Efficacy and safety of ripretinib in patients with KIT-altered metastatic melanoma

BACKGROUND

Ripretinib, a broad-spectrum KIT and platelet-derived growth factor receptor A switch-control tyrosine kinase inhibitor, is approved for the treatment of adult patients with advanced gastrointestinal stromal tumor as ≥ fourth-line therapy. We present the efficacy and safety of ripretinib in patients with KIT-altered metastatic melanoma enrolled in the expansion phase of the ripretinib phase I study.

PATIENTS AND METHODS

Patients with KIT-altered metastatic melanoma were enrolled and treated with ripretinib at the recommended phase II dose of 150 mg once daily in 28-day cycles. Investigator-assessed responses according to Response Evaluation Criteria In Solid Tumors version 1.1 were carried out on day 1 of cycles 3, 5, 7, every three cycles thereafter, and at a final study visit.

RESULTS

A total of 26 patients with KIT-altered metastatic melanoma (25 with KIT mutations, 1 with KIT-amplification) were enrolled. Patients had received prior immunotherapy (n = 23, 88%) and KIT inhibitor therapy (n = 9, 35%). Confirmed objective response rate (ORR) was 23% [95% confidence interval (CI) 9%-44%; one complete and five partial responses] with a median duration of response of 9.1 months (range, 6.9-31.3 months). Median progression-free survival (mPFS) was 7.3 months (95% CI 1.9-13.6 months). Patients without prior KIT inhibitor therapy had a higher ORR and longer mPFS (n = 17, ORR 29%, mPFS 10.2 months) than those who had received prior KIT inhibitor treatment (n = 9, ORR 11%, mPFS 2.9 months). The most common treatment-related treatment-emergent adverse events (TEAEs) of any grade in ≥15% of patients were increased lipase, alopecia, actinic keratosis, myalgia, arthralgia, decreased appetite, fatigue, hyperkeratosis, nausea, and palmar-plantar erythrodysesthesia syndrome. There were no grade ≥4 treatment-related TEAEs.

CONCLUSIONS

In this phase I study, ripretinib demonstrated encouraging efficacy and a well-tolerated safety profile in patients with KIT-altered metastatic melanoma, suggesting ripretinib may have a clinically meaningful role in treating these patients.

The subgingival microbiomes in periodontitis and health of individuals with rheumatoid arthritis and at risk of developing rheumatoid arthritis

Serum anti-citrullinated protein antibodies (ACPAs), present in 70% of people with rheumatoid arthritis (RA), can be detected ≤10years before the onset of clinical disease. RA and periodontitis are epidemiologically associated and we have reported a high incidence of periodontitis in people who are ACPA+ and at risk of RA. Periodontal bacteria may contribute by multiple routes to the generation of RA-autoantibodies. This study aims to characterise the subgingival microbiomes from periodontitis and health in individuals with/without RA and at risk of RA.

Forty-five ACPA+ no RA (RA-at-risk; RAR), 31 healthy controls (HC) and 30 ACPA+ RA patients (RA) underwent a periodontal examination. DNA from subgingival plaque from healthy and deep pocket sites were paired-end sequenced using the Illumina HiSeq3000 and data analysed using MG-RAST + DESeq.

Metagenomes in RA samples had high proportions of Actinobacteria; RAR microbiomes contained higher proportions of Bacteroidetes than HC. The relative abundance of P. gingivalis was high in periodontitis and RAR; Aggregatibacter actinomycetemcomitans was detected with similar frequency in each group. Other bacteria implicated in periodontitis and/or autoantibody generation (Filifactor alocis, Prevotella spp, Leptotrichia spp.) were detected. Analyses are on-going to elucidate the diversity and functional potential of the subgingival microbiome associated with RA.

Abstract P3-03-05: Establishment and evaluation of ER+ breast cancer models using an optimized methodology for exogenous hormone delivery

Preclinical in vivo models of estrogen receptor positive (ER+) breast cancer rely on exogenous supplementation of hormones for growth. This requirement leads to animal toxicity and mortality over time, limiting development and drug testing in these types of models. Efficacy of test agents, particularly endocrine therapies, may also be altered in these models due to excessive hormone exposure, highlighting the need to improve methods for the establishment and testing of ER+ breast models.

We have developed an alternative method of hormone supplementation in ER+ breast cancer models and optimized this method for testing of endocrine therapies. Using two cell-based breast models, we demonstrated improved breast tumor take and time to tumor volume endpoint while reducing animal toxicity and mortality associated with standard hormone supplementation. Subsequent studies identified the lowest effective dose (LED) of supplement for hormone dependent model growth with a preclinically relevant time to tumor volume endpoint. Activity of endocrine therapies including tamoxifen, letrozole, fulvestrant and exemestane were compared at the standard and LED hormone concentrations. In these studies tamoxifen treatment resulted in tumor regressions which was not appreciably improved using the LED dose of supplement. However letrozole activity was improved in the LED study suggesting hormone supplementation can impact activity of some agents. Using this process we also generated a panel of ER+ patient-derived xenograft (PDX) models, including two novel hormone therapy responsive models from chemo-naïve or hormone therapy pretreated patients, designated ST986 and ST2177, respectively.

This improved method of hormone supplementation diminishes the adverse effects of standard hormone supplementation and provides utility for development of anticancer therapies in ER+ breast models.

Citation Format: Wick MJ, Vaught T, Meade J, Gamez L, Farley M, Tolcher AW, Rasco D, Patnaik A, Drengler RL, Rosenthal A, Papadopoulos KP. Establishment and evaluation of ER+ breast cancer models using an optimized methodology for exogenous hormone delivery. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-03-05.

Brood sex ratio variation in a cooperatively breeding bird

In cooperatively breeding species, the fitness consequences of producing sons or daughters depend upon the fitness impacts of positive (repayment hypothesis) and negative (local competition hypothesis) social interactions among relatives. In this study, we examine brood sex allocation in relation to the predictions of both the repayment and the local competition hypotheses in the cooperatively breeding long-tailed tit Aegithalos caudatus. At the population level, we found that annual brood sex ratio was negatively related to the number of male survivors across years, as predicted by the local competition hypothesis. At an individual level, in contrast to predictions of the repayment hypothesis, there was no evidence for facultative control of brood sex ratio. However, immigrant females produced a greater proportion of sons than resident females, a result consistent with both hypotheses. We conclude that female long-tailed tits make adaptive decisions about brood sex allocation.

Migration and stopover in a small pelagic seabird, the Manx shearwater Puffinus puffinus: insights from machine learning

The migratory movements of seabirds (especially smaller species) remain poorly understood, despite their role as harvesters of marine ecosystems on a global scale and their potential as indicators of ocean health. Here we report a successful attempt, using miniature archival light loggers (geolocators), to elucidate the migratory behaviour of the Manx shearwater Puffinus puffinus, a small (400 g) Northern Hemisphere breeding procellariform that undertakes a trans-equatorial, trans-Atlantic migration. We provide details of over-wintering areas, of previously unobserved marine stopover behaviour, and the long-distance movements of females during their pre-laying exodus. Using salt-water immersion data from a subset of loggers, we introduce a method of behaviour classification based on Bayesian machine learning techniques. We used both supervised and unsupervised machine learning to classify each bird's daily activity based on simple properties of the immersion data. We show that robust activity states emerge, characteristic of summer feeding, winter feeding and active migration. These can be used to classify probable behaviour throughout the annual cycle, highlighting the likely functional significance of stopovers as refuelling stages.

Dissemination of Cronobacter spp. (Enterobacter sakazakii) in a powdered milk protein manufacturing facility

The microbial contamination of air filters and possible links to contaminated product in a powdered milk protein-processing facility were investigated. Over a 10-month period, seven air filters, the environment, and powdered product were analyzed for the presence of Cronobacter spp. The effects of air filter installation, maintenance, and subsequent dissemination of Cronobacter were investigated. A total of 30 isolates were characterized by pulsed-field gel electrophoresis (PFGE). PFGE revealed the presence of three clonal populations distributed throughout the manufacturing site. This study highlights the need for proper installation of air filters to limit the dissemination of microorganisms into processing sites.

Latex allergy in the workplace

While less than 1% of the general population is sensitized to latex, the U.S. Occupational Safety and Health Administration estimates that 8-12% of health-care workers are sensitized. The major source of workplace exposure is powdered natural rubber latex (NRL) gloves. NRL is harvested from HEVEA: brasiliensis trees and ammoniated to prevent coagulation resulting in the hydrolysis of the latex proteins. Prior to use in manufacturing, the latex is formulated by the addition of multiple chemicals. Thus, human exposure is to a mixture of residual chemicals and hydrolyzed latex peptides. Clinical manifestations include irritant contact dermatitis, allergic contact dermatitis (type IV), and type I immediate hypersensitivity response. Type I (IgE-mediated) NRL allergy includes contact urticaria, systemic urticaria, angioedema, rhinitis, conjunctivitis, bronchospasm, and anaphylaxis. Taking an accurate history, including questions on atopic status, food allergy, and possible reactions to latex devices makes diagnosis of type-I latex allergy possible. To confirm a diagnosis, either in vivo skin prick testing (SPT) or in vitro assays for latex-specific IgE are performed. While the SPT is regarded as a primary confirmatory test for IgE-mediated disease, the absence of a U.S. Food and Drug Administration-licensed HEVEA: brasiliensis latex extract has restricted its use in diagnosis. Serological tests have, therefore, become critically important as alternative diagnostic tests. Three manufacturers currently have FDA clearance for in vitro tests, to detect NRL-specific IgE. The commercially available assays may disagree on the antibody status of an individual serum, which may be due to the assay's detecting anti-NRL IgEs to different allergenic NRL proteins. Sensitized individuals produce specific IgE antibody to at least 10 potent HEVEA: allergens, Hev b 1-Hev b 10, each of which differs in its structure, size, and net charge. The relative content and ratios of Hevs in the final allergen preparation most probably could effect diagnostic accuracy. The Hev proteins have been cloned and expressed as recombinant proteins. Sequencing demonstrates both unique epitopes and sequences commonly found in other plant proteins. Sequence homology helps to explain the cross reactivity to a variety of foods experienced by latex allergic individuals. The development of recombinant allergens provides reagents that should improve the diagnostic accuracy of tests for latex allergy. Although clinical and exposure data have been gathered on the factors affecting response in latex-allergic individuals, less is known regarding the development of sensitization. Coupled with in vitro dermal penetration studies, murine models have been established to investigate the route of exposure in the development of latex sensitization. Time-course and dose-response studies have shown subcutaneous, intratracheal, or topical administrations of non-ammoniated latex proteins to induce IgE production. Both in vitro penetration and in vivo studies highlight the importance of skin condition in the development of latex allergy, with enhanced penetration and earlier onset of IgE production seen with experimentally abraded skin. The diagnosis of latex allergy is complicated by these variables, which in turn hinder the development of intervention strategies. Further epidemiological assessment is needed to more explicitly define the scope, trends, and demographics of latex allergy. Diagnostic accuracy can be improved through greater knowledge of proteins involved in the development of latex allergy, and better documentation of the presently available diagnostic tests. In vivo and in vitro models can elucidate mechanisms of sensitization and provide an understanding of the role of the exposure route in latex allergy-associated diseases. Together, these efforts can lead to intervention strategies for reducing latex allergy in the workplace.

Determinants of HIV risk among men who have homosexual sex and inject drugs

Men with histories of both homosexual contact and injecting drug use (IDU) are at increased risk of HIV infection over men who have only one such risk. Despite this, their special needs and circumstances have been neglected by AIDS prevention programmes. A survey of a wide spectrum of homosexual male IDUs was carried out in Melbourne and Sydney in 1993 to inform the development of specific policy and programmes for HIV prevention in these subcultures. Of 169 men, self-reported HIV prevalence was 27%. Decreasing compliance with safe sex guidelines (as measured by numbers of casual partners, participation in anal intercourse and use of condoms) was associated with HIV seropositivity, increased age, and increased participation in sex work; having a regular male partner was not protective against unsafe sexual behaviour, no matter the length of the relationship. A substantial proportion (15%) reported inconsistent condom use during anal sex with more than two partners in the preceding month: they were slightly more likely to be engaging in sex work, less 'stable' and more likely to be HIV infected. Sexual risk was not strongly associated with unsafe injecting, which was in general safe. Men who both have homosexual sex and inject drugs are groups at high risk of HIV, more from unsafe sex than from shared injecting equipment; men who believed themselves to be HIV infected were continuing to have sex in such a way that would allow transmission. These are clearly groups in need of priority targeted interventions.

Comparison of PT, aPTT, and factor VII values obtained by concurrent sample collection by direct venipuncture and peripheral venous catheters

STUDY OBJECTIVE

To compare prothrombin time (PT), activated partial thromboplastin time (aPTT), and factor VII values in concurrent blood samples obtained by direct venipuncture and from a peripheral venous catheter.

DESIGN

Concurrent samples obtained from catheters and by direct venipuncture were studied. In a separate crossover bioequivalence assessment of DNA-derived factor VIIa (rFVIIa) from two different batches, sample results of each technique were compared.

SETTING

University hospital clinical research unit.

PATIENTS

Six patients with hemophilia A under nonbleeding conditions.

INTERVENTIONS

The patients received a single dose of rFVIIa 70 micrograms/kg administered by intravenous push over 2 minutes. Concurrent blood samples were collected at 2, 3, 4, 6, 8, 10, and 12 hours after rFVIIa administration. Catheter blood samples were drawn from a three-way stopcock attached to an 18-gauge peripheral venous catheter in the patient's forearm and connected to an intravenous solution of 5% dextrose with half normal saline maintained at a rate of 30 ml/hour. Venipuncture samples were drawn from the opposite arm.

MEASUREMENTS AND MAIN RESULTS

The PT and aPTT values were determined by using a BBL Fibrometer (PT) and a Coagamate X-2 with automated aPTT reagent. Blood samples were analyzed for factor VII concentration using the Novo Clot assay. The mean venipuncture-obtained PT (8.9 +/- 1.0 sec) and aPTT (48.7 +/- 13.6 sec) values were numerically equivalent to mean catheter-derived PT (9.0 +/- 1.0 sec) and aPTT (48.3 +/- 12.5 sec) results, as were mean venipuncture and catheter-obtained FVII:C values.

CONCLUSIONS

The PT and aPTT values determined after venipuncture and through the peripheral catheter were not statistically different (p > 0.05) when compared by paired or unpaired analysis. Similarly, values of FVII:C measured after venipuncture were statistically equivalent to those after sampling through the peripheral catheter. All six patients preferred the catheter method of blood collection over venipuncture.

Motor behavior and motor nervous system function in the nematode Ascaris suum

Ascaris suum has a nervous system that is very simple both numerically and morphologically. It comprises only 298 neurons almost all of which are extremely simple in shape. Extensive anatomical descriptions of the morphology of neurons and of their synaptic connections, together with the study, by using intracellular recording techniques, of their physiological properties, have led to a prediction of how the motor nervous system controls behavior. Subsequent discovery of endogenous neuropeptides that have potent activity on subsets of the motor neurons suggests that the description of the motor circuitry is more complex than is apparent from its anatomy.

Adrenal regulation of mammary tumorigenesis in female Sprague-Dawley rats: incidence, latency, and yield of mammary tumors

Huggins and Morii (J. Exp. Med., 114: 741, 1961) reported that massive adrenal necrosis occurs in 79 and 100% of female Sprague-Dawley rats receiving 20 and 30 mg, respectively, of the mammary carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). Here, adrenal necrosis and regeneration were studied in 158 rats for up to 21 days post-DMBA by radioautography of the adrenals of animals given 50 microCi [3H]thymidine 30 min before sacrifice. Adrenal cell proliferation was markedly inhibited 21 days post-DMBA. Regenerated adrenals were more susceptible to this adrenocorticolytic effect. To investigate if alterations in adrenal function modify tumorigenesis, animals underwent adrenalectomies (ADX), hypophysectomies, ovariectomies, and pituitary transplants alone or in combination 6 days after receiving DMBA (20 mg/100 g intragastrically) at 50 days of age. To prevent adrenal necrosis, 24 animals were pretreated with metyrapone. Methylprednisolone acetate, 1 mg i.m., was given to 40 animals every 5 days beginning 6 days post-DMBA. There were 50 non-DMBA-treated intact and surgical controls. DMBA was necessary but not sufficient to induce mammary tumors. No tumors developed in controls or in 46 animals hypophysectomized 6 days after DMBA. Metyrapone reduced tumor incidence and yield. ADX after DMBA treatment increased the tumorigenic response and eliminated resistance to tumorigenesis in older rats. Only three tumors developed in DMBA-treated rats receiving methylprednisolone acetate. Mammary tumorigenesis was increased by pituitary transplant 6 days after DMBA to intact and ADX animals. Ovariectomy 6 days after DMBA was as effective as methylprednisolone acetate in preventing tumorigenesis; ADX did not overcome either inhibition. We conclude that adrenal hormones inhibit proliferation of initiated mammary cells.

The relationship between hypertrophy and dilatation in the postmortem heart

Confusion may exist at the time of postmortem examination as to whether the diseased heart is dilated, hypertrophied, or both. Ventricular dilatation and ventricular hypertrophy were therefore evaluated by cardiac partition techniques in 441 subjects at autopsy to determine their relationship. Specific weight and surface area of each ventricle were obtained and patients were divided into categories of disease. Wall thickness measurements, a parameter routinely used in the ordinary autopsy, were found to be unreliable in defining hypertrophy. Ventricular surface area (an index of dilatation) was highly correlated with ventricular weight in most disease categories. Exceptions were cardiomyopathy and aortic stenosis, in which hypertrophy predominated. We conclude from these data that dilatation and hypertrophy occur proportionately in the postmortem heart in most disease categories except in cardiomyopathy and aortic stenosis. These findings clarify the relationship of dilatation and hypertrophy at the time of autopsy in most cases. Therefore, uncertainty as to whether cardiac dilatation or hypertrophy is present or which predominates is usually related to the inability to assess these states critically at the time of autopsy when the ordinary pathological methods are used.

Expression and regulation of the Escherichia coli glutamate dehydrogenase gene (gdh) in Rhizobium japonicum

The glutamate dehydrogenase (gdh) gene of Escherichia coli was transferred into an ammonium assimilation deficient mutant (Asm-) of Rhizobium japonicum (CJ9) using plasmid pRP301, a broad host range derivative of RP4. Exconjugants capable of growth on ammonia as sole N-source occurred at a frequency of 6.8 X 10(-6). Assimilatory GDH (NADP+) activity was detected in the strain carrying the E. coli gdh gene and the pattern of ammonia assimilation via GDH was similar to that of the Asm+ wild type strain. However, GDH mediated ammonia assimilation was not subject to regulation by L-glutamate. Nitrogenase activity was expressed ex planta in R. japonicum CJ9 harbouring the gdh gene, however, the presence of the gdh gene did not restore symbiotic effectiveness to the CJ9 Asm- strain in nodules. The gdh plasmid was maintained in approximately 90% of the isolates recovered from soybean nodules.

Studies on the Inoculation and Competitiveness of a Rhizobium leguminosarum Strain in Soils Containing Indigenous Rhizobia

The competitiveness of a Rhizobium leguminosarum strain was investigated at two separate locations in field inoculation studies on commercially grown peas. The soil at each location (sites I and II) contained an indigenous R. leguminosarum population of ca. 3 × 10 4 rhizobia per g of soil. At site I it was necessary to use an inoculum concentration as large as 4 × 10 7 CFU ml −1 (2 × 10 6 bacteria seed −1 ) to establish the inoculum strain in the majority of nodules (73%). However, at site II the inoculum strain formed only 33% of nodules when applied at this (10 7 CFU ml −1 ) level. Establishment could not be further improved by increasing the inoculum concentration even as high as 10 9 CFU ml −1 (9.6 × 10 7 bacteria seed −1 ). The inoculum strain could be detected at both sites 19 months after inoculation. Analysis by intrinsic antibiotic resistance patterns and plasmid DNA profiles indicated that a dominant strain(s) and plasmid pool existed among the indigenous population at site II. Competition experiments were carried out under laboratory conditions between a dominant indigenous isolate and the inoculum strain. Both strains were shown to be equally competitive.

Sensitivity of electrocardiographic criteria for left ventricular hypertrophy according to type of cardiac disease

The sensitivity of 30 electrocardiographic criteria for left ventricular (LV) hypertrophy, isolated or combined, was examined to determine the relation to the underlying disease. Patients with coronary artery disease (CAD), systemic hypertension, valvular heart disease and cardiomyopathy were evaluated. A cardiac partition technique was used to define ventricular hypertrophy. Single electrocardiographic criteria often showed high sensitivity for 1 disease state, but not for others. Precordial voltage criteria were most sensitive for those with hypertensive and valvular disease. A QRS axis of more than -30 degrees occurred most often in patients with CAD. Both left atrial abnormality and abnormal T-wave inversion of more than 1 mm in V6 occurred with a high sensitivity in general; however, T-wave inversion of more than 1 mm in V6 had a low sensitivity in cardiomyopathy. Methods using combinations of various electrocardiographic criteria improved sensitivity. Using these methods, sensitivity of the electrocardiogram for LV hypertrophy was excellent for patients with systemic hypertension and valvular heart disease and acceptable by usual standards for patients with CAD and cardiomyopathy. Because the use of a single criterion is often ineffective, methods using multiple electrocardiographic criteria to detect LV hypertrophy are recommended when the patients under study have diverse cardiac diseases.

Reevaluation of electrocardiographic criteria for left, right and combined cardiac ventricular hypertrophy

Cardiac chamber weight was determined at necropsy in 323 men to develop correlative studies of electrocardiographic criteria for ventricular hypertrophy. Thirty recommended criteria for left ventricular (LV) hypertrophy, 10 for right ventricular (RV) hypertrophy, and combinations of both criteria for combined hypertrophy were evaluated. Four methods for electrocardiographic diagnosis of LV hypertrophy were derived: (1) a modification of the Romhilt-Estes point system; (2) the presence of any 1 of 3 criteria: (a) S V1 + R V5 or V6 greater than 35 mm, (b) left atrial abnormality, or (c) intrinsicoid deflection in lead V5 or V6 greater than or equal to 0.05 second; (3) a combination of any 2 criteria or of 1 criterion (above) plus at least 1 of the following 3 additional criteria: (a) left-axis deviation greater than -30 degrees, (b) QRS duration greater than 0.09 second, or (c) T-wave inversion in lead V6 of 1 mm or more; and (4) the use of a single criterion--left atrial abnormality. Sensitivity varied from 57 to 66% and specificity from 85 to 93% among these 4 methods. Myocardial infarction increased sensitivity of the foregoing methods, but the specificity was reduced. Method 2 is preferred for the electrocardiographic diagnosis of LV hypertrophy. Two methods were useful for right ventricular (RV) hypertrophy: (1) the use of any 1 of 4 criteria: (a) R/S ratio in lead V5 or V6 less than or equal to 1; (b) S V5 or V6 greater than or equal to 7 mm; (c) right-axis deviation of more than +90 degrees, or (d) P pulmonale; and (2) use of any 2 combinations of the foregoing criteria. Sensitivity ranged from 18 to 43% and specificity from 83 to 95%. Combined hypertrophy was best diagnosed using left atrial abnormality as the sole criteria of LV hypertrophy, plus any 1 of 3 criteria of RV hypertrophy: (a) R/S ratio in lead V5 or V6 less than or equal to 1, (b) S V5 or V6 greater than or equal to 7 mm, or (c) right axis deviation greater than +90 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)

Descriptive characteristics of the electrocardiogram from autopsied men free of cardiopulmonary disease--a basis for evaluating criteria for ventricular hypertrophy

Most measurements establishing standard values for the normal electrocardiogram have been derived from a healthy population, whereas many electrocardiographic interpretations are necessary in hospitalized or seriously ill patients. Therefore, the characteristics of the electrocardiogram were described from 48 autopsied men known to be free of cardiopulmonary disease by clinical assessment and by a special cardiac examination using postmortem coronary angiography and a chamber partition technique. Highest values, mean and standard deviation, and the upper 97.5 percentile or lower 2.5 percentile when appropriate were noted for QRS voltage, QRS axis and duration, and intrinsicoid deflection in V5 or V6. Any ST-segment and T-wave changes were noted as well as left and right atrial abnormalities. Twenty-eight electrocardiographic criteria recommended to detect left ventricular hypertrophy and 10 recommended to detect right ventricular hypertrophy were evaluated for percentage of false-positive results and the 97.5 percentile value for each criterion was developed from the present data base. The data in this study can be used as a standard for comparing electrocardiographic variation in middle-aged men with specific relevance for electrocardiographic criteria of ventricular hypertrophy.

Two temperature-sensitive mutants of Saccharomyces cerevisiae with altered expression of mating-type functions

Two mutants of Saccharomyces cerevisiae have been isolated from normal haploid MAT alpha strains and characterized as having temperature-sensitive, pleiotropic phenotypes for functions associated with mating. At the permissive temperature, 23 degrees C, they were found to behave as normal MAT alpha haploids with respect to mating efficiency, sporulation in diploids formed with MAT a strains, secretion of alpha-factor, and failure to secrete the MATa-specific products, a-factor and Barrier. At higher temperatures they were found to decline in mating and sporulation efficiency and to express the a-specific functions. Genetic analysis established that one of these mutants, PE34, carries a temperature-sensitive allele of the MAT alpha 2 gene and that the other, PD7, carries a temperature-sensitive allele of the TUP1 gene.

A mathematical model for deriving hospital service areas

The basic premise explored in this paper is that patient flow in rural areas is based on the proximity to medical care. The hospital is defined as the center of care and hospital catchment areas are defined by patient movements. A methodology is described to analyze patient flow among an assemblage of hospitals. Finally, a model which mathematically replicates patient movement is introduced to act as an aid in the hospital planning process.