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Biomedical subjects

R Patterson

Publications and source records attributed to R Patterson.

At least 325 records · Page 18Linked to original sources
PubMed1986

Stereoacuity in young children.

Previous investigations of stereopsis in children have found that stereoacuity improves gradually over time and does not reach adult levels until well into childhood. The unusually protracted period of development implied by these data is at odds with the development of other visual capacities, such as acuity, contrast sensitivity, increment thresholds, and flicker fusion. When tested on those dimensions, children, by the age of five, achieve thresholds that are only moderately higher than those achieved by adults. To determine if the elevated thresholds for stereopsis found in children could be attributable to the methods used to obtain them, the authors assessed stereoacuity of children, 3 to 5 yr of age, using a laboratory test combined with procedures designed to optimize the limited attentional, motivational, and response capabilities of young children. The thresholds obtained (median = 12.6 sec) are much lower than previously reported and are close, but not equal, to the thresholds of adults. These data suggest that the development of stereopsis is not unusually protracted relative to the development of other visual capacities. The elevation of threshold relative to adult values is similar to the shortfall found in studies of other visual capacities and has led investigators to suggest, and the authors concur, that children do not possess the sophisticated cognitive strategies that adults can employ when thresholds are approached and uncertainty is high. Given that interpretation, it is suggested that the maturation of stereoscopic capacity is nearly complete in children 3 to 5 yr of age.

Adolescent↗
PubMed1985

Effects of intravitreal administration of steroids on experimental subretinal neovascularization in the subhuman primate.

To elucidate the role of inflammation in the occurrence of experimental subretinal neovascularization caused by high-intensity laser photocoagulation, we investigated the effects of vitreal infusion of steroids on laser lesions in a primate model. Dexamethasone, with or without triamcinolone, was infused continuously for two weeks through an indwelling cannula system. The animals were followed up clinically for up to eight weeks. The frequency of subretinal neovascularization in the steroid-treated animals was significantly lower than that in a control group of untreated animals. Although steroids have multiple effects, these results suggest that the inflammatory response, possibly macrophage infiltration, may plan an important role in the occurrence of subretinal neovascularization in our experimental model.

Animals↗
PubMed1985

Intraocular cannula for continuous, chronic drug delivery. Histopathologic observations and function.

An indwelling cannula for drug delivery was implanted in rabbit eyes. Rabbits were followed up for as long as 1 1/2 years after surgery. They showed almost no adverse effects as a result of the implantation, and cannula patency was demonstrated by the injection of fluorescein sodium through the cannula at various times following surgery. Histopathologic studies using light and electron microscopy were performed at various times to determine the effect of cannula implantation on the eye. Cellular proliferation along the cannula after 1 1/2 years was limited to the region immediately adjacent to the wound and rarely extended to the surrounding retina or ciliary body. The proliferative tissue at the wound site originated mainly from the episclera; the retina and the choroid at the posterior fundus remained intact. Photoreceptor cell metabolism was studied by light microscopic autoradiography following intraocular injection of tritiated leucine to assess photoreceptor outer-segment renewal. Autoradiography showed normal receptor uptake of leucine. A broad band of radioactive labeling of the outer segments resulted from continuous, chronic drug delivery, while a narrow band of labeling resulted from a single intravitreous injection. These data indicate that the cannula system continuously delivered tritiated leucine into the vitreous cavity. We believe that the implanted intraocular cannula, which allows continuous drug delivery on a relatively long-term basis, will be a valuable technique for research and possibly clinical studies.

Animals↗
PubMed1985

Fibronectin of the chorioretinal interface in the monkey: immunohistochemical and immunoelectron microscopic studies.

The distribution of fibronectin in the chorioretinal interface of the monkey eye was studied by indirect immunofluorescent and immunoelectron microscopic techniques. Immunofluorescent staining revealed fibronectin in Bruch's membrane and the choriocapillaris. Immunoelectron microscopic techniques revealed fibronectin associated with basement membranes, collagen fibers and elastic fibers in Bruch's membrane; the stromal side of the basement membrane of the choriocapillaris also showed staining. This study thus demonstrates that fibronectin is an integral component of Bruch's membrane in the monkey eye.

Animals↗
PubMed1985

Factitious desquamative gingivitis simulating a possible immunologic disease.

A case of a unique factitious disorder resulted from self-inducement of oral lacerations, erosions, and abrasions. Previous medical investigations included evaluations by two general dentists, one oral surgeon, two periodontists, one internist, one otolaryngologist, and one infectious-disease physician. The patient had two gingival biopsies and one hospitalization. The lesions were unresponsive to several therapeutic regimens including temporary discontinuation of tooth brushing, antibiotics, and gingival dressings. The differential diagnosis included infectious, nutritional, immunologic, and factitious disorders. An apparent initial response to corticosteroids suggested the possibility of an immunologic inflammatory disease; however, no organic cause could be found. The enigma was resolved by discussion with the patient who reported that the lesions were self-induced and the manner in which this was done.

Adult↗
PubMed1985

Metabisulfite challenge in patients with idiopathic anaphylaxis.

Bronchospasm, urticaria, angioedema, and anaphylactoid reactions have been attributed to sulfiting agents. These compounds are commonly used as preservatives in some drugs and foods, often in restaurants. Oral challenges with sodium metabisulfite were performed in 12 patients with idiopathic anaphylaxis (IA). Nine of these had episodes possibly caused by sodium metabisulfite because of clear temporal relation of episodes of IA to restaurant meals. One patient who had severe urticaria with exacerbations with restaurant meals and 10 control subjects were studied. No urticarial, asthmatic, or anaphylactoid reactions occurred in our patients. Sulfiting agents did not trigger episodes of IA in these 12 patients or urticaria in the patient with severe chronic idiopathic urticaria.

Adult↗
PubMed1985

Polymerized soluble venom--human serum albumin.

Extensive previous studies have demonstrated that attempts to produce polymers of Hymenoptera venoms for human immunotherapy resulted in insoluble precipitates that could be injected with safety but with very limited immunogenicity in allergic patients. We now report soluble polymers prepared by conjugating bee venom with human serum albumin with glutaraldehyde. The bee venom-albumin polymer (BVAP) preparation was fractionated on Sephacryl S-300 to have a molecular weight range higher than catalase. 125I-labeled bee venom phospholipase A was almost completely incorporated into BVAP. Rabbit antibody responses to bee venom and bee venom phospholipase A were induced by BVAP. Human antisera against bee venom were absorbed by BVAP. No new antigenic determinants on BVAP were present as evidenced by absorption of antisera against BVAP by bee venom and albumin. BVAP has potential immunotherapeutic value in patients with anaphylactic sensitivity to bee venom.

Animals↗
PubMed1985

The occurrence of multiple physical allergies in the same patient: report of three cases.

The syndromes of idiopathic anaphylaxis, exercise-induced anaphylaxis, and other physical allergies are well described as separate entities. This article describes the combination of these problems in the same patient. Two patients with idiopathic anaphylaxis are described. One also has exercise-induced anaphylaxis, and one also has exercise-induced bronchospasm and exercise-induced urticaria and angioedema. A third patient with exercise-induced anaphylaxis, idiopathic urticaria, angioedema, cholinergic urticaria, and dermatographism is described.

Adolescent↗
PubMed1985

Factitious sneezing.

We report a case of hysterical, intractable paroxysmal sneezing in an adolescent girl. The patient had been observed by two pediatricians, an allergist, an emergency room physician, and a chiropractor. She had been treated with antihistamines, epinephrine, corticosteroid nasal spray, and a 1-week course of an oral corticosteroid without improvement. She was referred for evaluation of an allergic etiology before continuing her workup with a computed tomographic head scan. The patient had been sneezing almost daily for 3 mo up to 2000 times a day. The patient did not sneeze at night. She had nasal congestion but no rhinorrhea or eye symptoms. She did not sneeze during the interview. The results of a physical examination were normal except for mild obesity. No organic cause was found. Most cases of intractable paroxysmal sneezing reported in the literature occur in adolescents and appear to have a psychogenic etiology. The problem was discussed with the child and parents, and psychologic therapy was recommended. Considerable decrease in sneezing subsequently occurred, but the parents credited this is further chiropractic therapy.

Adolescent↗
PubMed1985

Immunotherapy: parameters of assessment.

Allergen immunotherapy has proved safe and effective for selected aeroallergens that can be studied under controlled conditions. Various mechanisms of action have been proposed with limited evidence for their role in the protection resulting from immunotherapy. The exception is blocking antibody, which was discovered 50 years ago. In eight successive studies sponsored or carried out by one institution in which clinical efficacy was demonstrated, the serum level of IgE antibody was unchanged or slightly increased. All eight studies showed a significant rise in the serum level of IgG antibody, and this response is the logical immunologic explanation for clinical efficacy. For aeroallergens that cannot be avoided or subjected to clinical efficacy studies, demonstrations of safety and of significant IgG antibody response constitute the appropriate method of assessment.

Aerosols↗
PubMed1985

Modified forms of allergen immunotherapy.

There have been many attempts to modify allergens and thus to improve upon conventional immunotherapy, which has been proved effective but has several drawbacks. These include the risk of systemic reactions and the time and cost involved. The modifications have taken three major approaches. One approach, to impede allergen release from the site of deposition, has met with limited success. An example is alum precipitation, which has modestly reduced the number of injections and incidence of systemic reactions. A second approach, to suppress specific IgE production and to induce specific tolerance, has not been successful in man. The third approach, to reduce allergenicity while retaining immunogenicity of allergens, has been the most successful and appears to have the most promise. One example is polymerized allergens, which have been shown to be safe, efficacious, and immunogenic in multiple clinical trials. Other examples include allergoids and glutaraldehyde-treated, tyrosine-adsorbed allergens.

Allergens↗
PubMed1985

Characterization of an antigen in acute anaphylactic dialysis reactions: ethylene oxide-altered human serum albumin.

Anaphylactic reactions to dialysis have been associated with antibody to human serum albumin (HSA) that has been reacted with ethylene oxide (ETO). ETO, an agent used to sterilize dialyzers, is a potent alkylator of proteins. We have studied the antigenic characteristics of ETO-HSA. By use of immunoelectrophoresis we have demonstrated differences in electrophoretic mobility between HSA and ETO-HSA. By gel chromatography we have observed an apparent increase in the molecular weight of ETO-HSA as compared to HSA. Antigenic activity of ETO-HSA as determined by the technique of Lidd and Farr is found in all molecular weight fractions. Cutaneous reactivity to ETO-HSA can be transferred to subhuman primates. That reactivity is lost if the sera are heated to 56 degrees C for 4 hours. Antibody activity to ETO-HSA cannot be inhibited by ETO-glycine or HSA but can partially be inhibited by ETO-polylysine or ETO-ovalbumin. This suggests that antibody is directed against a new antigenic determinant on the ETO-protein moiety, probably an ETO-amino acid determinant like lysine.

Anaphylaxis↗
PubMed1985

Allergenicity, immunogenicity, and safety of immunotherapy with various molecular weight ranges of polymerized ragweed.

Since the observation had been made that allergenicity of polymerized ragweed (PRW) varies inversely with molecular weight over ranges we had studied previously, we conducted this study to determine the utility of immunotherapy with PRW molecular weight greater than 20,000,000 alone or as part of a final product pool. Twenty-one patients with ragweed pollinosis were randomized into three groups on the basis of ragweed skin test titration. Each patient received 500 micrograms AgE (50,000 PNU) of one of the following molecular-weight ranges: PRW A greater than 500,000; PRW B 200,000 to 20,000,000; and PRW C greater than 20,000,000. There was no difference between PRW A, B, and C by intradermal end point titration, by incidence of large local reactions, by amount of erythema or induration from injections, or by rise in blocking antibody that was significant in each group. There were no systemic reactions nor any changes in clinical laboratory parameters. In summary, each of the molecular-weight ranges of PRW studied was similarly allergenic, immunogenic, and safe to administer, and thus PRW greater than 20,000,000 can be used for immunotherapy as a part of the final product pool. This has the advantages of increasing yields and of simplifying the fractionation by eliminating one chromatographic process.

Analysis of Variance↗
PubMed1985

IgE against ethylene oxide-altered human serum albumin in patients with anaphylactic reactions to dialysis.

We have measured total antibody and IgE directed against ethylene oxide-altered human serum albumin (ETO-HSA) in the sera of 24 patients who have experienced anaphylaxis during hemodialysis and of 41 patients who have not had such episodes during hemodialysis. ETO is used to sterilize dialyzers and other medical equipment. The geometric mean level of IgE to ETO-HSA in patients with reactions (0.9 ng ETO-HSA bound to IgE per milliliter of serum) is significantly higher than in nonreacting patients (0.1 ng/ml, p less than 0.0001). Sixteen of 24 patients with reactions had detectable levels of IgE to ETO-HSA, whereas only three of 41 nonreacting patients had detectable levels (p less than 0.0001 chi-square). The geometric mean level of total antibody to ETO-HSA is also significantly higher in patients with reactions (270 ng ETO-HSA bound per milliliter) than in nonreacting patients (31 ng/ml, p less than 0.0001). Fourteen of 24 patients with reactions but only four of 39 nonreacting patients had total antibody binding of ETO-HSA (p less than 0.0001 chi-square). These data extend our previous observations on a small group of 13 patients receiving hemodialysis (seven patients with reactions, and six nonreacting patients) and clearly demonstrate an association between the presence of IgE or total antibody to ETO-HSA and immediate anaphylactic reactions in this group of 65 patients receiving hemodialysis.

Anaphylaxis↗
PubMed1985

A familial occurrence of allergic bronchopulmonary aspergillosis: a probable environmental source.

This is the first article of a familial occurrence of allergic bronchopulmonary aspergillosis in a father and daughter. Serologic studies revealed serum precipitins and elevated IgG or IgE antibody activity against certain Aspergillus species. Investigation of the home revealed an environmental source of exposure. Another family member demonstrated serum precipitins and an IgG antibody response to the isolated Aspergillus species without evidence of allergic bronchopulmonary aspergillosis.

Adult↗