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Biomedical subjects

J L Davis

Publications and source records attributed to J L Davis.

At least 37 records · Page 2Linked to original sources

Attitude alignment in close relationships.

On the basis of principles of balance theory and interdependence theory, this research examined a phenomenon termed attitude alignment, or the tendency of interacting partners to modify their attitudes in such a manner as to achieve attitudinal congruence. The results of three experiments generally were consistent with the proposed model. First, tendencies toward attitude alignment were greater to the extent that attitudinal discrepancies were salient. Second, alignment tendencies were greater to the extent that an issue was central to the partner; there was also evidence that the degree to which an issue was peripheral to the self affected alignment processes (e.g., for changes in centrality of issue, with regard to persuasion methods). Third, degree of alignment tended to be greater in dating-partner interactions than in stranger interactions and tended to be greater among couples with high adjustment than among those with low adjustment.

Adult↗

Lisinopril therapy for hemodialysis hypertension: hemodynamic and endocrine responses.

To evaluate the antihypertensive effects of lisinopril, a renally excreted angiotensin-converting enzyme inhibitor, we assessed supervised administration of the drug after hemodialysis (HD) three times weekly. Blood pressure (BP) was assessed by interdialytic 44-hour ambulatory BP (ABP) monitoring, and endocrine responses were assessed by plasma renin activity (PRA) before and after dialysis. Lisinopril dose was titrated at biweekly intervals. If this was not effective after full titration (lisinopril to 40 mg three times weekly), ultrafiltration was added to reduce dry weight. The primary outcome variable was change in BP from the end of the run-in period to the end of the study. No change in mean ABP was noted during run-in. However, mean 44-hour ABP decreased from 149 +/- 14 (SD)/84 +/- 9 to 127 +/- 16/73 +/- 9 mm Hg, a decrease of 22/11 mm Hg (P < 0.001) at final evaluation. Of 11 patients who completed the trial, only 2 patients had systolic hypertension (>/=135 mm Hg) and 1 patient had diastolic hypertension (>/=85 mm Hg) at the final visit. Four patients were administered 10 mg of lisinopril; 5 patients, 20 mg; and 2 patients, 40 mg; only 1 of these patients required ultrafiltration therapy. There was a persistent antihypertensive effect over 44 hours. BP reduction was achieved without an increase in intradialytic symptomatic or asymptomatic hypotensive episodes. PRA increased in response to dialysis, as well as lisinopril. In conclusion, supervised lisinopril therapy is effective in controlling hypertension in chronic HD patients. This may be related to blockade of angiotensin II generation by kidneys despite the loss of excretory function.

Adult↗

Predictors of medical examinations following child and adolescent rapes in a national sample of women.

Childhood rape occurs frequently in our society and is associated with adverse consequences. Despite the severity of these outcomes, there appear to be many obstacles for children to receive postrape medical care. To date, it is unclear what proportion of childhood rape victims receive postrape medical examination or what factors predict receipt of this medical care. This study instigated the factors predicting immediate medica care for women who were raped during childhood. Data for the study were obtained from the final wave of the 2-year, longitudinal National Women's Study. Results indicated that the majority of women did not receive medical care following their childhood rape. Although women raped as adolescents were more likely to receive a postrape exam, logistic regression analyses indicated that rape characteristics (e.g., reporting the assault, concerns about sexually transmitted diseases [STDs]) mediated the relationship between age of victimization and receipt of medical care. Implications of these findings are discussed.

Adolescent↗

Signal polymorphism in the web-decorating spider Argiope argentata is correlated with reduced survivorship and the presence of stingless bees, its primary prey.

Many spiders, and in particular those in the genus Argiope, spin highly visible web decorations whose function and significance are the subject of spirited debate. In this work, we present data to address two of the competing hypotheses that fuel this controversy. In particular, we examine the relationship between the presence of web decorations and spider survivorship (predator-protection hypothesis) and the relationship between the presence of prey and spider decorating behavior (the prey-attraction hypothesis). Our laboratory studies reveal that the decorating behavior of the spider A. argentata has a genetic component but that the expression of decorating behavior tends to be elicited only when a spider is well fed. Furthermore, our field studies show that in the presence of abundant stingless bees, spider decorating behavior is induced. Nevertheless, our field surveys also suggest that spiders that decorate their webs show reduced survivorship. We propose that the high correlation between web decorating in the presence of stingless bees supports the hypothesis that A. argentata engage in decorating behavior when attracting or targeting specific prey types. However, we also propose that web decorations attract the predators of A. argentata because high-frequency decorators suffer lower survivorship than spiders that decorate moderately or rarely. These findings suggest that spider web decorating behavior is affected by conflicting selection pressures: the positive effect of prey attraction versus the negative effect of predator attraction. Due to the heritable component of decorating behavior, web decorating among A. argentata is likely to be particularly sensitive to the spider's local ecology as well as local patterns of gene flow.

Animals↗

Relationship between aqueous humor protein level and outflow facility in patients with uveitis.

PURPOSE: To determine whether there is a relationship between the aqueous humor protein level and outflow facility in patients with uveitis. METHODS: Aqueous humor protein levels were determined by laser flare photometry, and outflow facility was determined by Schiotz tonography. RESULTS: Thirty patients with uveitis and 10 control subjects were studied. Outflow facility was lower in patients with uveitis (0.21 +/- 0.12 microl/min x mm Hg) than in control subjects (0.33 +/- 0.05 microl/min x mm Hg, P < 0.001). Patients with uveitis and laser flare photometry results (flare) more than 20 photon units/msec (n = 21) had a lower outflow facility (0.17 +/- 0.07 microl/min x mm Hg) than patients with uveitis and flare less than 20 photon units/msec (n = 9, 0.32 +/- 0.14 microl/min x mm Hg, P = 0.004). Furthermore, no difference was identified between outflow facility in patients with active uveitis (those who had anterior chamber cells) and flare less than 20 photon units/msec and outflow in control subjects. In patients with uveitis, there was a linear correlation between flare and outflow facility (r = -0.50, P = 0.005). There was no relationship between flare measurements and either intraocular pressure or aqueous humor cell levels when scored with a clinical, semiquantitative system. CONCLUSIONS: Outflow facility is significantly reduced in patients with uveitis who have high aqueous humor protein levels. Outflow facility appears to be normal in patients with active uveitis whose flare levels are low, and therefore the association between flare and outflow facility does not appear to be an indirect reflection of elevated anterior chamber cells. It is possible that elevated aqueous humor protein levels contribute to the development of uveitic glaucoma in some individuals by decreasing aqueous humor outflow facility, although a causal relationship cannot be established on the basis of this study.

Adult↗

Mutations conferring ganciclovir resistance in a cohort of patients with acquired immunodeficiency syndrome and cytomegalovirus retinitis.

Cytomegalovirus (CMV) retinitis is among the most common opportunistic infections in patients with acquired immunodeficiency syndrome. In a prospective study of 210 patients with CMV retinitis, 26 were identified as having either a phenotypic or a genotypic ganciclovir-resistant isolate from either blood or urine cultures. For blood culture isolates with an IC(50) >6.0 microm for ganciclovir, the sensitivity and specificity for detecting a UL97 mutation were 95% and 98%, respectively, whereas for an IC(50) >8.0 microM they were 79% and 99%, respectively. Although there were trade-offs between the 2 thresholds for blood culture isolates, for urine culture isolates an IC(50) >8.0 microM appeared to be better at identifying genotypic resistance. UL97 mutations identified in both the blood and urine cultures of individual patients were identical in 87.5% of cases. High-level ganciclovir resistance (IC(50), >30 microM) typically, but not invariably, was associated with a mutation in both the UL97 and UL54 genes.

AIDS-Related Opportunistic Infections↗

Intravitreal antiviral injections as adjunctive therapy in the management of immunocompetent patients with necrotizing herpetic retinopathy.

PURPOSE: To report the use of intravitreal antiviral injections as adjunctive therapy in the management of three immunocompetent patients with necrotizing herpetic retinopathy. METHOD: Case series. RESULTS: Three patients with necrotizing herpetic retinopathy received intravitreal antiviral injections for treatment of progressive retinitis, despite standard intravenous acyclovir therapy. The retinitis resolved and visual acuity improved after a minimum of 6 months of follow-up in each case. CONCLUSION: Intravitreal antiviral injections may be a safe and efficacious adjunctive therapy in the management of patients with necrotizing herpetic retinopathy.

Acyclovir↗

Endogenous endophthalmitis caused by Histoplasma capsulatum var. capsulatum: a case report and literature review.

OBJECTIVE: We report the first case of clinically diagnosed endogenous endophthalmitis caused by Histoplasma capsulatum var. capsulatum in a patient with the acquired immune deficiency syndrome. DESIGN: Interventional case report and literature review. INTERVENTION: Pars plana vitrectomy and scleral buckling procedure in the left eye with intravenous and intravitreal amphotericin in both eyes. MAIN OUTCOME MEASURES: The clinical features, culture results, visual outcome, and complications were studied. RESULTS: This case demonstrates a bilateral endophthalmitis with severe subretinal exudation, choroidal granulomas, and intraretinal hemorrhage leading to exudative bilateral retinal detachments. Vitreous cultures grew H. capsulatum var. capsulatum. Treatment consisted of intravenous amphotericin, intravitreal amphotericin (both eyes), pars plana vitrectomy (left eye), and scleral buckling procedure (left eye) with resulting counting fingers vision (right eye) and 20/300 (left eye). Four cases of Histoplasma endophthalmitis have been reported previously, all of which had a documented history of disseminated histoplasmosis and resulted in enucleation. CONCLUSIONS: H. capsulatum should be considered a possible etiologic agent of endophthalmitis, especially in patients with a history of disseminated histoplasmosis and/or immune deficiency.

AIDS-Related Opportunistic Infections↗

Naproxen-associated linear IgA bullous dermatosis: case report and review.

Linear IgA bullous dermatosis (LABD) is an acquired autoimmune subepidermal blistering disorder in which linear deposits of IgA are found along the basement membrane. Idiopathic, systemic disorder-related, and drug-induced forms of LABD have been described. Drug-induced LABD occurs in association with drug administration and resolves when the offending agent is discontinued. Other forms of LABD assume a more chronic course. The nonsteroidal anti-inflammatory drugs piroxicam and diclofenac have been previously reported to induce LABD. To our knowledge, this article describes the first documented case of LABD associated with naproxen administration, which resolved after discontinuation of the drug.

Aged↗

Ground penetrating radar surveys to locate 1918 Spanish flu victims in permafrost.

The "Spanish Flu" killed over 40 million people worldwide in 1918. Archival records helped us identify seven men who died of influenza in 1918 and were interred in Longyearbyen, Svalbard, Norway, 1,300 km from the North Pole. Ground Penetrating Radar (GPR) was used successfully, in a high-resolution field survey mode, to locate a large excavation with seven coffins, near the existing seven grave markers. The GPR indicated that the ground was disturbed to 2 m depth and was frozen below 1 m. Subsequent excavation showed that: a) the GPR located the position of the graves accurately, b) the coffins were buried less than 1 m deep, and c) that the frozen ground was 1.2 m deep where the coffins were located. The GPR assisted in planning the exhumation, safely and economically, under the high degree of containment required. Virologic and bacteriologic investigations on recovered tissues may give us an opportunity to isolate and identify the micro-organisms involved in the 1918 influenza and expand our knowledge on the pathogenesis of influenza.

Burial↗

Relentless placoid chorioretinitis: A new entity or an unusual variant of serpiginous chorioretinitis?

OBJECTIVE: To characterize an unusual clinical entity resembling acute posterior multifocal placoid pigment epitheliopathy (APMPPE) and serpiginous choroiditis but with an atypical clinical course. PATIENTS: We describe 6 patients, aged 17 through 51 years, exhibiting this unusual entity who were seen at 6 different centers from 1984 to 1997. RESULTS: The acute retinal lesions in this series were similar to those of APMPPE or serpiginous choroiditis, both clinically and on fluorescein and indocyanine green angiography. However, the clinical course, number of lesions, and location of these lesions were atypical. These patients had evidence of numerous posterior and peripheral retinal lesions predating or occurring simultaneously with macular involvement. Older, healing pigmented lesions were often accompanied by the appearance of new active white placoid lesions. Additionally, these cases all demonstrated prolonged periods of activity resulting in the appearance of more than 50 and sometimes hundreds of lesions scattered throughout the fundus. Growth of subacute lesions and the appearance of new lesions continued for 5 to 24 months after initial examination, and relapses were common. CONCLUSIONS: This entity has clinical features similar to APMPPE and serpiginous choroiditis but has a prolonged progressive clinical course and widespread distribution of lesions. It may represent a variant of serpiginous choroiditis or may be a new entity. We call it relentless placoid chorioretinitis. Arch Ophthalmol. 2000;118:931-938

Acute Disease↗

A trial of two iron-dextran infusion regimens in chronic hemodialysis patients.

AIM: To test the ability to elicit a hemoglobin (Hb) response in patients on chronic hemodialysis, we prospectively compared two regimens of iron dextran administration, 100 mg once weekly (QW) or 100 mg once every dialysis (QD), both given for 10 doses. PATIENTS AND METHODS: Twenty-three consecutive patients on chronic hemodialysis received iron dextran intravenously if they had absolute or functional iron deficiency. There was no difference in the Hb response between regimens. RESULTS: Both groups had a significant increase in Hb from 10.5+/-1.5 g/dl at baseline, to 11.1+/-1.7 g/dl at 1 month, 1.4+/-2.1 g/dl at 2 months and 11.6+/-1.9 g/dl at 3 months. The increment in Hb at 1 month was similar (QD 0.62+/-1.245 g/dl vs. QW 0.64+/-1.464 g/dl) between the two groups despite a large difference in the amount of iron received. Serum ferritin, transferrin saturations or epoetin dose did not change significantly. At the end of 3 months 12 patients did not need further iron therapy as judged by the serological markers of iron stores. Of these 12 patients, 3 had serum ferritins of > 1,000 ng/ml. Weekly dosing of iron was associated with more medication errors than dosing every dialysis. Baseline iron stores could not predict the responsiveness to intravenous iron therapy as judged by an increase in Hb concentration at 1 month or at 3 months. CONCLUSION: This study confirms the efficacy of 1,000 mg of intravenous iron administered over a 3-month period in patients with functional iron deficiency. It underscores the importance of careful monitoring of iron stores and highlights the need for developing better parameters of functional iron stores in hemodialysis patients.

Anemia, Iron-Deficiency↗

Treatment of recurrent cytomegalovirus retinitis with the ganciclovir implant.

PURPOSE: To evaluate preoperative characteristics and outcome of the treatment of recurrent cytomegalovirus (CMV) retinitis with the ganciclovir implant. METHODS: Records of 54 patients with acquired immunodeficiency syndrome and active, previously treated CMV retinitis who received a ganciclovir implant in one (n = 31) or both (n = 23) eyes were reviewed. Entry criteria included prior insertion and removal of an indwelling catheter or failure to respond to tolerated doses of ganciclovir and foscarnet. Preoperative factors that might correlate with outcome were analyzed, including demographic factors, duration of human immunodeficiency virus disease and CMV retinitis, indications for surgery, prior anti-CMV treatment, and extent of retinitis. RESULTS: Forty-six patients completed 1 month of follow-up and were analyzed for outcome. Thirty-one (67.4%) had inactive retinitis at 1 month vs 15 (32.6%) with active retinitis, and they received a mean of 23.5 +/- 22.9 weeks of preoperative ganciclovir vs 58.0 +/- 52.0 weeks in patients with active retinitis (P = .003). Involvement of more than 25% of retinal area by CMV retinitis was also correlated with activity at 1 month (P < .001). Patients who received implants because of lack of venous access had a median time to progression of 8.0 +/- 3.0 months vs 2.0 +/- 1.2 months for patients who had inadequate response or intolerance to intravenous medication (P = .073). Patients with 6 months or less vs more than 6 months of preoperative ganciclovir treatment had progression at a median time of 8.0 +/- 1.7 months vs 2.0 +/- 0.3 months, respectively (P = .016). CONCLUSION: Longer duration of preoperative ganciclovir or larger area of CMV retinitis correlates with lower success of ganciclovir implant therapy for recurrent retinitis.

AIDS-Related Opportunistic Infections↗

Use of the ganciclovir implant for the treatment of cytomegalovirus retinitis in the era of potent antiretroviral therapy: recommendations of the International AIDS Society-USA panel.

PURPOSE: To describe the risks, benefits, and recommended use of the ganciclovir implant for the treatment of human immunodeficiency virus-related cytomegalovirus (CMV) retinitis in the era of potent antiretroviral therapy. METHODS: A panel of physicians with expertise in the use of the ganciclovir implant and in the management of CMV retinitis was convened by the International AIDS Society-USA. The panel reviewed and discussed available data, and developed recommendations for the use of the ganciclovir implant, the surgical technique, and related management issues. Recommendations were rated according to the strength and quality of the supporting evidence. RESULTS: The effect of potent antiretroviral therapy on the immunologic status of patients with human immunodeficiency virus disease has changed the manifestation and course of CMV retinitis in many patients. The clinical management of CMV retinitis and the role of the ganciclovir implant are thus changing. Factors in the decision to choose the ganciclovir implant include the patient's potential for immunologic improvement, location and severity of CMV retinitis, and the risks and costs associated with implantation and concomitant oral ganciclovir therapy. CONCLUSIONS: The ganciclovir implant is safe and effective for the treatment of CMV retinitis. The indications for its use should be modified to account for increased patient survival and the potential for CMV retinitis to be controlled by effective antiretroviral therapy. Optimal use of the ganciclovir implant and discontinuation of therapy in selected patients with improvement in immunity may result in better long-term visual outcomes.

AIDS-Related Opportunistic Infections↗