Search PubMed⌕ Search

Biomedical subjects

B Fisher

Publications and source records attributed to B Fisher.

At least 127 records · Page 7Linked to original sources
PubMed1995

Risks associated with long-term homelessness among women: battery, rape, and HIV infection.

The purposes of this study were to determine the prevalence of battery, rape, and HIV risk practices in a sample of long-term homeless women and to explore correlates of HIV risk practices. Fifty-three women who had been homeless for at least three months in the last year were interviewed at day and night shelters. The women were demographically similar to other samples of homeless men and women and had similar rates of drug use. However, a higher proportion of homeless women were exposed to battery (91 percent), rape (56 percent), and mental distress, and they had a smaller support network (three people). Eighty-six percent had been battered prior to homelessness. A positive association was found between HIV risk practices and the use of certain drugs and having a protector. A higher level of assertiveness was associated with less HIV risk. The study demonstrated that homeless women are at very high risk of battery and rape. Being homeless may require life-styles that increase the risk of HIV infection and transmission.

Adolescent↗
PubMed1994

Identification of lef-7: a baculovirus gene affecting late gene expression.

We have examined a 15-kb region of the Autographa californica nuclear polyhedrosis virus (AcMNPV) genome, from 66 to 78 map units, for the presence of genes which transactivate expression from late and very late viral promoters in transient expression assays. One gene in this region activated reporter gene expression approximately six- to eightfold when the reporter gene was under the control of the late promoter of the major capsid protein gene, vp39, or the very late promoter of the polyhedrin gene, polh, but not when the reporter gene was under the control of the early promoter of etl, a homolog of proliferating cell nuclear antigen. The sequence of the predicted polypeptide product of this gene, lef-7, shared no obvious sequence homology to other sequences in available databases. Transcriptional analysis indicated that lef-7 was transcribed early in infection from an initiation site 14 to 16 bp upstream of the putative translational start site and was also transcribed late in infection from an initiation site(s) further upstream. The lef-7 promoter and the promoter of another previously defined late expression factor, lef-3, were both dependent on the multifunctional transregulatory gene, ie-1, for activity in transient expression assays. While sequencing the region of the AcMNPV genome containing lef-7, we also found a 215-codon open reading frame (ORF-215) approximately 1 kb downstream of lef-7 with sequence homology to eIF2 alpha kinases (e.g., rabbit eIF2 alpha and yeast GCN-2 kinase). However, only the six C-terminal conserved domains of protein kinases were present in the predicted ORF-215 product and several of these domains varied from the consensus sequence. ORF-215 did not strongly influence expression from the vp39 promoter-controlled reporter gene in the transient expression assays employed.

Animals↗
PubMed1994

Endometrial cancer in tamoxifen-treated breast cancer patients: findings from the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-14.

BACKGROUND: Tamoxifen is advantageous in treating all stages of breast cancer. However, studies have suggested that incidence and severity of endometrial cancer increase in women treated with tamoxifen. PURPOSE: We compared rates of endometrial and other cancers in tamoxifen- and non-tamoxifen-treated patients and described the pathologic characteristics of the endometrial cancers. METHODS: Data were analyzed on 2843 patients with node-negative, estrogen receptor-positive, invasive breast cancer randomly assigned to placebo or tamoxifen (20 mg/d) and on 1220 tamoxifen-treated patients registered in NSABP B-14 subsequent to randomization. Average time on study is 8 years for randomly assigned patients and 5 years for registered patients. RESULTS: The incidence rates of liver, gastrointestinal, urinary tract, and nonuterine genital tumors were not increased by tamoxifen treatment. Twenty-five endometrial cancers were originally reported, one of which was reclassified after subsequent review. Two cases occurred in the placebo group in patients whose medical status subsequent to random assignment had required tamoxifen treatment. Twenty-three occurred in the tamoxifen groups. Twenty-one of the 24 originally reported endometrial cancers were FIGO stage 1; 18 of 23 gradable cases were of good to moderate histologic grade. Four tamoxifen-treated women died of uterine cancer. The average annual hazard rate of endometrial cancer as a first event within the first 5 years of follow-up in the randomized, tamoxifen-treated group was 1.2/1000 patient-years; the cumulative hazard rate was 6.3/1000. Findings for the registered, tamoxifen-treated group were similar. Including all originally reported endometrial cancers, the annual hazard rate through all follow-up was 0.2/1000 in the placebo group and 1.6/1000 in the randomized, tamoxifen-treated group; the relative risk of endometrial cancer for the latter versus the former group was 7.5. Again for the latter group, using population-based rates of endometrial cancer from SEER data and information from another NSABP (B-06) trial, relative risks were 2.2 and 2.3, respectively. The 5-year cumulative hazard rate for disease-free survival in the randomized tamoxifen group was 38% less than that in the placebo group. Some data in this paper were provided by an investigator who submitted fraudulent data to the NSABP [see the "News" section]; therefore, the reader must read the entire text including Table 10 and the Editor's notes. In brief, data on 182 of the 2843 randomly assigned patients and 37 of the 1220 registered patients were provided by the investigator in question. After review, 24 of the 182 records showed falsification, all involving characteristics of patients prior to random assignment. Of the 37 registered-patient records, 8 showed falsification. CONCLUSIONS: Risk of endometrial cancer increases following tamoxifen therapy for invasive breast cancer; however, net benefit greatly outweighs risk. Endometrial cancers occurring after tamoxifen therapy do not appear to be of a different type with a worse prognosis than are such tumors in non-tamoxifen-treated patients. IMPLICATIONS: Tamoxifen treatment for breast cancer should continue. In addition, the relative risk of endometrial cancer observed in B-14 tamoxifen-treated patients is consistent with the twofold relative risk used in the initial risk-benefit computation for the NSABP breast cancer prevention trial.

Adult↗
PubMed1994

Multiple parallel access in visual attention.

It is widely accepted that there exists a region or locus of maximal resource allocation in visual perception--sometimes referred to as the spotlight of attention. We have argued that even if there is a single locus of processing, there must be multiple loci of parallel access--several places in the visual field must be indexed at once and these indexes can be used to determine where attention is allocated. We have carried out a variety of studies to support these ideas, including experiments showing that subjects can track multiple independent moving targets in a field of identical distractors, that the enhanced ability to detect changes occurring on these targets does not accrue to nontargets nor to items lying inside the convex polygon that they form (so that a zoom-lens of attention does not fit the data). We have used a visual search paradigm to show that (serial or parallel) search can be confined to a subset of indexed items and the layout of these items is of little importance. We have also studied the phenomenon known as subitizing and have shown that subitizing occurs only when items can be preattentively individuated and in those cases location precuing has little effect, compared with when counting occurs, which suggests that subitizing may be carried out by counting active indexes rather than items in the visual field. And finally we have run studies showing that a certain motion effect that is sensitive to attention can occur at multiple precued loci. We believe that this evidence suggests that there is an early preattentive stage in vision where a small number of salient items in the visual field are indexed and thereby made readily accessible for a variety of visual tasks.

Attention↗
PubMed1994

Catheter ablation of accessory pathways in children.

The efficacy and safety of catheter ablation of accessory pathways (AP) was studied in 79 children (age, 4-16 years), using DC shocks (n = 25) or radiofrequency energy (n = 54). All patients had documented arrhythmias including ventricular fibrillation in four. Organic heart disease was present in four patients. AP locations were left lateral (n = 36), posteroseptal (n = 36), right lateral (n = 8), Mahaim fibres (n = 2) and right anteroseptal (n = 6). Seven patients had multiple AP. One patient had a preexcitation which appeared secondary to an atrio-infundibular connection (Fontan procedure). The ablation site of concealed or overt AP was identified by retrograde or anterograde conduction mapping, respectively. A mean of 2.6 +/- 1 cathodal shocks (80-160 J) was delivered to 25 patients over 29 sessions, resulting in initial AP ablation in all. Fulguration was uncomplicated in all except in one patient (4%) who developed a secondary complete AV block post-ablation. During a follow-up period of 30-69 months, intermittent preexcitation recurred in two asymptomatic patients, but no significant tachycardia was inducible at late electrophysiological study, including under isoproterenol infusion. Radiofrequency energy was applied to 54 patients during 62 sessions, using 20-40 watts for 30-60 s. AP ablation was initially achieved in all patients using a median of three impulses, without significant immediate side-effects. Two patients (4%) developed a short episode of blurred vision possibly due to a microembolism. After discharge, the follow-up period was 10 +/- 5 months (range 1 to 24). All patients but one (98%) were asymptomatic without any drug therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Neuropathology of intracranial arteriovenous malformations following conventional radiation therapy.

Conventional fractionated radiation therapy was used in 15 patients to treat arteriovenous malformations (AVMs) of the brain deemed inoperable or incompletely obliterated using endovascular or surgical techniques. The AVMs measured from 0.8 to 85 cm3 (mean 28.2 cm3; median 24 cm3). Angiography in 12 patients 1-21 years following radiation therapy demonstrated no significant change in 7, slight reduction in 2, near complete obliteration in 1, and complete obliteration in 2. Magnetic resonance imaging further demonstrated apparent obliteration in one other case. Three irradiated AVMs were available for pathological examination following fatal recurrent hemorrhage after 21 years in case 1 and following surgery after 5 years in cases 2 and 3. Doses of 20 and 45 Gy were delivered to the area of the AVM in 10 and 15 fractions with a 6-MV linear accelerator in case 1 and in cases 2 and 3, respectively. A blinded histopathological comparison was made of the latter cases and three AVMs removed at surgery that were not previously irradiated and that were comparable in size, number of arterial feeders, and location within the brain. Segmental hyalinization of some blood vessels was seen in both irradiated and nonirradiated cases. The single postmortem specimen showed extensive thrombosis but a patent nidus. The findings are in keeping with the clinical impression that conventional fractionated radiation therapy fails to alter the natural history of cerebral AVMs. The favorable outcome of radiosurgery on small- to medium-sized AVMs appears attributable to the shorter duration of therapy using relatively high-dose prescriptions to the nidus.

Adult↗
PubMed1994

The role of thymidylate synthase expression in prognosis and outcome of adjuvant chemotherapy in patients with rectal cancer.

PURPOSE: We assessed the prognostic importance of the level of thymidylate synthase (TS) expression in patients with primary rectal cancer and whether, for Dukes' B and C cancer patients, the benefit of chemotherapy was associated with TS expression. PATIENTS AND METHODS: The level of TS expression in the primary rectal cancers of 294 of 801 patients enrolled on protocol R-01 of the National Surgical Adjuvant Breast and Bowel Project (NSABP) was immunohistochemically assessed with the monoclonal antibody TS 106. RESULTS: Forty-nine percent of patients whose tumors had low TS levels (n = 91) were disease free at 5 years compared with 27% of patients with high levels of TS (n = 203; P < .01). Moreover, 60% of patients with low TS levels were alive after 5 years compared with 40% of patients with high TS levels (P < .01). The level of TS protein was significantly associated with Dukes' stage (P < .01); patients with a more advanced Dukes' stage had a significantly higher level of TS. The level of TS expression remained prognostic for both disease-free survival (P < .01) and survival (P < .05) independent of Dukes' stage and other pathologic characteristics evaluated. Thirty-eight percent and 54% of patients with high TS levels (n = 71) were disease free and alive, respectively, after 5 years when treated with chemotherapy, compared with 17% and 31%, respectively, of similar patients when treated with surgery alone (n = 64) (P < .01). No difference was noted in disease-free survival (P = .46) or survival (P = .43) in patients with low TS levels. CONCLUSION: The expression of TS is an important independent prognosticator of disease-free survival and survival in patients with rectal cancer. Adjuvant fluorouracil (5-FU)-based chemotherapy demonstrated significant improvement in disease-free and overall survival for patients with high TS levels. Prospective studies measuring TS levels will be needed to understand further the role of TS as a prognosticator of survival and chemotherapeutic benefit.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Cause-specific mortality in long-term survivors of breast cancer who participated in trials of radiotherapy.

PURPOSE: To examine long-term cause-specific mortality in patients irradiated for breast cancer as part of a randomized clinical trial. PATIENTS AND METHODS: We studied all available information from randomized trials initiated before 1975 in which radiotherapy was the randomized option and surgery was the same for both treatment arms. Eight such trials were identified. RESULTS: The increased all-cause mortality rate in 10-year survivors previously reported is no longer significant, although a numerical difference in favor of non-irradiated patients remains. This result was strongly influenced by the earliest trials, and more recent trials have found a nonsignificant net benefit in overall mortality associated with radiation therapy. An excess of cardiac deaths was apparent in both early and more recent trials (P < .001), but this was offset by a reduced number of deaths due to breast cancer, especially in more recent trials. CONCLUSION: The reduction of breast cancer deaths suggests that radiation therapy may have a value beyond the clearly established improvements obtainable for local control. Use of techniques that minimize cardiac dose is important in reducing the risks of adjuvant radiotherapy, especially in good-prognosis patients.

Breast Neoplasms↗
PubMed1993

Lumpectomy compared with lumpectomy and radiation therapy for the treatment of intraductal breast cancer.

BACKGROUND AND METHODS: Women with ductal carcinoma in situ have been treated both by lumpectomy and by lumpectomy followed by radiation therapy, but the benefit of combined therapy is uncertain. A group of 818 women with ductal carcinoma in situ were randomly assigned to undergo lumpectomy or lumpectomy followed by breast irradiation (50 Gy). Sufficient tissue was removed that the margins of the resected specimens were histologically tumor-free. The mean duration of follow-up was 43 months (range, 11 to 86). The principal end point of the study was event-free survival, as defined by the presence of no new ipsilateral or contralateral breast cancers, regional or distant metastases, or other cancers and by no deaths from causes other than cancer. RESULTS: Five-year event-free survival was better in the women who received breast irradiation (84.4 percent, vs. 73.8 percent for the women treated by lumpectomy alone; P = 0.001). The improvement was due to a reduction in the occurrence of second ipsilateral breast cancers; the incidence of each of the other events was similar in the two groups. Of 391 women treated by lumpectomy alone, ipsilateral breast cancer developed in 64 (16.4 percent); it was noninvasive in 32 and invasive in the remaining 32. Of 399 women treated with lumpectomy and breast irradiation, ipsilateral breast cancer developed in 28 (7.0 percent) (noninvasive in 20 and invasive in 8). The five-year cumulative incidence of second cancers in the ipsilateral breast was reduced by irradiation from 10.4 percent to 7.5 percent for noninvasive cancers and from 10.5 percent to 2.9 percent for invasive cancers (P = 0.055 and P < 0.001, respectively). CONCLUSIONS: Breast irradiation after lumpectomy is more appropriate than lumpectomy alone for women with localized ductal carcinoma in situ.

Breast Neoplasms↗
PubMed1993

Pathologic findings from the National Surgical Adjuvant Breast Project protocol B-06. 10-year pathologic and clinical prognostic discriminants.

BACKGROUND: Prognostic pathologic and clinical features for 10-year survival were determined from 22 pathologic and 5 clinical variables encountered in 1090 node-negative and 651 node-positive patients enrolled in NSABP protocol B-06. METHODS: All factors were first screened univariately. Those exhibiting P values < 0.01 were entered into multivariate Cox regression models. The model with the best fit consisted of 951 negative-node and 496 node-positive patients. RESULTS: Better survival in node-negative patients was noted for whites rather than blacks, for patients with favorable tumor types (tubular, mucinous, papillary) rather than intermediate (lobular invasive, classical medullary, and not otherwise specified [NOS] combinations) or unfavorable forms (NOS pure and atypical medullary), and for tumors with good rather than poor nuclear grade. Number of nodal metastases, degree of tumor elastosis, and patient age younger than 40 years of age and 65 years of age and older in addition to nuclear grade and race were found significant for node-positive patients. Relative risks for combinations of these prognostic factors were multiplicative. CONCLUSIONS: The prognostic factors for node-negative patients were similar to those observed for this cohort at 8 years. Some differences noted between patients of both nodal groups in NSABP B-04 and B-06 may be related to selection requirements in the latter and hence different patient characteristics or more speculatively a change in tumor biology.

Adult↗
PubMed1993

Pathologic findings from the National Surgical Adjuvant Breast Project (Protocol 4). Discriminants for 15-year survival. National Surgical Adjuvant Breast and Bowel Project Investigators.

Twenty-one pathologic and five clinical features of Stage I and II invasive breast cancers from 620 patients enrolled in National Surgical Adjuvant Breast Project Protocol B-04 were analyzed to determine their predictive value for 15-year survival. Ten pathologic features had a statistically significant univariate prognostic relationship with long-term survival. These were analyzed further using a Cox regression model that found only the number of nodal metastases (0, 1-3, 4-9, or 10+), tumor size (< or = 2.0 cm versus 2.1-4 and 4.1 + cm), and the presence or absence of nipple involvement to be significant independent prognostic discriminants. Combinations of these three characteristics modestly increased their individual prognostic value. Differences in the findings in this study from those observed in the same patient population at 5 and 10 postoperative years and their relationship to other markers detected by ancillary pathologic techniques briefly are discussed.

Aged↗