 4 years old (37 female, 49 male) and hospitalized for acute nonsurgical illness. Hierarchical regression analyses indicated that, of the subset of variables tested (SES, number of children at home, gender, age, number of previous hospitalizations, state anxiety, and security of attachment), quality of attachment was the only significant predictor of maternal visitation rate. Mothers who reported that their children displayed insecure attachment behaviors maintained a significantly lower rate of visitation than mothers who reported that their children displayed secure attachment behaviors. Results of this study highlight the importance of understanding parent-child attachment in predicting maternal visitation when a child is hospitalized.

Child, Hospitalized↗
PubMed1996

Improved ocular bioavailability of indomethacin by novel ocular drug carriers.

The ability of different drug carriers to improve the ocular bioavailability of drugs was investigated in the rabbit eye. The assayed drug carriers were suspensions of nanoparticles, nanocapsules and microparticles made of poly-epsilon-caprolactone (PECL) and a submicron emulsion. Results indicated that the three submicron systems, nanoparticles, nanocapsules and emulsion, increased more than 3-fold the indomethacin concentration in the cornea, aqueous humour and iris-ciliary body at 0.5 and 1 h post-instillation. Furthermore, an increased indomethacin ocular bioavailability of 300% was observed after instillation of the submicron systems in comparison with the value obtained for a commercial solution. In contrast, the microparticles hardly increased the ocular bioavailability of indomethacin. The mechanism of interaction of the colloidal carriers with the corneal epithelium was investigated by confocal laser scanning microscopy. Confocal images indicated that submicron particles penetrate into the corneal epithelium cells by an endocytic mechanism. The similar behaviour of the three colloidal carriers suggests that any of their specific ingredients (PCEL, lecithin and oil) acts as a penetration enhancer or an endocytotic stimulator. On the other hand, the favourable ocular penetration of indomethacin when encapsulated in the colloidal carriers, but not in the microparticles, led us to assume that the colloidal nature of these carriers is the main factor responsible for the increased ocular bioavailability of indomethacin. PECL nanoparticles and nanocapsules as well as submicron emulsions are shown to be novel corneal drug carriers, thus representing a useful approach for increasing the ocular bioavailability of drugs.

Analysis of Variance↗
PubMed1996

Skull base tumors. A critical appraisal and clinical series employing image guidance.

Two of the most significant developments in neurosurgery over the past ten years have been the application of intraoperative navigational units and the widespread use of "skull base" surgical techniques. These developments have independently revolutionized the way in which neurosurgeons approach intracranial pathology. The combination of these two developments has had a profound effect in our clinical practice to improve outcome and extend our capabilities. This ability to see around the corner, "x-ray" vision as some have called it, provides an added measure of safety for the patient while allowing the surgeon to treat the lesion in a more aggressive fashion.

Adolescent↗
PubMed1996

Primary amoebic meningoencephalitis after swimming in the Rio Grande.

We report a case of fatal primary amoebic meningoencephalitis (PAM) with Naegleria fowleri in a 13-year-old male, and review the clinical course and diagnostic autopsy findings. The boy developed the infection after swimming with relatives in the Rio Grande and in a holding tank containing water pumped from the river. The clinical and neuropathologic features of PAM are presented. The microscopic features of motile unicellular organisms with pathognomonic broad, lobate pseudopodia are diagnostic and, if recognized before death, allow for timely treatment. A public health investigation into this case implicated river water from the Rio Grande polluted with sewage as the infection source. Exposure to polluted river water from some areas of the Rio Grande may represent a risk factor for infection with Naegleria fowerli, because the high levels of coliform bacteria found in sewage and the warm, sluggish water of the river are favorable growth conditions for the amoebae. Because the Rio Grande is an international border, this case illustrates the importance of international cooperation in pollution control in the prevention of a potentially fatal infectious disease.

Adolescent↗
PubMed1995

Hypermetaphase fluorescence in situ hybridization for quantitative monitoring of Philadelphia chromosome-positive cells in patients with chronic myelogenous leukemia during treatment.

Using Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) as a model, our aim has been to develop a molecular cytogenetic method of high resolution analysis for monitoring the frequency of cells with nonrandom chromosome rearrangements in the bone marrow of patients receiving treatment for hematologic malignancies. Long-term exposure (24 hours) of bone marrow cultures to colcemid (0.1 microgram/mL) maximized a high frequency of metaphase collection. Such preparations were subjected to fluorescence in situ hybridization (FISH) using a 5 Mb probe that overlapped the region of the translocation at chromosome 9q34. This detected the Ph translocation in the resultant large number of overly contracted chromosome spreads. The procedure was validated and verified by studying 70 double-blind marrow samples from patients in different stages of Ph+ CML and from patients with Ph- hematologic malignancies (controls). This hypermetaphase FISH (HMF) method clearly identified Ph+ metaphases and allowed the analysis of 500 hypermetaphases per sample in less than 1 hour after FISH. HMF (1) identified statistically significant differences between the frequencies of Ph+ cells in samples that differed by less than 4%; (2) resolved such differences among patient samples that were all judged 100% Ph+ by standard G-band cytogenetics (CG); (3) resulted in the reclassification of response status in 23% of the patients initially classified by CG; (4) recognized Ph+ cells in 16% of patients characterized as having a complete cytogenetic response and in one patient with an original diagnosis of Ph- CML; and in one patient with an original diagnosis of Ph- CML; and (5) was informative where insufficient metaphases were obtainable for analysis by CG. HMF appears to be uniquely suitable for monitoring the status of patients with CML receiving treatment. It should also be applicable for patients with any hematologic diseases where chromosomal alterations are known and appropriate FISH probes are available.

Azure Stains↗
PubMed1995

Expression of basement membrane and endothelial cell adhesion molecules in vascular malformations of the brain: preliminary observations and working hypothesis.

Little is known about the pathogenesis and subsequent cellular biologic behaviour of human cerebral vascular malformations. Innovative therapeutic strategies will depend on more fundamental understanding of structural and functional lesion biology. We have freeze-processed four specimens of arteriovenous malformation (AVM), two cavernous malformations (CM), and resected cortex from one case of Sturge-Weber disease (SWD) for immunohistochemical studies. Probes of vascular maturity and cellular adhesion were examined, including Factor 8 related antigen (F8RAG), laminin, fibronectin, and adhesion molecules VCAM, ELAM and ICAM-1 (CD 54). Sections of the same lesions were permanently fixed and stained using Haematoxylin and Eosin, and MOVAT Pentachrome stain for identification of vascular wall structures. A double antibody staining battery was utilized with ultraviolet fluorescent microscopy, and was analysed by an observer blinded to the antibody and lesion type. All malformations showed strong expression on their luminal endothelial surface for F8RAG. There was no expression of ELAM in any lesion. Two AVMs expressed VCAM on the endothelial surface of some vessels. ICAM-1 was expressed faintly within two AVMs. The CMs expressed fibronectin within the endothelium and subendothelial matrix, and both lesions were devoid of laminin expression. The AVMs and the SWD vessels stained for laminin, while none of the AVMs expressed fibronectin. These preliminary observations are consistent with the hypothesis that AVMs and SWD represent more mature vessels, consistent with possible lesion genesis during early phases of embryonic vascular development (dysvasculogenesis). In contrast, CMs represent immature vessels devoid of laminin and other features of mature vessels, consistent with ongoing dysangiogenesis within a fibronectin rich matrix. Further studies should be aimed at better elucidation of these biologic probes, and correlation with specific lesion behaviour.

Basement Membrane↗
PubMed1994

Consistency of visual assessments of arch height among clinicians.

Flat feet and high-arched feet have been cited as risk factors for musculoskeletal injury and functional problems among runners and other active individuals, although there are no established quantitative definitions or measures for assessing either condition. As part of a larger study, four-plane photographs were made of the weight-bearing right foot of 246 young male Army trainees. These photographs were independently evaluated by six clinicians and rated on a scale of clearly flat-footed (category 1) to clearly high arched (category 5). There was much interclinician variability in the assessments, even for extremes of foot type. The probability of a clinician assessing a foot as clearly flat, given that another clinician had rated the foot as clearly flat, ranged from 0.32 to 0.79, with a median probability of 0.57, while for clearly high-arched feet, probabilities ranged from 0.0 to 1.00, with a median of 0.17. These findings demonstrate the need for objective standards and quantitative methods of evaluating foot morphology.

Flatfoot↗
PubMed1993

Foot morphologic characteristics and risk of exercise-related injury.

OBJECTIVE: It is widely accepted that persons with flat or high-arched feet are at increased risk of exercise-associated injury, even though this purported association has not been scientifically evaluated. We evaluate the risk of exercise-associated injury among young men with flat, normal, and high-arched feet. DESIGN: A prospective study of 246 US Army Infantry trainees followed up over a rigorous 12-week training program. All subjects were evaluated prior to onset of training. Evaluation included photographs of the right, weight-bearing foot that were digitized and utilized to make several measures of arch height. SETTING: An army initial entry training center. SUBJECTS: All trainees beginning army training on 2 successive weeks were potential volunteers. There were no criteria for exclusion other than declining to participate (n = 3). The subjects were healthy, active young men with a mean age of 20.3 years. OUTCOME MEASURE: The occurrence of a lower-extremity musculoskeletal injury resulting in a visit to and a diagnosis by an army physician or physician assistant. Treating physicians and physician assistants were blind to participation status and were not study staff members. RESULTS: On univariate analysis, there was an association between arch height and risk of injury using several alternative operational definitions of foot type. The 20% with the flattest feet were at the lowest risk (reference group; odds ratio, 1.0), with adjusted odds ratios for any musculoskeletal injury of 3.0 (P < .05) for the middle 60% group and 6.1 (P < .05) for the highest 20% group. CONCLUSIONS: These findings do not support the hypothesis that low-arched individuals are at increased risk of injury, and they have implications for runners, exercise enthusiasts, and clinicians. It may be possible to prevent substantial morbidity among active populations by identifying individuals at high risk and advising alternate activities.

Adolescent↗
PubMed1993

Polyanionic hydrogel as a gastric retentive system.

Gastric emptying of a polyanionic hydrogel, polycarbophil (PC), from the canine stomach was studied using a duodenal cannulation technique. The basis of the study is to employ a certain quantity of swelling hydrogel that, by virtue of its swollen size and viscosity, converts a fasted stomach to a fed state and resists discharge from the stomach for an extended period of time. Different amounts of PC, in 200 ml water plus buffering agents, were administered orally to fasted canines. The gastric emptying lag time was found to increase with the viscosity of the administered dose. Addition of a base, sodium bicarbonate, to PC increased gastric retention via an increase in its apparent viscosity. The polymer mass is retained in the canine stomach until a sufficient quantity of stomach acid secretion reduces the viscosity of the viscous mass, through protonation of polycarbophil, and, at that point, discharge of the hydrogel will commence. Thus, gastric retention of PC hydrogel in the canine stomach can be prolonged by increasing the apparent viscosity of the hydrogel administered.

Acrylic Resins↗