Derivation of the SLEDAI. A disease activity index for lupus patients. The Committee on Prognosis Studies in SLE

OBJECTIVE

To standardize outcome measures in systemic lupus erythematosus (SLE). Three indices were identified which could adequately describe outcome (disease activity, damage from disease, and health status); we describe here the development of the Disease Activity Index.

METHODS

Twenty-four variables were identified as important factors in a disease activity index. These were used to generate 574 patient profiles, which were rated on a disease activity scale of 0-10 by 14 rheumatologists. A second rating of 10 of the profiles yielded scores that were not significantly different from the first, indicating that experienced clinicians can reliably make global estimates of disease activity. Multiple regression models were used to estimate the relative importance of the 24 clinical variables in the physicians' global rating of disease activity. These were estimated on a "training set" of 75% of physicians' ratings, and then validated on a "testing set," consisting of the remaining 25% of physicians' ratings.

RESULTS

The explanatory power of the models in the training set was high (R2 = 0.93). The models' regression coefficients for the organ systems were simplified for easier use in clinical practice. This generated a "weighted" index of 9 organ systems for disease activity in SLE, the SLEDAI, as follows: 8 for central nervous system and vascular, 4 for renal and musculoskeletal, 2 for serosal, dermal, immunologic, and 1 for constitutional and hematologic. The maximum theoretical score is 105, but in practice, few patients have scores greater than 45. The SLEDAI predicted well the physicians' ratings in the testing set (Pearson's correlation coefficients = 0.64-0.79).

CONCLUSION

The SLEDAI is a validated model of experienced clinicians' global assessments of disease activity in lupus. It represents the consensus of a group of experts in the field of lupus research.

Recursive partitioning analysis of prognostic factors in three Radiation Therapy Oncology Group malignant glioma trials

BACKGROUND

Despite notable technical advances in therapy for malignant gliomas during the past decade, improved patient survival has not been clearly documented, suggesting that pretreatment prognostic factors influence outcome more than minor modifications in therapy. Age, performance status, and tumor histopathology have been identified as the pretreatment variables most predictive of survival outcome. However, an analysis of the association of survival with both pretreatment characteristics and treatment-related variables is necessary to assure reliable evaluation of new approaches for treatment of malignant glioma.

PURPOSE

This study of malignant glioma patients used a non-parametric statistical technique to examine the associations of both pretreatment patient and tumor characteristics and treatment-related variables with survival duration. This technique was used to identify subgroups with survival rates sufficiently different to create improvements in the design and stratification of clinical trials.

METHODS

We used a recursive partitioning technique to analyze survival in 1578 patients entered in three Radiation Therapy Oncology Group malignant glioma trials from 1974 to 1989 that used several radiation therapy (RT) regimens with and without chemotherapy or a radiation sensitizer. This approach creates a regression tree according to prognostic variables that classifies patients into homogeneous subsets by survival. Twenty-six pretreatment characteristics and six treatment-related variables were analyzed.

RESULTS

The years). Patients younger than 50 years old were categorized by histology (astrocytomas with anaplastic or atypical foci [AAF] versus glioblastoma multiforme [GBM]) and subsequently by normal or abnormal mental status for AAF patients and by performance status for those with GBM. For patients aged 50 years or older, performance status was the most important variable, with normal or abnormal mental status creating the only significant split in the poorer performance status group. Treatment-related variables produced a subgroup showing significant differences only for better performance status GBM patients over age 50 (by extent of surgery and RT dose). Median survival times were 4.7-58.6 months for the 12 subgroups resulting from this analysis, which ranged in size from 32 to 256 patients.

CONCLUSIONS

This approach permits examination of the interaction between prognostic variables not possible with other forms of multivariate analysis.

IMPLICATIONS

The recursive partitioning technique can be employed to refine the stratification and design of malignant glioma trials.

FACT, a factor that facilitates transcript elongation through nucleosomes

The requirements for transcriptional activation by RNA polymerase II were examined using chromatin templates assembled in vitro and a transcription system composed of the human general transcription factors and RNA polymerase II. Activator-induced, energy-dependent chromatin remodeling promoted efficient preinitiation complex formation and transcription initiation, but was not sufficient for productive transcription. Polymerases that initiated transcription on remodeled chromatin templates encountered a block to transcription proximal to the promoter. Entry into productive transcription required an accessory factor present in HeLa cell nuclear extract, FACT (facilitates chromatin transcription), which we have purified. FACT acts subsequent to transcription initiation to release RNA polymerase II from a nucleosome-induced block to productive transcription. The biochemical properties and polypeptide composition of FACT suggest that it is a novel protein factor that facilitates transcript elongation through nucleosomes.

Structure of Rhodopseudomonas sphaeroides R-26 reaction center

The molecular replacement method has been successfully used to provide a structure for the photosynthetic reaction center of Rhodopseudomonas sphaeroides at 3.7 A resolution. Atomic coordinates derived from the R. viridis reaction center were used in the search structure. The crystallographic R-factor is 0.39 for reflections between 8 and 3.7 A. Validity of the resulting model is further suggested by the visualization of amino acid side chains not included in the R. viridis search structure, and by the arrangements of the reaction centers in the unit cell. In the initial calculations quinones or pigments were not included; nevertheless, in the resulting electron density map, electron density for both quinones QA and QB appears along with the bacteriochlorophylls and bacteriopheophytins. Kinetic analysis of the charge recombination shows that the secondary quinone is fully functional in the R. sphaeroides crystal.

Comparison of postoperative radiotherapy and combined postoperative radiotherapy and chemotherapy in the multidisciplinary management of malignant gliomas. A joint Radiation Therapy Oncology Group and Eastern Cooperative Oncology Group study

Recently, the RTOG and ECOG concluded a joint randomized study on malignant gliomas that was in progress for the past five years. A total of 626 patients entered this protocol. Sixty-seven percent of the 535 evaluable patients have died and thus this represents a preliminary report of a major joint clinical trial. The objective of this study was to evaluate the efficacy after neurosurgery of three new treatment options as compared with control treatment of radiotherapy alone. The four options were: (1) control radiation; 6000 rad/6-7 weeks to whole brain; (2) a higher radiation dose; Control dose plus a booster dose of 1000 rad/1-2 weeks to the tumor; (3) control radiation dose plus BCNU (80 mg/m2/day IV X 3 and repeat BCNU every 8 weeks); (4) Control radiation dose plus combination methyl-CCNU (125 mg/m2/day orally X 1 and repeat methyl-CCNU every 8 weeks), and DTIC (150 mg/m2/day IV X 5 and repeat DTIC every 4 weeks). All pertinent patient characteristics were studied and several important prognostic factors have been identified. Notably, age, histologic type (Astrocytoma with anaplastic foci, versus glioblastoma multiforme), initial performance status, time since first symptoms and presence or absence of seizure. At this time, it appeared that there was no treatment option which was significantly better than the control. The study identified that age was the most important prognostic factor. Patients who were younger than age 40 years had an 18-month survival of 64%, patients who were age 40-60 years had an 18-month survival of 20%, and patients who were older than age 60 had an 18-month survival of 8%. The study also demonstrated that a modified histologic classification of anaplastic astrocytoma versus glioblastoma provided better prognostic information than the astrocytoma grading system of Kernohan. Patients with anaplastic astrocytoma had a median survival of 27 months as compared to 8 months for patients with glioblastoma. In further evaluation of any beneficial effect of chemotherapy, it was identified that only among the 40-60-year-old groups, BCNU treated patients appeared to have significantly increased survival than patients in the control groups (P = 0.01, one-sided). Similarly, methyl-CCNU + DTIC was suggestively better than the control (P = 0.08, one-sided). The higher radiation dose, 7000 rad/8-9 weeks appeared to give no significantly better survival over the control dose option. Both BCNU and methyl-CCNU + DTIC produced some toxicity. The combination of methyl-CCNU + DTIC was more toxic than BCNU, producing severe or worse thrombocytopenia in 23% of the patients as compared to 6% on BCNU.

The treatment of medulloblastoma. Results of a prospective randomized trial of radiation therapy with and without CCNU, vincristine, and prednisone

In a prospective randomized trial designed to study the effectiveness of adjuvant chemotherapy following standard surgical treatment and radiation therapy, 233 eligible patients with medulloblastoma were treated by members of the Children's Cancer Study Group and the Radiation Therapy Oncology Group. Eligible patients were randomly assigned to receive radiation therapy with or without adjuvant chemotherapy consisting of 1-(2-chloroethyl)-3-cyclohexyl-nitrosourea (CCNU), vincristine, and prednisone. The estimated 5-year event-free survival probability was 59% for patients treated with radiation therapy and chemotherapy and 50% for patients treated with radiation therapy alone, a difference which is not statistically significant. The 5-year survival probability was 65% for both groups. Although the treatment difference was not statistically significant when all patients were combined, in the small number of patients with more extensive tumors, event-free survival was better in the group receiving chemotherapy (48% vs. 0%, p = 0.006). In these latter patients the survival time is also significantly prolonged. Extent of disease (as measured by the M staging criteria described by Chang) and age at diagnosis were significantly associated with outcome; advanced disease and young age had a worse prognosis. The extent of tumor resection was not an independent prognostic factor. It is concluded that chemotherapy does not benefit patients with low-stage medulloblastoma, but may benefit those with more advanced stages of disease.

Mice lacking the MHC class II transactivator (CIITA) show tissue-specific impairment of MHC class II expression

CIITA activates the expression of multiple genes involved in antigen presentation and it is believed to be required for both constitutive and IFN gamma-inducible expression of these genes. To understand the role of CIITA in vivo, we have used gene targeting to generate mice that lack CIITA. CIITA-deficient (-/-) mice do not express conventional MHC class II molecules on the surface of splenic B cells and dendritic cells. In addition, macrophages resident in the peritoneal cavity do not express MHC class II molecules upon IFN gamma stimulation nor do somatic tissues of mice injected with IFN gamma, in contrast with wild-type mice. The levels of Ii and H-2M gene transcripts are substantially decreased but absent in CIITA (-/-) mice. The transcription of nonconventional MHC class II genes is, however not affected by CIITA deficiency. A subset of thymic epithelial cells express MHC class II molecules. Nonetheless, very few mature CD4 T cells are present in the periphery of CIITA (-/-) mice despite MHC class II expression in the thymus. Consequently, CIITA(-/-) mice are impaired in T-dependent antigen responses and MHC class II-mediated allogeneic responses.

The functions of tryptophan residues in membrane proteins

Membrane proteins have a significantly higher Trp content than do soluble proteins. This is especially true for the M and L subunits of the photosynthetic reaction center from purple bacteria. The Trp residues are not uniformly distributed through the membrane but are concentrated at the periplasmic side of the complex. In addition, Trp residues are not randomly aligned. Within the protein subunits, many form hydrogen bonds with carbonyl oxygens of the main chain, thereby stabilizing the protein. On the surface of the molecule, they are correctly positioned to form hydrogen bonds with the lipid head groups while their hydrophobic rings are immersed in the lipid part of the bilayer. These observations suggest that Trp residues are involved in the translocation of protein through the membrane and that following translocation, Trp residues serve as anchors on the periplasmic side of the membrane.

Structure of the membrane-bound protein photosynthetic reaction center from Rhodobacter sphaeroides

The structure of the photosynthetic reaction center (RC) from Rhodobacter sphaeroides was determined at 3.1-A resolution by the molecular replacement method, using the Rhodopseudomonas viridis RC as the search structure. Atomic coordinates were refined with the difference Fourier method and restrained least-squares refinement techniques to a current R factor of 22%. The tertiary structure of the RC complex is stabilized by hydrophobic interactions between the L and M chains, by interactions of the pigments with each other and with the L and M chains, by residues from the L and M chains that coordinate to the Fe2+, by salt bridges that are formed between the L and M chains and the H chain, and possibly by electrostatic forces between the ends of helices. The conserved residues at the N-termini of the L and M chains were identified as recognition sites for the H chain.

Class II transactivator (CIITA) is sufficient for the inducible expression of major histocompatibility complex class II genes

The class II transactivator (CIITA) has been shown to be required for major histocompatibility complex (MHC) class II gene expression in B cells and its deficiency is responsible for a hereditary MHC class II deficiency. Here we show that CIITA is also involved in the inducible expression of class II genes upon interferon gamma (IFN-gamma) treatment. The expression of CIITA is also inducible with IFN-gamma before the induction of MHC class II mRNA. In addition, CIITA mRNA expression does not require new protein synthesis, although new protein synthesis is necessary for the transcription of class II. This suggests that synthesis of new CIITA protein may be essential to induce class II gene expression. We also showed that the JAK1 protein tyrosine kinase activity is required to induce the expression of CIITA upon IFN-gamma stimulation. This finding indicates that CIITA is part of the signaling cascade from the IFN-gamma receptor to the activation of class II genes. In addition, the expression of CIITA is sufficient to activate class II genes in the absence of IFN-gamma stimulation suggesting that CIITA is the major regulatory factor for the inducible expression of class II genes. Together, these data suggest that CIITA is the IFN-inducible cycloheximide sensitive factor previously shown to be required for the induction of MHC class II gene expression.

Class II transactivator regulates the expression of multiple genes involved in antigen presentation

CIITA (a major histocompatibility complex [MHC] class II transactivator) has been shown to be required for the expression of MHC class II genes in both B cells and interferon gamma-inducible cells. Here we demonstrate that CIITA not only activates MHC class II genes but also genes required for antigen presentation. Mutant HeLa cells, defective in the expression of classic MHC class II genes, invariant chain, and the newly described human histocompatibility leukocyte antigen-DM genes, were used to study the role of CIITA in the regulation of these genes. Upon transfection with CIITA cDNA, the mutant cells expressed all three genes, suggesting that CIITA is a global regulator for the expression of genes involved in antigen presentation.

Comparison of reaction centers from Rhodobacter sphaeroides and Rhodopseudomonas viridis: overall architecture and protein-pigment interactions

Photosynthetic reaction centers (RCs) from the photosynthetic bacteria Rhodobacter sphaeroides and Rhodopseudomonas viridis are protein complexes closely related in both structure and function. The structure of the Rps. viridis RC was used to determine the structure of the RC from Rb. sphaeroides. Small but meaningful differences between the positions of the helices and the cofactors in the two complexes were identified. The distances between helices AL and AM, between BL and BM, and between bacteriopheophytins BPL and BPM are significantly shorter in Rps. viridis than they are in Rb. sphaeroides RCs. There are a number of differences in the amino acid residues that surround the cofactors; some of these residues form hydrogen bonds with the cofactors. Differences in chemical properties and location of these residues account in some manner for the different spectral properties of the two RCs. In several instances, the hydrogen bonds, as well as the apparent distances between the histidine ligands and the Mg atoms of the bacteriochlorophylls, were found to significantly differ from the Rb. sphaeroides RC structure previously described by Yeates et al. [(1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7993-7997] and Allen et al. [(1988) Proc. Natl. Acad. Sci. U.S.A. 85, 8487-8491].

Midline pineal tumors and suprasellar germinomas: highly curable by irradiation

Sixty-one patients with midline pineal tumors and 16 patients with suprasellar germinomas were treated with surgical decompression and relatively high-dose radiotherapy of the primary site. Results were excellent, and there were no long-term complications. Ten per cent of midline pineal tumors and 37% of suprasellar germinomas metastasized to the cerebral or spinal subarachnoid space within 6 months to 5 years. Irradiation of the entire neural axis is recommended for locally extensive tumors, simultaneous pineal and hypothalamic lesions, and all biopsy-proved germinomas. The five-year survival rate was 79% for midline pineal tumors and 77% for suprasellar germinomas.

Studying outcomes and hospital utilization in the elderly. The advantages of a merged data base for Medicare and Veterans Affairs hospitals

That veterans aged 65 years and older are eligible to receive care either in the Veteran Affairs (VA) health care system or in the private sector under Medicare confounds the analysis of veterans' health services utilization and outcomes in two ways. First, changes in eligibility or financial barriers to access with regard to either system influence veterans' decisions about where to seek needed care. Second, analyses of VA care for elderly veterans that rely solely on VA data sources underestimate both overall utilization and treatment complications. Similarly, failure to consider the contribution of health care delivery in the VA system may confound analyses of health care utilization by the Medicare-eligible population. To study the magnitude of such confounding influences, we linked the Medicare and VA health care administrative databases for residents of New England and New York. Results indicated that, for ten surgical procedures commonly performed in the elderly, as well as for hospitalizations resulting from acute myocardial infarction and hip fracture, VA patients receive from 17.6% to 37.4% of hospital care outside the VA system. Private hospitalizations account for 5.5% to 19.5% of the care received by veterans within 6 months after an initial episode of care in a VA hospital. It was also found that initial hospitalizations for study conditions in the VA accounted for 3.6% of all such hospitalizations among elderly Medicare-eligible men. Although overall hospital utilization appears to be underestimated in VA data sources, it was found that ascertaining mortality from sources available within the VA produced excellent results when compared with deaths recorded in the Medicare enrollment files. A national, merged VA-Medicare data base is feasible and would enhance the validity of analyses of health care delivery both for elderly veterans and for the Medicare population.

Pembrolizumab versus placebo as post-nephrectomy adjuvant therapy for clear cell renal cell carcinoma (KEYNOTE-564): 30-month follow-up analysis of a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

The first interim analysis of the KEYNOTE-564 study showed improved disease-free survival with adjuvant pembrolizumab compared with placebo after surgery in patients with clear cell renal cell carcinoma at an increased risk of recurrence. The analysis reported here, with an additional 6 months of follow-up, was designed to assess longer-term efficacy and safety of pembrolizumab versus placebo, as well as additional secondary and exploratory endpoints.

METHODS

In the multicentre, randomised, double-blind, placebo-controlled, phase 3 KEYNOTE-564 trial, adults aged 18 years or older with clear cell renal cell carcinoma with an increased risk of recurrence were enrolled at 213 hospitals and cancer centres in North America, South America, Europe, Asia, and Australia. Eligible participants had an Eastern Cooperative Oncology Group performance status of 0 or 1, had undergone nephrectomy 12 weeks or less before randomisation, and had not received previous systemic therapy for advanced renal cell carcinoma. Participants were randomly assigned (1:1) via central permuted block randomisation (block size of four) to receive pembrolizumab 200 mg or placebo intravenously every 3 weeks for up to 17 cycles. Randomisation was stratified by metastatic disease status (M0 vs M1), and the M0 group was further stratified by ECOG performance status and geographical region. All participants and investigators involved in study treatment administration were masked to the treatment group assignment. The primary endpoint was disease-free survival by investigator assessment in the intention-to-treat population (all participants randomly assigned to a treatment). Safety was assessed in the safety population, comprising all participants who received at least one dose of pembrolizumab or placebo. As the primary endpoint was met at the first interim analysis, updated data are reported without p values. This study is ongoing, but no longer recruiting, and is registered with ClinicalTrials.gov, NCT03142334.

FINDINGS

Between June 30, 2017, and Sept 20, 2019, 994 participants were assigned to receive pembrolizumab (n=496) or placebo (n=498). Median follow-up, defined as the time from randomisation to data cutoff (June 14, 2021), was 30·1 months (IQR 25·7-36·7). Disease-free survival was better with pembrolizumab compared with placebo (HR 0·63 [95% CI 0·50-0·80]). Median disease-free survival was not reached in either group. The most common all-cause grade 3-4 adverse events were hypertension (in 14 [3%] of 496 participants) and increased alanine aminotransferase (in 11 [2%]) in the pembrolizumab group, and hypertension (in 13 [3%] of 498 participants) in the placebo group. Serious adverse events attributed to study treatment occurred in 59 (12%) participants in the pembrolizumab group and one (<1%) participant in the placebo group. No deaths were attributed to pembrolizumab.

INTERPRETATION

Updated results from KEYNOTE-564 support the use of adjuvant pembrolizumab monotherapy as a standard of care for participants with renal cell carcinoma with an increased risk of recurrence after nephrectomy.

FUNDING

Merck Sharp & Dohme LLC, a subsidiary of Merck & Co, Inc, Rahway, NJ, USA.

Cation binding by bacteriorhodopsin

We have found that extensively washed purple membrane has about 1 calcium and 3-4 magnesium ions bound per bacteriorhodopsin molecule. When these divalent cations are removed by any of a variety of means, the pigment changes its color from purple to blue (lambda(max) approximately 600 nm). This blue pigment, which can be formed at near neutral pH, is probably very similar to blue species formed when the pH of a purple membrane sample is lowered to approximately 2. When any of a wide variety of cations are added to a blue membrane preparation, the characteristic purple color of bacteriorhodopsin returns. Divalent and trivalent cations are much more efficient than monovalent cations in restoring the purple color and are effective at a ratio approaching one cation per pigment molecule. Besides shifting the absorption spectrum, removal of the divalent cations drastically alters the photochemical cycle of bacteriorhodopsin, including abolishing the unprotonated Schiff base (M-type) intermediate. Finally, lanthanum not only displaces the divalent cations normally bound to the purple membrane but also greatly reduces both the rate of decay of the M412 intermediate and proton uptake.

Efficient transformation of chicken embryo fibroblasts by c-Jun requires structural modification in coding and noncoding sequences

To assess the transforming capability of the c-Jun protein, we introduced the chicken c-jun proto-oncogene into a replication competent avian retroviral expression vector (RCAS). Viral Jun efficiently transformed chicken embryo fibroblasts (CEFs) when expressed from this vector. Overexpression of c-Jun leads to transformation of CEFs with an efficiency that is 15- to 25-fold less than that seen for v-Jun, suggesting that v-Jun contains structural features that increase its oncogenic potential relative to c-Jun. There are four structural differences between v-Jun and c-Jun. To determine the relative contribution that each of these structural differences between v-Jun and c-Jun has on oncogenic activity, several deletion and substitution mutants were constructed. Each of these mutants was expressed in CEF and assayed for transformation by focus formation. Analysis of the results reveals that deletion of a region of 27 amino acids near the amino terminus of c-Jun and deletion of 3'-untranslated sequences are critical in activating the full oncogenic potential of Jun.

Cyclic HIV protease inhibitors: synthesis, conformational analysis, P2/P2' structure-activity relationship, and molecular recognition of cyclic ureas

High-resolution X-ray structures of the complexes of HIV-1 protease (HIV-1PR) with peptidomimetic inhibitors reveal the presence of a structural water molecule which is hydrogen bonded to both the mobile flaps of the enzyme and the two carbonyls flanking the transition-state mimic of the inhibitors. Using the structure-activity relationships of C2-symmetric diol inhibitors, computed-aided drug design tools, and first principles, we designed and synthesized a novel class of cyclic ureas that incorporates this structural water and preorganizes the side chain residues into optimum binding conformations. Conformational analysis suggested a preference for pseudodiaxial benzylic and pseudodiequatorial hydroxyl substituents and an enantiomeric preference for the RSSR stereochemistry. The X-ray and solution NMR structure of the complex of HIV-1PR and one such cyclic urea, DMP323, confirmed the displacement of the structural water. Additionally, the bound and "unbound" (small-molecule X-ray) ligands have similar conformations. The high degree of preorganization, the complementarity, and the entropic gain of water displacement are proposed to explain the high affinity of these small molecules for the enzyme. The small size probably contributes to the observed good oral bioavailability in animals. Extensive structure-based optimization of the side chains that fill the S2 and S2' pockets of the enzyme resulted in DMP323, which was studied in phase I clinical trials but found to suffer from variable pharmacokinetics in man. This report details the synthesis, conformational analysis, structure-activity relationships, and molecular recognition of this series of C2-symmetry HIV-1PR inhibitors. An initial series of cyclic ureas containing nonsymmetric P2/P2' is also discussed.

Detection and identification of Mycobacterium tuberculosis by DNA amplification

The polymerase chain reaction (PCR) was used to identify mycobacterial DNA sequences in uncultured clinical specimens. Two oligonucleotide primers derived from the sequence of a gene that codes for the 65-kilodalton antigen of Mycobacterium tuberculosis amplified DNA from all 11 species of mycobacteria tested. Amplified DNAs of nontuberculosis mycobacteria were found to be approximately 20 to 40 bases shorter than those from M. tuberculosis and Mycobacterium bovis BCG. DNA equivalent to that present in as few as 40 M. tuberculosis cells either alone or in the presence of DNA equivalent to that in 10(6) human cells could be detected. Results from analysis of cultured bacteria and clinical specimens showed PCR was sensitive and specific both in detecting mycobacteria and in differentiating M. tuberculosis and BCG from other species of mycobacteria. The PCR method with the primers reported here may become a useful tool in the early and rapid detection of mycobacterial infections in uncultured clinical specimens.

Stimulatory effects of atrial natriuretic factor on phosphoinositide hydrolysis in cultured bovine aortic smooth muscle cells

The effects of atrial natriuretic factor (ANF) on phosphoinositide hydrolysis were examined in preparations of cultured bovine aortic smooth muscle cells. In homogenates or particulate fractions from cultured bovine aortic smooth muscle cells, ANF and atriopeptin I increased the formation of inositol phosphates and GTPase activity. The effects on inositol phosphates were markedly enhanced with guanosine 5'[gamma-thio]triphosphate. Both atrial peptides also stimulated the formation of diacylglycerol in intact cultured cells. In these experiments, atriopeptin I was about 10-fold more potent than ANF. These studies indicate that atrial peptides have stimulatory effects on phosphoinositide hydrolysis which are mediated through a guanine nucleotide regulatory protein. The greater potency of atriopeptin I on GTPase activity and the accumulation of inositol phosphates suggests that the nonguanylate cyclase-coupled receptor for ANF (ANF-R2) mediates the stimulatory effects of ANF on phosphoinositide hydrolysis through a guanine nucleotide regulatory protein.

Potential human exposures to neonicotinoid insecticides: A review

Due to their systemic character and high efficacy to insect controls, neonicotinoid insecticides (neonics) have been widely used in global agriculture since its introduction in early 1990. Recent studies have indicated that neonics may be ubiquitous, have longer biological half-lives in the environment once applied, and therefore implicitly suggested the increasing probability for human exposure to neonics. Despite of neonics' persistent characters and widespread uses, scientific literature in regard of pathways in which human exposure could occur is relatively meager. In this review, we summarized results from peer-reviewed articles published prior to 2017 that address potential human exposures through ingestion and inhalation, as well as results from human biomonitoring studies. In addition, we proposed the use of relative potency factor approach in order to facilitate the assessment of concurrent exposure to a mixture of neonics with similar chemical structures and toxicological endpoints. We believe that the scientific information that we presented in this review will aid to future assessment of total neonic exposure and subsequently human health risk characterization.