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Biomedical subjects

P Hall

Publications and source records attributed to P Hall.

At least 91 records · Page 5Linked to original sources
PubMed1997

Incidence of primary malignancies other than breast cancer among women treated with radiation therapy for benign breast disease.

This report presents data on the long-term risks of developing malignancies other than breast cancer after exposure to scattered doses of ionizing radiation. The estimates were based on a cohort of 3,090 women who were diagnosed clinically with benign breast disease between 1925 and 1961. A total of 1,216 women were treated with radiation therapy. The breasts received a mean absorbed dose of 5.84 Gy. Mean absorbed doses owing to scatter to 14 other organs were also determined. The lung received the highest mean scattered dose (0.75 Gy; range 0.004-8.98 Gy) and rectum the lowest (0.008 Gy; range 0-0.06 Gy). Median age at first exposure was 40 years. The follow-up lasted up to 61 years after treatment (mean follow-up 27 years). End-point data were obtained from population-based registers. With internal reference the relative risk for non-breast solid tumors was 1.2 (95% confidence interval 1.0-1.5). However, this excess was not apparent when comparison with the general population was made (standardized incidence ratio = 0.95; 95% confidence interval 0.84-1.07). Among individual sites no significantly increased risks were observed. For stomach cancer there was a linear increase with dose (ERR/Gy = 1.3; two-sided P = 0.05). No increased risk was observed for leukemias. In two earlier reports, breast cancer incidence has been shown to be significantly increased in this cohort of irradiated women. Our results suggest that the scattered doses from the breast irradiation may have increased the risk of cancers of other sites, but the small number of cases in different locations precludes strong interpretations.

Breast Diseases↗
PubMed1996

A randomized comparison of combined ticlopidine and aspirin therapy versus aspirin therapy alone after successful intravascular ultrasound-guided stent implantation.

BACKGROUND: Previous studies have shown that it is feasible to withhold anticoagulation after a successful intracoronary stent procedure with a low incidence of stent thrombosis. The importance of specific antiplatelet agents when stenting is performed without anticoagulation is unknown. METHODS AND RESULTS: After successful intravascular ultrasound-guided stenting, 226 patients were randomly assigned to receive either aspirin therapy alone (n = 103) or a combination of ticlopidine and short-term aspirin therapy (n = 123). Primary angiographic and clinical end points were stent thrombosis, death, myocardial infarction, the need for postprocedure coronary artery bypass surgery or repeated angioplasty, and significant medication side effects requiring termination of the medication within the first month of a successful procedure. At 1 month, the rate of stent thrombosis was 2.9% in the aspirin only group and 0.8% in the ticlopidine-aspirin group (P = .2). Cumulative major clinical events after successful stenting occurred in 3.9% of the patients in the aspirin group and in 0.8% in the ticlopidine-aspirin group (P = .1). There were no medication side effects in the aspirin group; in the combined ticlopidine-aspirin group, medication side effects occurred in 3 patients (P = .2). CONCLUSIONS: At 1 month, there was no difference in the incidence of stent thrombosis or other clinical end points between the two poststent antiplatelet regimens. However, the relatively small size of the study and the low incidence of thrombosis events may have contributed to the failure to detect differences in angiographic and clinical end points between the two groups.

Aged↗
PubMed1996

Implantation of the peripheral Wallstent for diffuse lesions in coronary arteries and vein grafts.

The Wallstent (Schneider, Bulach, Switzerland) is available in different lengths without much compromise in flexibility and radial support compared to some other stents. We treated 24 patients (26 vessels) with diffuse coronary lesions or vein graft lesions with intravascular ultrasound-guided peripheral Wallstent implantation. Average balloon pressure during stent optimization was 16.4 +/- 2.7 atm. The stents could be successfully implanted in 24 vessels. Minimal lumen diameter and percent diameter stenosis after stenting were 3.60 +/- 0.62 mm and -8 +/- 13%, respectively. Average stent length was 63.7 +/- 22.7 mm. There was one procedure-related complication. After stenting, all patients were treated only with antiplatelet agents. During 1-month follow-up, there was one subacute stent thrombosis due to incomplete coverage of a distal dissection. These preliminary results show the feasibility of this novel approach in selected lesions.

Adult↗
PubMed1996

Acute recoil of Palmaz-Schatz stent: a rare cause of suboptimal stent implantation--report of two cases with intravascular ultrasound findings.

It is generally believed that the Palmaz-Schatz stent maintains a strong radial force, preventing stent recoil. However, the capacity to prevent recoil is largely governed by the hardness or resistance of the lesion. We report two cases of "acute Palmaz-Schatz stent recoil," documented by intravascular ultrasound, and suggest a novel treatment of this unusual problem.

Angioplasty, Balloon, Coronary↗
PubMed1996

Gender differences in the relation between interview-derived hostility scores and resting blood pressure.

We examined the correlations between Structured Interview (SI)-derived hostility scores and resting blood pressure (BP) to see if they would be the same or different for healthy men and women. Standard risk factor information and resting BP measures were obtained from 193 undergraduates (109 men, 84 women), who underwent the SI. Subjects were rated for Potential for Hostility, Hostile Style, Intensity and Content, and completed Antagonism and Neuroticism scales. As expected, SI hostility scores were related to higher resting SBP in men, however; in women, they were related to lower resting SBP and Neuroticism. Regression analyses controlling for standard CHD risk factors indicated that SI-derived hostility predicted resting SBP and hypertensive status in both men and women, though in opposite directions. Thus, SI-derived hostility may assess a different construct in women than in men.

Arousal↗
PubMed1996

Thyroid cancer after diagnostic administration of iodine-131.

To provide quantitative data on the risk of thyroid cancer after exposure to 131I, 34,104 patients administered 131I for diagnostic purposes were followed for up to 40 years. The mean thyroid dose was estimated as 1.1 Gy, and 67 thyroid cancers occurred in contrast to 49.7 expected (standardized incidence ratio = 1.35; 95% confidence interval 1.05-1.71). Excess cancers were apparent only among patients referred because of a suspected thyroid tumor, and no increased risk was seen among those referred for other reasons. Further, risk was not related to radiation dose to the thyroid gland, time since exposure or age at exposure. The slight excess of thyroid cancer thus appeared to be due to the underlying thyroid condition and not radiation exposure. Among those under age 20 years when 131I was administered, a small excess risk (3 cancers compared to 1.8 expected) was about 2-10 times lower than that predicted from data for the A-bomb survivors. These data suggest that protraction of dose may result in a lower risk than an acute X-ray exposure of the same total dose.

Adolescent↗
PubMed1996

Thyroid nodularity after diagnostic administration of iodine-131.

In contrast to external X and gamma radiation, radiation from internally deposited 131I has not been clearly shown to cause thyroid tumors or nodules. Given the wide use of 131I in medicine and concern about health risks associated with the release of radioiodines from nuclear reactors, more information is needed. The purpose of this study was to evaluate the risk of thyroid nodularity among women previously exposed to radioiodine (131I) for diagnostic reasons. A clinical examination survey, including thyroid palpation, was conducted for a sample of women drawn from a cohort of patients exposed to 131I and a comparison group of women attending a mammography screening clinic. The study was conducted during 1991-1993 at Radiumhemmet, Karolinska Hospital, Stockholm, Sweden. A total of 1,005 women referred for a thyroid scintigraph or tracer test during the period 1952-1977 were included in the study. For comparison, 248 nonexposed women attending a mammography screening clinic were also enrolled. The primary outcome measure was the presence or absence of palpable thyroid nodules at the time of the clinical examination. Odds ratios were used as estimates of relative risk (RR). The mean dose to the thyroid from 131I was 0.54 Gy, and the average age at 131I administration was 26 years. The prevalence of thyroid nodularity was 10.6% among women who had been exposed to 131I and 11.7% among the nonexposed women [RR = 0.9; 95% confidence interval (CI) 0.6-1.4]. When analysis was restricted to women exposed to 131I, prevalence was associated positively with thyroid dose (excess RR = 0.9 per Gy; 95% CI 0.2-1.9). However, the excess RR was similar for women exposed before age 20 years and those exposed after age 20, which is contrary to findings for populations exposed to external radiation. While results demonstrated a positive association between diagnostic administration of 131I and the subsequent occurrence of thyroid nodules, it is unclear whether the association is causal, as the possibility of confounding by indication for 131I administration cannot be ruled out. No tumors that were subsequently diagnosed as cancer were found during the thyroid examinations, which supports the view that exposure to 131I administered for diagnostic reasons during adulthood rarely causes thyroid cancer.

Adolescent↗
PubMed1995

Non-Hodgkin's lymphoma and skin malignancies--shared etiology?

The Stockholm-Gotland Cancer Register was used to evaluate the clinical observation that patients with non-Hodgkin's lymphoma (NHL) had an increased risk of malignant melanoma or squamous-cell carcinoma of the skin (SCCS) and vice versa. During 1958-1992, NHL was diagnosed in a total of 6,176 patients. Of these patients, 504 developed a second primary cancer of any type except NHL, compared to 301.9 expected, giving a standardized incidence ratio (SIR) of 1.7 [95% confidence interval (CI) 1.5-1.8]. The risk of SCCS and malignant melanoma in patients with NHL was 4.8 (95% CI 3.6-6.2; n = 54) and 1.7 (95% CI 0.8-3.1; n = 10), respectively. The hazard risk for a second malignancy was relatively constant over time, whereas the skin malignancies revealed the highest risks 3-10 years after initial diagnosis. Similarly, the risk of a secondary NHL was studied in patients with malignant melanoma and SCCS during the same period and found to be 1.3 (95% CI 0.8-2.1; n = 17) and 1.8 (95% CI 1.2-2.5; n = 34), respectively. The highest risk for NHL following malignant melanoma was seen 3-10 years after first diagnosis, while the highest risk following SCCS was observed 0-2 years after initial diagnosis. One of several possible explanations or the development of NHL and a skin malignancy in the same patient is an immunological defect caused by sun exposure.

Aged↗
PubMed1995

Intracoronary stenting without anticoagulation accomplished with intravascular ultrasound guidance.

BACKGROUND: The placement of stents in coronary arteries has been shown to reduce restenosis in comparison to balloon angioplasty. However, clinical use of intracoronary stents is impeded by the risk of subacute stent thrombosis and complications associated with the anticoagulant regimen. To reduce these complications, the hypothesis that systemic anticoagulation is not necessary when adequate stent expansion is achieved was prospectively evaluated on a consecutive series of patients who received intracoronary stents. METHODS AND RESULTS: From March 1993 to January 1994, 359 patients underwent Palmaz-Schatz coronary stent insertion. After an initial successful angiographic result with < 20% stenosis by visual estimation had been achieved, intravascular ultrasound imaging was performed. Further balloon dilatation of the stent was guided by observation of the intravascular ultrasound images. All patients with adequate stent expansion confirmed by ultrasound were treated only with antiplatelet therapy (either ticlopidine for 1 month with short-term aspirin for 5 days or only aspirin) after the procedure. Clinical success (procedure success without early postprocedural events) at 2 months was achieved in 338 patients (94%). With an inflation pressure of 14.9 +/- 3.0 atm and a balloon-to-vessel ratio of 1.17 +/- 0.19, optimal stent expansion was achieved in 321 of the 334 patients (96%) who underwent intravascular ultrasound evaluation, with these patients receiving only antiplatelet therapy after the procedure. Despite the absence of anticoagulation, there were only two acute stent thromboses (0.6%) and one subacute stent thrombosis (0.3%) at 2-month clinical follow-up. Follow-up angiography at 3 to 6 months documented two additional occlusions (0.6%) at the stent site. At 6-month clinical follow-up, angiographically documented stent occlusion had occurred in 5 patients (1.6%). At 6-month clinical follow-up, there was a 5.7% incidence of myocardial infarction, a 6.4% rate of coronary bypass surgery, and a 1.9% incidence of death. Emergency intervention (emergency angioplasty or bailout stent) for a stent thrombosis event was performed in 3 patients (0.8%). The overall event rate was relatively high because of intraprocedural complications that occurred in 16 patients (4.5%). Intraprocedural complications, however, decreased to 1% when angiographically appropriately sized balloons were used for final stent dilations. There was one ischemic vascular complication that occurred at the time of the procedure and one ischemic vascular complication that occurred at the time of angiographic follow-up. By 6 months, repeat angioplasty for symptomatic restenosis was performed in 47 patients (13.1%). CONCLUSIONS: The Palmaz-Schatz stent can be safely inserted in coronary arteries without subsequent anticoagulation provided that stent expansion is adequate and there are no other flow-limiting lesions present. The use of high-pressure final balloon dilatations and confirmation of adequate stent expansion by intravascular ultrasound provide assurance that anticoagulation therapy can be safely omitted. This technique significantly reduces hospital time and vascular complications and has a low stent thrombosis rate.

Adult↗
PubMed1995

Rwanda.

Explore the source record for details and available documents.

Adolescent↗
PubMed1995

Techniques for Palmaz-Schatz stent deployment in lesions with a large side branch.

Palmaz-Schatz coronary stent implantation in lesions with a large side branch are reported. The first case describes how to manage plaque shifting after stent implantation. The second and third cases demonstrate a kissing balloon predilatation and stent dilatation technique of a bifurcational lesion. The final case demonstrates a stent implantation technique through the stent struts of a previously deployed stent.

Aged↗
PubMed1995

What does potential for hostility measure? Gender differences in the expression of hostility.

We examined the construct validity of Potential for Hostility (PH) for healthy undergraduate males and females. In Study 1, 45 males and 76 females were rated for PH. Subjects then completed the Cook Medley Hostility Scale (Ho) and a trait negative affectivity (NA) scale. For males, PH correlated with Cynicism, a subscale of the Ho, but was unrelated to NA. However, for females, PH was unrelated to self-reported hostility and minimally related to NA. In Study 2, 52 males and 91 females again were rated for PH in addition to state NA; subjects also provided self-reported state NA and PH measures. For males, convergence was found between observed and self-reported PH scores, but no such relation was found for females; only self-reported and observed state NA predicted females' PH rating. Thus, the Structured Interview method of hostility assessment may not be measuring the same hostility construct in females as it is in males.

Adolescent↗
PubMed1995

A long-term study of the interaction between iron and alcohol in an animal model of iron overload.

BACKGROUND/AIMS: The hypothesis that chronic alcohol ingestion potentiates iron-associated liver injury was investigated in the 'carbonyl iron-overload rat model'. METHODS: Newborn male and female Wistar-Furth rats (seven per group) were used to investigate iron-alcohol interaction over a 26-week period. Groups 1 and 2 were iron loaded from birth, while the others received normal diet. At 10 weeks all rats commenced Lieber-DeCarli liquid diet; additional treatments were: group 1 6 g carbonyl iron/1000 ml diet plus alcohol; group 2 carbonyl iron in the liquid diet; group 3 alcohol in the liquid diet; group 4, the controls, received liquid diet only. RESULTS: This study confirmed our previous observation that iron-loading from birth resulted in grade III-IV siderosis, in both male and female rats, and caused fibrosis associated with periportal macrophages. Alcohol-feeding, in addition to iron-feeding for 26 weeks significantly lowered the hepatic iron concentration in both male and female rats compared to those fed iron only (p < 0.05). Alcohol feeding did increase hepatic fibrosis in the iron-loaded animals. However, serum alanine aminotransferase activity was significantly higher in the iron-alcohol group than in the other groups (p < 0.05). CONCLUSIONS: Thus, contrary to expectation, chronic alcohol feeding failed to potentiate hepatic fibrosis in iron-overloaded rats, although there was rather more hepatocyte necrosis, and the serum alanine aminotransferase activity was significantly higher in the iron-alcohol group than in the other groups.

Alcoholism↗