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Biomedical subjects

R Vander Zwaag

Publications and source records attributed to R Vander Zwaag.

At least 19 recordsLinked to original sources
PubMed1997

Effect on survival of estrogen replacement therapy after coronary artery bypass grafting.

We examined the relation between postmenopausal estrogen placement therapy (ERT) and survival in 1,098 women who underwent coronary artery bypass grafting (CABG). Patients were selected for the study if their age was > or = 55 years at the time of preoperative coronary angiography or if they had previously undergone bilateral oophorectomy. Life-table analysis was used to compare survival after surgery in 92 women who received ERT and 1,006 women who did not. Five-year survival was 98.8% in the estrogen users and 82.3% in the non-users. Ten-year survival was 81.4% in the users and 65.1% in the nonusers (p = 0.0001 by Lee Desu test). The women who did not take estrogen were significantly older (p < 0.001), had more vessels with significant stenosis (p = 0.033), lower ejection fractions (p = 0.051), and more prior myocardial infarctions (p = 0.054). However, a Cox proportional-hazards model selected the number of coronary arteries narrowed (RR 1.43, p < 0.0001), estrogen use (RR 0.38, p = 0.001), left main coronary stenosis (RR 1.83, p = 0.001), and diabetes mellitus (RR 1.57, p = 0.003) as the significant independent predictors of survival. These data suggest that ERT improves survival significantly after CABG in postmenopausal women with coronary artery disease.

Case-Control Studies↗
PubMed1995

Impact of the Crohn's-like lymphoid reaction on staging of right-sided colon cancer: results of multivariate analysis.

The presence of lymphoid aggregates within the muscularis propria or pericolic fibroadipose tissue apposing invasive colorectal carcinoma, termed the Crohn's-like lymphoid reaction, has been related to improved patient length of survival according to univariate statistical analysis. We tested the Crohn's-like lymphoid reaction as an indicator of prognosis in a multivariate statistical analysis of 344 resected right-sided colonic cancers. Improved 5-year survival in univariate analysis was associated with low tumor grade, regular tubule configuration, expanding tumor growth pattern, prominent peritumoral lymphocytic infiltration, absence of tumoral invasion of extramural veins, all levels of intramural and extramural invasion short of widespread local tumor permeation, conspicuous Crohn's-like lymphoid reaction, and absence of both nodal metastasis and nodal-independent tumor nodules in pericolic fat. By the Cox proportional hazard model using the stepwise method, depth of tumor invasion, lymph node metastasis, Crohn's-like lymphoid reaction, and metastatic tumor nodules in pericolic fat retained independent prognostic significance. Combining the four variables to formulate pathological prognostic categories yielded a highly favorable prognostic group-92% 5-year survival and 95% confidence limits (88% to 96%)--encompassing 53% of the study population. It included all Dukes' stage A carcinomas, 66% of Dukes' stage B adenocarcinomas, and 11% of Dukes' stage C cancers. Lymph node metastases coupled with intramural and extramural extent of tumor invasion are the cornerstones of colorectal cancer staging. Addition of other variables improves prognostication for the cecum and ascending colon. From this study the Crohn's-like lymphoid reaction and metastatic tumor nodules in pericolic fat emerge as significant independent indicators of prognosis for right-sided colon cancer. Complex correlations of both indicators with nonselected variables were observed.

Adenocarcinoma↗
PubMed1995

The effect of noncritical coronary artery disease on long-term survival.

This study was designed to determine the impact of noncritical (less than 70% narrowing of the luminal diameter) coronary stenoses on the long-term survival rate of patients with coronary artery disease. The survival rate of 3,342 patients with normal coronary arteries (Group 1A) was compared with that of 2,184 patients with only noncritical stenoses (Group 1B). Similarly, the survival rate of 1,128 patients with one or more critical lesions (Group 2A) was compared with that of 5,944 cases with noncritical plus critical lesions (Group 2B). Patients with noncritical lesions had significantly lower 10-year survival rates (85.8%) than did those with normal coronary arteries (90.1%). However, the difference in survival rate was attributable to older age, male sex, and higher prevalence of cigarette smoking, diabetes mellitus, and hypertension in Group 1B than in Group 1A; presence of noncritical stenoses was not a statistically significant independent determinant of survival. Long-term survival rates of the patients with one or more critical lesions (Group 2A) were equivalent to that of patients with critical stenoses plus one or more noncritical lesions (Group 2B). Therefore, 1) patients with only noncritical stenoses have more risk factors for coronary artery disease than do those with normal coronary arteries; 2) these patients have a reduced long-term survival rate that reflects these risk factors rather than the presence of noncritical lesions; and 3) in patients with critical lesions, the presence of additional non-critical stenoses does not affect the long-term survival rate.

Adult↗
PubMed1995

Long-term survival of patients with coronary artery disease during the 1970s. A cohort study.

STUDY OBJECTIVE: This study was undertaken to determine the effects of altered risk factors and treatment modalities on the short- and long-term survival of patients with documented coronary artery disease whose conditions were diagnosed from 1972 through 1982. STUDY DESIGN: The study was a retrospective database analysis of clinical, angiographic, and follow-up information. SETTING: Data from all patients referred for cardiac catheterization at the Baptist Memorial Hospital, Memphis, Tenn, were studied. PATIENTS: Risk factors and survival of patients who underwent cardiac catheterization from 1972 through 1982 and who were followed up for at least 5 years were evaluated. Cohort A included 1,821 patients studied from 1972 through 1977; cohort B included 5,369 patients studied between 1977 and the end of 1982. Each cohort was subdivided based on type of therapy (medical or surgical) that the patients received. MEASUREMENTS AND RESULTS: The 30-day (short-term) and 5-year (long-term) survival rates were compared by life table methods. Short-term survival improved significantly in both medical (from 94.9% to 97.5%, p < 0.001) and surgical (from 95.5% to 97.6%, p < 0.001) groups from cohort A to cohort B. Long-term survival, however, did not differ significantly between the two cohorts. In the medical group, 5-year survival in cohort A was 86.3% and in cohort B it was 86.9% (p = NS); in the surgical group, cohort A it was 89.1% while in cohort B it was 89.4% (p = NS). Prevalence of both cigarette smoking and hypercholesterolemia declined significantly from cohort A to cohort B in both surgical and medical groups. However, advanced age, female gender, and previous myocardial infarction were significantly more common in cohort B than in cohort A for both treatment groups. CONCLUSIONS: These results indicate that during the study period, a significant decline in short-term mortality occurred for patients with angiographically documented coronary artery disease. Long-term survival did not, however, improve possibly due to a complex interplay between factors that promote coronary artery disease, eg, cigarette abuse and hypercholesterolemia, and factors that determine survival, eg, increase in age and history of prior infarction and advances in medical and surgical therapy.

Aged↗
PubMed1994

From Dukes through Jass: pathological prognostic indicators in rectal cancer.

In the recently described Jass staging system for resected adenocarcinoma of the rectum, peritumoral lymphocytic infiltration and tumor growth pattern are introduced as significant indicators of prognosis in conjunction with depth of tumor invasion and lymph node metastasis. The authors of this study have tested the applicability of the Jass system by reviewing 348 resected rectal cancers for 12 pathological variables, including two newly recognized features, namely the Crohn's-like lymphoid reaction and metastatic tumor nodules in pericolic fat. By univariate analysis improved 5-year survival rate was associated with tubular-type adenocarcinoma, low tumor grade, retention of tubule configuration and nuclear polarity, expanding tumor growth pattern, prominent peritumoral lymphocytic infiltration, absence of extramural vein invasion by tumor, all levels of intramural and extramural invasion short of widespread local tumor dissemination, a Crohn's-like lymphoid reaction pattern, and absence of both nodal metastasis and tumor nodules in perirectal fat. By Cox stepwise proportional hazards analysis, depth of tumor invasion, lymph node metastasis, Crohn's-like lymphoid reaction, and extramural venous invasion retained independent prognostic significance. Peritumoral lymphocytic infiltration and tumor growth pattern of the Jass staging system failed to compete successfully with other variables in the proportional hazards model, in part because of their correlation with the model's selected variables. Both intramural and extramural extent of tumor invasion coupled with lymph node metastasis form the cornerstones of rectal cancer staging. However, other factors do refine prognostication. From this study the Crohn's-like lymphoid reaction emerges as a significant new independent indicator of prognosis for survival from rectal cancer. Although the Crohn's-like lymphoid reaction and extramural vein invasion took precedence as staging variables in this study, a complex interrelationship with other parameters was observed.

Adenocarcinoma↗
PubMed1994

Eccentric and concentric muscle performance in patients with spastic paresis secondary to motor neuron disease. A preliminary report.

This study investigated the potential value of eccentric (ECC) and concentric (CONC) isokinetic testing for quantifying motor deficit in patients with spastic paresis secondary to motor neuron disease. We hypothesized that, at a moderately fast (120 degrees s-1) angular velocity, spastic patients would demonstrate different ECC-CONC torque relationships from healthy controls or patients with non-spastic neuromuscular disorders. Eleven patients with motor neuron disease having clinical evidence of spasticity, and 11 disease-control patients (with non-spastic disorders, e.g. lower motor neuron disease or myopathy) underwent isokinetic testing. One healthy subject was matched to each of the 22 patients. The average torque generated during maximal voluntary ECC and CONC knee flexion (KF) and extension (KE) was measured using an isokinetic dynamometer (Kin-Com). Reliability was established (all ICC > or = 0.97) for patient torque measurements. Relative strength (% of control subject torque) in spastic patients was significantly higher for ECC than for CONC actions in both KF and KE; conversely, in non-spastic disease-control patients relative strength was not affected by the type of muscle action. The ECC/CONC average torque ratios for KE and KF at 120 degrees s-1 were significantly greater in spastic patients than controls, but did not differ from controls in non-spastic patients. In spastic patients the ECC-CONC imbalances were related to ambulatory dysfunction. In four spastic patients followed with serial testing, the disproportion between ECC and CONC voluntary capacity persisted over time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Myocardial viability assessment with dynamic low-dose iodine-123-iodophenylpentadecanoic acid metabolic imaging: comparison with myocardial biopsy and reinjection SPECT thallium after myocardial infarction.

Aggressive cardiac revascularization requires recognition of stunned and hibernating myocardium, and cost considerations may well govern the technique used. Dynamic low-dose (1 mCi) [123I]iodophenylpentadecanoic acid (IPPA) metabolic imaging is a potential alternative to PET using either 18FDG or 15O-water. Resting IPPA images were obtained from patients with severe ischemic cardiomyopathy, and transmural myocardial biopsies were obtained during coronary bypass surgery to confirm viability. Thirty-nine of 43 (91%) biopsies confirmed the results of the IPPA images with a sensitivity for viability of 33/36 (92%) and a specificity of 6/7 (86%). Postoperatively, wall motion improved in 80% of IPPA-viable, dysfunctional segments. Furthermore, when compared to reinjection thallium (SPECT-TI) scans after myocardial infarction, IPPA-SPECT-TI concordance occurred in 27/35 (77%) (K = 0.536, p = 0.0003). Similar to PET, IPPA demonstrated more viability than SPECT-TI, 26/35 (74%) versus 18/35 (51%) (p = 0.047). Metabolic IPPA cardiac viability imaging is a safe, inexpensive technique that may be a useful alternative to PET.

Adult↗
PubMed1993

The pagetoid variant of urothelial carcinoma in situ.

The frequency, distribution, and clinical significance of pagetoid changes in urothelial carcinoma in situ (CIS) were studied in over 600 tissue slides from 102 patients followed for a mean period of over 4 years. Results indicate that pagetoid changes are unusual, randomly distributed, and never widespread. These changes occur in a histologic setting of CIS and apparently never appear as the initial lesion, even in cases in which CIS is the primary or only neoplasm. Patients manifesting pagetoid CIS had essentially the same progression and survival rates as patients without pagetoid changes. Our data suggest that this histologic pattern represents a peculiar reaction to injury confined to small areas of urothelium in susceptible hosts.

Adult↗
PubMed1992

Racial differences in coagulation studies in stroke.

Racial differences in stroke are known to exist with persons in the black race having a higher morbidity, mortality and incidence of stroke compared to whites. We evaluated coagulation factors in black and white stroke patients and compared the results between races. D-dimer was elevated more frequently in blacks than whites to a statistically significant degree. There were non-significant trends for blacks to have a positive lupus anticoagulant, low protein C and protein S, higher platelet factor 4, and hyporesponsive platelets to 10 microM epinephrine. The significance of these findings in understanding racial differences in stroke is discussed.

Aged↗
PubMed1991

Adenocarcinoma of the stomach with invasion limited to the muscularis propria.

Adenocarcinoma of the stomach having invasion limited to the muscularis propria with or without lymph node metastasis, termed PM (proper muscle) gastric cancer by Japanese investigators, has a prognosis superior to that of carcinoma extending to the serosa and approaching that of early gastric cancer in Japan. To evaluate the occurrence and significance of PM gastric cancer in the United States, we analyzed 272 gastric carcinomas resected at our institution between 1964 and 1983. Forty-two PM cancers (15%) were identified. Improved 5-year survival rate was noted for PM cancer when compared with survival rate for 215 neoplasms exhibiting serosal invasion (29% versus 7%, P less than 0.001). In univariate analysis, a survival advantage was also associated with absence of lymph node metastasis, intestinal-type histopathology of the Lauren classification, the expanding pattern of the Ming classification, and polypoid or fungating gross configuration of tumor. In multivariate analysis, depth of tumor invasion remained significantly associated with improved 5-year survival rate independently of other variables, including lymph node metastasis. Using continuous survival curves, the prognostic significance of PM cancer prevailed throughout the 5-year postgastrectomy interval. Our data indicate that PM gastric cancer occurs in the United States and need not be considered "advanced" gastric carcinoma; depth of tumor invasion should be recognized as a nodal metastasis-independent prognosticator of gastric cancer survival.

Adenocarcinoma↗
PubMed1991

Case-control study of coronary heart disease risk factors in the elderly.

We undertook a case-control study utilizing a large coronary arteriography database to determine if traditional cardiovascular risk factors are as predictive of the presence of angiographically-proven coronary artery disease (CAD) in elderly patients as in younger patients. Among the patients aged 65 years or more, there were 2120 cases and 193 controls, while for the patients aged 35-49 years there were 1493 cases and 707 controls. Odds ratios obtained from logistic regression indicated that age, male sex, diabetes, cigarette smoking, hypertension, total cholesterol and left ventricular hypertrophy were all significant risk factors for CAD in both age groups, although the odds ratios tended to be somewhat lower in the elderly. Logistic regression analysis for gender subgroups generally revealed similar findings when compared with the combined (males + females) age groups, although power was limited for the subgroup of elderly males which had few controls. We conclude that most of the traditional cardiovascular risk factors which have been described as correlated with the presence of CAD in younger populations are also correlated with angiographically-proven CAD in older patients.

Adult↗
PubMed1991

Efficacy of high voltage pulsed current for healing of pressure ulcers in patients with spinal cord injury.

The purpose of this study was to assess the efficacy of high voltage pulsed direct current (HVPC) for healing of pressure ulcers in patients with spinal cord injury. Seventeen patients having pressure ulcers in the pelvic region were randomly assigned to either an HVPC group or a placebo HVPC group. Treatments were given for 1 hour a day for 20 consecutive days. The HVPC protocol consisted of an aluminum-foil electrode placed over the ulcer and set at negative polarity in reference to the dispersive electrode placed on the thigh. Stimulator frequency was set at 100 pps, and an intensity of 200 V was used. Measurements of ulcer surface area were conducted before treatment and after treatment days 5, 10, 15, and 20. To measure ulcer area (in square millimeters), slides taken at each measurement time were projected at actual size, traced, and digitized. Percentage of change compared with pretreatment ulcer size was calculated for each measurement time. Ulcers in the HVPC group demonstrated significantly greater percentage-of-change decreases from their pretreatment size than did ulcers in the placebo group at days 5, 15, and 20. The results suggest that HVPC, in conjunction with good nursing care, can significantly increase the healing rate of pelvic ulcers in patients with spinal cord injury.

Adolescent↗
PubMed1991

Suture adjustment for postkeratoplasty astigmatism.

Excessive corneal astigmatism following penetrating keratoplasty is a frequent problem. A technique that adjusts a single running 10-0 nylon suture after keratoplasty was used in this series of patients. The procedure requires a keratometer, slitlamp, topical anesthesia, and tying forceps. In 52 eyes, with an average of 10.0 diopters of keratometric astigmatism, we adjusted the suture to flatten the steep corneal axis. We were able to reduce astigmatism an average of 7.2 diopters and this remained stable three months post wound revision.

Adult↗
PubMed1990

Clinical and pathophysiologic correlates of ST-T-wave abnormalities in coronary artery disease.

Clinical, hemodynamic and coronary angiographic data from 9,801 patients were evaluated to determine the correlates of ST-segment depression, with or without T-wave inversion, on the resting routine electrocardiogram. The relative risk (RR) of having a measured clinical or angiographic variable was computed whether or not ST-T-wave abnormalities were observed. ST-segment depression was seen significantly more often in subjects greater than 55 years of age (RR = 1.4) who were women (RR = 1.3) or nonwhite (RR = 1.5), were hypertensive (RR = 1.8), had diabetes mellitus (RR = 1.6) or who smoked cigarettes (RR = 1.5). Angiographic findings related to presence of ST-T-wave abnormalities included severe coronary obstruction (less than 70%), higher number of diseased vessels, and the presence of obstruction in the left anterior descending coronary artery. In a multivariate model, the most significant correlates of ST-T-wave abnormalities were presence of left ventricular contraction abnormality, followed by age, gender, presence of left anterior descending coronary artery disease, elevated end-systolic volume index, and a diagnosis of hypertension. Thus, electrocardiographic ST-T abnormalities has specific and significant clinical and pathophysiologic correlates.

Cardiac Catheterization↗
PubMed1990

Vaginal radiation brachytherapy to reduce central recurrence after radical hysterectomy for cervical carcinoma.

Seventeen (17%) of one hundred and two patients were treated with radiation brachytherapy (without external-beam therapy) to the proximal vagina to reduce the possibility of central pelvic recurrence following radical hysterectomy for cervical carcinoma. The 17 were considered to be at greater risk of developing recurrent cancer in the central pelvis because the cancer invaded halfway through the cervix; however, no lesions extended beyond the cervix, nor were metastases to lymph nodes present or surgical margins involved. The brachytherapy treatment was evaluated for prevention of central pelvis recurrence and for related complications. The 17 women treated with radiation brachytherapy were also compared with 74 patients who did not receive brachytherapy after radical hysterectomy because their cancers were smaller and did not invade halfway through the cervix. Both groups were similar with respect to age (41 and 40 years, respectively), weight (69.5 and 65.9 kg), operative characteristics, and the proportions of squamous cell carcinoma and adenocarcinoma. Recurrences have not been observed among the patients treated with brachytherapy during a mean follow-up of 39 months (range, 9-92 months). No complications were attributed to the brachytherapy. However, two patients with large tumors refused adjuvant brachytherapy and suffered central pelvic recurrences. Brachytherapy in selected patients following radical hysterectomy was safely administered and appeared to reduce the risk of central pelvic recurrence.

Adenocarcinoma↗
PubMed1990

Interactive effects of age and other risk factors on long-term survival after coronary artery surgery.

The effect of age at the time of coronary artery bypass graft surgery on postoperative survival was studied in 2,507 patients with significant coronary artery disease. Patients were subdivided into five groups based on age at the time of surgery: 20 to 39, 40 to 49, 50 to 59, 60 to 69 and greater than or equal to 70 years. The observed death rate was compared with that expected for subjects from the general U.S. population matched for age, gender, race and calendar year. For patients less than or equal to 59 years of age, the ratio of observed to expected death rates was significantly greater than unity (observed/expected = 4.9 for ages 20 to 39, 1.9 for ages 40 to 49 and 1.3 for ages 50 to 59 years, p less than 0.01). The prevalence of risk factors, including diabetes mellitus, hypertension, hypercholesterolemia and cigarette smoking, was evaluated in the different age subgroups. When patients were subdivided on the basis of history of cigarette smoking, the decreased relative survival rate of younger (less than 60 years old) patients existed only in those who smoked (observed/expected = 6.0 for ages 20 to 39, 2.2 for ages 40 to 49 and 1.4 for ages 50 to 59 years). In nonsmokers, observed/expected ratios for every age group were not significantly different from unity. Thus, the reduced relative survival rate of younger patients after coronary artery bypass graft surgery may be attributed to the interactive harmful effects of cigarette smoking.

Adult↗
PubMed1990

Estrogen replacement and coronary artery disease. Effect on survival in postmenopausal women.

The relationship among postmenopausal estrogen use, coronary stenosis, and survival was examined retrospectively in 2268 women undergoing coronary angiography. The patients were selected for study if their age was 55 years or older at the time of angiography or if they had previously undergone bilateral oophorectomy. Postmenopausal estrogen use in 1178 patients with coronary artery disease (greater than 70% stenosis) and 644 patients with mild to moderate coronary artery disease (5% to 69% stenosis) was compared with 446 control subjects (0% stenosis) using life-table analysis. Over 10 years of follow-up, there was no significant difference in survival among patients initially free of coronary lesions on arteriography who had either never used (377) or ever used (69) estrogens. Among patients with mild to moderate coronary stenosis, 10-year survival of those who had never used estrogens was 85.0% and it was 95.6% among 99 "ever users." Survival was 60.0% among those with more than 70% coronary stenosis who had never used estrogen and it was 97.0% among 70 ever users. The "never users" group were older (65 vs 59 years), had a lower proportion of cigarette smokers (40% vs 57.1%), a higher proportion of subjects with diabetes (21.7% vs 12.9%) and hyperlipidemia (58% vs 44%), and approximately equal numbers of hypertensives (56.0% vs 54.3%). Cox's proportional hazards model was used to estimate survival as a function of multiple covariables. Estrogen use was found to have a significant, independent effect on survival in women. We conclude that estrogen replacement after menopause prolongs survival when coronary artery disease is present, but it has less effect in the absence of coronary artery disease.

Aged↗