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Biomedical subjects

J Halpern

Publications and source records attributed to J Halpern.

At least 19 recordsLinked to original sources
PubMed1992

Characteristics relating to ovarian cancer risk: collaborative analysis of 12 US case-control studies. I. Methods. Collaborative Ovarian Cancer Group.

Data from 12 US case-control studies of ovarian cancer, conducted during the period 1956-1986 and representing some 3,000 cases and 10,000 controls, were pooled and reanalyzed. Separate analyses were conducted for four subgroups of the pooled data: invasive epithelial ovarian cancers in white women; epithelial ovarian cancers of low malignant potential in white women, epithelial ovarian cancers in black women, and nonepithelial ovarian cancers. This paper gives a brief description of the participating studies and describes the methods used in the collaborative analysis.

Black or African American↗
PubMed1992

[Primary breast cancer: conservation therapy].

A series of 200 patients with primary breast cancer, treated with breast conservation between 1981 and 1988, was analyzed retrospectively. The mean age was 54 +/- 14 years and mean follow-up 36 months. 58 patients (29%) were in pathological Stage I, 85 (42.5%) in II A, 34 (17%) in II B, and 7 (3.5%) in III. 16 (8%) were in clinical Stages I-II; 40 (20%) had multifocal tumors and 40 intraductal components. 45% of the lesions were excised with good margins, 13.5% with close margins (0.5 cm), 9% with microscopic residual, 4% with macroscopic residual and in 57 (28.5%) margins could not be determined. Level II axillary lymph node dissection was performed in 193 (96.5%). Adjuvant therapy (combined chemotherapy and/or hormones) was given to 105 (52.5%). Radiotherapy usually consisted of 50 GY tangential photon irradiation to the whole breast in 25 fractions. Electron or photon boost to the tumor bed was given to 112 (59%). Most patients received 20 GY, and most node-positive patients 50 GY to the lymphatic drainage. 69% tolerated combined radiotherapy-chemotherapy well and radiotherapy did not have to be interrupted. A year after completion of radiotherapy the cosmetic result was rated as good in 166/173 (96%) and fair in 7 (4%); there were no poor ratings. 11 (5.5%) developed breast recurrence and 5 (2.5%) supraclavicular or axillary lymph node metastases. 1 (0.5%) developed local recurrence and supraclavicular lymph node metastases simultaneously. 50 (10%) developed distant metastases, of whom 2 developed loco-regional recurrences simultaneously.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Studies on tumor induced angiogenesis.

Methods were developed to test angiogenic response to human tumor implants and various biologic agents in the cornea of rabbits and non-human primates (Macaca arctoides). Crude PDGF preparations were found to have significant angiogenic effect. Purified, recombinant PDGF preparations were also effective inhibitors (e.g. pentoxifylline (Px) (which also were found to release PgI2 and t-PA) inhibited human tumor implant induced angiogenesis and reduced spontaneous metastases in 3 transplantable murine tumors (Furth-Columbia Wilms' tumor in Furth-Wistar rats, C-1300 neuroblastoma in A/J mice and HM-Kim mammary carcinoma in Wistar rats) but not in the NIH adenocarcinoma in Balb/c mice. Sodium diethyldithiocarbamate (DDTC), a metal complexing agent with special affinity to copper and anti-thyroid as well as, immune stimulating activity was shown to be anti-angiogenic and to potentiate the effect of Px. The anti-fibrinolytic agents epsilon amino caproic acid (EACA) and tranaxamic acid (t-AMCHA) were anti-angiogenic. DDTC and Px were synergistic from this point of view.

Adenocarcinoma↗
PubMed1992

The value of postoperative irradiation in renal cell cancer.

This is a retrospective analysis of 147 evaluable patients, with histologically proven renal cell carcinoma, who were referred to our center between 1977 through 1988. All patients with disease limited to the kidney underwent nephrectomy. Post-operative megavoltage irradiation, with a median dose of 46 Gy, was given to 56 patients, using parallel opposing portals, or multiple field technique. Five and 10 year actuarial survivals in irradiated patients (Rt+) were 50 and 44%, respectively, and in non-irradiated patients (Rt-) 40 and 32%, respectively. The disease recurred locally in a total of 19 patients; 16 had tumor bed recurrence and three had scar recurrence. Local recurrence by stage was as follows: T2 N0M0: RT+ 0/17, RT- 2/28; T3 N0M0: RT+ 4/37 (10%), RT- 11/30 (37%) (p less than 0.05); T4 N0M0: RT+ 1/2, RT- 1/5. Two of the local recurrences in irradiated patients developed in a surgical scar which was not included in the treatment volume. Significant toxicity developed in three patients (5%). It is concluded that post-operative irradiation can reduce local recurrence rate in T3 N0M0 renal cell carcinoma. It is recommended that the surgical scar should always be included in the treatment volume and irradiated to a full dose.

Actuarial Analysis↗
PubMed1991

The interferon system in carcinoma of the cervix. Effect of radiation and chemotherapy.

Thirteen patients with advanced carcinoma of the cervix were studied for parameters of the interferon system compared with 40 age-matched and sex-matched controls. All patients had measurable serum interferon levels; controls did not. All patients had non-antibody-type interferon-inhibitory activity, and controls had none. Interferon-synthesizing potential was higher in controls than in patients. After successful radiation and chemotherapy, these parameters normalized in the patients. No change was seen in one patient who did not respond to therapy.

Adenocarcinoma↗
PubMed1991

27-year mortality in the Western Collaborative Group Study: construction of risk groups by recursive partitioning.

The relationship of selected biological and behavioral characteristics measured at baseline examination to 27-year mortality due to coronary heart disease (CHD), cancers of all sites, and total mortality in the 3154 men that form the Western Collaborative Group Study was investigated using tree-structured survival analysis or recursive partitioning (RP). Intake (1960-61) characteristics included in the present analyses were age, serum cholesterol, systolic blood pressure (SBP), cigarette smoking, body mass index (BMI), Type A/B behavior, and behavioral hostility. Tree-structured survival analysis for CHD mortality partitioned the cohort into six groups and identified five groups with distinct survival experience. Exceptionally high CHD mortality rates (17.3 and 14.6 per thousand) were experienced by 89 older men with elevated hostility ratings and SBP less than or equal to 150, and 238 men whose initial SBP was greater than 150 mmHg. Younger men (age less than or equal to 48) with SBP less than or equal to 150 and with serum cholesterol levels greater than 227 had a death rate of 4.8 per thousand, compared with a rate of 1.7 in similar men with lower cholesterol levels. Applied to 27-year cancer mortality, the RP algorithm partitioned the cohort into four distinct survival groups. Younger (age less than 45) Type B men had superior survival compared with Type A men of similar ages, and the proportion of ever cigarette smokers in these two groups was not statistically different. The results obtained by tree-structured survival analyses were compared with results obtained by Cox regression survival analyses.

Adult↗
PubMed1991

Effects of milrinone on left ventricular remodeling after acute myocardial infarction.

BACKGROUND: Left ventricular remodeling after an acute myocardial infarction may result in progressive left ventricular dilation that may be associated with increased mortality. We studied the effects of the phosphodiesterase inhibitor milrinone on left ventricular remodeling after acute myocardial infarction. METHODS AND RESULTS: Rats (n = 90) were randomized to undergo either left coronary artery ligation or sham operation. Three weeks after surgery, rats received either no treatment or milrinone, which was continued until 2 days before the rats were killed. Ninety days after the initial surgery, hemodynamic measurements were made before and after volume loading. The rats were killed, the hearts were removed, and passive pressure-volume curves were obtained. The hearts were fixed at a constant pressure and analyzed morphometrically. Compared with untreated infarcted rats, milrinone-treated infarcted rats had a lower left ventricular end-diastolic pressure (1.7 +/- 0.4 versus 4.3 +/- 1.4 mm Hg, p less than 0.05), a lower left ventricular volume (1.25 +/- 0.20 versus 2.37 +/- 0.30 ml/kg, p less than 0.001) and a lower left ventricular wall stress index (1.3 +/- 0.2 versus 1.7 +/- 0.1, p less than 0.05). Left ventricular chamber stiffness was higher in milrinone-treated infarcted rats than in untreated infarcted rats. Milrinone had no cardiac effect on uninfarcted animals. CONCLUSION: Chronic milrinone therapy after acute myocardial infarction improves cardiac hemodynamic indexes and attenuates progressive left ventricular dilation.

Animals↗
PubMed1991

Income, race, and surgery in Maryland.

BACKGROUND: We describe common surgical and medical hospital admission rates for Maryland residents, exploring systematic effects of race and income. METHODS: The data comprise Maryland hospital discharges and population estimates for 1985 to 1987. Patient income is the race-specific median family income of residence zip code. Logistic regression is used to measure incidence by race, income, and residence for surgical and medical reasons for admission. RESULTS: Population rates for discretionary orthopedic, vascular, and laryngologic surgery tend to increase with community income levels. Coronary and carotid artery surgery rates are two to three times higher among Whites. The more discretionary the procedure, the lower is the relative incidence among Blacks. By contrast, admission rates for most medical reasons decline with increasing income levels and are elevated among Blacks. The affluent receive coronary artery procedures whereas the poor are hospitalized for coronary artery disease. CONCLUSIONS: Blacks and the poor appear to have higher illness burdens requiring hospital care. Discretionary surgeries have a White predominance and increase with income; medical admissions have a Black predominance and decline with income. Race and community income level are important factors in differential hospital utilization rates.

Adult↗
PubMed1990

Irradiation of prosthetically augmented breasts: a retrospective study on toxicity and cosmetic results.

Eleven patients with subcutaneous prosthetic breast implants were followed 3-16 years after mammary irradiation. Radiation doses ranged between 45 Gy and 50 Gy to the whole breast, supplemented in five cases with 10-21 Gy scar boost. Evaluation of the cosmetic results revealed a good score in three patients, moderate to fair in three, and poor in five. Of the five patients who had poor postirradiation cosmesis, three had fibrotic changes and encapsulation of the prostheses prior to the irradiation, and two received their irradiation 1 month after the reconstruction. In most of the patients, the nonirradiated breast was augmented with a prosthesis and both breasts could be followed for comparison. The irradiated side usually looked and felt on palpation worse than the nonirradiated, but both breasts exhibited a steady deterioration in appearance over time. The patients who enjoyed better cosmetic results after irradiation had better breast appearance before the radiotherapy. Of three patients treated with lower doses (45 Gy/4.5-5 weeks), two enjoyed good cosmesis. Both patients who received irradiation immediately after reconstructive surgery had poor cosmetic results. Three observations could be made: (a) when the implanted breast was free of fibrotic changes, radiotherapy produced acceptable results, (b) whenever feasible, 45 Gy/5 weeks seemed preferable over higher doses, (c) irradiation immediately after the reconstructive surgery appeared to produce poorer cosmetic results.

Adult↗
PubMed1990

Locally advanced breast cancer treated with neutron beams: long-term follow-up in 28 patients.

Between 1972 and 1978, 28 patients with locally advanced breast cancer were treated, 15 with neutron beams only and 13 with mixed neutron and photon beams. Half the patients had inflammatory cancer. For neutrons only, doses ranged between 13.35-25.34 nGy. In mixed-beam regimens, the prescribed total dose ranged between 62 and 76 Gy photon equivalent. Nine patients (32%) had a complete response without local recurrence for the duration of their survival ranging from 1 to 14+ years; 18 patients had a partial response (64%); and one patient had no change. Late toxicity was high: of 24 patients who received tangential breast irradiation, 5 (21%) had ulceration of the breast or chest wall, or both. In four patients, mastectomy and skin grafts were necessary for repair. In only one patient did the skin necrosis heal without corrective surgery. Twelve patients received axillary neutron irradiation, resulting in severe edema in four patients, and brachial plexopathy in six patients. Radiation-induced complications progressed steadily for the duration of the patients' survival after the neutron irradiation. The high complication rate encountered is attributed to high doses resulting from an under estimation of the relative biological effect of the neutron beam for late effects, and to the poor physical and geometrical characteristics of the neutron beam.

Adult↗
PubMed1990

Prognostic significance of actual dose intensity in diffuse large-cell lymphoma: results of a tree-structured survival analysis.

While diffuse large-cell lymphoma (DLCL) is considered to be highly curable with current therapy, treatment failures are observed even with intensive combination chemotherapy regimens. In order to study the prognostic significance of actual dose intensity of chemotherapy in DLCL, we retrospectively analyzed 115 previously untreated patients treated as Stanford between 1975 and 1986 with cyclophosphamide, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), vincristine, and prednisone (CHOP), methotrexate, bleomycin, Adriamycin, cyclophosphamide, vincristine, and dexamethasone ([M]BACOD), or methotrexate, Adriamycin, cyclosphosphamide, vincristine, prednisone, and bleomycin (MACOP-B). The actual relative dose intensity (RDI), the amount of drug actually administered to each patient during the first 12 weeks of therapy, was calculated as standardized to CHOP and analyzed in addition to clinical factors prognostic for survival by univariate analysis. Multivariate recursive partitioning (tree-structured) survival analysis identified the actual RDI of Adriamycin greater than 75% as the single most important predictor of survival. A model incorporating the actual RDI of Adriamycin and performance status, in combination with serum lactate dehydrogenase (LDH) and extranodal disease, defined three overall prognostic groups of patients with respective 3-year survival rates of 89%, 63%, and 18%. The three prognostic groups remained distinct, even when restricted to complete responders. This model was also predictive of survival when dose intensity was analyzed relative to the optimum dose defined for each of the three regimens and when applied to a subgroup of patients aged 50 years or younger. We conclude that actual RDI is an important prognostic factor for survival in DLCL and that analysis of RDI early in the course of treatment may allow modification of the treatment plan.

Aged↗
PubMed1990

Platelet aggregation in septic shock. Effect of pentoxifylline.

In contrast to normal individuals, patients suffering from adult respiratory distress syndrome (ARDS) due to septic shock had increased platelet aggregation and circulatory platelet aggregates in blood. In vitro incubation with pentoxifylline (Trental) decreases platelet aggregates. This suggests that in addition to its platelet aggregation inhibitory effect, it also causes platelet disaggregation. Platelet aggregate patterns were shown to normalize two weeks after clinical recovery.

Adult↗
PubMed1989

Prognostic indicators of laparotomy findings in clinical stage I-II supradiaphragmatic Hodgkin's disease.

Between July 1968 and July 1986, 915 patients with clinical stage (CS) I and II Hodgkin's disease limited to sites above the diaphragm underwent laparotomy and splenectomy at Stanford University. Fifteen percent were CS I, of whom 76% had cervical/supraclavicular disease, 13% axillary disease, and 9% mediastinal presentations. CS I patients were more likely to be male, were significantly older, and were significantly less likely to have nodular sclerosis (NS) histology than CS II patients. Twenty percent of CS I patients and 30% of CS II patients were pathologically upstaged. No CS I patients were upstaged to pathological stage (PS) IV. Univariate and multivariate analyses of presenting clinical characteristics were performed to predict staging laparotomy findings. CS I women, CS I patients with mediastinal-only disease, and CS I men with either lymphocyte predominance or interfollicular histologies were at low risk for having disease below the diaphragm (5%) or requiring chemotherapy (0%). CS II women who were less than 27 years old and had only two or three sites of disease were also at low risk for upstaging (9%) or requiring chemotherapy (2%). Mixed cellularity histology and male gender were associated with increased risk for subdiaphragmatic disease and require laparotomy; the presence of systemic symptoms was not correlated with laparotomy findings. These results confirm the importance of performing staging laparotomy for the majority of patients who present with supradiaphragmatic Hodgkin's disease if treatment programs are based on the presence and extent of subdiaphragmatic disease. Selected subgroups are at low risk for subdiaphragmatic disease and might be spared laparotomy if they are treated with mantle, paraaortic, and splenic irradiation.

Adolescent↗
PubMed1989

Radio-protective effect of sodium meclofenamate. A prospective clinical trial.

Twentyfour patients treated with irradiation to either their pelvis or their chest for neoplastic disease were included in a randomized study of radioprotection with sodium meclofenamate (Meclomen) (SM). Seventeen patients received SM 100 mg, p.os, t.i.d., and seven received placebo. The long-range radiation related chronic gastrointestinal and urinary tract toxicity was diminished by SM. At 12 months post irradiation, SM treated patients experienced less gastrointestinal and urinary symptoms, as well as less measured bladder contraction, than the controls. Acute gastrointestinal signs of radiotoxicity, however, seemed to have been enhanced by SM. The treated patients suffered from nausea, vomiting, and diarrhea. These acute toxic effects were temporary and reversible.

Adult↗
PubMed1985

Mechanisms of coenzyme B12-dependent rearrangements.

Coenzyme B12 serves as a cofactor in various enzymatic reactions in which a hydrogen atom is interchanged with a substituent on an adjacent carbon atom. Measurement of the dissociation energy of the coenzyme's cobalt-carbon bond and studies of the rearrangement of model free radicals related to those derived from methylmalonyl-coenzyme A suggest that these enzymatic reactions occur through homolytic dissociation of the coenzyme's cobalt-carbon bond, abstraction of a hydrogen atom from the substrate by the coenzyme-derived 5'-deoxyadenosyl radical, and rearrangement of the resulting substrate radical. The only role thus far identified for coenzyme B12 in these reactions--namely, that of a free radical precursor--reflects the weakness, and facile dissociation, of the cobalt-carbon bond.

Carbon↗