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Biomedical subjects

R Patterson

Publications and source records attributed to R Patterson.

At least 289 records · Page 16Linked to original sources

Formation of drusen in the human eye.

Light and electron microscopy of drusen formation in the human eye showed yellow-white spots in the fundus with two morphologic patterns: that of typical drusen and a nodular accumulation of cellular components beneath the retinal pigment epithelial cells. By electron microscopy, the progression of drusen formation could be classified into four stages. Stage I showed budding or evagination of retinal pigment epithelial cells into the subpigment epithelial space. This evaginated portion was connected to the retinal pigment epithelial cell cytoplasm and was surrounded by its basement membrane. In Stage II the evaginated portion of the cell was completely separate from the cytoplasm of its parent retinal pigment epithelial cell. In Stage III, the evaginated portion showed degeneration and disintegration. Finally, in Stage IV, an accumulation of vesicular, granular, tubular, and linear material was seen free within the nodular space beneath the retinal pigment epithelial cell.

Aged↗

Allergic bronchopulmonary aspergillosis. Natural history and classification of early disease by serologic and roentgenographic studies.

Eighty-four patients with allergic bronchopulmonary aspergillosis (ABPA) were evaluated for a total of 294 patient-years with a mean observation period of 3.7 years and classified by the stage of ABPA. The largest percentage of patients were in the stage IV (corticosteroid-dependent asthma stage) group. The next largest percentage were in the stage V (fibrotic, end-stage lung disease) group. Of the latter 24 patients, eight had died. In addition, we describe 13 patients with all serologic characteristics of ABPA but without central bronchiectasis. We propose that these patients have seropositive ABPA and represent the earliest cases of it that can be diagnosed in contrast with ABPA with central bronchiectasis in which lung damage is already present.

Adrenal Cortex Hormones↗

Retinal wound healing. Cellular activity at the vitreoretinal interface.

Cellular activity at the vitreoretinal interface after full-thickness retinal wounds was studied in rabbit eyes, using light and electron microscopy. Glial cell extensions grew initially on the retinal surface around the wound site. This brief period of glial proliferation was associated with the posttraumatic inflammatory response and, more specifically, with phagocytic monocyte accumulation at the vitreoretinal interface. Once the inflammation subsided, this abortive attempt to grow membranes on the retinal surface stopped and true epiretinal membranes did not develop. Our observations suggest that intraocular inflammation and macrophage response determine the extent of healing and scarring on an injured retinal surface, and thus may play a key role in the pathogenesis of epiretinal membranes.

Animals↗

An intravitreal cannula system: long-term follow-up study.

An intravitreal cannula for chronic drug delivery was implanted in the eyes of two rabbits and one monkey. The rabbits were followed up for three years after surgery and the monkey was followed up for two and one-half years. Clinical observations did not reveal any adverse effects from the cannula implantation. Patency of the cannula was demonstrated by using sodium fluorescein. Histopathological studies with light and electron microscopy revealed the scar tissue around the cannula to be minimal and localized to the wound site. The optic nerve and the retina and choroid at the posterior pole did not show any abnormalities. These results suggest that this system can be used for repeated or continuous drug delivery to the vitreous over a long period of time in experimental models.

Animals↗

Effect of the vitreous on retinal wound-healing.

The healing process of experimental retinal wounds in nonvitrectomized and vitrectomized rabbit eyes was compared. Using light, transmission and scanning electron microscopy, a significant difference was observed at the late stages of the healing process. The retinal wounds in the nonvitrectomized eyes healed properly, forming regular and smooth scars, while the scars that developed in the vitrectomized eyes were irregular and hypertrophic. Our observations suggest that the vitreous plays a role in normal healing of retinal wounds.

Animals↗

Contributions to the impedance cardiogram waveform.

We have developed a cylindrically symmetric model with which to study what physiologic variables might contribute to the impedance cardiogram signal. We find the major contributions in this model to be due to dilation of the aorta and carotid arteries, changes in conductivity of blood in these same vessels due to red cell reorientation during flow, changes in the conductivity of the lungs, and changes in heart volume. The calculations suggest that the popular equation used to determine stroke volume from thoracic impedance data is not accurate under all conditions of the circulatory system.

Adult↗

Soluble copolymer of wasp venom with human albumin for venom immunotherapy.

Polymerization of allergens decreases allergenicity while retaining immunogenicity, as we have demonstrated for ragweed, grass, and tree pollens. We have also polymerized bee venom with human albumin to form soluble, high-molecular-weight copolymers that are immunogenic in rabbits. We now have prepared a soluble wasp venom-albumin polymer (WVAP), molecular weight greater than or equal to 240,000 daltons, by glutaraldehyde treatment and Sephacryl S-300 column fractionation. Rabbits immunized with WVAP produced IgG to both WVAP and wasp venom (WV), as measured by ELISA. IgG against WVAP was totally inhibitable by a mixture of WV and albumin, demonstrating both retention of native antigens and absence of new antigenic determinants in WVAP. IgG against WV in serum from patients receiving maintenance doses of WV immunotherapy was inhibited by WVAP. In summary, we have synthesized a soluble, high-molecular-weight copolymer of WV that retains the immunogenicity of native WV, contains no new antigenic determinants, and has potential value in the treatment of patients with WV anaphylaxis.

Animals↗

A double-blind placebo-controlled trial of polymerized whole grass administered in an accelerated dosage schedule for immunotherapy of grass pollinosis.

Forty-four patients were entered into a study of the efficacy and safety of individually polymerized grass (IPG) immunotherapy with an accelerated dosage schedule. Patients were paired on the basis of cutaneous end point titrations to timothy, orchard, and Bermuda grass-pollen extracts. In a double-blind manner, one patient in each pair was treated in nine weekly visits with 13 injections that totaled 24,000 PNU of each grass to which the patient had cutaneous reactivity. The other patient in each pair received caramelized glucose histamine placebo. Symptom and medication score sheets were completed by 33 patients each day of the grass season. Blocking antibody rose significantly in the IPG-treated group but was unchanged in the placebo-treated group. By Wilcoxon paired signed-rank test, the symptom medication scores in the IPG-treated group were significantly lower than those in the placebo-treated group. There were no systemic reactions and no clinically significant changes in routine laboratory tests in either group. In summation, this study demonstrates the safety, immunogenicity, and efficacy of IPG therapy in an accelerated dosage schedule for treatment of grass pollinosis.

Adult↗

Safety and immunogenicity of immunotherapy with polymerized tree, grass, and ragweed in patients with multiple inhalant sensitivities.

Immunotherapy with polymerized ragweed (PRW) and individually polymerized grasses (IPG) previously has been demonstrated to be safe and effective. We conducted this trial in order to assess safety and immunogenicity of individually polymerized trees (IPT) and to assess safety of concomitantly administering IPT, IPG, and PRW in patients with multiple inhalant sensitivities. Sixteen patients with typical tree pollinosis were recruited; all but one had grass pollinosis, and all had ragweed pollinosis. Patients were treated in 12 weekly visits with allergens to which they were sensitive, 48,850 PNU of IPT; 2668 AU (50,000 PNU) of PRW; and 48,850 PNU of IPG. There were no systemic reactions and no changes in laboratory parameters, including renal and hepatic functions with injections. Blood was drawn for immunologic studies before and after the injection series. There were significant rises in IgG titers by ELISA to each tree allergen administered, oak, elm, and box elder. There were significant rises in total antibody binding of ragweed AgE and rye grass group I in patients treated with PRW and IPG, respectively. Changes in IgE to oak, elm, box elder, AgE, and rye grass group I were minimal. In summary, IPT is safe, immunogenic, and can be administered concomitantly with PRW and IPG in patients with multiple inhalant sensitivities.

Blood Proteins↗

Use of haptenizing ELISA to evaluate respiratory disease in a worker exposed to capacitor-coating powder.

We were asked to evaluate respiratory disease in a worker exposed to a powder containing unidentified components that was heated and used to coat capacitors. Because the powder was used as a coating material, we hypothesized that the capacitor-coating powder (CCP) contained either an anhydride or an isocyanate. We modified the initial step of a standard ELISA so that we could use CCP as a hapten in this assay. With this modified ELISA technique and inhibition analysis with antisera of known specificity, we determined that CCP contained a substance that cross-reacted with trimellitic anhydride. Later, we confirmed from the manufacturer that it contained benzophenone tetracarboxylic dianhydride. With the modified ELISA assay we also determined that the worker we were to evaluate did not have antibody to CCP or trimellitic anhydride. From clinical and immunologic evaluation we diagnosed chronic obstructive lung disease. Thus, this modified assay has proved useful in the evaluation of a worker exposed to a powder whose contents were not initially known and may prove useful in immunologic evaluation of workers in other industrial settings.

Adult↗

Emergency administration of radiocontrast media in high-risk patients.

Patients with previous anaphylactoid reactions to radiographic contrast media (RCM) are at increased risk for subsequent reactions on repeat exposure. The most efficacious pretreatment regimens require administration of medications up to 13 hours before the anticipated procedure. Emergency administration of RCM in patients requiring essential procedures precludes prolonged pretreatment. We report results of pretreatment in nine patients requiring emergency administration of RCM. We recommend hydrocortisone, 200 mg intravenously, immediately, and every 4 hours until the procedure is completed, and diphenhydramine, 50 mg intravenously, 1 hour before the procedure. No reactions occurred in these patients, suggesting that this pretreatment regimen may be valuable in prophylaxis for patients requiring emergency administration of RCM who have experienced previous anaphylactoid reactions. Although used in only one additional patient, ephedrine, 25 mg orally, 1 hour before the procedure may also be valuable.

Anaphylaxis↗

Some indications for depot methylprednisolone for asthma or other severe allergic disease.

Corticosteroid-dependent asthma is asthma of such severity that function of the patient cannot be maintained without long-term corticosteroid therapy. Occasionally, the optimal alternative day single-dose prednisone regimen that is preferable is not possible because of the inability of patients to comply with such a regimen. We describe cases in which we have to advise depot methylprednisolone to prevent potentially fatal asthma or vasculitis, although this type of therapy is suboptimal in terms of avoiding sustained corticosteroid levels in tissue, adrenal cortical suppression, and potential side effects. The decision to use depot corticosteroids was made after exhausting other alternatives and considering the risk and benefit ratio.

Adult↗

Rectus sheath hematoma complicating an exacerbation of asthma.

Hematoma of the rectus sheath is a rare complication of asthma. We describe a case of rectus sheath hematoma precipitated by a paroxysm of cough during an exacerbation of asthma. Diagnosis and management of this clinical entity is discussed.

Abdominal Muscles↗

Psychosomatic nasal disorder.

Present day allergy therapy can provide substantial symptomatic relief to patients with allergic and nonallergic rhinitis. Available measures are so effective that treatment failures with our most potent medications should raise the question of the presence of genuine pathology. Psychosomatic symptoms often involve nasal function. We present three such cases in which failure to relieve symptoms suggested a neurotic fixation on the condition of the nose and no demonstrable nasal pathology.

Adult↗