PubMed Health⌕ Search

Biomedical subjects

R Patterson

Publications and source records attributed to R Patterson.

At least 199 records · Page 11Linked to original sources

Sitting forces and wheelchair mechanics.

The effects of back angle and leg height on sitting forces in a wheelchair were studied, using a force plate mounted on a wheelchair seat. Readings of both normal force (perpendicular to the seat) and shear force were measured while the chair's back angle and footrest height were changed. Pressure under the ischial tuberosities was also measured during the footrest height adjustments. Five normal subjects sat directly on the plate as well as upon ROHO and Jay cushions placed on the force plate. Returning the back to the upright position after a recline caused the normal force (+/- SD) to increase 5.4 +/- 2.5, 9.5 +/- 4.0, and 10.0 +/- 2.3 kg for the hard surface, Jay cushion, and ROHO cushion respectively, while shear at the plate increased to 5.1 +/- 2.2, 11.6 +/- 2.6, and 12.3 +/- 2.7 kg for the hard surface, Jay cushion, and ROHO cushion respectively. Leaning forward (away from the back) caused all the forces to return to measurements close to the starting values. The results suggest that the wheelchair user should momentarily lean forward after a recline to reduce undesired forces. If a cushion with firm thigh support is used, ischial tuberosity pressure can be reduced by lowering the leg height as much as possible, which causes a levering action by lifting the pelvis.

Biomechanical Phenomena↗

Insulin allergy: re-evaluation after two decades.

We reevaluated IgE-mediated insulin allergy using sera obtained 16 to 21 years ago and, 1 and 5 years ago. All antibodies had specificity for human and bovine insulin. We reevaluated Prausnitz-Kustner reactivity after 15 years and the IgE antibody and cutaneous reactivity appeared unchanged. IgE-mediated insulin allergy appears to be declining.

Antibodies, Anti-Idiotypic↗

Evaluation of ketotifen in corticosteroid-dependent idiopathic anaphylaxis.

To study the possible efficacy of ketotifen (K) in the treatment of idiopathic anaphylaxis (IA), K was administered in an open-label trial to six patients with IA who required corticosteroids at doses below which their disease could not be controlled. During the study, patients continued to receive noncorticosteroid medications (eg, antihistamines, oral adrenergic agents) that had been used on a regular basis for treatment of IA before study, but periodic attempts to reduce corticosteroid doses were made. A reduction of prednisone dose with continued control of disease was judged to be evidence for a beneficial effect of K. After 7 to 16 months of K administration, three patients were judged to have had probable benefits from K (reductions in alternate day prednisone dose requirement from 40 mg to none, 35 mg to 15 mg, and 30 mg to none), and one patient had a possible benefit from K (dose reduction from 100 to 120 mg to 77 mg). Two other patients were unable to tolerate major decreases in prednisone without developing symptoms or signs of IA. Within the limitations of this study design, we conclude that K may be efficacious in the treatment of some patients with IA, and that further trials of K in the treatment of IA are indicated.

Adult↗

Asthma and pregnancy: responsibility of physicians and patients.

The successful management of asthma during pregnancy requires a cooperative approach between the obstetrician, the physician managing the asthma, and the patient. This is emphasized by a case report describing a patient with uncontrolled asthma subsequently managed with appropriate medical and obstetrical care. Concern for maternal and fetal health and reassurance of patients are primary concerns. Guidelines for physicians and patients are outlined as are the safety of drugs and therapy in pregnant patients. Physicians must have knowledge of appropriate use of medications during pregnancy.

Administration, Inhalation↗

Pharyngeal transit time: assessment with videofluoroscopic and scintigraphic techniques.

The swallowing function of 31 normal and dysphagic subjects between the ages of 39 and 79 was tested with both videofluoroscopy and scintigraphy. Pharyngeal transit times for the pair of tests were compared. A statistically significant correlation of 0.66 was found. Normal pharyngeal transit time was under 1.2 s with either method, but mean values for scintigraphy were slightly longer than those for videofluoroscopy.

Adult↗

Obtaining permission for an autopsy: its importance for patients and physicians.

This paper reviews the importance, benefits, and methods of increasing autopsy percentages. Its focus is on specific procedures for obtaining autopsy consent, particularly in terms of addressing the problems that most often interfere with obtaining permission for postmortem examination. Techniques for handling various misconceptions about autopsies are discussed. These guides for postmortem-related discussions with families will lead to improvement in overall physician performance and satisfaction.

Attitude to Death↗

Safety and immunogenicity of immunotherapy with accelerated dosage schedules of polymerized grass and ragweed in patients with dual inhalant sensitivity.

Immunotherapy with individually polymerized grasses (IPG) and immunotherapy with polymerized ragweed (PRW) have been demonstrated to be immunogenic and safe and to result in lowering of symptom-medication scores compared to placebo. We conducted this study to evaluate the immunogenicity and safety of immunotherapy with concomitantly administered accelerated dosage schedules of IPG and PRW in 12 patients with dual inhalant sensitivities. Patients were treated in nine weekly visits with IPG, comprising 71,950 PNU; they were treated in 11 weekly visits with PRW comprising 2955 allergy units. Eleven additional patients who had been previously treated with IPG received only PRW. There were no systemic reactions and no clinically significant changes in routine laboratory parameters, including hepatic and renal functions, with injections. There were significant rises in IgG titers by ELISA to each grass-pollen allergen administered, orchard, timothy, and Bermuda, and in total antibody binding of antigen E. Changes in IgE against orchard, timothy, Bermuda, and antigen E were minor. Thus, IPG and PRW administered concomitantly in accelerated dosage schedules are safe and immunogenic in patients with dual inhalant sensitivities.

Adult↗

Lung injury induced by short-term intermittent trimellitic anhydride (TMA) inhalation.

We have developed a rat model of lung injury with interstitial pneumonitis, lung hemorrhage, and a systemic and pulmonary immune response to trimellitic anhydride (TMA)-haptenized proteins induced by TMA inhalation for 10 days. The present studies explored the induction of lung injury induced by short-term intermittent TMA inhalation, a model more likely to simulate short-term industrial exposures during inadvertent spills of TMA. Sprague-Dawley rats inhaled TMA powder (500 micrograms/m3) on days 1, 5, and 10, and were necropsied on day 30, 18 hours after a 6-hour TMA-inhalation challenge on day 29. Rats were bled every second day and at necropsy. Serum IgG, IgA, and IgM antibody to trimellityl rat serum albumin was measured by ELISA. There was a rise in IgM and IgA antibody to trimellityl rat serum albumin starting at day 5 that peaked at day 20 with a decline in IgM by day 30. IgG antibody rose at day 7, peaked at day 20, and plateaued. The IgG antibody level was 10 times higher than the IgA or IgM level. In a second experiment, 18 rats were administered TMA-inhalation exposure on days 1, 5, and 10, and a TMA challenge on day 22. The number of hemorrhagic foci, lung weights, and lung-displacement volumes at necropsy on day 23 were highly correlated with IgG, IgA, and IgM serum-antibody levels. In a final experiment, rats developed a mean of 112 hemorrhagic foci per lung on day 30 after receiving only two TMA-inhalation exposures on days 1 and 5 with a rechallenge on day 29. (ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗

Specific serum antibodies against isocyanates: association with occupational asthma.

Although increased levels of specific IgE and/or IgG antibodies have been documented in individual cases of occupational asthma caused by common types of isocyanates (hexamethylene diisocyanate [HDI] and diphenylmethane diisocyanate [MDI]), the frequency among workers with occupational asthma is still unknown. The sera of 62/65 workers referred for specific inhalation challenges with isocyanates were analyzed for the presence of specific antibodies to the relevant isocyanate. Most workers (39, 63%) were exposed to HDI, some to MDI (17, 27%), and a few to toluene diisocyanate (six, 10%). Specific inhalation challenges were positive in 29 subjects, eliciting either immediate (seven), early late (two), late (13), or dual (seven) reactions. Specific inhalation challenges were more often positive in those subjects with increased nonspecific bronchial responsiveness. Twenty-nine subjects demonstrated increased levels of specific IgE and/or IgG antibodies to isocyanates in the absence of antibodies against human serum albumin (increased IgE only, no subject; IgG only, 20; both IgE and IgG, nine subjects). Although there was a loose association between the results of specific inhalation challenges and levels of specific IgE, the association was much better with the level of specific IgG. Indeed, 21 of the 29 subjects (72%) with positive challenges had increased levels of specific IgG, whereas 25 of the 33 subjects (76%) with negative challenges had normal levels of antibodies. The association was significant with both HDI and MDI. The levels of antibodies were not significantly associated with the type of temporal reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗

Corticosteroid-dependent idiopathic anaphylaxis: a report of five cases.

Idiopathic anaphylaxis (IA) is a life-threatening disease that is being increasingly recognized. In patients with frequent episodes of anaphylaxis, prednisone controls the events and then either induces remission or suppresses the manifestations of the disease until a spontaneous remission occurs. We report five patients with IA who have recurrent episodes whenever prednisone is tapered below a threshold dose, ranging from 15 to 65 mg every other day. These patients demonstrate the concept of a threshold dose of prednisone that may exist in a subset of patients with IA, and they provide further evidence of the previously reported efficacy of corticosteroids in the treatment of IA. We use the term corticosteroid-dependent IA to refer to the serious problem of chronic IA requiring maintenance prednisone therapy.

Adult↗