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Biomedical subjects

W Richards

Publications and source records attributed to W Richards.

At least 55 records · Page 3Linked to original sources
PubMed1992

Differential plasma duration of antiplatelet-activating factor and antihistamine activities of oral Sch 37370 in humans.

Preclinical studies have established that Sch 37370 (1-acetyl-4-(8-chloro-5,6-dihydro-11H-benzo[5,6]-cyclohepta [1,2-b]pyridin-11-ylidene)piperidine) is an orally active antagonist of platelet-activating factor (PAF) and histamine H1-receptors with potential therapeutic use in the treatment of asthma. To evaluate the efficacy and duration of anti-PAF and antihistamine actions of oral Sch 37370 in humans, a single dose (5 mg/kg) of Sch 37370 was given orally to each of 10 male subjects in a placebo-controlled, double-blind crossover study. Blood samples were drawn before and at various times (2 to 48 hours) after Sch 37370 or placebo. Plasma samples were analyzed for Sch 37370 by a gas chromatographic method, for the anti-PAF activity by measuring the aggregation of platelets stimulated with PAF, and for the antihistamine activity by measuring displacement of [3H]pyrilamine from rat brain membrane binding sites. The plasma anti-PAF activity declined from high levels at 2 hours to barely detectable levels at 24 hours; however, significant activity was still present at 12 hours. The plasma levels of Sch 37370 closely paralleled the anti-PAF profile. The plasma antihistamine activity reached a maximum within 2 to 8 hours and declined thereafter. However, 48 hours after Sch 37370, the antihistamine activity was still present at a significant level in most subjects. It is concluded that, in humans, oral Sch 37370 antagonizes both PAF and histamine with plasma antihistamine activity lasting longer than plasma anti-PAF activity.

Administration, Oral↗
PubMed1992

Hypercarbia during carbon dioxide gas insufflation for therapeutic laparoscopy: a note of caution.

During the past decade, the number of laparoscopic procedures performed in the United States, primarily with cholecystectomy, has increased phenomenally. We recently had a patient who developed hypercarbia and cardiovascular compromise during laparoscopic cholecystectomy. The cardiovascular compromise was caused by mechanical factors directly related to increasing intra-abdominal pressures affecting ventilation and venous return as well as the absorption of carbon dioxide (CO2) into the circulation, leading to acidosis and further depression of the cardiopulmonary system. Cardiovascular compromise can be avoided with early recognition of increased end-tidal CO2 concentrations and by preventing intra-abdominal pressures from exceeding 16 mm Hg.

Aged↗
PubMed1991

Underdiagnosis and undertreatment of chronic sinusitis in children.

A review of outpatients diagnosed with sinusitis during the previous year by the allergy services of Childrens Hospital of Los Angeles and Kaiser Permanente, Orange County, revealed 34 patients who had protracted discomforting and debilitating symptoms. The mean duration of symptoms was approximately six months (range 1-14 months). None had been previously diagnosed as having sinusitis or received appropriate treatment. Although all were referred for evaluation of allergic rhinitis and/or asthma, approximately 1/3 were found to have neither of these conditions. Among patients who had asthma, their asthmatic symptoms were aggravated by the sinusitis. All patients eventually responded favorably to appropriate antibiotic therapy. Earlier diagnosis and appropriate therapy would have foreshortened the course of this very discomforting condition. In recent years, we have observed a marked increase in the number of patients referred with the chief complaint of "worsening allergy" and who were subsequently found to have sinusitis. Most of the patients experienced significant incapacitation for protracted periods before a correct diagnosis was made and treatment instituted. In all but a few cases, prompt and sustained improvement followed appropriate therapy. The purpose of this report is to present a retrospective review of 34 illustrative cases.

Child↗
PubMed1990

Hydralazine dose-response curve analysis.

A multicenter, parallel, double-blind, 181-patient study compared the safety and antihypertensive efficacy of immediate-release (IR) and extended-release (ER) hydralazine. After 2 to 4 weeks on diuretic, patients were maintained on diuretic and randomized to a hydralazine treatment regimen: IR thrice daily, ER twice daily, or ER once daily. Daily doses of hydralazine were 75, 150, or 300 mg. Although designed as a titration study, important dose-response data were available for analysis with nonlinear mixed effect modeling (NONMEM). Sitting diastolic blood pressure (BP) was selected as the response variable. Several factors were tested for importance, including body weight, time (week) effects, concomitant beta-blocker (BB) therapy, acetylator class, and treatment regimen. All factors were important (p less than 0.05) except treatment regimen (p greater than 0.30). The maximum antihypertensive response (Emax) to hydralazine was 9.4 mm Hg. The daily dose that elicited 50% of the maximum response (D50) was 0.87 mg/kg for slow acetylators and 1.68 mg/kg for fast acetylators. BP fell 0.52 mm Hg per week independent of other effects, and concomitant BB therapy induced a drop of 6.6 mm Hg in addition to hydralazine, diuretic and week effects. NONMEM's use assisted in evaluations and provided information not obtainable through traditional means.

Administration, Oral↗
PubMed1990

The usefulness of small-bowel manometry in the diagnosis of gastrointestinal motility disorders.

Motility disorders of the gastrointestinal (GI) tract have traditionally been diagnosed by excluding mechanical small-bowel obstruction. In order to diagnose GI motility disorders in a positive fashion, small-bowel manometry was performed on 15 patients who were referred to the authors with intestinal motility disorders. Intestinal manometry was performed after first positioning a 200-cm multilumen tube into the small intestine. Ports located at 10-cm intervals were perfused with sterile water and connected to pressure transducers to record intraluminal pressures with a multichannel chart recorder. This low compliance water perfusion manometry system allowed examination of both fasting and postprandial motility. Intestinal manometry was able to assist in the diagnosis of two patients that had true mechanical small-bowel obstruction. One patient had a stenosis of the gastrojejunostomy and three patients had a functional gastric outlet obstruction secondary to a motility disorder in the Roux limb. One patient had a functional obstruction from a reversed jejunal loop and eight patients were identified as having intestinal pseudo-obstruction. We found intestinal manometry was a helpful adjunct in the diagnosis of GI motility disorders.

Adult↗
PubMed1989

A community systems approach to research strategies.

Conflict management skills are needed when dealing with research projects, in multi-cultural settings. Alcohol projects are especially prone to conflict because of the variety of different models of causation and intervention. There are a number of theories of conflict and type of conflict management approaches. The role of people who are in "cultural broker" or interface roles between conflicting parties has been reviewed elsewhere (Spiegel, 1973). My own approach--one of a number of possible alternatives--is briefly outlined here. It involves a form of systems analysis, and a role that many researchers might not initially feel comfortable with. The role goes beyond that of the "objective scientific reporter," and even beyond that of "conflict manager" or "culture broker." I am not sure quite what to call it: there are active attempts to get community members to resolve conflicts and carry out projects, but also what I consider a research orientation to try to carefully observe and describe and measure what is done. It is, I suppose, a form of "participant-observation," but the participation involves developing an overall strategic approach to the community's perceived problems. There is careful attention to who gets defined as the "problem," and who will actually be carrying out the project. Local community factions may need assistance in developing a very clear vision of the targeted results for the project. One has to also be keenly aware of possible problems that can result from differences in world view, pressures from funding sources or other intermediary groups who may have their own agendas for the research, as well as the overall context or environmental constraints.(ABSTRACT TRUNCATED AT 250 WORDS)

Alaska↗
PubMed1989

Fatal and disastrous complications following percutaneous endoscopic gastrostomy.

Percutaneous endoscopic gastrostomy (PEG) has become the preferred method of nutritional support in virtually every patient in whom this procedure is technically feasible because of its apparent technical facility, cost containment, and bedside insertion. PEG can, however, be associated with serious complications and death. This is a report of three patients who developed life-threatening abdominal wall abscesses and four patients who died after PEG insertion. The patients ranged in age from 30 to 80 years, four female and three male. Complicating medical conditions included cirrhosis, diabetes, heart-lung transplantation, neurological dysfunction, and psychosis. The four patients who died were all noted to have had unsatisfactory adhesion between the gastric serosa and the anterior abdominal wall, resulting in large gastric defects where the PEG had been placed and intraperitoneal contamination with gastric contents and feedings. Three additional patients developed abdominal wall abscesses requiring operative debridement. The patient considered to be high risk for surgical gastrostomy may be a higher risk for PEG. Alternatives to PEG should be considered in patients with poor nutritional status or debilitating medical conditions, or in patients undergoing immunosuppressive therapy and steroid use. Psychosis and dementia should be considered relative contraindications to PEG because these patients may dislodge the gastrostomy tube, resulting in severe wound infection and, possibly, death.

Adult↗
PubMed1989

Hospitalization of children with status asthmaticus: a review.

A review of hospital admissions of patients with status asthmaticus at the Childrens Hospital of Los Angeles showed a marked increase in admissions in recent years. Asthma mortality did not increase. Patients tended to be young, boys, and black as compared with patients admitted to a general hospital. Interviews with 100 patients and/or their parents admitted between February and June 1988 indicated that the majority of patients had frequent, severe, and/or disabling symptoms and a significant number were undertreated. Forty-five percent of these patients and 46% of all patients admitted between January 1986 and October 1988 because of status asthmaticus also had sinusitis, otitis, or pneumonitis.

Adolescent↗
PubMed1989

Pseudo-pseudo-obstruction. A clinically relevant concept.

Four patients with small bowel obstruction were treated nonoperatively after being misdiagnosed as chronic idiopathic intestinal pseudo-obstruction. Three patients with pseudo-pseudo-obstruction developed significant morbidity, and one patient died while being treated medically. Differentiation between pseudo-obstruction and mechanical obstruction can be difficult and may require laparotomy to establish the diagnosis. Intestinal manometry suggested a mechanical cause for obstruction in two patients and should be done in all patients that carry the diagnosis of intestinal pseudo-obstruction. Other clues to the diagnosis of intestinal pseudo-obstruction are discussed. Intestinal pseudo-obstruction is an uncommon disease that should not be a diagnosis of exclusion but should be diagnosed using historical, radiographic, manometric, pathologic, and operative data.

Aged↗
PubMed1988

Evaluation of a new, shorter method of administration of adrenergic aerosols in the treatment of asthma.

Approximately 15 to 20 minutes are usually required to administer adrenergic agents by nebulization in the treatment of asthma. But young children often do not tolerate these prolonged treatment periods. A "5-breath" method was found to provide comparable improvements in pulmonary function and result in minimal and comparable side effects, but required only one minute to administer. The "5-breath" method may, therefore, be the method of choice in the young or otherwise uncooperative patients.

Administration, Inhalation↗
PubMed1988

Cardiac arrest associated with halothane anesthesia in a patient receiving theophylline.

A case of a 10-year-old asthmatic patient who had cardiac arrest during induction for elective ear surgery is presented. The patient's serum theophylline level was 21.6 micrograms/mL one hour after surgery. It is likely that, since other factors that can contribute to cardiac arrest during the perioperative period were not present, the combined use of aminophylline and halothane was responsible.

Anesthesia↗
PubMed1987

ACT-asthma control y tratamiento para niños: a progress report.

A randomized clinical trial is in progress to evaluate an asthma educational program for Latino children and their parents. The intervention, "ACT-Asma Control y Tratamiento Para Niños," was adapted from ACT for Kids, an asthma self-management program for English-speaking families. Results of a pilot study indicated that socioeconomic status was a critical variable to be considered in the design of such programs. Latino children and parents encounter significant barriers to access and continuity of medical care. Therefore, the intervention was redesigned to include "linkages" using a nurse to reduce barriers and to coordinate care. The lesson plans emphasize concrete, experimental learning experiences, with repetition of key points in each session.

Asthma↗