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Biomedical subjects

A Hartz

Publications and source records attributed to A Hartz.

At least 19 recordsLinked to original sources
PubMed1992

Progression of nonproliferative diabetic retinopathy and visual outcome after extracapsular cataract extraction and intraocular lens implantation.

Twenty-one patients with symmetric nonproliferative retinopathy who underwent extracapsular cataract extraction and intraocular lens implantation were followed up postoperatively for an average (+/- standard deviation) of 18 +/- 7 months to determine the incidence of progression of diabetic retinopathy, the final visual acuity, and factors predictive of progression of retinopathy and final visual acuity. Progression of retinopathy, defined as the development of clinically significant macular edema, an increase in intraretinal hemorrhages or hard exudate, or the development of proliferative diabetic retinopathy, was assessed in both eyes of 19 patients; in two remaining patients, dense preoperative cataract in the fellow eye precluded comparison of retinopathy progression in the operated-on eye to progression in the fellow eye. Overall, retinopathy progressed in 14 of 19 operated-on eyes (74%). Cataract extraction was highly associated with asymmetric progression of nonproliferative retinopathy; it progressed only in the operated-on eye in seven of 19 patients (37%), but in no patients did progression occur in the fellow eye alone (P = .0078). Women had a significantly increased risk of progression of retinopathy in the operated-on eye compared to men (P = .005). Visual acuity improved in 19 of 21 operated-on eyes (86%); however, only 11 eyes (52%) achieved a visual acuity of 20/50 or better and only six eyes (14%) achieved a visual acuity of 20/25 or better. In only five eyes was the final visual acuity in the operated-on eye more than two lines better than the final visual acuity in the fellow eye.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Risk factors for postvitrectomy fibrin formation.

We prospectively studied 194 patients undergoing vitrectomy between July 1988 and April 1989 to determine the incidence of postvitrectomy intraocular fibrin formation and the association of a variety of preoperative and intraoperative variables with the formation of severe postvitrectomy fibrin. Overall, 62 (32%) patients developed postvitrectomy fibrin; 25 (13%) had mild fibrin formation, 13 (6.5%) had moderate fibrin formation, and 24 (12.4%) had severe fibrin formation. By logistic multivariate analysis, preoperative factors that were independently predictive of severe fibrin formation included severe flare (P = .004), the presence of a previously placed scleral buckle (P = .001), and poor preoperative visual acuity (P = .007). Anterior epiretinal membrane dissection was the only intraoperative factor that was independently associated with an increased fibrin risk (P = .0003). A risk score derived from the multivariate analysis effectively categorized patients according to their likelihood of developing severe postvitrectomy fibrin. Results of this study may be useful in designing prophylactic interventions to decrease postvitrectomy fibrin formation.

Adult↗
PubMed1990

Clinical signs of androgen excess as risk factors for coronary artery disease.

Women with androgen excess have been found to have higher triglycerides and lower high-density lipoprotein cholesterol concentrations than nonhirsute women and are presumed to be at increased risk of coronary artery disease. However, definitive data linking androgen excess with coronary artery disease is lacking. We evaluated 102 women coming to coronary artery catheterization for signs and symptoms of androgen excess. Hirsutism was found more commonly in those women with confirmed coronary artery disease (chi 2 = 10.11). Waist:hip ratio (an index of android fat distribution) was associated with hirsutism (by ANOVA, F-test) and with coronary artery disease (t-test). The strongest associations were found in older women (aged greater than or equal to 60). Androgen excess in women may signal risk for coronary artery disease.

Acne Vulgaris↗
PubMed1990

Efficacy and safety of mercuric oxide in the treatment of bacterial blepharitis.

A double-masked, placebo-controlled, randomized study was done to assess the safety and clinical and quantitative microbiologic efficacy of 1% mercuric oxide (yellow) ophthalmic ointment in the treatment of eyelid infections, i.e., bacterial blepharitis. A total of 39 patients with bacterial counts and clinical signs indicative of eyelid infection were treated twice daily for 7 days. Clinical biomicroscopic examination and quantitative microbiologic cultures were done just prior to initiation of treatment and again on days 3 and 7. Statistical analysis revealed a significant improvement in the clinical signs, bacterial count, cure rate, and improvement rate for subjects taking the active medication, compared with those taking the placebo on days 3 and 7. In addition, the medication was well tolerated.

Adult↗
PubMed1990

The association of waist hip ratio and angiographically determined coronary artery disease.

Body fat distribution as measured by the ratio of waist circumference to hip circumference (WHR) is now accepted as an important risk factor for a number of diseases. This study evaluated the association of WHR and coronary artery disease (CAD). Measurements included the subjects' height, weight, waist girth, hip girth, significant CAD on coronary angiography, and cholesterol levels. A history of myocardial infarction, angina, diabetes or hypertension was obtained from subject interviews. The subjects were analyzed in two age groups: younger than age 60 (88 men and 39 women) and age 60 or older (85 men and 63 women). For older women the relative odds of CAD comparing women at the 75th percentile of WHR to women at the 25th percentile was 3.67 (P = 0.003), with a 95 percent confidence interval of 1.57-8.57. The relative odds was reduced to 2.80 after adjusting for all other risk factors. WHR was significantly associated with angiographic evidence of CAD in all women combined after adjusting for age (P = 0.0004), but it was not significantly associated with CAD in younger women or in men. The results suggest that in older women the risk of CAD increases with a greater percentage of body fat in the abdomen.

Adipose Tissue↗
PubMed1989

The inexact use of Fisher's Exact Test in six major medical journals.

We reviewed the use of Fisher's Exact Test in 71 articles published between 1983 and 1987 in six medical journals. Thirty-three of 56 selected articles did not specify use of a one- or two-tailed test, and 12 (36%) of these actually used the one-tailed test. Five (42%) of these 12 articles contained at least one table in which the standard significance level of P less than .05 was no longer met when a two-tailed analysis was run instead. Eleven (65%) of 17 articles with a statistical consultant compared with 10 (28%) of 36 articles without a consultant specified use of a one- or two-sided test. The use of Fisher's Exact Test without specification as a one- or two-tailed version may misrepresent the statistical significance of data. A uniform specification statement should be required for all manuscripts to correct such potential errors in interpretation.

Periodicals as Topic↗
PubMed1989

Quantitative analysis of the exercise tolerance test for determining the severity of coronary artery disease.

Results were compiled from the literature on the use of the exercise tolerance test to identify patients with severe coronary artery disease. Pooled estimates of sensitivity and specificity were derived for the ability of the exercise tolerance test to identify three-vessel or left main coronary artery disease. There was great variability among the studies examined in the estimated sensitivity and specificity of a given criterion for severe coronary artery disease. This variability could not be explained by reported variations in study design. The findings suggest that the accuracy of the exercise tolerance test and other tests cannot be properly interpreted without much greater detail presented in the literature on patient selection and test administration.

Coronary Disease↗
PubMed1989

Research collaboration.

The complexity and cost of cardiovascular medical care dictate research to deliver high quality and cost-conscious cardiovascular care. This goal is aided by modeling medical decision making. To be useful, the modeling must be based on real data so that the results can serve as a guide to actual practice. It is suggested that a registry of randomized clinical trials and larger data bases in cardiovascular disease and health care delivery be established. The registry would be a resource for those desiring to model decision making. The registry would contain key words allowing retrieval by modelers accessing the registry and would contain contact information for consideration of possible collaborative work. The initiation of such a registry should contain plans for its evaluation to determine whether the registry itself is a cost-effective tool to encourage the needed research.

Clinical Trials as Topic↗
PubMed1989

Mechanisms of intraocular pressure elevation after pars plana vitrectomy.

A prospective study of 222 consecutive patients undergoing pars plana vitrectomy was done to determine the incidence and mechanisms of postoperative intraocular pressure (IOP) elevation. Within 48 hours of surgery, postoperative IOP increased by at least 5 to 22 mmHg in 136 eyes (61.3%) and to 30 mmHg or more in 79 eyes (35.6%). Presumed mechanisms of open-angle glaucoma included intraocular gas expansion (28.4%), inflammatory trabecular meshwork obstruction (4.5%), silicone oil-related glaucoma (3.6%), and erythroclastic glaucoma (2.2%). Closed-angle mechanisms included pupillary block glaucoma (6.8%) and ciliary body edema (3.6%). Factors which were associated with postvitrectomy pressure elevation included placement of a scleral buckle, either intraoperatively (P = 0.003) or before vitrectomy (P = 0.001), intraoperative scatter endophotocoagulation (P = 0.041), intra-operative lensectomy (P = 0.024), and development of postoperative fibrin membranes (P = 0.038). Surgery was required to lower IOP or relieve pupillary block in 25 eyes (11.3%).

Adolescent↗
PubMed1989

Results of vitrectomy for diabetic traction retinal detachments using the en bloc excision technique.

En bloc excision is a technique in which fibrovascular diabetic membranes and the posterior hyaloid are separated from the retina as a single unit. In a consecutive series of 69 eyes with diabetic traction retinal detachment treated with this technique, initial retinal reattachment was accomplished in 100% (69/69) of the eyes. With a minimum of 6 months' follow-up, the retina remained completely attached in 83% (57/69) of eyes, while the macula was attached in 88% (61/69) of eyes. Final visual acuity was 5/200 or better in 71% (49/69) of eyes. While current surgical techniques allow a high rate of anatomic success in the repair of diabetic traction retinal detachment, visual results remain limited by irreversible alterations in retinal function.

Adolescent↗
PubMed1989

Factors associated with severity of symptoms in patients with chronic unexplained muscular aching.

Subjects with chronic, diffuse, unexplained muscular aching were recruited--21 from a primary care practice, nine from a rheumatology practice, and two from a pain clinic. No additional criteria were used to select subjects. Subjects with mild or moderate symptoms differed from those with severe symptoms with respect to the following characteristics: the presence of fatigue on awakening, the number of tender points, difficulty in sleeping, and the degree of tenderness in typical fibromyalgia areas as measured by a dolorimeter. These findings suggest that muscular aching is likely to be of greater severity if other symptoms or signs of fibromyalgia are also present.

Adult↗
PubMed1988

Intravitreal clearance of tissue plasminogen activator in the rabbit.

The clearance of tissue plasminogen activator (t-PA) injected into the midvitreous cavity was studied in the phakic, vitrectomized rabbit eye with and without intravitreal fibrin clots. The quantity and activity of t-PA in the vitreous, serum, and aqueous were determined at ten minutes and at 3, 6, 15, 24, and 48 hours after initial injection by an enzyme-linked immunosorbent assay (ELISA) and a spectrophotometric solid-phase fibrin assay (SOFIA). In eyes without an intravitreal fibrin clot, the estimated half-life for t-PA was 4.3 hours by SOFIA and 5.8 hours by ELISA. In eyes containing a vitreal fibrin clot, the half-life increased to 9.8 hours by SOFIA and 11.9 hours by ELISA. Both of these half-lives were significantly greater than the half-life for eyes without fibrin. Regardless of the presence of fibrin, intravitreal t-PA activity was significantly less than t-PA quantity, suggesting the presence of a t-PA inhibitor. A peak in aqueous t-PA occurred before six hours, indicating that t-PA was cleared in part through the anterior chamber. There was no measurable serum t-PA at any of the sampling times.

Animals↗
PubMed1988

A method of quantify confounding in regression analyses applied to data on diet and CHD incidence.

We present a method to display the results of linear regression when the independent variables are highly correlated. In this method the sum of squares of regression (SSR) for pairs of variables are partitioned into orthogonal and shared components. A shared component is the reduction in the SSR of one of the variables when the other variable is added to the regression equation. This method shows how the SSR for one variable depends on the other variables present in the regression equation and explains apparent inconsistencies between forward and backward stepwise regression. To demonstrate the potential usefulness of this method we reanalyzed previously reported data on the relationship between coronary heart disease (CHD) and diet. The analysis suggested that carbohydrate and alcohol intake are negatively associated with CHD because they are associated with greater caloric intake. Protein and fat intake are also associated with greater caloric intake, but in addition they are associated with factors that increase the risk of CHD.

Alcohol Drinking↗
PubMed1987

Brain metastasis in patients with superior sulcus tumors.

During a 20-year period, from 1963 to 1983, 68 patients were treated for carcinoma of the lung presenting in the superior sulcus. Their ages ranged from 41 to 79 years (median, 56 years). Thirty-six patients had squamous cell carcinoma, 13 had adenocarcinoma, 14 had large cell carcinoma, two had small cell carcinoma, and three had clinical diagnosis only. All tumors were considered to be inoperable or unresectable and were treated with external irradiation alone. The 3-year disease-free survival was 25%. Brain metastasis developed in 23 patients (34%); the brain was the first site of metastasis in 16 patients (24%), five of whom eventually developed other sites of metastasis. The cumulative probability of brain metastasis was 53% at 3 years. Brain metastases were seen in ten patients (28%) with squamous cell carcinoma, five patients (38%) with adenocarcinoma, seven patients (50%) with large cell carcinoma, and one patient without a histocytologic diagnosis. The proportion of patients younger than 60 years (19/41, 46%) who developed brain metastasis was significantly greater than that for patients 60 years or older (4/27, 15%) (P less than or equal to 0.01). Nine of 11 patients with metastasis only to the brain died as a consequence of the intracranial disease 1 to 13 months (median, 6 months) after the diagnosis of brain metastases. The other two patients received therapeutic irradiation to the entire brain and survived longer than 5 days after the whole-brain irradiation: one died at 62 months of intercurrent disease, and the other is alive and well 129 months after diagnosis. The high probability of brain metastasis from superior sulcus tumors, regardless of histopathologic type and the frequency with which the brain is the only site of clinical failure, suggest that systematic prophylactic cranial irradiation could reduce the morbidity and perhaps even contribute favorably to the survival of these patients.

Adult↗
PubMed1987

Undetected fibrositis in primary care practice.

The prevalence of symptoms related to fibrositis was investigated for patients seen in a primary care setting. Of 692 adult patients evaluated, 33 (4.6 percent) had symptoms of unexplained, chronic, diffuse muscular pain. Only three patients had been diagnosed as having fibrositis by their physician. Eighteen of 31 patients had symptoms sufficiently severe to interfere with their ability to perform their job or household chores. The percentages of these patients who met the fibrositis criteria ranged from 17 to 55 percent. These results suggest that unexplained, diffuse muscular aching is a common problem, that it is rarely diagnosed, and that the use of several criteria to define fibrositis excludes many patients with the typical primary symptoms.

Adult↗
PubMed1986

Usefulness of right ventricular diastolic collapse in diagnosing cardiac tamponade and comparison to pulsus paradoxus.

To compare the sensitivity, specificity and predictive value of right ventricular (RV) diastolic collapse and pulsus paradoxus as signs of cardiac tamponade, 21 consecutive patients with pericardial effusion and suspected cardiac tamponade underwent prospective hemodynamic and echocardiographic evaluation. Simultaneous hemodynamic and echocardiographic data were obtained in all patients before and after pericardiocentesis. Cardiac tamponade was considered present when there was diastolic equilibration of the intrapericardial, right atrial and pulmonary capillary wedge pressures and elevation of these pressures to more than 10 mm Hg. RV diastolic collapse was 93% sensitive and 100% specific in diagnosing cardiac tamponade, whereas pulsus paradoxus was only 79% sensitive and 40% specific. The positive and negative predictive values of RV diastolic collapse (100% and 83%) were considerably better than pulsus paradoxus (81% and 40%) and demonstrate that RV diastolic collapse is more sensitive, specific and predictive of cardiac tamponade than is pulsus paradoxus. Serial simultaneous hemodynamic and echocardiographic observations at multiple points during pericardiocentesis in a smaller subgroup (5 patients) also suggest that the hemodynamic effects of RV diastolic collapse in cardiac tamponade are mediated by an increase in intrapericardial pressure.

Adult↗
PubMed1986

Prognostic influence of TNM staging and LDH levels in small cell carcinoma of the lung (SCCL).

To better define the prognostic factors influencing the response to therapy and survival in small cell carcinoma of the lung (SCCL), an expanded "TNM" type staging system was developed and investigated in a series of 73 protocol treated patients. Because serum LDH levels at disease presentation have been correlated to disease extent, response to therapy, and treatment outcome in a number of malignancies, including SCCL, these interrelationships were also analyzed in the protocol patients. The TNM system was found to be a more descriptive and specific "shorthand" for denoting sites of involvement and for indicating the body burden of tumor than the traditional limited-extensive disease (LD-ED) system. A clear statistical advantage could not be shown over the LD-ED system for predicting chemotherapy response or survival, although there were trends suggesting the TNM system could divide patients into three prognostic subgroups. Serum LDH proved to be a useful index of disease extent and therapy outcome. LDH levels at presentation were proportionately higher with more extensive tumor, measured by either the LD-ED or TNM staging. High LDH predicted poorer responses to chemotherapy and lower survival within similar stage subgroups compared to patients with normal LDH levels. The negative effect of elevated LDH was independent of hepatic involvement and did not predict subsequent hepatic failure in any consistent way. The SCCL TNM staging system proposed needs further refinement and should be tested with larger patient numbers. LDH, along with other tumor markers recently identified, need to be integrated into the staging system to form an overall prognostic index.

Aged↗