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Biomedical subjects

J D Long

Publications and source records attributed to J D Long.

At least 19 recordsLinked to original sources
PubMed2001

Risks for individuals with schizophrenia who are living in the community.

OBJECTIVE: This study examined the incidence and predictors of police contact, criminal charges, and victimization among noninstitutionalized individuals with schizophrenia living in the community. METHODS: A total of 172 individuals with schizophrenia or schizoaffective disorder were recruited from community-based programs in urban Los Angeles between 1989 and 1991 and were monitored for three years. At baseline, all participants were housed and did not have co-occurring substance use disorders. Face-to-face interviews were conducted every six months. RESULTS: Eighty-three individuals (48 percent) had contact with the police during the study period. A small percentage of the contacts involved aggressive behavior against property or persons. Being younger, having had more address changes at baseline, and having a history of arrest and assault were significant predictors of police contact. Thirty-seven individuals (22 percent) reported that charges had been filed against them. Poorer social functioning, more address changes, fewer days of taking medication at baseline, and a history of arrest and assault were significant predictors of criminal charges. Sixty-five participants (38 percent of the sample) reported having been the victim of a crime during the three years, 91 percent of which was violent. Having more severe clinical symptoms and more substance use at baseline were significant predictors of victimization. CONCLUSIONS: Individuals in this sample were at least 14 times more likely to be victims of a violent crime than to be arrested for one. In general, the risk associated with being in the community was higher than the risk these individuals posed to the community

Activities of Daily Living↗
PubMed2000

Eicosanoids and the esophagus.

Eicosanoids are products of arachidonic acid metabolism. Among the products produced are the prostaglandins and leukotrienes, products which are known to play important roles in health and disease of many gastrointestinal tissues. Here, we review current knowledge about eicosanoids in the esophagus, including production in healthy and diseased tissues and potential physiologic and pathophysiologic effects in two important esophageal mucosal disorders, reflux esophagitis and esophageal cancer.

Animals↗
PubMed2000

Community-based psychosocial rehabilitation and prospective change in functional, clinical, and subjective experience variables in schizophrenia.

In a previous study, we found that the intensity, specificity, and longitudinality of community-based psychosocial rehabilitation services were related to superior functional outcomes for individuals diagnosed with schizophrenia. The purpose of this study was to assess the degree to which the intensity and longitudinality of services were related to improvements in subjective experience and clinical outcomes, and to examine the relationships among prospective changes in functional, clinical, and subjective experience variables. One hundred seventy-two individuals diagnosed with a schizophrenia spectrum disorder were followed for 36 months in three distinct models of community-based care. Functional, clinical, and subjective experience outcome data were gathered every 6 months over a 3-year period. Data were analyzed using hierarchical linear modeling (HLM) and P-technique factor analysis. The results indicated that (1) greater service intensity and the longitudinality of services were associated with improvement in client self-esteem; (2) there was evidence for three distinct factors of prospective rehabilitative change that corresponded to the conceptual domains of clinical, functional, and subjective experience outcomes; and (3) there was no differential program impact on symptom levels or the intrapsychic deficits. In addition, the three-factor model of outcome consisting of functional change, clinical change, and subjective experience change was similar to Strauss and Carpenter's "open-linked" system of outcome in schizophrenia. The implications of these findings for research and practice in the area of community-based rehabilitation for individuals with schizophrenia are discussed.

Adult↗
PubMed1999

Strongyloidiasis colitis: a case report and review of the literature.

A case is described of a nonimmunocompromised man who presented with diarrhea, weight loss, and microcytic anemia. Colonoscopy revealed a pancolitis characterized by aphthoid ulceration on endoscopy and intense tissue eosinophilic infiltrates on biopsy. Both colonic biopsies and stool aspirates revealed the larvae of Strongyloides stercoralis, thus confirming this parasite as the causative agent for the colitis.

Aged↗
PubMed1999

Esophageal submucosal glands: structure and function.

A three-tiered defense system exists in the esophagus, which serves a dual purpose of both limiting the degree of gastroesophageal reflux and minimizing the risk of acid-induced mucosal injury. The antireflux barrier, composed of both the lower esophageal sphincter and the diaphragmatic pinchcock, is the first line of defense and serves to limit the frequency and volume of refluxed gastric contents. When the antireflux barrier fails, the second line of defense, esophageal clearance, comes into play and serves to limit the duration of contact between gastric contents and the esophageal epithelium. Mechanisms involved in esophageal clearance include gravity and esophageal peristalsis, which remove volume, and secretions from swallowed saliva and esophageal submucosal glands, which neutralize acid. The third line of defense, tissue resistance, is necessary when acid contact time is prolonged such as when esophageal clearance is either ineffective or not operative (e.g., during sleep). Most studies that have examined esophageal clearance mechanisms have focused on the roles of esophageal peristalsis and salivary secretion, but the role of submucosal gland secretions is less well understood. This article reviews the structure and function of esophageal submucosal glands and discusses the potential role of their secretory products in esophageal clearance and tissue resistance.

Animals↗
PubMed1998

Incorporating systematic reviews into nursing education.

Systematic reviews of research are important to the quality of nursing care. A number of sources of systematic reviews of nursing research are available. Nursing education programs should introduce students to these as crucial resources for utilizing research in practice. This article describes sources of systematic reviews and proposes teaching strategies for incorporating the use of systematic reviews into undergraduate and graduate programs. Nurse educators are invited to contribute to this ongoing column their accounts of successful teaching strategies.

Journal Article↗
PubMed1998

Luminal hypertonicity and the susceptibility of rabbit esophagus to acid injury.

The esophagus is regularly exposed to hypertonic luminal environments, some of which have the capacity to increase epithelial permeability. The present experiments were designed to determine what impact such environments have on epithelial resistance to injury by acid. Rabbit esophageal epithelium mounted in Ussing chambers was exposed to luminal acid while monitoring electrical resistance (R), a marker of epithelial permeability, and morphology was assessed in tissues luminally pretreated with either urea (1 M), mannitol (1 M), or normal Ringer. Hypertonic mannitol, which had little effect on R, was associated with a minor increase in susceptibility to acid injury, pH 1.6. In contrast, hypertonic urea lowered R and was associated with marked injury upon exposure to acid. This susceptibility to acid injury occurred within 15 minutes of exposure and converted a non-damaging concentration of acid (pH 2.0) to a damaging one. Moreover, urea's effects were abolished if it was removed from the bath allowing R to return to baseline before acidification. We conclude that hypertonic luminal environments that impair epithelial barrier function predispose the esophagus to acid injury. Such findings may provide insight into additional mechanisms contributing to the development of heartburn following meals.

Acid-Base Imbalance↗
PubMed1997

Management of secretions in esophageal cancer patients with glycopyrrolate.

BACKGROUND: There has been little emphasis in the past upon management of excessive secretions in patients with esophageal cancer. We used the drug glycopyrrolate for controlling secretions in patients with esophageal cancer. PATIENTS AND METHODS: Between January 1991 and September 1995, 45 patients with esophagus cancer were referred for evaluation. Seven of these patients were treated with glycopyrrolate for increased secretions. Secretions were measured in suction canisters which were used by patients. RESULTS: All the patients showed a decrease in secretions within 24 48 hours of administration. The incidence of side effects was minimal. CONCLUSIONS: Glycopyrrolate is quite effective in palliating esophageal cancer patients with excessive secretions.

Esophageal Neoplasms↗
PubMed1997

The impact of service characteristics on functional outcomes from community support programs for persons with schizophrenia: a growth curve analysis.

A total of 172 individuals diagnosed with a schizophrenia spectrum disorder were followed for 36 months in 3 distinct models of community-based care. Functional outcome data gathered every 6 months were combined with service implementation data to test hypotheses concerning the impact of service characteristics on prospective client outcomes. The results using hierarchical linear modeling supported associations between the intensity, specificity, and longitudinality of services and improved client outcomes. Specifically, more intense services were associated with higher levels or rates of improvement on all indices of clinical and psychosocial functioning. The specificity results suggested that services needed to be targeted to specific areas of functioning in order for improvement to occur. The effect of longitudinality was contingent on the outcome domain examined.

Adult↗
PubMed1997

Effects of luminal hypertonicity on rabbit esophageal epithelium.

The human esophagus is exposed daily to luminal contents that are hypertonic with respect to blood. Because the effects of such exposure are unknown, we investigated the impact of luminal hypertonicity on esophageal epithelial structure and (barrier and transport) function. Rabbit esophageal epithelium was mounted in Ussing chambers and exposed luminally to hypertonic (1,200 mosmol/kgH2O) solutions of mannitol, urea, or NaCl or to normal Ringer solution (300 mosmol/kgH2O). The potential difference (PD), short-circuit current (Isc), and resistance (R) were monitored and, after exposure, tissues were assessed morphologically by light and electron microscopy. Hypertonic mannitol had no significant effect on the electrical or morphological properties of the tissue. However, hypertonic urea and NaCl increased Isc by 91 +/- 31% and 305 +/- 51%, respectively, and decreased R by 20 +/- 6% and 57 +/- 3%, respectively (both P < 0.05 vs. Ringer or mannitol). Furthermore, serosal ouabain blocked the urea-induced increase in Isc completely and the NaCl-induced increase partially (65%) but had no effect on the decline in R. The decline in R for both urea and NaCl was associated with increased [14C]mannitol fluxes and, morphologically, with dilated intercellular spaces but not cell necrosis. These data suggest that hypertonic urea and NaCl, but not hypertonic mannitol, stimulate net Na+ transport in esophageal epithelium and increase permeability via the paracellular route. Notably, the effects of hypertonic urea and NaCl occur rapidly at clinically relevant osmolalities and, though reversible, resolve more slowly. We conclude that hypertonic luminal environments can significantly alter esophageal epithelial structure and function, but that the impact of such exposure depends as much on the nature of the solute as on its osmolality and duration of contact.

Animals↗
PubMed1995

A robotics-based liquid chromatographic assay for the measurement of atovaquone in plasma.

A precise and specific robotics-based liquid chromatographic (LC) method for measuring atovaquone concentrations in plasma was developed and validated, and the method was compared with an existing manual LC method. The compound was isolated from plasma by liquid-liquid extraction, separated by reversed-phase LC, and quantitated against an internal standard with UV detection. Least-squares linear regression with 1/concentration2 weighting was used as the calibration model. The range of the calibration curve for the assay under routine conditions was 0.25-50 micrograms ml-1. No endogenous interferences with the compound or the internal standard were noted in either untreated human plasma or in plasma from patients enrolled in Phase III clinical trials of atovaquone. The accuracy of the assay (determined as the percent bias) ranged from -4.8% to -9.4% in the validation runs. The intra- and interassay precisions (determined as the relative standard deviation) were less than 6.8% and 6.4%, respectively. The contribution of an internal standard on assay accuracy and precision also was examined. Interassay variability was marginally improved by the incorporation of an internal standard to the assay; accuracy and intra-assay precision were essentially unchanged. A paired t-test between estimates of atovaquone concentrations in healthy volunteer and HIV + patient human plasma samples assayed by the automated and manual methods demonstrated no significant difference (p = 0.31) between the values determined by each method.

Antifungal Agents↗
PubMed1995

Apollo MEED mycology revisited and reviewed, including the Trichophyton terrestre keratinophilic growth at splashdown and 23 years after exposure to space parameters.

Keratinophilic Trichophyton terrestre conidia were exposed to selected parameters of space flight including 254, 280 and 300 nm UV light, full light and total darkness of space. Phenotypic isolates were grown on human hair collected from one source at years 1 and 23 after splashdown. The patterns of fungal growth on the hair, and the hair deterioration rates, were noted according to the space exposure. Growth and deterioration were consistent but slightly reduced at year 23.

Darkness↗
PubMed1994

High-performance liquid chromatographic assay for the measurement of atovaquone in plasma.

A rapid and efficient isocratic high-performance liquid chromatographic assay for the measurement of atovaquone in plasma has been developed and validated. The drug was extracted from plasma with organic solvents, assayed on a C1 column with a mobile phase of methanol-0.1% acetic acid (70:30, v/v), and detected by ultraviolet absorbance at 254 nm. Recovery of atovaquone from plasma was greater than 85%. Intra- and inter-assay variability were less than 8%, and the average accuracy of the assay (expressed as % bias) ranged from -7.4 to + 2.2%. The upper and lower limits of quantitation were 100 and 0.25 microgram/ml, respectively. Measurement of atovaquone in spiked plasma control samples during routine runs of clinical trial samples confirmed the reliability of the assay.

Antiprotozoal Agents↗
PubMed1994

Effects of rotavirus on epithelial transport in rabbit small intestine.

The present study investigated changes in small intestinal epithelial transport in rabbits infected with rotavirus. The crypt depth-villus height ratio was increased in infected ileal tissue as a result of a significant increase in crypt depth and patchy shortening of the villi. Similar villus damage was seen in the jejunum. Despite these histological changes, basal fluid absorption by both the ileum and jejunum of infected animals was unaltered. Values for basal short-circuit current and resistance were similar; however, the increase in short-circuit current evoked by prostaglandin E2 was significantly smaller in rotavirus-infected tissues than in controls. The apparent Vmax for electrogenic glucose and alanine uptake by the jejunum was significantly increased following inoculation with rotavirus. Reduced responsiveness to the secretory effect of prostaglandin E2 and increased nutrient uptake may limit diarrhea that would otherwise be expected to occur as a result of the changes in mucosal architecture. This has important implications on the clinical treatment of rotavirus diarrhea, suggesting that oral rehydration therapy, which depends on the active transport of nutrients, may provide a more effective treatment than the use of cyclooxygenase inhibitors.

Alanine↗
PubMed1993

A one-year experience in the antenatal evaluation of suspected abdominal wall and bowel defects at a military tertiary referral center.

A variety of fetal abdominal wall defects and bowel anomalies are detected or suspected antenatally at institutions providing primary, secondary, and tertiary level care. Presented is a summary of a 1-year experience at a tertiary care center demonstrating a working referral network and its advantages. Of the 10 cases presented, 8 were referred and 2 originated from within our institution. The initial diagnosis was uncertain or differed from the final diagnosis in half of referred cases. Within the military, a reliable route for referral enhances prenatal evaluation and provides intensive neonatal support at delivery if needed and more immediately available surgery if indicated.

Abdominal Muscles↗
PubMed1990

Cocaine-mediated impairment of cardiac conduction in the dog: a potential mechanism for sudden death after cocaine.

Deaths from cocaine abuse continue to increase, while the mechanism of lethality remains unclear. Previous investigations have focused on potential ventricular dysrhythmias and myocardial ischemic events from enhanced autonomic tone or seizure activity from central stimulation. However, cocaine is a local anesthetic and may impair cardiac conduction. To evaluate this, 16 conscious dogs received i.v. cocaine over 30 sec to mimic "recreational" use in doses of 3 mg/kg (n = 6), 5 mg/kg (n = 6) or 7 mg/kg (n = 4). Another group of anesthetized dogs (n = 6) received two infusions of cocaine (5 mg/kg) 1 hr apart. Plasma cocaine levels and His bundle electrograms were obtained at control and at 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0, 10 and 15 min after cocaine administration. At 0.5 min, plasma cocaine reached peak levels of 30.0, 45.0 and 59.6 micrograms/ml with increasing dose. Cocaine rapidly produced severe prolongation of His to ventricle interval and widening of the R wave. Slowing of conduction was dose-dependent, with maximal increases in His to venticle interval of 37 to 56% (P = .0299) and R wave duration of 34 to 77% (P less than .025). Furthermore, significant conduction impairment developed at cocaine levels that did not produce seizures. Conduction effects were equally pronounced during repeated administration of cocaine. These data indicate that cocaine causes marked conduction slowing, which could play an important role in cocaine death.

Animals↗