Biology Criteria Research Articles

Long-term follow-up of patients with intermediate-risk neuroblastoma treated with response- and biology-based therapy: A report from the Children's Oncology Group study ANBL0531.

We previously reported excellent three-year overall survival (OS) for patients with newly diagnosed intermediate-risk neuroblastoma treated with a biology- and response-based algorithm on the Children's Oncology Group study ANBL0531. We now present the long-term follow-up results. All patients who met the age, stage, and tumor biology criteria for intermediate-risk neuroblastoma were eligible. Treatment was based on prognostic biomarkers and overall response. Event-free survival (EFS) and OS were estimated by the Kaplan-Meier method. The 10-year EFS and OS for the entire study cohort (n=404) were 82.0% (95% confidence interval (CI), 77.2%-86.9%) and 94.7% (95% CI, 91.8%-97.5%), respectively. International Neuroblastoma Staging System stage 4 patients (n=133) had inferior OS compared with non-stage 4 patients (n=271; 10-year OS: 90.8% [95% CI, 84.5%-97.0%] vs 96.6% [95% CI, 93.9%-99.4%], p=.02). Infants with stage 4 tumors with ≥1 unfavorable biological feature (n=47) had inferior EFS compared with those with favorable biology (n=61; 10-year EFS: 66.8% [95% CI, 50.4%-83.3%] vs 86.9% [95% CI, 76.0%-97.8%], p=.02); OS did not differ (10-year OS: 84.4% [95% CI, 71.8%-97.0%] vs 95.0% [95% CI, 87.7%-100.0%], p=.08). Inferior EFS but not OS was observed among patients with tumors with (n=26) versus without (n=314) 11q loss of heterozygosity (10-year EFS: 68.4% [95% CI, 44.5%-92.2%] vs 83.9% [95% CI, 78.7%-89.2%], p=.03; 10-year OS: 88.0% [95% CI, 72.0%-100.0%] vs 95.7% [95% CI, 92.8%-98.6%], p=.09). The ANBL0531 trial treatment algorithm resulted in excellent long-term survival. More effective treatments are needed for subsets of patients with unfavorable biology tumors.

Conservation of medicinal germplasm: a proposal to establish priorities based on conservation biology and ethnobotanical criteria

Conservation of medicinal germplasm: a proposal to establish priorities based on conservation biology and ethnobotanical criteria

Congenital Nephrotic Syndrome: About A Case

Summary: Congenital nephrotic syndrome is a nephrotic syndrome present from birth or in the first three months of life, while infantile nephrotic syndrome is defined by a later onset but in the first year of life. Finnish-type congenital nephrotic syndrome and diffuse mesangial sclerosis represent the two main etiologies. Accurate diagnosis is based on clinical, histological and molecular biology criteria, and antenatal diagnosis is possible in some cases. We report the case of a female newborn, premature 35 WA + 9J, without particular pathological ATCDS admitted on D1 of life for a positive infectious assessment objectifying a bicytopenia made of thrombocytopenia and a neutropenia requested following an infectious anamnesis. positive in the mother, put on ATB, the evolution was marked by the appearance of edema of the two lower limbs on D6 of hospitalization taking the bucket in front generalized with puffiness of the face on D13 of hospitalization, a biological assessment was made and confirmed the nephrotic syndrome: hypoproteinemia at 20.3 g/l + hypoalbuminemia at 10.3 g/l + proteinuria for 24 hours at 3.3 g/24 hours proteinuria/creatinuria ratio 55. Associated symptomatic treatment nephroprotective treatment based on converting enzyme inhibitors was started with regular monitoring of renal function. In conclusion the congenital and infantile nephrotic syndromes are rare and generally have a poor prognosis whose evolution towards terminal renal insufficiency requires a program of dialysis and renal transplantationto the in the intensive Care Department A1 of the Hassan II University Hospital of Fez for the management of CT.

Physiomimetic Façade Design

Adaptive façades are designed to actively regulate the exchange of material and energy flows and thus improve the balance between comfort and energy consumption. However, their technical complexity leads to higher development efforts, maintenance and costs, and ultimatelyfewer implementations. Embedded adaptive functions could be an opportunity to reduce these drawbacks. If embedded adaptivity is to work within a design, the particularities of geometry and material arrangements must be considered. Nature offers fascinating models for this approach, which frames the objectives of this doctoral dissertation. The dissertation examines both adaptive façades and biology criteria that support a function-oriented transfer of thermo-adaptive principles in the early design stage. The research work discusses whether the technical complexity can be reduced by biomimetic designs and which role geometric design strategies play for thermo-adaptive processes. The research work is divided into three phases, following the top-down process in the discipline biomimetics, supplemented by methods from product design and semantic databases. The first phase is dedicated to the analysis of the contextual framework and criteria of façades aiming at thermal adaptation. Further, transfer systematics are developed that guide the analysis and selection process. In the second phase, analogies in biology are collected that appear suitable. Selected examples are examined to identify and systematically describe their functional principle. Two exemplary descriptions herald the third phase, in which functional façade models are created and evaluated. The result of this research work provides a conceptual approach to generate function-imitating biomimetic façade designs, so-called physio-mimetic façade designs.

The 2020 WHO Classification of Tumors of Soft Tissue: Selected Changes and New Entities.

Soft tissue tumors are a relatively rare and diagnostically challenging group of neoplasms that can have varying lines of differentiation. Accurate diagnosis is important for appropriate treatment and prognostication. In the 8 years since the publication of the 4th Edition of World Health Organization (WHO) classification of soft tissue tumors, significant advances have been made in our understanding of soft tissue tumor molecular biology and diagnostic criteria. The 5th Edition of the 2020 WHO classification of tumors of soft tissue and bone incorporated these changes. Classification of tumors, in general, but particularly in soft tissue tumors, is increasingly based on the molecular characteristics of tumor types. Understanding tumor molecular genetics improves diagnostic accuracy for tumors that have been difficult to classify on the basis of morphology alone, or that have overlapping morphologic features. In many large hospitals in the United States and Europe, molecular tests on soft tissue tumors are a routine part of diagnosis. Therefore, surgical pathologists should be familiar with newly emerging molecular genetic techniques in clinical settings. In the near future, molecular tests, particularly in soft tissue tumor diagnosis, will become as routine during diagnosis as immunohistochemistry is currently. This new edition provides an updated classification scheme and essential diagnostic criteria for soft tissue tumors. Newly recognized entities and subtypes of existing tumor types, several reclassified tumors, and newly defined molecular and genetic data have been incorporated. Herein, we summarize the updates in the WHO 5th Edition, focusing on major changes in each category of soft tissue tumor, and the newly described tumor entities and subtypes.

Diagnostic Accuracy of CEUS LI-RADS for the Characterization of Liver Nodules 20 mm or Smaller in Patients at Risk for Hepatocellular Carcinoma.

Background American College of Radiology contrast agent-enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS) was developed to improve the accuracy of hepatocellular carcinoma (HCC) diagnosis at contrast agent-enhanced US. However, to the knowledge of the authors, the diagnostic accuracy of the system in characterization of liver nodules 20 mm or smaller has not been fully evaluated. Purpose To evaluate the diagnostic accuracy of CEUS LI-RADS in diagnosing HCC in liver nodules 20 mm or smaller in patients at risk for HCC. Materials and Methods Between January 2015 and February 2018, consecutive patients at risk for HCC presenting with untreated liver nodules 20 mm or less were enrolled in this retrospective double-reader study. Each nodule was categorized according to the CEUS LI-RADS and World Federation for Ultrasound in Medicine and Biology (WFUMB)-European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) criteria. Diagnostic performance of CEUS LI-RADS and WFUMB-EFSUMB characterization was evaluated by using tissue histologic analysis, multiphase contrast-enhanced CT and MRI, and imaging follow-up as reference standard and compared by using McNemar test. Results The study included 175 nodules (mean diameter, 16.1 mm ± 3.4) in 172 patients (mean age, 51.8 years ± 10.6; 136 men). The sensitivity of CEUS LR-5 versus WFUMB-EFSUMB criteria in diagnosing HCC was 73.3% (95% confidence interval [CI]: 63.8%, 81.5%) versus 88.6% (95% CI: 80.9%, 94%), respectively (P < .001). The specificity of CEUS LR-5 versus WFUMB-EFSUMB criteria was 97.1% (95% CI: 90.1%, 99.7%) versus 87.1% (95% CI: 77%, 94%), respectively (P = .02). No malignant lesions were found in CEUS LR-1 and LR-2 categories. Only two nodules (of 41; 5%, both HCC) were malignant in CEUS LR-3 category. The incidences of HCC in CEUS LR-4, LR-5, and LR-M were 48% (11 of 23), 98% (77 of 79), and 75% (15 of 20), respectively. Two of 175 (1.1%) histologic analysis-confirmed intrahepatic cholangiocarcinomas were categorized as CEUS LR-M by CEUS LI-RADS and misdiagnosed as HCC by WFUMB-EFSUMB criteria. Conclusion The contrast-enhanced US Liver Imaging Reporting and Data System (CEUS LI-RADS) algorithm was an effective tool for characterization of small (≤20 mm) liver nodules in patients at risk for hepatocellular carcinoma (HCC). Compared with World Federation for Ultrasound in Medicine and Biology-European Federation of Societies for Ultrasound in Medicine and Biology criteria, CEUS LR-5 demonstrated higher specificity for diagnosing small HCCs with lower sensitivity. Published under a CC BY 4.0 license. See also the editorial by Crocetti in this issue.

Selecting patients with hepatocellular carcinoma for liver transplantation: incorporating tumor biology criteria.

Liver transplantation (LT) is the optimal therapeutic option for patients with liver cirrhosis and hepatocellular carcinoma (HCC). Due to universal donor shortage, only the patients with limited tumor burden (under the so-called Milan criteria) are considered as potential candidates for LT in most institutions. It is expected that in the near future, more liver grafts will be available for patients with HCC due to the implementation of new direct antivirals against hepatitis C, leaving a prone scenario to consider expanding Milan criteria. A moderate expansion of Milan criteria could be implemented without increasing the risk of tumor recurrence if patients with favorable biological behavior are carefully selected. Incorporating information regarding tumor biology in the decision-making algorithm would result in a more rational use of LT in patients with HCC. In the present review, surrogate markers of tumor biology are critically evaluated as potential tools to be combined with existing radiological criteria. In addition, the current state of liquid biopsy is discussed, as this cutting-edge technology may reshape the management of HCC in the upcoming years.

Future Innovations in Viral Immune Surveillance: A Novel Place for Bioinformation and Artificial Intelligence in the Administration of Health Care.

Novel developments in bioinformation, bioinformatics and biostatistics, including artificial intelligence (AI), play a timely and critical role in translational care. Case in point, the extent to which viral immune surveillance is regulated by immune cells and soluble factors, and by non-immune factors informs the administration of health care. The events by which health is regained following viral infection is an allostatic process, which can be modeled using Hilbert's and Volterra's mathematical biology criteria, and biostatistical methodologies such as linear multiple regression. Health regained following viral infection can be given as Y being the sum-total of the positive factors and events (∏) that inherently push allostasis forward (i.e., the orderly process of immune activation and maturation) and the negative (N) factors and events that, allostatically speaking, interfere with regaining health. Any gaps in knowledge are filled by AI-aided immune tweening. Proof of concept can be tested with the fast-gaining infection using tick-borne Bunyavirus that cause severe fever with thrombocytopenia syndrome (SFTS).

A note on a derivation method for SDE models: Applications in biology and viability criteria

ABSTRACTWe discuss a method, which was popularized by E. J. Allen and that is frequently used in applications to construct SDE models. The derivation procedure is based on information about the elementary processes involved in the dynamics and their corresponding probabilities. We formulate criteria for the viability of the resulting models. In particular, explicit necessary and sufficient conditions are deduced for the non-negativity and/or boundedness of solutions. Moreover, we show that the class of deterministic models for which the construction leads to an admissible SDE extension is strongly limited. Several examples are presented to illustrate the implications of our results.

Proposal of phylogenetic revision of the subgenus “Morphocarabus” on the basis of molecular biology criteria

Proposal of phylogenetic revision of the subgenus “Morphocarabus” on the basis of molecular biology criteria

Bone Marrow Wilms Tumor Gene 1 Expression before Allogeneic Hematopoietic Cell Transplantation Correlates with Relapse in Acute Myeloid Leukemia Patients

IntroductionEvaluation of WT1 expression is becoming an attractive marker in acute myeloid leukaemia (AML) for minimal residual disease (MRD) detection. Recent studies correlate therapy response with WT1 copy levels in the bone marrow (BM) offering an additional tool beside multiparameter flow-cytometry (MFC). No well-known data are available regarding its impact on the outcome after hematopoietic cell transplantation (HCT).Patients/MethodsOne hundred and two consecutive clinically and molecularly well characterized AML patients (pts) were transplanted in a single hematology center from 2004 to 2013. Indication for allogeneic HCT included high cytogenetic and molecular risk according to WHO criteria, high leukocytosis, extramedullary manifestations or secondary AML at diagnosis. Further, primary induction failure was considered as an indication for allogeneic HCT.WT1 expression was analyzed by real time polymerase chain reaction (RT-PCR), using the standardized European LeukemiaNet method on BM samples before HCT and during each follow up control. Only pts in first CR before HCT were included in the analysis.Cumulative incidence of relapse (CIR) was estimated considering death for other causes than relapse as a competing event. Univariate and multivariate Fine & Gray Regression models were used to test the association between CIR and pre-HCT BM WT1 levels. Linearity of the relationship between CIR and the WT1 level was investigated using a mathematical transformation (restricted cubic spline).Aim of this retrospective analysis was to investigate the impact of pre-HCT BM WT1 expression in first CR pts on predicting relapse after HCT.ResultsA BM WT1 evaluation pre-HCT was available in 89 out of 102 pts. Among them, 62 achieved a CR after induction treatment. Relapsed pts in CR after reinduction chemotherapy (n=16) or with disease persistence pre-HCT (n=2) and pts refractory to treatment (n=9) were excluded from analysis.The patient subgroup displaying a first CR before HCT had a median age at diagnosis of 49 years (range: 20-65). Patient/donor relationship involved 26 (42%) sibling, 32 (52%) matched unrelated and 4 (6%) haplo-identical donors. On the basis of standard cytogenetics, molecular biology and clinical criteria (global disease risk) pts were classified according to the following risk groups: 54 (87%) high, 5 (8%) intermediate and 3 (5%) low risk. Acute GVHD occurred in 24 (39%) whereas chronic GVHD was documented in 18 (28%) pts. Twenty-six (42%) deaths were documented after HCT, 21 (34%) due to relapse and 5 (8%) because of treatment related mortality (TRM).Pre-HCT BM WT1 expression was correlated with CIR. A cut point of 150 WT1 copies was applied according to the slope change of relapse hazard, and subsequently used for CIR analysis. Pts displaying a pre-HCT BM WT1 level > 150 copies (n=18) had a higher CIR (2-year CIR 52.5%, 95% CI: 27.1-77.8) compared to pts with a BM WT1 level ≤ 150 copies (n=44, 2-year CIR 27.7% (95% CI: 13.4-42.1). WT1 copy level > 150 showed a significantly higher risk of relapse in univariate analysis (HR 2.9, 95% CI 1.2-6.7, p=0.014). In multivariate analysis pre-HCT BM WT1 expression was confirmed as a significant independent risk factor for CIR when adjusted for patient/donor relationship, presence of GVHD, global disease risk and competitive risk of mortality due to TRM (HR 3.4, 95% CI 1.3-8.5, p=0,010), Figure.Conclusions In the present study, pre-HCT BM WT1 levels discriminated significantly for CIR in a cohort of AML in first CR. A cut off level of 150 BM WT1 copies pre-HCT had a powerful statistically significant discriminating value to predict the risk of relapse, independently from already established risk factors. The prognostic value of WT1 was confirmed also when TRM as competitive risk for mortality was added in the multivariable model. Based on these results, WT1 is a promising candidate as MRD tool. Further prospective studies are required to confirm these results. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Nuclear Matrix Proteome Analysis of Drosophila melanogaster

The nucleus is a highly structured organelle and contains many functional compartments. Although the structural basis for this complex spatial organization of compartments is unknown, a major component of this organization is likely to be the non-chromatin scaffolding called nuclear matrix (NuMat). Experimental evidence over the past decades indicates that most of the nuclear functions are at least transiently associated with the NuMat, although the components of NuMat itself are poorly known. Here, we report NuMat proteome analysis from Drosophila melanogaster embryos and discuss its links with nuclear architecture and functions. In the NuMat proteome, we found structural proteins, chaperones, DNA/RNA-binding proteins, chromatin remodeling and transcription factors. This complexity of NuMat proteome is an indicator of its structural and functional significance. Comparison of the two-dimensional profile of NuMat proteome from different developmental stages of Drosophila embryos showed that less than half of the NuMat proteome is constant, and the rest of the proteins are stage-specific dynamic components. These NuMat dynamics suggest a possible functional link between NuMat and embryonic development. Finally, we also showed that a subset of NuMat proteins remains associated with the mitotic chromosomes, implicating their role in mitosis and possibly the epigenetic cellular memory. NuMat proteome analysis provides tools and opens up ways to understand nuclear organization and function.

Formulating and testing hypotheses in functional genomics

The ultimate goal of any genome-scale experiment is to provide a functional interpretation of the results, relating the available genomic information to the hypotheses that originated the experiment. Initially, this interpretation has been made on a pre-selection of relevant genes, based on the experimental values, followed by the study of the enrichment in some functional properties. Nevertheless, functional enrichment methods, demonstrated to have a flaw: the first step of gene selection was too stringent given that the cooperation among genes was ignored. The assumption that modules of genes related by relevant biological properties (functionality, co-regulation, chromosomal location, etc.) are the real actors of the cell biology lead to the development of new procedures, inspired in systems biology criteria, generically known as gene-set methods. These methods have been successfully used to analyze transcriptomic and large-scale genotyping experiments as well as to test other different genome-scale hypothesis in other fields such as phylogenomics.

From genes to functional classes in the study of biological systems

BackgroundWith the popularisation of high-throughput techniques, the need for procedures that help in the biological interpretation of results has increased enormously. Recently, new procedures inspired in systems biology criteria have started to be developed.ResultsHere we present FatiScan, a web-based program which implements a threshold-independent test for the functional interpretation of large-scale experiments that does not depend on the pre-selection of genes based on the multiple application of independent tests to each gene. The test implemented aims to directly test the behaviour of blocks of functionally related genes, instead of focusing on single genes. In addition, the test does not depend on the type of the data used for obtaining significance values, and consequently different types of biologically informative terms (gene ontology, pathways, functional motifs, transcription factor binding sites or regulatory sites from CisRed) can be applied to different classes of genome-scale studies. We exemplify its application in microarray gene expression, evolution and interactomics.ConclusionMethods for gene set enrichment which, in addition, are independent from the original data and experimental design constitute a promising alternative for the functional profiling of genome-scale experiments. A web server that performs the test described and other similar ones can be found at: .

Functional Interpretation of Microarray Experiments

Over the past few years, due to the popularisation of high-throughput methodologies such as DNA microarrays, the possibility of obtaining experimental data has increased significantly. Nevertheless, the interpretation of the results, which involves translating these data into useful biological knowledge, still remains a challenge. The methods and strategies used for this interpretation are in continuous evolution and new proposals are constantly arising. Initially, a two-step approach was used in which genes of interest were initially selected, based on thresholds that consider only experimental values, and then in a second, independent step the enrichment of these genes in biologically relevant terms, was analysed. For different reasons, these methods are relatively poor in terms of performance and a new generation of procedures, which draw inspiration from systems biology criteria, are currently under development. Such procedures, aim to directly test the behaviour of blocks of functionally related genes, instead of focusing on single genes.

Adrenal Incidentaloma (Adrenaloma)

The management of adrenalomas should include the following: 1. A detailed history and physical examination to detect subtle evidence of hormonal hypersecretion or the possibility of metastatic carcinoma. 2. Hormonal studies: Short dexamethasone suppression test (2 mg of dexamethasone) followed by a high-dose dexamethasone suppression test (8 mg), CRH assay and analysis of the diurnal cortisol rhythm if serum cortisol value post dexamethasone is greater than 3 microg/dL, 24-hour (or spot) urinary catecholamine metabolites (metanephrine and normetanephrine), In the hypertensive or normotensive patient with serum potassium less than 3.9 nmol/L, the upright aldosterone level to plasma renin activity (PRA) ratio. 3. Additional studies, such as: Glucose tolerance test, Bone mineral density evaluation, Body composition and fat distribution by DEXA (Dual energy X-Ray absorptiometry). The role of FNA is limited. It may be helpful only in the patient with coexistent extradrenal carcinoma to confirm adrenal metastasis. Although genetic and molecular biology studies do not have wide clinical application, they should be encouraged and supported. Once all of these data are collected, the recommendations are: 1. All clearly nonfunctioning adrenalomas that are not suspicious for malignancy in asymptomatic patients should be observed for several years, mainly with hormonal studies, until their secretory and benign nature is confirmed. 2. All patients with adrenalomas and evidence of subclinical function, suspicion for malignancy (using size, imaging, FNA and molecular biology criteria) and symptoms, such as hypertension, obesity, impaired glucose tolerance, central fat deposition and reduced bone mineral density, should undergo laparoscopic adrenalectomy. The age, the overall medical condition and the anxiety of the patient should also be considered in the decision to operate on a patient with an adrenaloma.

MANAGEMENT APPROACHES TO ADRENAL INCIDENTALOMAS (ADRENALOMAS): A View from Athens, Greece

We believe the management of adrenalomas should include the following: 1. A detailed history and physical examination to detect subtle evidence of hormonal hypersecretion or the possibility of metastatic carcinoma 2. Hormonal studies, such as The short dexamethasone suppression test (2 mg of dexamethasone) followed by a high-dose dexamethasone suppression test (8 mg), CRH assay, and analysis of the diurnal cortisol rhythm if serum cortisol is greater than 3 micrograms/dL 24-Hour (or spot) urinary catecholamine metabolites (metanephrine and normetanephrine) Plasma aldosterone level and renin activity in the hypertensive or normotensive patient with serum potassium less than 3.9 nmol/L 3. Additional imaging studies, such as MR imaging 131I-iodocholesterol (NP59) scanning to detect a subclinically functioning adenoma or carcinoma (MIBG scanning is rarely indicated) The role of FNA is limited. This modality may be helpful only in the patient with coexistent extradrenal carcinoma to confirm adrenal metastasis. Although genetic and molecular biology studies do not have wide clinical application, they should be encouraged and supported. Once all of these data are collected, the clinician should perform the following two steps: 1. All clearly nonfunctioning adrenalomas that are not suspicious for malignancy should be observed for several years, mainly with hormonal studies, until their secretory and benign nature is confirmed. 2. All patients with adrenalomas with evidence of subclinical function or potential for malignancy (using size, imaging, FNA, and molecular biology criteria) should undergo laparoscopic adrenalectomy for definitive diagnosis and therapy. The age, the overall medical condition, and the anxiety of the patient should be considered in the decision to operate on a patient with an adrenaloma.

Automata, Living and Non-Living: Descartes' Mechanical Biology and His Criteria for Life

Despite holding to the essential distinction between mind and body, Descartes did not adopt a life-body dualism. Though humans are the only creatures which can reason, as they are the only creatures whose body is in an intimate union with a soul, they are not the only finite beings who are alive. In the present note, I attempt to determine Descartes' criteria for something to be 'living.' Though certain passages associate such a principle with the presence of a properly functioning heart, I show that there are important reasons for also understanding life in terms of a degree of complexity of design.

Functional characterization and mRNA expression of pituitary adenylate cyclase activating polypeptide (PACAP) type I receptors in rat peritoneal macrophages

The present work characterizes the mRNA expression of PACAP type I receptors in rat peritoneal macrophages but not in peritoneal lymphocytes by both retrotranscriptase and polymerase chain reaction (RT-PCR) and homologous Southern hybridization and the stimulation by PACAP27, PACAP38 and vasoactive intestinal peptide (VIP) of sn-1,2-diacylglycerol production in rat peritoneal macrophage membranes. The binding of [ 125 I ]PACAP27 was time and cell concentration dependent. Scatchard analysis of displacement of the bound tracer by unlabeled PACAP27 indicates the existence of two classes of binding sites. The dissociation constant ( K d) was 0.64±0.08 nM and the maximal binding capacity ( B max) was 8.85±1.45 fmol/10 6 cells for the high affinity binding site. The low affinity binding site had a K d of 0.10±0.06 μM with a B max of 300±21.9 fmol/10 6 cells. Scatchard analysis of VIP displacement data indicated the presence of two classes of binding sites with a K d and B max different to those of PACAP27. These results suggest that PACAP binds to two binding sites, PACAP type I receptors and PACAP type II receptors. The PACAP27-stimulated diacylglycerol production was not affected by treatment with pertussis toxin. However, the presence of GTP partially inhibited this PACAP27 stimulation of 1,2-diacylglycerol in a dose dependent manner, although GTP alone stimulates diacylglycerol accumulation. In conclusion, for the first time we demonstrate by biochemical and molecular biology criteria the existence of PACAP type I receptors on rat peritoneal macrophages and the evidence for coupling with a pertussis toxin-insensitive G regulatory protein.