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Biomedical subjects

J Robb

Publications and source records attributed to J Robb.

At least 19 recordsLinked to original sources
PubMed2000

[CRIGOS: development of a compact robot for image-guided orthopedic surgery].

In this paper, we present a medical robot system dedicated to support the surgeon during challenging tasks within orthopedic interventions. The main goal of this work is to develop a system as technically simple as the surgical requirements allow to keep its cost and complexity to a minimum. Therefore, we primarily focus on calibrated X-ray imaging for image acquisition, an easy registration procedure and robotic execution using a positioning device with simple parallel kinematics. Examples of different orthopedic interventions using the compact robot system for image-guided orthopedic surgery (CRIGOS) are presented, as well as various modes of execution of the device.

Arthroplasty, Replacement, Knee↗
PubMed2000

Properties of herbage in relation to equine dysautonomia: biochemical composition and antioxidant and prooxidant actions.

To investigate the etiology of equine dysautonomia (ED), a degenerative polyneuropathy affecting grazing horses, the biochemical composition and antioxidant/prooxidant activities of aqueous extracts of plants collected from ED pastures were determined. Plants collected immediately after an outbreak of ED had reduced antioxidant and weak prooxidant activities when compared with control plants (plants collected from ED pastures out of ED season and control plants from ED pastures that were grown under favorable conditions). ED plants also had significantly increased concentrations of fructose and low molecular weight phenolic compounds, significantly more of one amino acid zone (probably valine), significantly less tartaric acid, and a nonsignificant decrease in ascorbic acid content when compared with control plants from ED pastures that were grown under favorable conditions. These findings suggest that ED plants may be under oxidative stress, possibly due to chilling, drought, or fungal colonization. However, experimental drought and chilling of plants did not reproduce the biochemical alterations identified in ED plants. It is possible that the altered biochemical content of ingested plants may contribute, directly or indirectly, to the development of ED in grazing horses.

Animal Feed↗
PubMed1998

Health-related quality of life assessment in euthymic and depressed patients with bipolar disorder. Psychometric performance of four self-report measures.

The purpose of this study was to evaluate the psychometric properties of selected health-related quality of life (HRQL) self-report measures in 62 euthymic and depressed patients diagnosed with bipolar disorder. Patients completed the Quality of Life in Depression Scale (QLDS), Mental Health Index-17 (MHI-17), Cognitive Function Scale, and Medical Outcomes Study Short Form-36 (SF-36) at baseline and 8 weeks following treatment. Hamilton and Young Rating Scales were used to assess clinical status and validate the HRQL measures. The MHI-17, Cognitive Function Scale, QLDS, and SF-36 social function, vitality, role limitations-emotional, and mental health scales have good reliability and validity, and are responsive to changes in clinical status in patients with bipolar disorder. Although the small sample size limits generalizablity, euthymic and depressed outpatients with bipolar disorder appear to contribute reliable self reports on selected aspects of their quality of life.

Adult↗
PubMed1997

Physiological changes occurring with positive pressure ventilation: Part one.

Critically ill patients requiring mechanical ventilation are subject to a variety of complications and adverse effects associated with positive pressure ventilation. An awareness of the major physiological effects is important, as recognition, prevention and appropriate treatment of complications is critical to optimizing patient outcome. Pierson (1990) suggests that complications due to ventilation occur with greater frequency than is generally appreciated, and can be a response to suboptimal ventilatory management as a result of poor communication and lack of understanding. This may also adversely affect patient comfort, morbidity and outcome. This can be avoided by improved knowledge of both the function of ventilators and the adverse effects associated with mechanical ventilation. Intensive care nurses face the challenge of caring not only for critically ill patients but also for complex machinery. To improve the delivery of care to the patients, an understanding of the machines and their adverse effects is essential. This increases the nurses' confidence and allows them to focus on the patients and associated problems while maintaining safe and informed care. With the introduction of mechanical ventilation, major physiological changes occur, for example airway resistance and intrathoracic pressures are increased and lung mechanics are altered. The following article provides explanation as to how and why mechanical ventilation produces these changes, and highlights areas where they occur.

Airway Resistance↗
PubMed1997

Physiological changes occurring with positive pressure ventilation: Part Two.

Although the physiological effects of positive pressure ventilation are numerous, sometimes undesirable and have varying degrees of significance, positive pressure ventilation still plays a major role in the resuscitation and treatment of critically ill patients. Advances in the various methods of delivering positive pressure, especially when incorporating spontaneous breathing, have reduced the severity of complications. Despite serious complications, mechanical ventilation has advantages. When it is instituted for ventilatory and hypoxaemic respiratory failure, the benefits can be viewed in the context of the work of breathing. Spontaneous breathing normally requires 5% of total oxygen delivery to meet its demands. In lung disease, the ratio of oxygen consumption by the respiratory muscles to whole body oxygen consumption can increase to 25-30% (Henning 1986, Pinksy 1990). Mechanical ventilation reduces the energy demand of respiratory muscles and increases the oxygen delivery to other vital organs. When mechanical ventilation improves hypoxaemia and/or hypercarbia, or significantly decreases the work of breathing, it may also normalize associated changes in heart rate (Perel & Pizov 1991 p53). When cardiac output is increased in response to the increased work of breathing and associated stress, the institution of mechanical ventilation may beneficially lower the cardiac output simply due to the decrease in oxygen demand; thus the physiological reduction in cardiac output may not necessarily be regarded as a complication. The effects of raised intrathoracic pressure during mechanical ventilation may be beneficial when used to prevent or reduce pulmonary oedema, though problematic in some other situations. Mechanical ventilation is a life-saving treatment which has many associated complications; nurses have to accept the unavoidable hazards and adapt their nursing care to minimize their effects.

Critical Care↗
PubMed1997

Morphology of the acetabulum in hip dislocations caused by cerebral palsy.

Twenty-four hip joints in 20 children with spastic cerebral palsy were assessed by standardised three-dimensional reconstructions from computed tomographic scans. All the hip joints showed a channel-like ebony deformity of the acetabulum along which the femoral bead had slid out, indicating a unidirectional instability. The channel was oriented along the longitudinal axis of the body within a sector of 25 degrees anteroposteriorly. In relation to the pelvis, the dislocation was directed more dorsally by 20 degrees as a result of a flexion contracture of the hip. The size of the femoral head corresponded with the size of the acetabulum in every case, even in long-standing dislocations.

Acetabulum↗
PubMed1997

The relationship between the supply of cardiac catheterization laboratories, cardiologists and the use of invasive cardiac procedures in northern New England.

OBJECTIVES: Utilization rates of coronary angiography and cardiac revascularization have been found to vary between areas. This study addresses the relationship between resource supply and procedure rates. METHODS: We compared the association of per capita catheterization laboratories, per capita cardiologists and multi-provider markets (where more than one hospital offers coronary angiography services) with the utilization rates for angiography and cardiac revascularization in northern New England, USA. Administrative data were used to capture invasive cardiac procedures. Small area analyses were used to create coronary angiography service areas. Linear regression methods were used to measure associations between the resource supply and utilization rates. RESULTS: Variation in the use of invasive cardiac procedures was strongly associated with the population-based availability of catheterization facilities and multi-provider markets and unrelated to cardiologist supply or need (as reflected in the hospitalization rates for myocardial infarction). In the multivariate model, an increase of 1 catheterization laboratory per 100,000 population was associated with an increase in the angiography rate of 1.62 per 1000 population; those service areas with multi-provider markets were associated with an additional increase in the angiography rate of 1.27 per 1000 population (R2 = 0.84, P = 0.0006). There was a moderately strong relationship between the catheterization laboratories per capita and the revascularization rates (R2 = 0.43, P = 0.029). Angiography rates were highly associated with cardiac revascularization rates: an increase in the angiography rate of 1 per 1000 population was associated with a 0.46 per 1000 increase in the cardiac revascularization rate (R2 = 0.85, P = 0.0001). CONCLUSIONS: Our work suggests that current efforts to address variation in cardiac procedures through activities such as appropriateness criteria, guidelines and utilization review are misdirected and should be redirected towards capacity, in this case the supply of catheterization facilities.

Cardiac Catheterization↗
PubMed1996

Comparison of Cyto-Shuttle and cytocentrifuge as processing methods for nongynecologic cytology specimens.

The Cyto-Shuttle (Cancer Diagnostics, Inc., Fairfax, VA) monolayer preparation method was compared to our routine cytocentrifuge method in 129 fluid cytology cases. A single sample from each case was split and prepared by each method. The Cyto-Shuttle preparation was superior to the cytocentrifuge preparation in 51% of cases, equal to it in 38%, and inferior to it in 11%: bronchial wash/lavage (45 cases), 38%, 49%, 13%; body cavity fluid (39 cases), 72%, 15%, 13%; urine (18 cases), 56%, 44%, 0%: peritoneal washing (16 cases), 44%, 44%, 12%; and miscellaneous (11 cases), 36%, 55%, 9%. Cyto-Shuttle preparations were superior due to decreased background and increased number of cells per slide; fixation and morphology were generally equivalent to cytocentrifuge preparations.

Body Fluids↗
PubMed1996

Using qualitative and quantitative patient satisfaction data to improve the quality of cardiac care.

BACKGROUND: In early 1993 leaders within the Hitchcock Clinic and cardiac services section at Dartmouth-Hitchcock Medical Center (Lebanon, NH) formed the Cardiac Services Improvement Group (CSIG) as a pilot program for patient-centered quality improvement (QI) at the sectional level. CSIG PROGRAM: For open heart surgery (OHS) and percutaneous transluminal coronary angioplasty (PTCA), a flowchart was constructed of sequential patient experiences. Content analysis of focus group discussions resulted in six key patient-defined quality characteristics: comfort, caring, certainty, convenience, communication, and cost. Linking of patient comments to points on the patient experience flowchart made it possible to determine where particular quality characteristics were most relevant. A patient satisfaction survey with questions that were specific to a patient experience and to a quality characteristic was mailed to 100 consecutively discharged OHS and PTCA patients; 35 of the 50 patients in each group responded. EVALUATING SUCCESS: Analysis of the survey results led to the formation of two QI teams. One team began work on development of a critical pathway for discharge preparation and identified marker questions to track and monitor pathway success in subsequent surveys. Another team began the development of protocols for more effective pain management during and after the PTCA procedure. A repeat patient satisfaction survey that took place from November 1994 to March 1995 suggested a global improvement in patient satisfaction for all patient experiences and all key quality characteristics. CONCLUSION: The CSIG pilot program of patients-based quality measurement and management at the sectional level has been successful in fostering QI team formation and has been associated with a positive deflection in patient-based quality measures. Additional sections of the medical center have initiated similar projects, beginning with process definition and focus groups.

Angioplasty, Balloon, Coronary↗
PubMed1994

Differential utilization of alternate initiation sites in a plant defense gene responding to environmental stimuli.

The upstream regulatory region of an efficiently expressed phenylalanine ammonia-lyase (PAL5) gene from tomato (Lycopersicon esculentum) was characterized by DNA sequencing and S1-nuclease-protection studies. Two transcription initiation sites giving rise to a long and a short transcript were identified, each corresponding to a different putative TATA sequence element with multiple conserved upstream regulatory motifs. When tomato plants were challenged with three different environmental stimuli, wounding, light and Verticillium infection, this gene was observed to utilize the alternate initiation sites differentially, in a tissue-dependent and stimulus-dependent manner. In general, basal levels of the shorter transcript were very low but preferentially and strongly stimulated by the environmental factors. In contrast, the longer transcript was less affected, essentially representing a constitutive expression of this gene. The results suggest that the multiple regulatory sites in the PAL5 gene promoter provide for both an essential constitutive expression of phenylalanine ammonia-lyase as well as an appropriate response to different environmental stresses.

Amino Acid Sequence↗
PubMed1994

The thyroid and mixed affective states.

The relationship between Grade II subclinical hypothyroidism and mixed affective states were examined in a cohort of 66 patients with bipolar affective disorder. The overall frequency of Grade II subclinical hypothyroidism was 20%. There was no difference in frequency of subclinical hypothyroidism or in mean thyroid hormone levels between the mixed state and non-mixed-state group.

Adult↗
PubMed1993

Body image and food consumption: three laboratory studies of perceived calorie content.

Three studies are reported that measured body image and mood changes consequent to the consumption of a milkshake that differed in perceived number of calories (high vs. low). The pilot investigation on normal-weight college females produced an interaction between perceived calorie content (PCC) and time of testing--subjects who received the high-calorie shake overestimated body size and were more dysphoric at posttest than subjects who received the low calorie shake. Study 2 provided a credibility check that the pilot investigation failed to include and replicated the interaction between PCC and time of testing for size estimation accuracy. The effect was also found for an attitudinal measure of body satisfaction, but only a main effect of time eventuated for the mood measure. Study 3 compared subjects who differed on exercise status (runners vs. sedentary controls). In general, runners were less negatively affected by the high-calorie shake than controls, however, none of the hypothesized three-way interactions among group, PCC, and time of testing were significant. The findings are discussed in terms of the need to further experimentally investigate factors that affect different aspects of body image.

Adolescent↗
PubMed1992

Truncated phenylalanine ammonia-lyase expression in tomato (Lycopersicon esculentum).

Southern blot analyses of genomic DNA fragments suggest there are five different classes of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) genomic sequence in tomato (Lycopersicon esculentum). Isolation and subsequent sequence analysis of three examples from genomic libraries reveal highly homologous coding sequences but also a surprisingly high frequency of single point mutations which would truncate protein synthesis. The nucleotide sequence for one of the genes (PAL5) encodes a normal polypeptide of 721 amino acids, interrupted by a 710-base pair intron in the codon for amino acid 139. In contrast, premature stop codons, 363 triplets from the end in PAL1 and 304 triplets from the end in PAL3 would result in substantially (51-43%) shorter polypeptides that are consistent with the protein polymorphism, recently reported in alfalfa (Jorrin, J., and Dixon, R. A. (1990) Plant Physiol. 92, 447-445) but ascribed to protein degradation. S1 mapping of the mRNA termini and polymerase chain reaction analysis of cDNA transcripts indicate that at least one of these truncated coding sequences is expressed, strongly suggesting that at least some of the shorter polypeptides constitute original gene products with a potentially important function.

Amino Acid Sequence↗
PubMed1992

Reduced PAL gene suppression in Verticillium-infected resistant tomatoes.

In tomato, resistance to the wilt fungus Verticillium albo-atrum is determined primarily by the Ve locus. When two tomato near-isolines which differ at this locus and in their susceptibility to the pathogen were compared, more rapid suberin coating in the xylem of resistant plants correlated closely with a more rapid increase in the activity of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), an enzyme which is essential to the suberization process. In contrast, levels of mRNA did not increase proportionally to the measured enzyme activities; rather, there was a substantial suppression of mRNA levels in the susceptible tomato line, consistent with a much lower elevation of PAL activity and significantly less vascular coating. The suppression was absent or substantially reduced in the resistant line. The results indicate that the pathogen can suppress defense genes in susceptible plants but suggest that their expression is altered in resistant hosts and that post-transcriptional regulation plays a significant role.

Amino Acid Sequence↗
PubMed1992

Adverse reactions of low osmolality contrast media during cardiac angiography: a prospective randomized multicenter study.

A multicenter study was performed to determine the incidence of adverse reactions to two contrast media with similar low osmolality during cardiac angiography. The study was of a randomized double-blind design comparing ioxaglate (an ionic dimer) and iopamidol (a nonionic compound) and included 500 patients; 250 patients received ioxaglate and 250 iopamidol. There were 58 adverse reactions attributed to the contrast media in the ioxaglate group and 29 in the iopamidol group (p less than 0.001). Chest pain occurred in 11 patients in the ioxaglate group compared with 5 in the iopamidol group (p = 0.123). Nausea or vomiting was present in 20 and 2 patients, respectively (p less than 0.0003). Allergic adverse reactions, such as bronchospasm, urticaria and itching, occurred in 15 of the ioxaglate group and only 1 of the patients receiving iopamidol (p less than 0.0007). Fifty-two patients in the ioxaglate group had a known allergic history (not to contrast medium) or asthma, whereas 77 receiving iopamidol had a similar history. Seven of the 52 ioxaglate-treated patients developed an allergic adverse reaction compared with none of the 77 in the iopamidol group (p = 0.001). Of 41 patients receiving ioxaglate who were premedicated with diphenhydramine, 4 had an allergic adverse event. In the iopamidol group 45 patients received similar premedication and none had an allergic adverse reaction (p less than 0.03). Thus, this multicenter study shows that adverse reactions occur more often with ioxaglate than with iopamidol and that patients with an allergic history have a greater risk with ioxaglate therapy compared with iopamidol.

Adult↗