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Biomedical subjects

K Martin

Publications and source records attributed to K Martin.

At least 37 records · Page 2Linked to original sources

A thermal beam-shape phantom for ultrasound physiotherapy transducers.

Acoustic beam nonuniformities are not uncommon in physiotherapy ultrasound equipment and can lead to errors in delivered dose. A relatively simple thermal technique is described for mapping the intensity distribution in physiotherapy ultrasound beams that could be used for routine QA checks. The technique uses a thermochromic material sandwiched between layers that absorb ultrasound. The structure is used in a water bath to intersect the ultrasound beam. Thermal models predict that, with suitable absorbing materials and careful control of the surface temperature of the layers, sufficient spatial resolution and sensitivity can be achieved to show the intensity distribution in physiotherapy ultrasound beams. Thermal images of sections through physiotherapy ultrasound beams using this method correlate well with corresponding intensity maps generated by planar scanning with a hydrophone.

Hot Temperature

Barrier precautions in trauma resuscitation: real-time analysis utilizing videotape review.

Blood-borne pathogens threaten all individuals involved in emergency health care. Despite recommendations by the Centers for Disease Control and the American College of Emergency Physicians, documented compliance with universal precautions in trauma resuscitation has been poor. The purpose of this study was to determine the factors that predispose to noncompliance with barrier precautions at a level I trauma center. Videotapes of trauma resuscitations performed during 1 month (n = 66) were reviewed. Full compliance with barrier precautions was documented in 89.1% of health care workers. Of the noncompliant health care workers, 50.7% were emergency department personnel and 47.8% were first responders to the trauma resuscitation area. Barrier precaution compliance improved from 62.5% to 91.8% with prenotification of patient arrival. Immediate access to barrier equipment is essential for all potential in-hospital first responders. Prehospital communication systems should be optimized to ensure prenotification.

Blood-Borne Pathogens

Three-dimensional polyethylene wear of a press-fit titanium prosthesis. Factors influencing generation of polyethylene debris.

Between 1985 and 1990, 108 consecutive Harris-Galante I (Zimmer, Warsaw, IN) total hip arthroplasties were performed by four surgeons at a single hospital. At the time of follow-up evaluation, 80 hips were available for review. The mean rate of linear wear was 0.15 mm/y, mean rate of three-dimensional femoral head displacement was 0.21 mm/y, and mean rate of volumetric wear was 121 mm3/y. Eight hips (10%) in this series had radiologic osteolysis around either the femoral or acetabular component. A significantly greater volumetric wear rate was found in patients who were younger, those with a higher activity level, those who received a 32-mm-diameter femoral head, and those with vertical orientation of their acetabular component. No relationship could be made with patient weight, gender, Harris hip score, or cup diameter.

Adult

Performance of a restrictive flow device and an electronic syringe driver for continuous subcutaneous infusion.

The aim of this study was to investigate the flow performance of the mechanical Springfusor 30 short model and the electronic Graseby MS16A. Flow rate was measured gravimetrically in a temperature-controlled cabinet. There was no statistically significant difference between the Graseby and Springfusor syringe drivers in the flow rate error at 25 degrees C. The percentage of flow rates within +/-20% accuracy during a 35-min periods at 25 degrees C was significantly less with the Graseby, being 91.9% compared with 100% for the Springfusor. Only 58.2% of flow rates with the Graseby were within the manufacturer claimed accuracy of +/-5%. The flow rate of the Springfusor was affected by temperature; at 30 degrees C the mean flow rate was 10.8% greater than at 25 degrees C. These results indicate that the Springfusor 30 had less flow rate variation than the Graseby MS16A. However, this would not be expected to cause noticeable clinical effects when used for opioid infusion in palliative care.

Electronics, Medical

Bolus administration of eltanolone, thiopental, or etomidate does not affect systemic vascular resistance during cardiopulmonary bypass.

OBJECTIVE: To discover possible effects on systemic vascular resistance of the anesthetic induction agent eltanolone in comparison with thiopental and etomidate. The measurements were performed during cardiopulmonary bypass to maintain a constant cardiac output (approximately pump flow). DESIGN: The patients were prospectively randomized in three groups to receive either eltanolone, thiopental, or etomidate. SETTING: University hospital as a single center. PARTICIPANTS: Seventy-five patients scheduled for elective coronary artery bypass grafting. INTERVENTIONS: The anesthetic induction agents were repeated at the same dosage when cardiopulmonary bypass was instituted. The respective mean dosages were eltanolone, 0.41 +/- 0.1 mg/kg; thiopental, 2.88 +/- 0.62 mg/kg; etomidate, 0.26 +/- 0.06 mg/kg. MEASUREMENTS AND MAIN RESULTS: Systemic vascular resistance was calculated from the mean of a triple measurement (normal pump flow and +/- 20%). Points of measurement were before, and 2 and 5 minutes after injection of the hypnotic agent. None of the injected drugs made a significant change in the systemic vascular resistance. A small (not significant) decrease from 1,295 +/- 296 dyne/s/cm-5 to 1,196 +/- 323 dyne/s/cm-5 (mean +/- SD) was seen in the eltanolone group, whereas the other patients did not show any change during the study period. CONCLUSIONS: The reason for the significant reduction of the arterial pressure attributed to anesthetic induction by eltanolone may be more a cardiodepressive effect than a direct vasodilation.

Anesthetics, Intravenous

Juvenile chronic arthritis: diagnosis and management of tibio-talar and sub-talar disease.

The aim of this study was to compare clinical evaluation of the site of hindfoot synovitis with contrast-enhanced magnetic resonance imaging (MRI) findings in children with juvenile chronic arthritis (JCA), and to evaluate the efficacy of selective guided intra-articular steroid injections. Thirteen symptomatic ankles of 11 consecutive JCA patients were examined clinically and with contrast-enhanced MRI. Pannus was demonstrated on MRI in both tibio-talar and sub-talar joints in 10 ankles, in the tibio-talar joint only in one ankle and in neither joint in two ankles. Correlation of clinical and MRI findings was good for the tibio-talar joint with concordance in 11/13 cases. Correlation was poor for the sub-talar joints. Of the 10 sub-talar joints shown to have pannus on MRI, only two were thought to have had definite clinical evidence of synovitis. Guided intra-articular steroid injection resulted in at least 6 months remission in 6/9 ankles compared with 1/10 ankles which had had previous unguided injections. We therefore recommend the use of image guidance for intra-articular triamcinolone hexacetonide injection in children with hindfoot synovitis.

Adolescent

Severe juvenile dermatomyositis complicated by pancreatitis.

We report two boys with juvenile dermatomyositis (JDM) complicated by pancreatitis. One also had hepatitis and probably mild bowel vasculitis, while the other had catastrophic bowel vasculitis with multiple perforations. Both were on corticosteroids, but had features of active vasculitis. The former improved with high-dose i.v. pulsed methylprednisolone, while the latter improved only after immunosuppression with i.v. methylprednisolone, cyclophosphamide and plasmapheresis. Although bowel vasculitis is a known complication of severe JDM, pancreatitis and hepatitis are extremely rare. We have found in a literature search only three other reports of pancreatitis complicating JDM. We wish to alert physicians that pancreatitis may develop in JDM. It should be considered as a differential diagnosis in the child with active disease who develops abdominal pain. Control of vasculitis with adequate immunosuppression, as well as general supportive measures, may be valuable in the treatment of pancreatitis in JDM.

Adolescent

Janibacter limosus gen. nov., sp. nov., a new actinomycete with meso-diaminopimelic acid in the cell wall.

New gram-positive bacteria were isolated from 1-year-old sludge from a wastewater treatment plant. The isolates are coccoid to rod-shaped, nonmotile aerobes that form neither spores nor mycelia. They are characterized by a peptidoglycan with directly cross-linked meso-diaminopimelic acid (type A1 gamma), by the presence of menaquinone MK-8(H4), and by the lack of mycolic acids. The strains have complex fatty acid patterns with i-C16:0 and straight-chain saturated and unsaturated fatty acids as major components. The G + C content of the DNA is 70 mol%. The results of chemotaxonomic studies and a 16S ribosomal DNA sequence comparison support our proposal to assign these bacteria to a new genus, the genus Janibacter gen. nov.; the type species is Janibacter limosus sp. nov., and the type strain of J. limosus is strain HKI 83 (= DSM 11140).

Actinomycetales

Bogoriella caseilytica gen. nov., sp. nov., a new alkaliphilic actinomycete from a soda lake in Africa.

A new gram-positive, alkaliphilic, nonsporulating, rod-shaped bacterium is described. The organism was isolated from soda soil (Lake Bogoria, Kenya) and has the following characteristics. It is nonmotile, not acid fast, halotolerant, and microaerophilic, and optimal growth occurs at pH values between 9 and 10. The peptidoglycan type is of type A4 alpha, with lysine as the characteristic diamino acid and glutamic acid as a component of the interpeptide bridge. The major menaquinone is MK-8(H4). The polar lipids are phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, and an unknown phospholipid. 12-Methyltetradecanoic acid is the predominant fatty acid. The G + C content of the DNA is 70 mol%. The results of 16S ribosomal DNA sequence comparisons revealed that strain HKI 0088T represents a new lineage in the order Actinomycetales. Therefore, we concluded that strain HKI 0088T should be assigned to a new genus and species, for which we propose the name Bogoriella caseilytica gen. nov., sp. nov. The type strain and only strain of this genus and species is HKI 0088 (= DSM 11294).

Actinomycetaceae

Demetria terragena gen. nov., sp. nov., a new genus of actinomycetes isolated from compost soil.

A novel actinomycete was isolated from compost soil and was studied taxonomically and phylogenetically. Cells of this organism were gram positive, not acid fast, nonmotile, nonsporulating, irregular coccoid to short rod shaped, and microaerophilic. The cell wall peptidoglycan contained lysine and was cross-linked via an L-Lys<--L-Ser<--D-Asp interpeptide bridge. The major menaquinone was MK-8(H4). The polar lipids were phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and two unknown phospholipids. Mycolic acids were absent. The cellular fatty acid profile was complex, with large amounts of saturated and monounsaturated straight-chain acids and smaller amounts of iso and anteiso branched-chain acids. The G+C content of the DNA was 66 mol%. Comparative 16S ribosomal DNA studies revealed that strain HKI 0089T represents a novel lineage within Actinobacteria (32) distinct from all previously described genera and most closely related to members of the genera Kytococcus, Dermacoccus, and Dermatophilus of the family Dermatophilaceae. On the basis of our results, we suggest that strain HKI 0089 should be classified in a new genus and species, for which we propose the name Demetria terragena. The type strain and the only strain of the genus and species is HKI 0089 (DSM 11295).

Actinomycetaceae

Palliative care in a multicultural society: perceptions of health care professionals.

This study assesses the perceived competence of 191 Australian palliative care professionals in delivering crosscultural care. The relationship between the perceived competence levels of professionals and their experience and training is examined. Strategies to improve crosscultural palliative care, as suggested by palliative care providers, are also presented. Information about perceived competence and the kinds of difficulties encountered in crosscultural palliative care interactions form the basis of suggested guidelines for proposed education programmes. The results of this study suggest that specific education, rather than individual experience of crosscultural interactions, which may not always be positive, is needed to improve the competence of palliative care professionals. Education, therefore, is the key to the provision of culturally appropriate care to patients and their families from all cultural backgrounds.

Adult

Relocation stress syndrome: the case of palliative care patients.

Transfer of patients from palliative care services to nursing homes is necessary at present when a patient is relatively stable, but does not have adequate support systems at home. With the ageing of the population and the increasing incidence of cancer, the need for inpatient palliative care beds is growing with corresponding pressure for patients to be transferred to nursing homes. Transfer to a nursing home in the general population has been described extensively in the gerontology literature where a critical early phase of relocation has been identified by a high incidence of morbidity and mortality. The vulnerability of terminally ill patients means that they are at increased risk of suffering from stress associated with a transfer. The prognosis of a patient may be shorter than the time required for adjustment to the patient's new home. The issues surrounding transfer of palliative care patients to nursing homes and possible strategies designed to reduce distress associated with transfers are explored.

Adaptation, Psychological

Effect of controlled extracorporeal blood cooling on ultrafiltration-induced blood volume changes during hemodialysis.

Considerable amounts of heat may be lost or gained through the extracorporeal circuit during hemodialysis and influence the hemodynamic stability of the dialysis patient. The effects of two levels of extracorporeal heat flux (Jtherm in W) on blood pressures and ultrafiltration-induced blood volume changes were studied in eight patients on conventional hemodialysis. Treatments were controlled automatically for mild to medium Jtherm of either -13.4 +/- 3.3 W (group A) or -30.2 +/- 3.7 W (group B) (1 W = 1 J/s = 3.6 kJ/h = 0.239 cal/s = 0.86 kcal/h) and repeated once. Values are given as mean +/- SD. With low blood flows (Qb = 251 +/- 21 ml/min), dialysate temperatures were automatically set at 37.3 +/- 0.3 degrees C (group A) and 35.3 +/- 0.2 degrees C (group B) for the two levels of Jtherm, respectively. Arterial blood temperatures increased by 0.4 +/- 0.4 degree C with mild extracorporeal cooling (group A), whereas arterial blood temperatures slightly decreased by -0.1 +/- 0.4 degree C in the group with medium negative heat flux (group B) (P < 0.01). Blood pressures tended to drop in the warm dialysate group and to remain unchanged in the cool dialysate group (P = NS). Relative blood volume changes calculated from on-line ultrasonic blood measurements were significantly larger with cool (-12.8 +/- 8.3 vol%) than with warm (-7.2 +/- 5.5 vol%, P < 0.05) dialysate, indicating reduced fluid removal from peripheral body compartments during cool hemodialysis ultrafiltration. Despite the larger reduction in intravascular volume, intradialytic hemodynamic stability was maintained with extracorporeal cooling and cool dialysate prescription.

Aged

Metabolic correlates of obesity and radiographic features of knee osteoarthritis: data from the Baltimore Longitudinal Study of Aging.

OBJECTIVE: To examine the relationship between metabolic correlates of obesity and radiographic knee osteoarthritis (OA). METHODS: We included 464 Caucasian men and 275 Caucasian women aged 40 years and above who were participants in the Baltimore Longitudinal Study of Aging. Subjects had bilateral anteroposterior standing knee radiographs read for features of OA using Kellgren-Lawrence scales. Resting blood pressure, fasting lipids, 2 h oral glucose tolerance test, and anthropometric measurements were obtained at the same visit as the knee radiograph. Metabolic correlates of obesity were compared between subjects with Kellgren-Lawrence grade > or = 2 (definite knee OA) and grade 0 (normal radiograph) by sex. RESULTS: Both men and women with knee OA had higher unadjusted systolic blood pressure than those with normal knee radiographs; unadjusted measures of glucose metabolism and lipids did not vary by presence of knee OA in men or women. After adjustment for age and obesity, systolic blood pressure did not vary by presence of knee OA in men. While women with knee OA did have higher adjusted mean systolic blood pressure than women with normal radiographs (127 +/- 2.4 vs 120 +/- 2.2 mm Hg; p = 0.04), both values were within normal range. Unexpectedly, men with knee OA had lower adjusted mean 2 h glucose levels compared to men without OA (7.5 +/- 0.2 vs 8.4 +/- 0.2 mmol/l; p = 0.01). Other adjusted variables did not differ by presence of knee OA. CONCLUSION: These data do not support the hypothesis that metabolic correlates of obesity are independently associated with radiographic knee OA after adjustment for age and obesity.

Adult