Selfishness and altruism can coexist when help is subject to diminishing returns.

Altruism and selfishness are 30-50% heritable in man in both Western and non-Western populations. This genetically based variation in altruism and selfishness requires explanation. In non-human animals, altruism is generally directed towards relatives, and satisfies the condition known as Hamilton's rule. This nepotistic altruism evolves under natural selection only if the ratio of the benefit of receiving help to the cost of giving it exceeds a value that depends on the relatedness of the individuals involved. Standard analyses assume that the benefit provided by each individual is the same but it is plausible in some cases that as more individuals contribute, help is subject to diminishing returns. We analyse this situation using a single-locus two-allele model of selection in a diploid population with the altruistic allele dominant to the selfish allele. The analysis requires calculation of the relationship between the fitnesses of the genotypes and the frequencies of the genes. The fitnesses vary not only with the genotype of the individual but also with the distribution of phenotypes amongst the sibs of the individual and this depends on the genotypes of his parents. These calculations are not possible by direct fitness or ESS methods but are possible using population genetics. Our analysis shows that diminishing returns change the operation of natural selection and the outcome can now be a stable equilibrium between altruistic and selfish alleles rather than the elimination of one allele or the other. We thus provide a plausible genetic model of kin selection that leads to the stable coexistence in the same population of both altruistic and selfish individuals. This may explain reported genetic variation in altruism in man.

Population genetic models can be used to study the evolution of the interacting behaviours of parents and their progeny.

An example of the evolution of the interacting behaviours of parents and progeny is studied using iterative equations linking the frequencies of the gametes produced by the progeny to the frequencies of the gametes in the parental generation. This population genetics approach shows that a model in which both behaviours are determined by a single locus can lead to a stable equilibrium in which the two behaviours continue to segregate. A model in which the behaviours are determined by genes at two separate loci leads eventually to fixation of the alleles at both loci but this can take many generations of selection. Models of the type described in this paper will be needed to understand the evolution of complex behaviour when genomic or experimental information is available about the genetic determinants of behaviour and the selective values of different genomes.

Consanguinity and the transmission/disequilibrium test for allelic association.

Consanguineous marriages, usually between first cousins or between uncle and niece, are common in certain societies. The transmission/disequilibrium test (TDT) compares the transmission from parents to an affected child of alleles at a marker locus, and differential transmission indicates linkage and allelic association between the marker locus and a disease locus. We investigate the consequences for the TDT, as a test for allelic association, of consanguineous marriages. For each parental marker mating type, we calculate the frequency of each disease mating type, and the associated probability that an offspring is affected. We use Bayes' Theorem to estimate the probability that an affected child inherits the given allele from a heterozygous parent, then combine our results across marker mating types. The effect of consanguineous marriage is usually small. For candidate genes, the effects were greater for uncle-niece marriages, for rare disease alleles, and for high genotype relative risk. For markers, the effects were generally negligible. The Type I error probability of the TDT is essentially unchanged by intermarriage, except for a purely recessive disease allele. The power of the TDT is increased for a recessive allele and decreased for a dominant allele. However, consideration of levels of consanguinity that arise in practice indicates that standard power calculations for the TDT will usually need only minor modification.

A phase II study of the bispecific antibody MDX-H210 (anti-HER2 x CD64) with GM-CSF in HER2+ advanced prostate cancer.

The proto-oncogene HER2 presents a novel therapeutic target. We report results in 25 patients with HER2+ advanced prostate cancer treated with the bispecific antibody MDX-H210 15 microg m(-2)by intravenous infusion plus GM-CSF 5 microg kg(-1)day(-1)by subcutaneous injection for 4 days repeated weekly for 6 weeks. Patients with stable disease or better received further cycles of treatment until disease progression or study withdrawal. 1 patient received no treatment and 4 received less than 1 cycle and are included in the toxicity analysis only. Median duration of follow up was 105+ (range 21-188) days. Toxicity was generally NCI-CTG 0-2. There were 2 grade 4 adverse events (heart failure and dyspnoea) and 1 grade 3 event (allergic reaction) resulting in discontinuation of the study medication. There were 9 further grade 3 events not resulting in trial withdrawal. There were no treatment-related deaths. 7/20 (35%) evaluable patients had a >50% PSA response of median duration 128 (range 71-184+) days. 7/12 (58%) patients with evaluable pain had improvements in pain scores. The PSA relative velocity on therapy decreased in 15/18 (83%) assessable patients compared to pre-study. GM-CSF and MDX-H210 is active in hormone refractory prostate carcinoma with acceptable toxicity; further studies are warranted.

Pharmacokinetic-pharmacodynamic relationships of the bispecific antibody MDX-H210 when administered in combination with interferon gamma: a multiple-dose phase-I study in patients with advanced cancer which overexpresses HER-2/neu.

INTRODUCTION: MDX-H210 is a Fab'xFab' bispecific antibody (BsAb) constructed chemically by crosslinking Fab' mAb 520C9 (anti-HER-2/neu) and Fab' mAbH22 (anti-CD64). STUDY DESIGN AND OBJECTIVES: This was a dose escalation study of intravenous MDX-H210 (1-70 mg/m(2)), preceded 24 h beforehand by subcutaneous IFNgamma (50 microg/m(2) to up-regulate FcgammaRI) administered three times a week for 3 weeks. We investigated the pharmacokinetic-pharmacodynamic relationships between MDX-H210 C(max) and AUC and (i) MDX-H210 binding to peripheral blood monocytes and neutrophils, (ii) the peak plasma G-CSF, IL-6, IL-8 and TNFalpha concentrations, and (iii) the observed clinical toxicity. RESULTS: 23 patients (19F:4M; median age 51.5; range 25-72 y) with advanced HER-2/neu positive cancers (19 breast, three prostate and one lung) were studied. Plasma MDX-H210 concentrations over time, circulating numbers of monocytes and neutrophils, percent saturation of monocyte and neutrophil FcgammaRI, and plasma concentrations over time of G-CSF, IL-6, IL-8 and TNFalpha were measured and clinical toxicity monitored. The E(max) pharmacodynamic model best fitted the relationship of MDX-H210 C(max) and the maximum percent saturation of both monocytes (E(max)=74.6; EC(50)=0.9 microg/ml) and neutrophils (E(max)=66.2; EC(50)=2.3 microg/ml) on the first day of treatment. On the last day of treatment, day 19, these parameters were E(max)=57.0% and EC(50)=0.46 microg/ml for monocytes and E(max)=61.9% and EC(50)=0.26 microg/ml for neutrophils. No positive relationship was defined between the log MDX-H210 C(max) and the log peak plasma IL-6, G-CSF, TNF or IL-8 concentrations on day 1. On day 19 these plasma cytokine concentrations were undetectable post MDX-H210 therapy. There was no consistent relationship between MDX-H210 C(max) and the observed clinical toxicities. CONCLUSIONS: These data suggest that MDX-H210 C(max) and AUC could be related by the E(max) model to maximum percent FcgammaRI saturation on circulating monocytes and neutrophils in the patients studied. After day 1, the post MDX-H210 therapy cytokine response attenuated over time, consistent with desensitization. We did not find a relationship between log MDX-H210 C(max) and peak plasma cytokine concentrations or clinical toxicities.

A phase I study of a HER2/neu bispecific antibody with granulocyte-colony-stimulating factor in patients with metastatic breast cancer that overexpresses HER2/neu.

A phase I study of escalating doses of humanized bispecific antibody (bsAb) MDX-H210 with granulocyte-colony-stimulating factor (G-CSF) was conducted in patients with metastatic breast cancer that overexpressed HER2/neu. The main objectives of the study were to define the maximal tolerated dose (MTD) of MDX-H210 when combined with G-CSF, to measure the pharmacokinetics of MDX-H210 when administered with G-CSF, and to determine the toxicity, biological effects and possible therapeutic effect of MDX-H210 with G-CSF. MDX-H210 is a F(ab)' x F(ab)' humanized bispecific murine antibody that binds to both HER2/neu and the FcgammaR1 receptor (CD64), and was administered intravenously weekly for three doses followed by a 2-week break and then three more weekly doses. A total of 23 patients were treated, and doses were escalated from 1 mg/m2 to 40 mg/m2 with no MTD reached. The toxicity of the bsAb + G-CSF combination was modest, with no dose-limiting toxicity noted: 19 patients had fevers, 7 patients had diarrhea, and 3 patients had allergic reactions that did not limit therapy. The beta-elimination half-life varied from 4 h to 8 h at doses up to 20 mg/m2. Significant release of cytokines interleukin-6, G-CSF, and tumor necrosis factor alpha was observed after administration of bsAb. Circulating monocytes disappeared within 1 h of bsAb infusion, which correlated with binding of bsAb, noted by flow-cytometric analysis. Significant levels of human anti-(bispecific antibody) were measured in the plasma of most patients by the third infusion. No objective clinical responses were seen in this group of heavily pre-treated patients.

Using information from both parents when testing for association between marker and disease loci.

Several extensions of the transmission/disequilibrium test (TDT) to multi-allelic markers now exist. In some of these, however, separate tests must be performed on male and female parents because of the non-independence of parental transmission patterns, reducing power, and complicating interpretation of the test results. Here we show that this non-independence is asymptotically irrelevant when using the allelic TDT of Bickeböller and Clerget-Darpoux [(1995) Genet Epidemiol 12:577-582], allowing the analysis of data from both parents simultaneously.

A likelihood ratio test for detecting patterns of disease-marker association.

A likelihood ratio test of disease-marker association is proposed, based on the observation of marker alleles transmitted from parents to affected children. The proposed association test has the advantage of identifying the population pattern of disease-marker association, differentiating between marker alleles that are positively and negatively associated with the disease. The power of the test for detecting association is evaluated and compared with three existing multi-allelic tests for some specific disease-marker association patterns. The power of the parametric tests depends crucially on the pattern of disease-marker association. An over-parameterised association model is less detrimental in terms of power than an under parameterised model.

Randomization tests of disease-marker associations.

A powerful test for population association of a disease with alleles at a bi-allelic marker locus is the transmission/disequilibrium test (TDT). A generalization of the test to multi-allelic marker loci is proposed which utilizes the maximal association of individual alleles with the disease, given by the maximum TDT statistic, TDT(max). To overcome the multiple testing problem encountered when using the maximal association to test the null hypothesis of no disease-marker association, a randomization procedure is developed. An investigation of the power of the test suggests that the randomization procedure performs almost as well as a recently proposed likelihood based test of linkage disequilibrium. The advantage of the new test is that it can be applied sequentially, based on a one-sided version of the TDT statistic, for investigating patterns of association of several individual alleles with the disease.

Testing candidate genes that may affect susceptibility to leprosy.

Several statistical methods have been used to search familial data sets for marker alleles associated with the occurrence of a disease. In the present paper, a recently developed method is used to re-analyze published data on leprosy and candidate genes at the HLA loci. This new method of analysis, the randomization transmission disequilibrium test (TDT), confirmed previous conclusions that there was no significant evidence against random transmission at the HLA-A locus but significant positive association with the HLA-DR2 allele. The randomization TDT detected significant protective associations, that had not previously been found, with alleles HLA-B8 in Egyptian families and HLA-B21 (current nomenclature B x 4901, 5001-5002) in South Indian families, highlighting a major advantage of permutation tests in analyzing candidate gene loci with rare alleles. These findings provide evidence that HLA class I restricted T lymphocytes may be of protective importance in leprosy.

Clinical experience with CD64-directed immunotherapy. An overview.

The class I IgG receptor (Fc gamma RI or CD64 receptor), which is present on key cytotoxic effector cells, has been shown to initiate the destruction of tumor cells in vitro and has been hypothesized to play a role in the destruction of antibody-coated cells such as platelets in idiopathic thrombocytopenia purpura (ITP). This overview summarizes the clinical experience with CD64-directed immunotherapy in cancer patients with the bispecific antibodies MDX-447 [humanized Fab anti-CD64 x humanized Fab anti-(epidermal growth factor receptor, EGFR)] and MDX-H210 (humanized Fab anti-DC64 x Fab anti-HER2/neu), and with the anti-CD64 monoclonal antibody (mAB) MDX-33 (H22) in the modulation of monocyte CD64 in vivo. In an ongoing phase I/II open-label trial with progressive dose escalation (1-15 mg/m2), patients with treatment refractory EGFR-positive cancers (renal cell carcinoma (RCC), head and neck, bladder, ovarian, prostate cancer and skin cancer) are treated weekly with intravenous MDX-447, with and without granulocyte-colony-stimulating factor (G-CSF). MDX-447 has been found to be immunologically active at all doses, binding to circulating monocytes and neutrophils (when given with G-CSF), causing monocytopenia and stimulating increases in circulating plasma cytokines. MDX-447 is well tolerated, the primary toxicities being fever, chills, blood pressure lability, and pain/ myalgias. Of 36 patients evaluable for response, 9 have experienced stable disease of 3-6 month's duration. The optimal dose and the maximal tolerated dose (MTD) have yet to be defined; dose escalation continues to define better the dose, toxicity, and the potential therapeutic role of this bispecific antibody. Three MDX-H210 phase II trials are currently in progress, all using the intravenous dose of 15 mg/m2 given with granulocyte/macrophage (GM-CSF). These consist of one trial each in the treatment of RCC patients, patients with prostate cancer, and colorectal cancer patients, all of whom have failed standard therapy. At the time of writing, 11 patients have been treated in these phase II trials. Four patients have demonstrated antitumor effects. Patients demonstrating responses include 2 with RCC and 2 with prostate cancer. One RCC patient has had a 54% reduction in size of a hepatic metastatic lesion and the other has had a 49% decrease in the size of a lung metastasis with simultaneous clearing of other non-measurable lung lesions. Regarding the two patients with prostate cancer, one has had a 90% reduction in serum prostate-specific antigen (PSA; 118-11 ng/ml), which has persisted for several months; the other patient with prostate has had a 70% reduction of serum PSA (872 ng/ml to 208 ng/ml) within the first month of treatment. Both patients have also demonstrated symptomatic improvement. In a completed phase I and in ongoing phase I/II clinical trials, patients with treatment-refractory HER2/neu positive cancers (breast, ovarian, colorectal, prostate) have been treated with MDX-H210, which has been given alone and in conjunction with G-CSF, GM-CSF, and interferon gamma (IFN gamma). These trials have been open-label, progressive dose-escalation (0.35-135 mg/m2) studies in which single, and more often, multiple weekly doses have been administered. MDX-H210 has been well tolerated, with untoward effects being primarily mild-to-moderate flu-like symptoms. The MTD has not yet been defined. MDX-H210 is immunologically active, binding to circulating monocytes, causing monocytopenia, as well as stimulating increases in plasma cytokine levels. Furthermore, some patients have evidence of active antitumor immunity following treatment with MDX-210. Antitumor effects have been seen in response to MDX-H210 administration; these include 1 partial, 2 minor, and 1 mixed tumor response; 15 protocol-defined stable disease responses have occurred. (ABSTRACT TRUNCATED)

Separating the environmental and genetic factors that may be causes of bovine spongiform encephalopathy.

The initial cause of the bovine spongiform encephalopathy (BSE) epidemic is generally accepted to have been the feeding of infected animal protein to cattle. The proportion of animals affected in any year in a particular herd has generally been low. This suggests either considerable variation in the extent of challenge of the individual animals or variation in their susceptibility to challenge or both. There is known to be genetic variation in susceptibility in other spongiform encephalopathies, such as scrapie in sheep. However, earlier indications that there may be associations between the incidence of BSE in cattle and polymorphisms and mutations in the PrP gene have not been confirmed (Hunter et al. 1994). Here, we attempt to model the likely extent of challenge of the individual animals in five Holstein Friesian pedigree herds and also the distribution of incubation times to the date of clinical onset. By studying the incidence of the disease in related animals we first found that single locus genetic models fitted the data much better than a non-genetic model. This was the first statistical evidence found of genetic variation in susceptibility to BSE. A check on the model in which individual animals were randomly allocated to 'parents' showed that the result was due to the lack of allowance in the non-genetic model for those animals insufficiently challenged or, for non-genetic reasons, resistant to their level of challenge. Thus there is still no evidence, molecular or statistical, for genetic variation in susceptibility. The importance of checking the attribution of genetic effects in complex models by the random allocation of progeny to parents is clear.

Optimal diets for egg production.

1. The Reading model for the egg production of a flock as determined by the intake of a single amino acid is based on the assumption that other amino acid intakes are not limiting egg production. This can result in an overestimation of the optimum intakes of each amino acid considered. 2. In this paper a model is introduced and an optimisation procedure presented that will allow the calculation of the optimal amounts of each of a number of amino acid intakes. 3. The method is illustrated by an example and the sensitivity of the results to different methods of calculation and different values of the parameters investigated. 4. A computer program, available from the authors, calculates optimal amino acid intakes for a flock defined in terms of the distribution of body weight and potential maximum egg production of the birds; the cost of the amino acids and the value of a unit of extra egg production. The program also allows the flock to be divided into 2 sub-flocks according to body weight and optimal diets calculated for each sub-flock.

The incidence of bovine spongiform encephalopathy in the progeny of affected sires and dams.

Case control study techniques were used to compare the incidence of bovine spongiform encephalopathy (BSE) in the progeny of two affected sires and 110 affected dams with the incidence of BSE in the progeny of animals known to be unaffected at the last record. All the progeny were born before the ban on ruminant-derived protein in feedstuffs issued in July 1988. The results provide little, if any, evidence of differences between the incidence in the progeny of the affected animals and the incidence in the progeny of the presumed unaffected animals. Data from five herds were used in a logistic regression analysis to study the effects of the disease status of the dam and the age of the dam at the birth of the calf on the incidence of BSE. The disease status of the dam did not significantly affect the disease status of its progeny, after allowance had been made for the effects of herd, year and the age at last record of the progeny. The difficulty of establishing maternal transmission if a high proportion of the dams are incubating the disease and transmission can occur early in the incubation period is discussed.

Using marker-maps in marker-assisted selection.

A method of using information on the location of markers to improve the efficiency of marker-assisted selection (MAS) in a population produced by a cross between two inbred lines is developed. The method is closer to mapping QTL than the selection index approaches to MAS described by previous authors. We use computer simulations to compare our method with phenotypic selection and two selection index approaches, simulations being performed on three genetic maps. The simulations show that whilst MAS can be considerably more efficient than phenotypic selection differences between the three MAS methods are slight. Which of the MAS methods is best depends on a number of factors: in particular the genetic map, the time scale under consideration ant the population size are of importance.

Lack of effect of CCKB receptor antagonists in ethological and conditioned animal screens for anxiolytic drugs.

The effects of the CCKB receptor antagonists L-365,260, CI-988 and L-740,093, a new compound with improved bioavailability and CNS penetration, were assessed for anxiolytic-like effects in three rat anxiolytic screens sensitive to benzodiazepines, the elevated plus maze (EPM), conditioned suppression of drinking (CSD) and conditioned emotional response (CER) tests. In the EPM, L-740,093 (0.1-1.0 mg/kg), L-365,260 (0.00001-10.0 mg/kg), and CI-988 (0.01-1.0 mg/kg) did not increase the time spent on the open arms of the maze or the number of entries onto the open arms. In contrast, the benzodiazepine receptor partial agonist, bretazenil (0.3-10.0 mg/kg), significantly increased both the time spent on the open arms and the number of open arm entries. In the CSD and the CER tests, L-740,093 (0.1-1.0 mg/kg) L-365,260 (0.0001-0.1 mg/kg) and CI-988 (0.01-10.0 mg/kg) failed to increase suppression ratios compared to the vehicle-treated control rats, whereas, the benzodiazepine receptor partial agonist FG 8205 (10.0 mg/kg) (CSD) and bretazenil (0.3-3.0 mg/kg) (CER) both significantly increased suppression ratios compared to vehicle-treated control rats. In addition, L-365,260 (1.0-50.0 mg/kg), CI-988 (0.1-10.0 mg/kg) and diazepam (0.1-1.0 mg/kg) were assessed in a squirrel monkey conflict procedure. Although diazepam significantly increased suppressed lever pressing rates, L-365,260 and CI-988 were without effect. The present findings provide little support for the hypothesis that CCKB receptor antagonists have anti-anxiety effects in animals.

The need for inpatient palliative care facilities for noncancer patients in the Thames Valley.

Inpatient facilities in palliative care units are generally considered to be mainly for cancer patients. We present and discuss the results of a survey that attempted to estimate the number of noncancer patients requiring inpatient palliative care. Questionnaires sent to all general practices in the Thames Valley area asked about the diagnosis and the number of bed-days that would have been required for each noncancer patient in the practice dying in the last year or still in their care. The replies suggest that about 11 noncancer patients per practice per year were in need of respite or continuing care. For the Thames Valley area this would amount to at least 66,000 bed-days per year for noncancer patients, compared with the current provision, mainly for cancer patients, of about 40,000 bed-days per year. The diagnoses involved and the reasons why our figures may overestimate need, are discussed. There can be no doubt that, if the need is to be met, current facilities will be inadequate and additional beds and services will be required.

Carrier risk calculations for recessive diseases when not all the mutant alleles are detectable.

The number of recessive diseases, such as cystic fibrosis, in which some but not all of the mutations causing the disease can be detected using genetic probes, is certain to increase. For counselling purposes, the probability that a consultand known not to have a detectable mutation is nevertheless a carrier, needs to be calculated with as much accuracy as possible. This paper describes a program, available from the author, written specifically to make these calculations. As an example, results are presented for cystic fibrosis, assuming an incidence of 1 in 2,400 and that 80% of the mutations, being delta F508 mutations, are detectable. Numerical results are given when information may be available on the parents, one or two sibs and one or two children of the consultand. When test results are available on the children, the test status of the spouse of the consultand is relevant and may also be available. Risk calculations are also presented when an aunt (uncle) of the consultand has cystic fibrosis. Finally, disease and carrier risks are given for the child of first cousins, neither of whom has a detectable mutation.

Lack of effect of flumazenil and CGS 8216 on the anxiolytic-like properties of loreclezole.

Loreclezole is a novel antiepileptic that interacts in a unique way with the GABAA receptor complex. Its anticonvulsant effect in rats is reversed by benzodiazepine receptor partial inverse agonists, such as CGS 8216 but not by the competitive benzodiazepine receptor antagonist, flumazenil (Ro 15-1788). In this study loreclezole (30.0-50.0 mg/kg i.p.) was found to induce an anxiolytic-like effect in a rat conditioned emotional response test that was reversed neither by flumazenil (10.0 mg/kg) nor by CGS 8216 (2-phenylpyrazolo[4,3-c]quinolin-3(5H)-one, 0.3-3.0 mg/kg). The results suggest that the anxiolytic-like effects of loreclezole are not mediated by the benzodiazepine receptor.