SAPPHIRE: phase III study of sitravatinib plus nivolumab versus docetaxel in advanced nonsquamous non-small-cell lung cancer

BACKGROUND

Checkpoint inhibitor (CPI) therapy revolutionized treatment for advanced non-small-cell lung cancer (NSCLC); however, most patients progress due to primary or acquired resistance. Sitravatinib is a receptor tyrosine kinase inhibitor that can shift the immunosuppressive tumor microenvironment toward an immunostimulatory state. Combining sitravatinib with nivolumab (sitra + nivo) may potentially overcome initial CPI resistance.

PATIENTS AND METHODS

In the phase III SAPPHIRE study, patients with advanced non-oncogenic driven, nonsquamous NSCLC who initially benefited from (≥4 months on CPI without progression) and subsequently experienced disease progression on or after CPI combined with or following platinum-based chemotherapy were randomized 1 : 1 to sitra (100 mg once daily administered orally) + nivo (240 mg every 2 weeks or 480 mg every 4 weeks administered intravenously) or docetaxel (75 mg/m2 every 3 weeks administered intravenously). The primary endpoint was overall survival (OS). The secondary endpoints included progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR), duration of response (DOR; all assessed by blinded independent central review), and safety.

RESULTS

A total of 577 patients included randomized: sitra + nivo, n = 284; docetaxel, n = 293 (median follow-up, 17.1 months). Sitra + nivo did not significantly improve OS versus docetaxel [median, 12.2 versus 10.6 months; hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.70-1.05; P = 0.144]. The median PFS was 4.4 versus 5.4 months, respectively (HR 1.08, 95% CI 0.89-1.32; P = 0.452). The ORR was 15.6% for sitra + nivo and 17.2% for docetaxel (P = 0.597); CBR was 75.5% and 64.5%, respectively (P = 0.004); median DOR was 7.4 versus 7.1 months, respectively (P = 0.924). Grade ≥3 treatment-related adverse events were observed in 53.0% versus 66.7% of patients receiving sitra + nivo versus docetaxel, respectively.

CONCLUSIONS

Although median OS was numerically longer with sitra + nivo, the primary endpoint was not met in patients with previously treated advanced nonsquamous NSCLC. The safety profiles demonstrated were consistent with previous reports.

Population structure, inbreeding and stripe pattern abnormalities in plains zebras

One of the most iconic wild equids, the plains zebra occupies a broad region of sub-Saharan Africa and exhibits a wide range of phenotypic diversity in stripe patterns that have been used to classify multiple subspecies. After decades of relative stability, albeit with a loss of at least one recognized subspecies, the total population of plains zebras has undergone an approximate 25% decline since 2002. Individuals with abnormal stripe patterns have been recognized in recent years but the extent to which their appearance is related to demography and/or genetics is unclear. Investigating population genetic health and genetic structure are essential for developing effective strategies for plains zebra conservation. We collected DNA from 140 plains zebra, including seven with abnormal stripe patterns, from nine locations across the range of plains zebra, and analyzed data from restriction site-associated and whole genome sequencing (RAD-seq, WGS) libraries to better understand the relationships between population structure, genetic diversity, inbreeding, and abnormal phenotypes. We found that genetic structure did not coincide with described subspecific variation, but did distinguish geographic regions in which anthropogenic habitat fragmentation is associated with reduced gene flow and increased evidence of inbreeding, especially in certain parts of East Africa. Further, zebras with abnormal striping exhibited increased levels of inbreeding relative to normally striped individuals from the same populations. Our results point to a genetic cause of stripe pattern abnormalities, and dramatic evidence of the consequences of habitat fragmentation.

Behavioral, climatic, and environmental risk factors for Zika and Chikungunya virus infections in Rio de Janeiro, Brazil, 2015-16

The burden of arboviruses in the Americas is high and may result in long-term sequelae with infants disabled by Zika virus infection (ZIKV) and arthritis caused by infection with Chikungunya virus (CHIKV). We aimed to identify environmental drivers of arbovirus epidemics to predict where the next epidemics will occur and prioritize municipalities for vector control and eventual vaccination. We screened sera and urine samples (n = 10,459) from residents of 48 municipalities in the state of Rio de Janeiro for CHIKV, dengue virus (DENV), and ZIKV by molecular PCR diagnostics. Further, we assessed the spatial pattern of arbovirus incidence at the municipal and neighborhood scales and the timing of epidemics and major rainfall events. Lab-confirmed cases included 1,717 infections with ZIKV (43.8%) and 2,170 with CHIKV (55.4%) and only 29 (<1%) with DENV. ZIKV incidence was greater in neighborhoods with little access to municipal water infrastructure (r = -0.47, p = 1.2x10^-8). CHIKV incidence was weakly correlated with urbanization (r = 0.2, p = 0.02). Rains began in October 2015 and were followed one month later by the largest wave of ZIKV epidemic. ZIKV cases markedly declined in February 2016, which coincided with the start of a CHIKV outbreak. Rainfall predicted ZIKV and CHIKV with a lead time of 3 weeks each time. The association between rainfall and epidemics reflects vector ecology as the larval stages of Aedes aegypti require pools of water to develop. The temporal dynamics of ZIKV and CHIKV may be explained by the shorter incubation period of the viruses in the mosquito vector; 2 days for CHIKV versus 10 days for ZIKV.

Genetic subdivision and candidate genes under selection in North American grey wolves

Previous genetic studies of the highly mobile grey wolf (Canis lupus) found population structure that coincides with habitat and phenotype differences. We hypothesized that these ecologically distinct populations (ecotypes) should exhibit signatures of selection in genes related to morphology, coat colour and metabolism. To test these predictions, we quantified population structure related to habitat using a genotyping array to assess variation in 42 036 single-nucleotide polymorphisms (SNPs) in 111 North American grey wolves. Using these SNP data and individual-level measurements of 12 environmental variables, we identified six ecotypes: West Forest, Boreal Forest, Arctic, High Arctic, British Columbia and Atlantic Forest. Next, we explored signals of selection across these wolf ecotypes through the use of three complementary methods to detect selection: FST /haplotype homozygosity bivariate percentilae, bayescan, and environmentally correlated directional selection with bayenv. Across all methods, we found consistent signals of selection on genes related to morphology, coat coloration, metabolism, as predicted, as well as vision and hearing. In several high-ranking candidate genes, including LEPR, TYR and SLC14A2, we found variation in allele frequencies that follow environmental changes in temperature and precipitation, a result that is consistent with local adaptation rather than genetic drift. Our findings show that local adaptation can occur despite gene flow in a highly mobile species and can be detected through a moderately dense genomic scan. These patterns of local adaptation revealed by SNP genotyping likely reflect high fidelity to natal habitats of dispersing wolves, strong ecological divergence among habitats, and moderate levels of linkage in the wolf genome.

Effect of maraviroc on non-R5 tropic HIV-1: refined analysis of subjects from the phase IIb study A4001029

We characterized maraviroc susceptibility of dual/mixed tropic viruses from subjects enrolled onto phase IIb study A4001029. Maraviroc baseline plasma samples from 13 multidrug-experienced subjects were sequenced and the HIV-1-env gene cloned into pNL4.3Δenv to obtain recombinant viruses. The V3 region was sequenced by the Sanger method and ultradeep sequencing. By analysing subjects having a weighted optimized background therapy susceptibility (wOBT) score of <1, 3/7 subjects were characterized by good in vivo and in vitro response to maraviroc therapy. Molecular docking simulations allowed us to rationalize the maraviroc susceptibility of dual/mixed tropic viruses. A subset of subjects with dual/mixed tropic viruses responded to maraviroc. Further investigations are warranted of CCR5 antagonists in subjects carrying dual/mixed tropic virus that explore the feasible use of maraviroc in subjects that is potentially larger than those infected with a pure R5 virus.

Metapopulation dynamics enable persistence of influenza A, including A/H5N1, in poultry

Highly pathogenic influenza A/H5N1 has persistently but sporadically caused human illness and death since 1997. Yet it is still unclear how this pathogen is able to persist globally. While wild birds seem to be a genetic reservoir for influenza A, they do not seem to be the main source of human illness. Here, we highlight the role that domestic poultry may play in maintaining A/H5N1 globally, using theoretical models of spatial population structure in poultry populations. We find that a metapopulation of moderately sized poultry flocks can sustain the pathogen in a finite poultry population for over two years. Our results suggest that it is possible that moderately intensive backyard farms could sustain the pathogen indefinitely in real systems. This fits a pattern that has been observed from many empirical systems. Rather than just employing standard culling procedures to control the disease, our model suggests ways that poultry production systems may be modified.

Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt

Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n=1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010-2012. Cloacal and tracheal swabs and serum samples from domestic (n=1242) and wild birds (n=807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n=306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n=51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F=15.7, p<0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F=29.5, p<0.0001).

Modelling response to HIV therapy without a genotype: an argument for viral load monitoring in resource-limited settings

In the absence of widespread access to individualized laboratory monitoring, which forms an integral part of HIV patient management in resource-rich settings, the roll-out of highly active antiretroviral therapy (HAART) in resource-limited settings has adopted a public health approach based on standard HAART protocols and clinical/immunological definitions of therapy failure. The cost-effectiveness of HIV-1 viral load monitoring at the individual level in such settings has been debated, and questions remain over the long-term and population-level impact of managing HAART without it. Computational models that accurately predict virological response to HAART using baseline data including CD4 count, viral load and genotypic resistance profile, as developed by the Resistance Database Initiative, have significant potential as an aid to treatment selection and optimization. Recently developed models have shown good predictive performance without the need for genotypic data, with viral load emerging as by far the most important variable. This finding provides further, indirect support for the use of viral load monitoring for the long-term optimization of HAART in resource-limited settings.

High degree of interlaboratory reproducibility of human immunodeficiency virus type 1 protease and reverse transcriptase sequencing of plasma samples from heavily treated patients

We assessed the reproducibility of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) and protease sequencing using cryopreserved plasma aliquots obtained from 46 heavily treated HIV-1-infected individuals in two laboratories using dideoxynucleotide sequencing. The rates of complete sequence concordance between the two laboratories were 99.1% for the protease sequence and 99.0% for the RT sequence. Approximately 90% of the discordances were partial, defined as one laboratory detecting a mixture and the second laboratory detecting only one of the mixture's components. Only 0.1% of the nucleotides were completely discordant between the two laboratories, and these were significantly more likely to occur in plasma samples with lower plasma HIV-1 RNA levels. Nucleotide mixtures were detected at approximately 1% of the nucleotide positions, and in every case in which one laboratory detected a mixture, the second laboratory either detected the same mixture or detected one of the mixture's components. The high rate of concordance in detecting mixtures and the fact that most discordances between the two laboratories were partial suggest that most discordances were caused by variation in sampling of the HIV-1 quasispecies by PCR rather than by technical errors in the sequencing process itself.

Laboratory guidelines for the practical use of HIV drug resistance tests in patient follow-up

HIV drug resistance is one of the major limitations in the successful treatment of HIV-infected patients using currently available antiretroviral combination therapies. When appropriate, drug susceptibility profiles should be taken into consideration in the choice of a specific combination therapy. Guidelines recommending resistance testing in certain circumstances have been issued. Many clinicians have access to resistance testing and will increasingly use these results in their treatment decisions. In this document, we comment on the different methods available, and the relevant issues relating to the clinical application of these tests. Specifically, the following recommendations can be made: (i) genotypic and phenotypic HIV-1 drug resistance analyses can yield complementary information for the clinician. However, insufficient information currently exists as to which approach is preferable in any particular clinical setting; (ii) when HIV-1 drug resistance testing is required, it is recommended that testing be performed on plasma samples obtained before starting, stopping or changing therapy, on samples that have a viral load above the detection limit of the resistance test; (iii) the panel recommends that genotypic and phenotypic HIV-1 drug resistance testing for clinical purposes be performed in a certified laboratory under strict quality control and quality assurance standards; and (iv) the panel recommends that resistance testing laboratories provide clinicians with resistance reports that include a list of drug-related resistance mutations (genotype) and/or a list of drug-related fold resistance values (phenotype), with interpretations of each by an experienced virologist. The interpretation of genotypic and phenotypic analysis is a complex and developing science, and in order to understand HIV-1 drug resistance reports, communication between the requesting clinician and the expert that interpreted the resistance report is recommended.

Avanti 3: A Randomized, Double-Blind Trial to Compare the Efficacy and Safety of Lamivudine plus Zidovudine versus Lamivudine plus Zidovudine plus Nelfinavir in HIV-1-Infected Antiretroviral-Naive Patients

The objective of our randomized, multicentre, double-blind, placebo-controlled study was to investigate the safety, tolerability, and antiretroviral and immunological effect of double and triple combination therapy regimens. A total of 105 antiretroviral therapy-naive patients were randomized to receive either zidovudine (300 mg twice per day) plus lamivudine (150 mg twice per day) plus nelfinavir placebo (three times per day) ( n=52), or zidovudine/lamivudine (dose as before) plus nelfinavir (750 mg three times per day) ( n=53) for 28 weeks. After this time, patients were allowed to switch to open-label zidovudine/lamivudine/nelfinavir. The overall log10 reduction from baseline in plasma HIV-1 RNA was significantly greater in the zidovudine/lamivudine/nelfinavir group than the zidovudine/lamivudine group ( P=0.001; median treatment difference, –1.01 log10 copies/ml; 95% confidence interval –1.23 to –0.79), as measured by the average area under the curve minus baseline over 28weeks. Increases from baseline in CD4 cell counts were statistically significantly greater in the zidovudine/lamivudine/nelfinavir group (101.5 cells/ml) than the zidovudine/lamivudine group (47.0 cells/ml; P=0.027) at week 28.

Of note, the addition of nelfinavir from weeks 28–52 led to an increase in the proportion of subjects with plasma HIV-1 RNA <400 copies/ml from 17% (9/52 patients on zidovudine/lamivudine) to 50% (13/26 patients who switched to zidovudine/lamivudine/nelfinavir). Incidence of drug-related adverse events was similar in the two groups, except for nausea (more common in zidovudine/lamivudine group; 40 versus 17%) and diarrhoea (more common in zidovudine/lamivudine/nelfinavir group; 45 versus 14%). In conclusion, our study confirms the efficacy of triple combination therapy with two nucleoside analogues and a protease inhibitor compared with double-nucleoside therapy. Interestingly, the addition of nelfinavir to zidovudine/lamivudine, even after 6 months of double nucleoside therapy, led to a substantial virological benefit that was sustained over 24weeks in a subset of patients.

Laboratory Guidelines for the Practical Use of HIV Drug Resistance Tests in Patient Follow-Up

HIV drug resistance is one of the major limitations in the successful treatment of HIV-infected patients using currently available antiretroviral combination therapies. When appropriate, drug susceptibility profiles should be taken into consideration in the choice of a specific combination therapy. Guidelines recommending resistance testing in certain circumstances have been issued. Many clinicians have access to resistance testing and will increasingly use these results in their treatment decisions. In this document, we comment on the different methods available, and the relevant issues relating to the clinical application of these tests. Specifically, the following recommendations can be made: (i) genotypic and phenotypic HIV-1 drug resistance analyses can yield complementary information for the clinician. However, insufficient information currently exists as to which approach is preferable in any particular clinical setting; (ii) when HIV-1 drug resistance testing is required, it is recommended that testing be performed on plasma samples obtained before starting, stopping or changing therapy, on samples that have a viral load above the detection limit of the resistance test; (iii) the panel recommends that genotypic and phenotypic HIV-1 drug resistance testing for clinical purposes be performed in a certified laboratory under strict quality control and quality assurance standards; and (iv) the panel recommends that resistance testing laboratories provide clinicians with resistance reports that include a list of drug-related resistance mutations (genotype) and/or a list of drug-related fold resistance values (phenotype), with interpretations of each by an experienced virologist. The interpretation of genotypic and phenotypic analysis is a complex and developing science, and in order to understand HIV-1 drug resistance reports, communication between the requesting clinician and the expert that interpreted the resistance report is recommended.

Culturally appropriate guidelines for alcohol and drug abuse prevention

Information on the efficacy of wellness protocols in culturally diverse populations is meager. A study was conducted to develop culturally appropriate guidelines to prevent alcohol and drug abuse. Five groups of women participated in focus groups; based on the participants' perceptions, Put Prevention into Practice guidelines for the prevention of alcohol and drug abuse were adapted for each group. Further research studies evaluating these adapted guidelines and developing additional culturally appropriate tools are needed.

Absence of zidovudine resistance in antiretroviral-naive patients following zidovudine/lamivudine/protease inhibitor combination therapy: virological evaluation of the AVANTI 2 and AVANTI 3 studies

OBJECTIVES

To assess the role of resistance mutations in subjects experiencing virological failure on zidovudine (ZDV) and lamivudine (3TC) combined with a protease inhibitor (PI) to those failing on ZDV/3TC alone.

DESIGN AND METHODS

Samples were obtained from previously antiretroviral therapy-naive subjects enrolled into two studies, AVANTI 2 and AVANTI 3. Subjects were randomized to receive either: ZDV/3TC or ZDV/3TC plus indinavir (IDV) for 52 weeks (AVANTI 2), and ZDV/3TC or ZDV/3TC and nelfinavir (NFV) for 28 weeks (AVANTI 3). Emergence of viral resistance mutations was monitored by population sequencing and phenotypic resistance was determined by the recombinant virus assay.

RESULTS

Genotypic data were obtained for subjects with plasma HIV-1 RNA > 400 copies/ml. In AVANTI 2, ZDV mutations were detected in 27% of ZDV/3TC-treated patients at week 52, but were absent in subjects treated with ZDV/3TC/IDV. No subjects from either arm of AVANTI 3 developed ZDV resistance mutations at week 28. The M184V mutation developed in most ZDV/3TC-treated subjects from both studies. The presence of M184V was, however, associated with significantly lower plasma viral RNA levels when compared with values obtained before initiation of treatment. There was a high frequency (4 of 11) of the protease L10F substitution in ZDV/3TC/IDV-treated patients that was associated with virological failure but did not result in phenotypic resistance to any of the PIs tested.

CONCLUSIONS

ZDV mutations were not detected in ZDV/3TC/PI-treated patients and they developed slowly in those treated with ZDV/3TC. Few protease mutations known to confer phenotypic PI resistance developed in the ZDV/3TC/PI arms of either study. The low prevalence of ZDV and PI mutations is encouraging regarding the future treatment options of these patients.

The relation between baseline HIV drug resistance and response to antiretroviral therapy: re-analysis of retrospective and prospective studies using a standardized data analysis plan

To assess the relation between resistance to antiretroviral drugs for treatment of HIV-1 infection and virological response to therapy, results from 12 different studies were re-analysed according to a standard data analysis plan. These studies included nine clinical trials and three observational cohorts. The primary end-point in our analyses was virological failure by week 24. Baseline factors that were investigated as predictors of virological failure were plasma HIV-1 RNA, the number and type of new antiretroviral drugs in the regimen, and viral susceptibility to the drugs in the regimen, determined by genotyping or phenotyping methods. These analyses confirmed the importance of both genotypic and phenotypic drug resistance as predictors of virological failure, whether these factors were analysed separately or adjusted for other baseline confounding factors. In most of the re-analysed studies, the odds of virological failure were reduced by about twofold for each additional drug in the regimen to which the patient's virus was sensitive by genotyping methods, and by about two- to threefold for each additional drug that was sensitive by phenotyping.

HIV-1 reverse transcriptase (RT) genotype and susceptibility to RT inhibitors during abacavir monotherapy and combination therapy

OBJECTIVE

To examine changes in HIV-1 susceptibility (genotype and phenotype) during an initial abacavir monotherapy phase followed by the addition of zidovudine and lamivudine.

DESIGN

Sixty HIV-1 infected, antiretroviral therapy-naive subjects were randomized to receive 100, 300 or 600 mg abacavir twice daily. Subjects completing 24 weeks of randomized therapy or meeting a protocol defined switch criterion could switch to open label abacavir/zidovudine/lamivudine.

METHODS

Plasma HIV-1 reverse transcriptase was genotyped at baseline, week 12, and at the last time point on ABC monotherapy. Drug susceptibility was analysed at baseline and on subsequent samples with sufficient HIV-1 RNA levels using the recombinant virus assay. Virological responses (week 24) were correlated to week 24 genotypes.

RESULTS

Mutant viruses were not detected before week 12 with the exception of one subject. At the latest time point on abacavir monotherapy (range, weeks 6-48), 21 out of 43 subjects harboured virus with resistance conferring mutations including single, double and triple combinations of K65R, L74V, Y115F and M184V. The most common mutational pattern was L74V + M184V (11/21 cases). Twenty of the 21 subjects with isolates containing abacavir-associated mutations reached week 48, and upon addition of lamivudine/zidovudiine, 16 out of 20 (80%) had week 48 plasma HIV-1 -RNA below 400 copies/ml. At week 48, 16 out of 46 genotypes were obtained; one of these was wild-type; 15 contained M184V either alone, in combination with K65R and/or L74V and/or Y115F or with thymidine analogue-associated mutations. Week 48 viral load levels for these 15 subjects was low (median 3.43 log10 copies/ml or -1.99 log10 copies reduction from baseline). Genotype correlated well with phenotypic resistance to ABC; four samples with three abacavir-associated mutations had high level abacavir resistance (> 8-fold) and six samples with two or three mutations showed intermediate (4-8-fold) resistance. All samples with single mutations retained full ABC susceptibility.

CONCLUSIONS

Resistance conferring mutations to abacavir were relatively slow to develop during the monotherapy phase, and did not preclude durable efficacy of abacavir/lamivudine/zidovudine up to 48 weeks.

Idiopathic neonatal hepatitis associated with a fatal coagulopathy

Idiopathic neonatal hepatitis (INH) remains a diagnosis of exclusion in the neonate with conjugated hyperbilirubinemia. The major diagnostic challenge for the clinician is to distinguish this condition from other treatable liver disorders such as biliary atresia. Although the prognosis varies for the familial and sporadic forms of neonatal hepatitis, a poor outcome is generally distinguished by chronic and progressive liver failure. After careful review of the literature, we were unable to find a case of INH associated with a profound, irreversible coagulopathy. Herein, we present a case with the primary presenting findings of persistent prolongation of the prothrombin time (PT) and hypofibrinogenemia, resulting in a catastrophic intracranial hemorrhage and death.

Antiretroviral therapy: 'the state of the art'

The field of antiretroviral therapy is evolving at a very rapid pace. At this time, the initiation and optimization of antiretroviral therapy is based on serial plasma viral load determinations which aim to suppress viral replication to as low as possible for as long as possible, thus preventing disease progression. Currently available antiretrovirals require combination therapy with at least three agents to achieve this goal. Increasing availability of newer and more potent antiretroviral regimens will continue to enhance and simplify the number of therapeutic options available in the not too distant future.

A rapid and simple method for extracting human immunodeficiency virus type 1 RNA from plasma: enhanced sensitivity

We present here a rapid and simple technique for processing human immunodeficiency virus (HIV)-infected plasma by high-speed centrifugation. HIV type 1 virions are pelleted from up to 1 ml of plasma, gently lysed with a nonionic detergent, and directly amplified. The procedure has few manipulations and requires approximately 1.5 h for the processing of 24 samples. Viral recovery ranges from 80 to 90%, with an analytical sensitivity approaching 20 copies/ml.

Prenatal cocaine exposure: implications for practice, policy development, and needs for future research

Terms such as coke babies and crack babies are appearing with increased frequency in the popular literature. Although the number of babies exposed to cocaine in utero has increased, synthesis of the literature to help determine the manifestations of cocaine exposure or to direct research on the problems experienced by cocaine-exposed infants and their care givers has yet to occur. In this analysis a synthesis of the literature related to the effects of perinatal cocaine exposure is provided. The manifestations, effects, and sequelae of cocaine exposure are explicated and a model is proposed to explain the mechanisms underlying physiologic and psychosocial expressions of exposure. Both time of exposure during gestation and dose relationships were identified as major predictor variables. Recommendations include the need for (1) an individualized intervention protocol and (2) prevention programs directed at pregnant women and women of childbearing age.

Perinatal grief: response to the loss of an infant

The grief response of parents following loss of an infant from a multiple gestation pregnancy was explored to describe the experience, compare and contrast mother's and father's responses, and analyze the properties of the Perinatal Grief Scale. Twenty-seven parents participated. Parental responses were complex and variable. Most parents disagreed with experiencing difficulty coping and despair. Confrontive, self reliant, and supportant coping strategies were used most frequently, while supportant, confrontive and optimistic strategies were reported the most effective. Anxiety, depression and alterations in activities of daily living were reported. The total impact of life events was slightly positive for this group. Although the instruments were reliable in this population of parents, sensitivity was reduced. A model of grief associated with multiple gestation perinatal loss was generated. Selection and effectiveness of coping strategies appear to be not only interrelated, but dependent on the time since the infants death and the length of the infants life. The length of an infant's life and time since death were affirmed as related to both the strength and type of relationship between variables associated with the grief response and to use and effectiveness of coping strategies. Responses of mothers and fathers appear to be similar.