Designing clinical trials with arbitrary specification of survival functions and for the log rank or generalized Wilcoxon test

This article describes a computer program that allows interactive determination of the length of accrual period and follow-up period sufficient to assure desired level of significance and power. The program allows for arbitrary specification of the hypothesized survival curves and the alternative survival curve. It allows use of either the generalized Wilcoxon test or the log rank test. The program can be run on an IBM personal computer.

Four factors that accurately predict hearing loss in "high risk" neonates

Two simple overall measures of health--length of stay in the Intensive Care Nursery (ICN) and gestational age--predict hearing loss in ICN graduates. Craniofacial anomalies, congenital perinatal infections, and meconium aspiration are strong predictors of hearing loss, especially in term infants. Findings are based on univariate and multivariate analyses of a number of variables that might be associated with permanent hearing loss. Study variables included all seven High Risk Register items and a number of other features of the ICN history. They were examined in 799 ICN graduates whose hearing had been monitored in their first few years of life. These babies composed 40% of the ICN population and were selected because they had one or more "high risk" factors in their neonatal history. Prevalence of hearing loss in this high risk sample was similar to that found in other ICN samples. Prevalence of hearing loss associated with individual Risk Register items was similar to other published findings for some items and not for others.

Methods for analyzing occupational cohort data with application to lung cancer in U.S. uranium miners

We used two methods to examine how lung cancer death rates vary with cumulative exposures to radiation and tobacco among U.S. uranium miners. We assumed that exposures act proportionately on age-specific death rates among nonsmokers who are unexposed to uranium. The two methods produced similar results when death rate ratios were taken to be the product of radiation and tobacco effects. The estimates were discrepant when death rate ratios were taken to be the sum of radiation and tobacco effects. Both methods indicated better fit for the multiplicative model, as judged by the maximized loglikelihood values. Death rates estimated in this way for white males in the absence of mining and smoking increased only weakly with age. This weak relation suggests that our models of death rates fit poorly. It may be that cumulative exposures are inappropriate measures of the effects of radiation and tobacco on lung cancer death rates.

Congenital see-saw nystagmus associated with retinitis pigmentosa

Two sibling patients with see-saw nystagmus associated with advanced retinitis pigmentosa are presented. The see-saw nystagmus was most likely congenital but demonstrated a torsional pattern different from that previously reported for congenital see-saw nystagmus. Anatomic and etiologic factors associated with see-saw nystagmus are discussed.

Sequential treatment allocation procedures in clinical trials--with particular attention to the analysis of results for the biased coin design

We discuss the advantages and problems of using sequential allocation procedures for assigning treatments in a clinical trial. We use Monte Carlo methods to study the exact distribution of the fourfold chi-squared statistic for the case of no stratifying variables except sequence of entry. We display situations in which the distribution is well-approximated by the chi-squared distribution or by Efron's adjusted chi-squared and situations where these approximations fail. We provide suggestions for recognition and handling of situations in which both approaches fail.

Propoxyphene and acetaminophen mixture (Darvocet)--related radiation-induced pneumonitis

In a patient undergoing radiation therapy for recurrent, metastatic breast cancer, a mixture of propoxyphene and acetaminophen (Darvocet) was given for intercurrent viral infection. Discontinuation of therapy with this medication coincided with appearance of pneumonitis, reminiscent of the steroid withdrawal--related radiation pneumonitis.

Evaluation of topically applied (AET) 2-aminoethyl-iso-thiouronium for radiation protection of the skin. A preliminary study in pigs

AET (Aminoethyl-iso-thiouronium) was applied topically on irradiated pig skin in different vehicles (emulsions and solutions) for testing a protective effect. A simple normal saline solution (200 mg/100 ml) proved to exert the best effect, both macroscopically and histologically. The solution was applied two hours and immediately before the irradiation which consisted of one 2000 rad fraction with a 20 MeV electron beam. A protective effect was noticed only in the superficial epithelial layers, the deeper radiobiological effect remained unaltered.

Quantitation of maternal-fetal IgG transport in the chicken

Quantitative and temporal features of maternal-fetal transport of IgG in the chicken have been determined by means of a sensitive and specific radioimmunoassay. The first step in this two-step process is the transport of maternal IgG from the hen plasma across the oolemma into the maturing oocyte in the ovarian follicle. Oocytes sequester IgG throughout most of their maturation from 10 mg pre-vitellogenic oocytes to fully mature 20 g oocytes ready to be shed into the oviduct. IgG uptake is exactly proportional to mass accumulation at every point. Thus, the concentration of IgG in the yolk is invariant throughout maturation of the oocyte (approximately 8 mg/ml) and the rate of uptake in this single specialized cell can be as great as 45 mg/day during its last 3 days of growth before ovulation. The second step, uptake of yolk IgG across the yolk sac and into the fetal circulation, is detectable at the earliest time points tested (Day 7), but accumulation into the embryonic plasma occurs at a relatively low rate (less than 100 micrograms/day) until a dramatic increase in uptake (greater than 600 micrograms/day) occurs in the last 3 days before hatching. The hatchling has 1-2 mg/ml of maternal IgG in its plasma. Increase in IgG uptake lags significantly (approximately 4 days) behind increase in mass by the developing embryo, suggesting that IgG uptake occurs predominantly in the last few days before hatching. This ensures that the hatching is endowed with those maternal IgGs which will be its planopy when it enters the hostile world.

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.

Multivariate analysis of factors associated with outcome of treatment for adults with acute myelogenous leukemia

Utilizing multivariate logistic regression statistical analysis, the authors evaluated prognostic features associated with achievement of complete remission (CR) and remission and survival duration in acute myelogenous leukemia (AML). These clinical variables were analyzed in 77 consecutive adult patients who underwent 108 courses of remission induction therapy with daunomycin, cytosine arabinoside, and 6-thioguanine (DAT) chemotherapy for newly diagnosed and first relapse of AML. Eight patients had developed leukemia in the setting of other malignant or immunologic diseases (therapy-linked AML) and 69 patients had not (primary AML). Sixty-three percent of patients with primary AML achieved CR with median remission and survival durations of 11 and 24 months, respectively. Significant unfavorable predictive features for achievement of CR were splenomegaly, and elevated leukocyte count or serum alkaline phosphatase levels. Patients who had leukocyte counts of less than or equal to 10,000/mm3 at diagnosis or less than or equal to 40,000/mm3 at the start of therapy, and those who received greater than 120 mg/m2 of daunomycin had significantly longer remissions and survival than those who did not. Fifty-seven percent of patients in first relapse also achieved CR; however, relative to first remissions, second remission durations were significantly shorter (median, 4.6 months). Sixty-two percent of patients with therapy-linked AML achieved CR, but remission durations (median, 2.8 months) were significantly shorter than first remissions of primary AML patients. These data identify clinical features associated with increased risk of failure to achieve CR and potential for short remission duration and survival. Alternative forms of therapy should be considered for such high-risk patients.

Primary Kaposi's sarcoma of the lung in an immunocompetent 32-year-old heterosexual white man

Primary visceral involvement by Kaposi's sarcoma in the immunocompetent adult American population is extremely rare. Six cases of primary Kaposi's sarcoma of the lung have been previously reported; all four patients in whom immune function was evaluated had abnormalities. A case of primary Kaposi's sarcoma of the lung in a young adult heterosexual man with normal immunologic function is described. The patient had no response to either weekly vinblastine or doxorubicin (Adriamycin). A subsequent solitary right occipital metastasis responded to 3500 rad of radiotherapy. The patient died 3 months after diagnosis; postmortem examination revealed only two small nodules of extrathoracic Kaposi's sarcoma, one in the liver and the other in the right posterior occipital lobe of the brain. Bacterial, mycobacterial, fungal, and viral cultures were negative.

Radiation induced brain edema in primates, studied with sequential brain cat scanning and histopathology. Protective effect of sodium meclofenamate. A preliminary report

Four Cynomologous monkeys (Mecaca fascicularis) received 2000 Rad whole brain irradiation. One remained untreated and exhibited loss of hair, facial edema, brain edema and hydrocephalus. There was loss of alertness and motor activity. One was scheduled to be treated with phenobarbital, but died in 24 hours after irradiation. One animal received 2 mg/kg dexamethasone I.M. daily. It died two weeks after irradiation apparently due to treatment related infection. One animal received 20 mg/kg sodium meclofenamate (Meclomen) orally daily. This animal showed no brain edema and only minimal hydrocephalus, delayed and incomplete hair loss and no facial edema. Further studies of this treatment appear to be justified.

Characterization of thyroid hormone stimulation of uridine uptake by rat pituitary tumor cells

T3 caused a dose-related increase in the rate of [3H]uridine uptake into GH4C1 rat pituitary tumor cells. T3 increased uridine uptake to 130-180% of the control value, with a half-maximal effect at approximately 1 nM. T3 exerted a half-maximal effect at 1 h and a maximal effect at 2 h. In contrast, epidermal growth factor also increased uridine uptake by 75%, with an ED50 of 0.6 ng/ml (0.1 nM), but a half-maximal response required 4 min and a maximal effect required 20 min. T3 increased the rate of uptake at all uridine concentrations from 30 nM to 130 microM. Equilibrium binding of [125I]T3 to nuclear receptors required from 15 min at 50 nM [125I]T3 to 1 h at 0.5 nM, indicating that occupancy of nuclear receptors precedes maximal stimulation of uridine uptake. T3 did not stimulate the rate of uridine uptake at 20 C, when binding to nuclear receptors does not occur. Various thyroid hormones caused an increase in uridine uptake, with the rank order of potency 3,3',5-triiodothyroacetic acid greater than T3 greater than L-T4 greater than D-T4 approximately equal to 3,3',5,5'-tetraiodothyroacetic acid; rT3 was inactive. This order parallels the affinities of these compounds for nuclear thyroid hormone receptors.

Malignant fibrous histiocytoma developing in irradiated sacral chordoma

Malignant fibrous histiocytoma (MFH), arising at the site of a sacral chordoma 8 years after massive radiotherapy, is described. Initially, the patient received 7000 rad to the sacral area and, on recurrence, 5 years later, an additional 4000 rad. Two years later, a sacral mass was noted again. Biopsy then revealed MFH; chest x-ray showed multiple lung metastases. A combination chemotherapy, consisting of cyclophosphamide, vincristine, adriamycin (doxorubicin), and DTIC, resulted in a 6 month partial response. Subsequently, the patient died because of progressive metastatic disease. At autopsy, 8 years after diagnosis, both the sacral lesion and the lung metastases proved to be MFH, and no residual chordoma was found.

Procarbazine, CCNU and vincristine (PCV) combination chemotherapy for brain tumors

12 patients with brain tumors were treated with a combination of procarbazine, CCNU (bis-2-chloroethyl-3-cyclohexyl-1-nitrosourea) and vincristine. 3 of 8 patients (37.5%) with primary brain tumors responded to chemotherapy, with a mean duration of 9.3 months. The mean survival of responders was 11.7 months, versus 3.6 months for nonresponders. 4 patients with metastatic brain tumors were also treated with the same combination chemotherapy; only 1, suffering from a lymphoma of the brain, responded partially.

Binding and internalization of epidermal growth factor by rat pituitary tumor cells

Epidermal growth factor (EGF) regulates hormone synthesis and decreases the growth rate of clonal lines of rat pituitary tumor cells. [125I]iodo-EGF bound to specific receptors on GH4C1 rat pituitary cells with an apparent Kd of 0.34 nM. At 0 degrees C, 84% of specifically bound [125I]iodo-EGF appeared to be on the cell surface, while at 37 degrees C, 84% of bound [125I]iodo-EGF appeared to be internalized and could not be removed by treatment with an acidic high-salt buffer. Internalization of surface-bound [125I]iodo-EGF required 10 min to reach completion and was markedly temperature-dependent. Monodansylcadaverine, bacitracin, ammonium chloride, chloroquine, quinacrine and vinblastin did not inhibit internalization of [125I]iodo-EGF, suggesting that transglutaminase is not involved; but these drugs did cause an increased accumulation of radioactivity, probably by inhibiting degradation. In 2 h at 37 degrees C, approx. 35% of cell-associated [125I]iodo-EGF was degraded as analyzed by gel filtration, and 72% of the material that dissociated from the cells migrated as low molecular weight material or iodo-Tyr. Incubation of GH4C1 cells with unlabeled EGF caused a prolonged and dose-related decrease in the ability of the cells to bind [125I]iodo-EGF in a subsequent incubation, i.e. down-regulation. The pathway for internalization and degradation of the EGF-receptor complex in GH4C1 cells resembles that described for fibroblasts, in which the cellular response is different, but differs from the behavior of other hormone-receptor complexes in GH4C1 pituitary cells.

Early precursors of pancreatic cancer in college men

From college data on 50,000 male former students, the records of 126 men who died of pancreatic cancer in a 16-50 yr follow-up period were compared with those of 504 surviving classmates with respect to physical and social characteristics. Return mail questionnaires received from 30,000 surviving alumni in 1962 or 1966 also were reviewed for characteristics that might predict altered risk of pancreatic cancer. Strong positive associations were found for cigarette smoking as reported both during college (p less than 0.001) and at time of questionnaire return (p = 0.03). Smoking 10 or more cigarettes per day during college corresponded to a relative risk of 2.6 with 95% confidence limits 1.5 to 4.6, and a positive smoking history at questionnaire return yielded a relative risk of 2.4 (1.1-5.1). No association was found for collegiate coffee drinking, either before or after adjustment for cigarette smoking. The relative risk for coffee drinking adjusted for smoking was 1.1 (0.7-1.8). In contrast, collegiate tea consumption was associated with a reduction in pancreatic cancer risk. The relative risk for tea drinking adjusted for smoking was 0.5 (0.3-0.9). Men who at college physical examination complained of occasional abdominal pain or discomfort had increased relative risk of pancreatic cancer (3.1 : 1.1-9.0) in the follow-up period.

Mechanism and Stereoselectivity of Asymmetric Hydrogenation

Rhodium complexes containing chiral phosphine ligands catalyze the hydrogenation of olefinic substrates such as alpha-aminoacrylic acid derivatives, producing chiral products with very high optical yields. Elucidation of the mechanisms of such reactions leads to the conclusion that the stereoselection is dictated not by the preferred initial binding of the substrate to the chiral catalyst, but rather by the much higher reactivity of the minor diastereomer of the catalyst-substrate adduct corresponding to the less favored binding mode.

Evidence for an active step in thyroid hormone transport to nuclei: drug inhibition of L-125I-triiodothyronine binding to nuclear receptors in rat pituitary tumor cells

When added to intact GH4Cl or GH3 cells, cytochalasin b, dansylcadaverine, and chloroquine inhibited the binding of L-125I-triiodothyronine (T3) to nuclear receptors within 30 min. These drugs also reduced the amount of 125I-T3 in the post-nuclear supernatant fraction of cells lysed with Triton X-100. If 125I-T3 was added before the drugs, 125I-T3 that was already bound did not dissociate, but further binding was blocked. Inhibition due to 10 microM cytochalasin b or 150 microM dansylcadaverine was reversible within 2 h of drug removal, and inhibition due to 150 microM chloroquine was partially reversible. Drug inhibition was overcome as the T3 concentration was raised. These drugs did not significantly inhibit 125I-T3 binding to isolated nuclei, and nuclei isolated from drug-treated cultures bound as much 125I-T3 as control nuclei. The results suggest that thyroid hormones reach their nuclear binding sites by an active transport process which is inhibited by the drugs studied.

DTIC and Actinomycin D with and without C. Parvum Immunotherapy in Advanced Malignant Melanoma

Fifteen patients were treated with a combination of DTIC and actinomycin D between January, 1977 and December, 1979. Patients with a Karnofsky performance status above 80 % were also given intravenous C. parvum immunotherapy. One partial response and one complete response resulted, both in the higher performance status group.

Direct visualization of receptors for thyrotropin-releasing hormone with a fluorescein-labeled analog

Thyrotropin-releasing hormone (TRH) binds to specific receptors on GH4C1 pituitary tumor cells. A fluorescently labeled analog of TRH was synthesized by coupling pGlu-His-ProNH(CH2)6NH2 to fluorescein isothiocyanate. The fluorescein-labeled peptide (FL-TRH) stimulated prolactin synthesis and release by GH4C1 cultures and bound to TRH receptors with an apparent Kd of 400 nM. Binding of FL-TRH to unfixed, viable GH4C1 cells was followed by fluorescence microscopy. After incubation with 1.4 microM FL-TRH for 1 hr at 37 degrees C, the surface of all cells was fluorescent and patches of intense fluorescence were evident. Control cultures incubated with FL-TRH and excess TRH were not fluorescent, and a line of pituitary tumor cells which lacks TRH receptors displayed little fluorescence after incubation with FL-TRH. When GH4C1 cells were incubated with FL-TRH for 1 hr at 37 degrees C and then with excess TRH for an additional 1 hr, the fluorescence associated with the cells was diminished to control levels. The results demonstrate that the fluorescein-labeled peptide labels specific TRH receptors.

Effect of sex of therapist and client on therapists' attitudes toward assertiveness problems

Four hypothetical cases that contained descriptions of various assertiveness problems of male and female pseudo clients were presented to 57 male and 88 female mental health professionals. In two out of the four cases presented, female therapists found the client more in need of counseling than did male therapists, independent of the sex of the client. All therapists perceived a female client with a conflict between sexual assertiveness and negative judgments from peers to be more in need of counseling than a male client. All therapist preferred working with a female client in one of the cases. Thus, the effect of sex of therapist and client was not consistent across cases.

Medical data-bases-telecommunications issues in the 1980s

This paper gives a brief description of the telecommunications problems encountered when accessing medical data-bases. In the first part of the article, the authors described how the creation of a special telecommunications working group at IMA (the French MEDLINE Centre) helped to handle and solve these problems. The second part shows how French users will be able to access new European data-bases; and discusses the changes brought about by the development of networks such as TRANSPAC and EURONET. It also compares the communications costs for all access configurations.

A comparison of age-specific burn injury rates in five Massachusetts communities

We measured burn incidence rates for residents of five Massachusetts cities. The data set included all non-occupational burn injuries and cases of smoke inhalation requiring treatment on an inpatient or an outpatient basis in a hospital, occurring between October 1, 1973 and September 30, 1976. Rates of burn injuries by age, and by burn type were calculated for each city. Examination of the data revealed large differences in the magnitude of the age-specific incidence rates among cities but remarkably similar patterns of rates for each city. Differences in the economic status among the cities and among census tracts within the cities appeared to explain a large proportion of the variation in the crude burn rates. A similar specificity of certain types of burn injury by age and sex was common to each city. These findings can be used by health education specialists to design and implement burn prevention programs in these communities appropriate for those individuals at highest risk.

The diagnosis of Briquet's syndrome in a male population: the Veterans Administration revisited

Fifty psychiatric inpatients at a VA Hospital felt to be at high risk for the development of somatic complaints were surveyed for Briquet's syndrome. When criteria for the syndrome were strictly applied, no men were found with the disorder. If the criteria were minimally relaxed, two patients did have a sufficient number of symptoms in multiple areas to qualify for the diagnosis. However, they had alternative clinical and research diagnoses and none of the personality characteristics noted in previous populations of women surveyed for Briquet's syndrome.

Effects of type of target, cognitive ability, and age on projection

It was hypothesized that older and more cognitively developed children would be less likely to use both attributive and contrast projection. Real and ambiguous target figures were used to assess the effect of the type of target on projection. 30 boys and 31 girls between the ages of 7 yr., 10 mo. and 14 yr., 10 mo. predicted a favored classmate's preferences in each of several categories. They also predicted the preferences of an unfavored classmate and of favored and unfavored ambiguous targets. These predictions were compared with the subjects' own preferences to measure attributive and contrast projection. Type of target affected the amount of projection. There was significantly more contrast projection onto ambiguous targets (dolls) than onto real targets (classmates). There was significantly more attributive than contrast projection for the real targets only. A significant negative correlation of -.26 (df = 59) was obtained between age and contrast projection onto the real targets. There were no significant correlations between the other measures of projection and the indices of cognitive ability, including age.

Output value analysis of an alcoholism treatment program

A form of cost--benefit analysis is used to measure the efficiency and effectiveness of an alcoholism treatment program in caring for patients grouped by year of admission, sex and level of impairment.

Exclusion of bacteriophage T1 by bacteriophage lambda. I. Early exclusion requires lambda N gene product and host factors involved in N gene expression

Two modes of exclusion of T1 by lambda are distinguished. "Early" exclusion depends on gene N, but not on gene Q. It is at least partially ineffective against T1am23. "Late" exclusion depends on gene Q and effects T1am23 as well as T1+. Early exclusion is a direct effect of N gene product, rather than N gene being required for the expression of some other lambda gene. Three host mutations, groN, nusA, and nusB, known to interfere with lambda replication by affecting N gene expression, also interfere with the ability of lambda to exclude T1.

Time-related increase in leucocyte yields by continuous-flow centrifugation (CFC) leukopheresis

Continuous flow centrifugation leukopheresis lasting 3 to 4 h was performed 18 times on 16 normal donors. The total yield of leucocytes collected was 1.59 +/- 0.14 x 10(10) (mean +/- SE). Comparison of leucocyte yields on the first, second, third and fourth hour of leukopheresis indicated a progressive increase with time in 15 out of 18 procedures, with 3.6 times more leucocytes collected within the last hour of leukophoresis as compared to the first hour. This increase was independent of the volume of leucocytes collected per unit time, since an equally significant increase was found when calculated per 100 ml of leucocyte concentrate. Although the mechanism of this improvement in yield with time is unknown, the present data indicate, that moderate prolongation of the duration of leukopheresis may result in an increase in efficiency which is comparable to that produced by the use of hydroxyethyl starch, etiocholanolone or corticosteroids.

Workload levels, program costs, and program benefits: an output value analysis

This study analyzes the relationship between program performance and workload levels. The results indicate that program effectiveness is highest under medium workloads while efficiency is greatest under high workloads. The management dilemma resulting from these findings is discussed.

Prediction of body composition in habitually active middle-aged men

In 45 physically active men (ages 35-67 yr) who underwent hydrostatic weighing to determine body composition, multiple regression equations were developed for the prediction of body density (D), lean body weight (LBW), fat body weight (FBW), and % fat using selected anthropometric measurements. The prediction accuracy for these parameters using several previously generated anthropometric regression equations was also determined. With equations developed from the present data a substantially higher correlation was obtained between measured and predicted LBW (r = 0.95) than between measured and predicted D (r = 0.85), FBW (r = 0.88), or % fat (r = 0.84). When previously developed equations were applied to the present sample, correlations between measured and predicted values were considerably lower (4-42%) than in the original studies; this reduction was least in the case of LBW. Analysis of previous data indicated that in selected populations total body weight can account for a relatively large fraction of the variance in LBW. LBW may be estimated quite accurately (r greater than or equal to 0.90) in physically active men with one of several regression equations which include total body weight as an independent variable.