Phase 2A Learnings Incorporated into RewinD-LB, a Phase 2B Clinical Trial of Neflamapimod in Dementia with Lewy Bodies

BACKGROUND

In an exploratory 91-participant phase 2a clinical trial (AscenD-LB, NCT04001517) in dementia with Lewy bodies (DLB), neflamapimod showed improvement over placebo on multiple clinical endpoints. To confirm those results, a phase 2b clinical study (RewinD-LB, NCT05869669 ) that is similar to AscenD-LB has been initiated.

OBJECTIVES

To optimize the choice of patient population, primary endpoint, and biomarker evaluations in RewinD-LB.

DESIGN

Evaluation of the efficacy results from AscenD-LB, the main results of which, and a re-analysis after stratification for absence or presence of AD co-pathology (assessed by plasma ptau181), have been published. In addition, the MRI data from a prior phase 2a clinical trial in Early Alzheimer's disease (AD), were reviewed.

SETTING

22 clinical sites in the US and 2 in the Netherlands.

PARTICIPANTS

Probable DLB by consensus criteria and abnormal dopamine uptake by DaTscan™ (Ioflupane I123 SPECT).

INTERVENTION

Neflamapimod 40mg capsules or matching placebo capsules, twice-a-day (BID) or three-times-a-day (TID), for 16 weeks.

MEASUREMENTS

6-test Neuropsychological Test Battery (NTB) assessing attention and executive function, Clinical Dementia Rating Sum-of-Boxes (CDR-SB), Timed Up and Go (TUG), International Shopping List Test (ISLT).

RESULTS

Within AscenD-LB, patients without evidence of AD co-pathology exhibited a neflamapimod treatment effect that was greater than that in the overall population and substantial (cohen's d effect size vs. placebo ≥ for CDR-SB, TUG, Attention and ISLT-recognition). In addition, the CDR-SB and TUG performed better than the cognitive tests to demonstrate neflamapimod treatment effect in comparison to placebo. Further, clinical trial simulations indicate with 160-patients (randomized 1:1), RewinD-LB conducted in patients without AD co-pathology has >95% (approaching 100%) statistical power to detect significant improvement over placebo on the CDR-SB. Preliminary evidence of positive treatment effects on beta functional connectivity by EEG and basal forebrain atrophy by MRI were obtained in AscenD-LB and the Early AD study, respectively.

CONCLUSION

In addition to use of a single dose regimen of neflamapimod (40mg TID), key distinctions between phase 2b and phase 2a include RewinD-LB (1) excluding patients with AD co-pathology, (2) having CDR-SB as the primary endpoint, and (3) having MRI studies to evaluate effects on basal forebrain atrophy.

Genetic variation of Plasmodium falciparum histidine-rich protein 2 and 3 in Assosa zone, Ethiopia: its impact on the performance of malaria rapid diagnostic tests

Background

Rapid diagnostic tests (RDT) are commonly used for the diagnosis of malaria caused by Plasmodium falciparum. However, false negative results of RDT caused by genetic variation of P. falciparum histidine-rich protein 2 and 3 genes (pfhrp2/3) threaten existing malaria case management and control efforts. The main objective of this study was to investigate the genetic variations of the pfhrp2/3 genes.

Methods

A cross-sectional study was conducted from malaria symptomatic individuals in 2018 in Assosa zone, Ethiopia. Finger-prick blood samples were collected for RDT and microscopic examination of thick and thin blood films. Dried blood spots (DBS) were used for genomic parasite DNA extraction and molecular detection. Amplification of parasite DNA was made by quantitative PCR. DNA amplicons of pfhrp2/3 were purified and sequenced.

Results

The PfHRP2 amino acid repeat type isolates were less conserved compared to the PfHRP3 repeat type. Eleven and eight previously characterized PfHRP2 and PfHRP3 amino acid repeat types were identified, respectively. Type 1, 4 and 7 repeats were shared by PfHRP2 and PfHRP3 proteins. Type 2 repeats were found only in PfHRP2, while types 16 and 17 were found only in PfHRP3 with a high frequency in all isolates. 18 novel repeat types were found in PfHRP2 and 13 novel repeat types were found in PfHRP3 in single or multiple copies per isolate. The positivity rate for PfHRP2 RDT was high, 82.9% in PfHRP2 and 84.3% in PfHRP3 sequence isolates at parasitaemia levels > 250 parasites/µl. Using the Baker model, 100% of the isolates in group A (If product of types 2 × type 7 repeats ≥ 100) and 73.7% of the isolates in group B (If product of types 2 × type 7 repeats 50–99) were predicted to be detected by PfHRP2 RDT at parasitaemia level > 250 parasite/μl.

Conclusion

The findings of this study indicate the presence of different PfHRP2 and PfHRP3 amino acid repeat including novel repeats in P. falciparum from Ethiopia. These results indicate that there is a need to closely monitor the performance of PfHRP2 RDT associated with the genetic variation of the pfhrp2 and pfhrp3 gene in P. falciparum isolates at the country-wide level.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03928-3.

Modeling Plasmodium falciparum Diagnostic Test Sensitivity Using Machine Learning With Histidine-Rich Protein 2 Variants

Malaria, predominantly caused by Plasmodium falciparum, poses one of largest and most durable health threats in the world. Previously, simplistic regression-based models have been created to characterize malaria rapid diagnostic test performance, though these models often only include a couple genetic factors. Specifically, the Baker et al., 2005 model uses two types of particular repeats in histidine-rich protein 2 (PfHRP2) to describe a P. falciparum infection, though the efficacy of this model has waned over recent years due to genetic mutations in the parasite. In this work, we use a dataset of 100 P. falciparum PfHRP2 genetic sequences collected in Ethiopia and derived a larger set of motif repeat matches for use in generating a series of diagnostic machine learning models. Here we show that the usage of additional and different motif repeats in more sophisticated machine learning methods proves effective in characterizing PfHRP2 diversity. Furthermore, we use machine learning model explainability methods to highlight which of the repeat types are most important with regards to rapid diagnostic test sensitivity, thereby showcasing a novel methodology for identifying potential targets for future versions of rapid diagnostic tests.

Detection of high prevalence of Plasmodium falciparum histidine-rich protein 2/3 gene deletions in Assosa zone, Ethiopia: implication for malaria diagnosis

Background

Rapid diagnostic tests (RDTs) targeting histidine rich protein 2(HRP2) are widely used for diagnosis of Plasmodium falciparum infections. Besides PfHRP2, the PfHRP3 antigen contributes to the detection of P. falciparum infections in PfHRP2 RDTs. However, the performance HRP2-based RDT is affected by pfhrp2/3 gene deletions resulting in false-negative test results. The objective of this study was to determine the presence and prevalence of pfhrp2/3 gene deletions including the respective flanking regions among symptomatic patients in Assosa zone, Northwest Ethiopia.

Methods

A health-facility based cross-sectional study was conducted in febrile patients seeking a malaria diagnosis in 2018. Blood samples were collected by finger-prick for microscopic examination of blood smears, malaria RDT, and molecular analysis using dried blood spots (DBS) prepared on Whatman filter paper. A total of 218 P. falciparum positive samples confirmed by quantitative PCR were included for molecular assay of pfhrp2/3 target gene.

Results

Of 218 P. falciparum positive samples, exon 2 deletions were observed in 17.9% of pfhrp2 gene and in 9.2% of pfhrp3 gene. A high proportion of deletions in short segments of pfhrp2 exon1-2 (50%) was also detected while the deletions of the pfhrp3 exon1-2 gene were 4.1%. The deletions were extended to the downstream and upstream of the flanking regions in pfhrp2/3 gene (above 30%). Of eighty-six PfHRP2 RDT negative samples, thirty-six lacked pfhrp2 exon 2. Five PfHRP2 RDT negative samples had double deletions in pfhrp2 exon 2 and pfhrp3 exon2. Of these double deletions, only two of the samples with a parasite density above 2000 parasite/µl were positive by the microscopy. Three samples with intact pfhrp3 exon2 in the pfhrp2 exon2 deleted parasite isolates were found to be positive by PfHRP2 RDT and microscopy with a parasite density above 10,000/µl.

Conclusion

This study confirms the presence of deletions of pfhrp2/3 gene including the flanking regions. Pfhrp2/3 gene deletions results in false-negative results undoubtedly affect the current malaria control and elimination effort in the country. However, further countrywide investigations are required to determine the magnitude of pfhrp2/3 gene deletions and its consequences on routine malaria diagnosis.

Quantitative proteomic analysis of the tizoxanide effect in vero cells

Nitazoxanide (NTZ) is effective against helminths and numerous microorganisms, including bacteria and viruses. In vivo, NTZ is metabolized into Tizoxanide (TIZ), which is the active circulating metabolite. With the emergence of SARS-Cov-2 as a Pandemic agent, NTZ became one of the molecules already approved for human use to engage clinical trials, due to results in vitro showing that NTZ was highly effective against the SARS-Cov-2, agent of COVID-19. There are currently several ongoing clinical trials mainly in the USA and Brazil involving NTZ due not only to the in vitro results, but also for its long-known safety. Here, we study the response of Vero cells to TIZ treatment and unveil possible mechanisms for its antimicrobial effect, using a label-free proteomic approach (LC/MS/MS) analysis to compare the proteomic profile between untreated- and TIZ-treated cells. Fifteen differentially expressed proteins were observed related to various biological processes, including translation, intracellular trafficking, RNA processing and modification, and signal transduction. The broad antimicrobial range of TIZ points towards its overall effect in lowering cell metabolism and RNA processing and modification. The decreased levels of FASN, HNRNPH and HNRNPK with the treatment appear to be important for antiviral activity.

Neflamapimod: Clinical Phase 2b-Ready Oral Small Molecule Inhibitor of p38α to Reverse Synaptic Dysfunction in Early Alzheimer's Disease

Neflamapimod (previously code named VX-745) is a clinical phase 2b-ready highly specific inhibitor of the intra-cellular enzyme p38 mitogen activated protein kinase alpha ("p38α") that is being developed as a disease-modifying drug for Alzheimer's disease (AD) that acts via targeting synaptic dysfunction. Neflamapimod was discovered through a proprietary structure-based drug discovery platform at Vertex Pharmaceuticals, and developed previously by Vertex through to phase 2a in rheumatoid arthritis. EIP Pharma licensed the compound in 2014 for development and commercialization as a treatment of central nervous system (CNS) disorders. Neflamapimod is the most advanced in the clinic drug that targets specific molecular mechanisms within neurons that leads to synaptic dysfunction, the pathogenic process that is now considered to be a major driver of the development of memory deficits and disease progression in the early stages of AD. Based on the scientific rationale of targeting synaptic dysfunction and the preclinical data, neflamapimod has the potential to both reverse memory deficits and slow disease progression. Phase 2a clinical data in patients with early-stage AD (MMSE 20-28, biomarker positive) provides evidence that the preclinical science may be translatable to human Alzheimer's, as 6- to 12-weeks of neflamapimod treatment led to significant improvement in episodic memory, the best clinical measure of synaptic dysfunction in AD. A phase 2b six-month placebo-controlled 150-patient clinical study is anticipated to start by end of 2017. This study is designed to definitively demonstrate that neflamapimod reverses memory deficits, and also to provide preliminary evidence that the drug slows disease progression.

A case of a single intracranial vertebral artery and cerebral infarct

The vertebral arteries are commonly affected by anatomical variation. This variation ranges from slight asymmetry in arterial diameter between the right and left sides to complete absence of a vertebral artery on one side. Asymmetry in diameter is a common observation, although complete absence of the artery is rare. Herein, we report on a 79-year-old male anatomical donor who, upon brain removal, was found to have a single intracranial vertebral artery which was the sole source of the basilar artery. During dissection of the neck, both right and left vertebral arteries were identified arising from the subclavian arteries. The vertebral arteries were dissected from the transverse foramina and followed into the skull. The right vertebral artery terminated by supplying the spinal cord, consistent with the distribution of the posterior spinal artery. Such vascular anomalies are clinically significant, as they may lead to abnormal patterns of sensory-motor deficiencies in stroke and are at risk of iatrogenic injury during surgical procedures.

Walleye Sander vitreus (Mitchill) are relatively resistant to experimental infection with VHSV IVb and extant walleye strains vary in susceptibility

Compared to fathead minnow, walleye demonstrate low susceptibility to experimental infection with VHSV IVb, regardless of route of exposure or water temperature at time of infection. In triplicate and duplicate groups, walleye were intraperitoneally (i.p.) injected (10² -10⁸  pfu/fish) or waterborne-exposed (w; 1.4 × 10⁷  pfu mL^-1 ) with VHSV IVb. High cumulative mortality (64-100%) and severe gross lesions associated with VHSV IVb infection were evident only in fish i.p. injected with 10⁸  pfu at 12 °C. These fish had multifocal necrosis of several tissues including the gill and heart. There was no difference in mortality between walleye infected (w or i.p.) at 12 °C (spring stocking) compared with a declining temperature profile from 18 to 12 °C (fall stocking). There were significant differences (P < 0.05) in mortality between four extant walleye strains following i.p. infection, indicating that the choice of walleye strain for stocking might be an important consideration. Viral antigen was found in both i.p. and w-exposed walleye using immunohistochemistry, mostly within the gill and skin of w-exposed fish and most prominently in dermal fibrocytes. VHSV IVb was detected in multiple tissues from 6 to 21 days post-infection using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR).

Search for gravitational-wave bursts from soft gamma repeaters

We present a LIGO search for short-duration gravitational waves (GWs) associated with soft gamma ray repeater (SGR) bursts. This is the first search sensitive to neutron star f modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190 lesser events from SGR 1806-20 and SGR 1900+14. The unprecedented sensitivity of the detectors allows us to set the most stringent limits on transient GW amplitudes published to date. We find upper limit estimates on the model-dependent isotropic GW emission energies (at a nominal distance of 10 kpc) between 3x10;{45} and 9x10;{52} erg depending on waveform type, detector antenna factors and noise characteristics at the time of the burst. These upper limits are within the theoretically predicted range of some SGR models.

Upper limits on a stochastic background of gravitational waves

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of omega0 < 8.4 x 10(-4) in the 69-156 Hz band is approximately 10(5) times lower than the previous result in this frequency range.

Limits on gravitational-wave emission from selected pulsars using LIGO data

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars.

A new animal model of binge eating: key synergistic role of past caloric restriction and stress

Dieting and stress are important in the etiology and maintenance of eating disorders, and dieting strongly predicts stress-induced overeating in humans. We hypothesized that caloric restriction and stress interact in a unique manner to promote binge eating. To test this hypothesis, a group of young female rats were cycled through a restriction period (4 days of 66% of control food intake) followed by 6 days of free feeding prior to being stressed by acute foot shock. After three of these cycles, the food intake of rats exposed only to restriction (R), or only to stress (S), did not differ from controls. However, R+S rats that were restricted and refed, despite normal body weight and food intake after free feeding, engaged in a powerful bout of hyperphagia when stressed (Experiment 1). The R + S effect was replicated in an older group of rats (Experiment 2). The hyperphagia was characteristically binge-like, it constituted a 40% selective increase in highly palatable (HP) food (P < .001) over a discrete period of time (within 24 h post-stress), and reflected feeding for reward (higher HP:chow ratio) over metabolic need as occurred after restriction (higher chow:HP ratio). Subsequent experiments revealed that binge eating did not occur if only chow was available (Experiment 3) or if restriction-refeeding (R-R) did not proximally precede stress (Experiment 4). Experiment 5 revealed that a history of R-R cycles followed by only one stress episode was sufficient to increase intake to 53% above controls as early as 2 h after stress (P < .001). This animal model of binge eating should facilitate investigations into the neurochemical changes induced by dieting and environmental stress to produce disordered eating and provide a preclinical tool to test preventive strategies and treatments more relevant to bulimia nervosa, multiple cases of binge eating disorder (BED) and binge-purge type anorexia nervosa.

The large subunit of the mammalian mitochondrial ribosome. Analysis of the complement of ribosomal proteins present

Identification of all the protein components of the large subunit (39 S) of the mammalian mitochondrial ribosome has been achieved by carrying out proteolytic digestions of whole 39 S subunits followed by analysis of the resultant peptides by liquid chromatography and mass spectrometry. Peptide sequence information was used to search the human EST data bases and complete coding sequences were assembled. The human mitochondrial 39 S subunit has 48 distinct proteins. Twenty eight of these are homologs of the Escherichia coli 50 S ribosomal proteins L1, L2, L3, L4, L7/L12, L9, L10, L11, L13, L14, L15, L16, L17, L18, L19, L20, L21, L22, L23, L24, L27, L28, L30, L32, L33, L34, L35, and L36. Almost all of these proteins have homologs in Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae mitochondrial ribosomes. No mitochondrial homologs to prokaryotic ribosomal proteins L5, L6, L25, L29, and L31 could be found either in the peptides obtained or by analysis of the available data bases. The remaining 20 proteins present in the 39 S subunits are specific to mitochondrial ribosomes. Proteins in this group have no apparent homologs in bacterial, chloroplast, archaebacterial, or cytosolic ribosomes. All but two of the proteins has a clear homolog in D. melanogaster while all can be found in the genome of C. elegans. Ten of the 20 mitochondrial specific 39 S proteins have homologs in S. cerevisiae. Homologs of 2 of these new classes of ribosomal proteins could be identified in the Arabidopsis thaliana genome.

The small subunit of the mammalian mitochondrial ribosome. Identification of the full complement of ribosomal proteins present

Identification of all the protein components of the small subunit (28 S) of the mammalian mitochondrial ribosome has been achieved by carrying out proteolytic digestions of whole 28 S subunits followed by analysis of the resultant peptides by liquid chromatography and tandem mass spectrometry (LC/MS/MS). Peptide sequence information was used to search the human EST data bases and complete coding sequences of the proteins were assembled. The human mitochondrial ribosome has 29 distinct proteins in the small subunit. Fourteen of this group of proteins are homologs of the Escherichia coli 30 S ribosomal proteins S2, S5, S6, S7, S9, S10, S11, S12, S14, S15, S16, S17, S18, and S21. All of these proteins have homologs in Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae mitochondrial ribosomes. Surprisingly, three variants of ribosomal protein S18 are found in the mammalian and D. melanogaster mitochondrial ribosomes while C. elegans has two S18 homologs. The S18 homologs tend to be more closely related to chloroplast S18s than to prokaryotic S18s. No mitochondrial homologs to prokaryotic ribosomal proteins S1, S3, S4, S8, S13, S19, and S20 could be found in the peptides obtained from the whole 28 S subunit digests or by analysis of the available data bases. The remaining 15 proteins present in mammalian mitochondrial 28 S subunits (MRP-S22 through MRP-S36) are specific to mitochondrial ribosomes. Proteins in this group have no apparent homologs in bacterial, chloroplast, archaebacterial, or cytosolic ribosomes. All but two of these proteins have a clear homolog in D. melanogaster while all but three can be found in the genome of C. elegans. Five of the mitochondrial specific ribosomal proteins have homologs in S. cerevisiae.

A new face on apoptosis: death-associated protein 3 and PDCD9 are mitochondrial ribosomal proteins

Two proteins known to be involved in promoting apoptosis in mammalian cells have been identified as components of the mammalian mitochondrial ribosome. Proteolytic digestion of whole mitochondrial ribosomal subunits followed by analysis of the peptides present using liquid chromatography-tandem mass spectrometry revealed that the proapoptotic proteins, death-associated protein 3 (DAP3) and the programmed cell death protein 9, are both components of the mitochondrial ribosome. DAP3 has motifs characteristic of guanine nucleotide binding proteins and is probably the protein that accounts for the nucleotide binding activity of mammalian mitochondrial ribosomes. The observations reported here implicate mitochondrial protein synthesis as a major component in cellular apoptotic signaling pathways.

Identification of four proteins from the small subunit of the mammalian mitochondrial ribosome using a proteomics approach

Proteins in the small subunit of the mammalian mitochondrial ribosome were separated by two-dimensional polyacrylamide gel electrophoresis. Four individual proteins were subjected to in-gel Endoprotease Lys-C digestion. The sequences of selected proteolytic peptides were obtained by electrospray tandem mass spectrometry. Peptide sequences obtained from in-gel digestion of individual spots were used to screen human, mouse, and rat expressed sequence tag databases, and complete consensus cDNAs for these species were deduced in silico. The corresponding protein sequences were characterized by comparison to known ribosomal proteins in protein databases. Four different classes of mammalian mitochondrial small subunit ribosomal proteins were identified. Only two of these proteins have significant sequence similarities to ribosomal proteins from prokaryotes. These proteins are homologs to Escherichia coli S9 and S5 proteins. The presence of these newly identified mitochondrial ribosomal proteins are also investigated in the Drosophila melanogaster, Caenorhabditis elegans, and in the genomes of several fungi.

The c-Abl tyrosine kinase is regulated downstream of the B cell antigen receptor and interacts with CD19

c-Abl is a nonreceptor tyrosine kinase that we have recently linked to growth factor receptor signaling. The c-Abl kinase is ubiquitously expressed and localizes to the cytoplasm, plasma membrane, cytoskeleton, and nucleus. Thus, c-Abl may regulate signaling processes in multiple subcellular compartments. Targeted deletion or mutation of c-Abl in mice results in a variety of phenotypes, including splenic and thymic atrophy and lymphopenia. Additionally, lymphocytes isolated from specific compartments of c-Abl mutant mice have reduced responses to a variety of stimuli and an increased susceptibility to apoptosis following growth factor deprivation. Despite these observations, little is known regarding the signaling mechanisms responsible for these phenotypes. We report here that splenic B cells from c-Abl-deficient mice are hyporesponsive to the proliferative effects of B cell Ag receptor (BCR) stimulation. The c-Abl kinase activity and protein levels are elevated in the cytosol following activation of the BCR in B cell lines. We show that c-Abl associates with and phosphorylates the BCR coreceptor CD19, and that c-Abl and CD19 colocalize in lipid membrane rafts. These data suggest a role for c-Abl in the regulation of B cell proliferation downstream of the BCR, possibly through interactions with CD19.

Autoimmunity to munc-18 in Rasmussen's encephalitis

Rasmussen's encephalitis (RE) is a rare disease of the central nervous system characterized by severe epileptic seizures, progressive degeneration of a single cerebral hemisphere, and autoimmunity directed against glutamate receptor subunit, GluR3. We report here the identification of high-titer autoantibodies directed against munc-18 in the serum of a single patient with RE previously shown to have anti-GluR3 antibodies. Munc-18 is an intracellular protein residing in presynaptic terminals, which is required for secretion of neurotransmitters. These findings are consistent with the possibility of intermolecular epitope spreading between GluR3, a postsynaptic cell surface protein, and munc-18, a presynaptic intracellular protein. Immune attack on these two proteins, which participate at distinct steps of synaptic transmission, could act in an additive or synergistic manner to impair synaptic function and lead to seizures and neuronal death.

A proteomics approach to the identification of mammalian mitochondrial small subunit ribosomal proteins

Mammalian mitochondrial small subunit ribosomal proteins were separated by two-dimensional polyacrylamide gel electrophoresis. The proteins in six individual spots were subjected to in-gel tryptic digestion. Peptides were separated by capillary liquid chromatography, and the sequences of selected peptides were obtained by electrospray tandem mass spectrometry. The peptide sequences obtained were used to screen human expressed sequence tag data bases, and complete consensus cDNAs were assembled. Mammalian mitochondrial small subunit ribosomal proteins from six different classes of ribosomal proteins were identified. Only two of these proteins have significant sequence similarities to ribosomal proteins from prokaryotes. These proteins correspond to Escherichia coli S10 and S14. Homologs of two human mitochondrial proteins not found in prokaryotes were observed in the genomes of Drosophila melanogaster and Caenorhabditis elegans. A homolog of one of these proteins was observed in D. melanogaster but not in C. elegans, while a homolog of the other was present in C. elegans but not in D. melanogaster. A homolog of one of the ribosomal proteins not found in prokaryotes was tentatively identified in the yeast genome. This latter protein is the first reported example of a ribosomal protein that is shared by mitochondrial ribosomes from lower and higher eukaryotes that does not have a homolog in prokaryotes.

Expression, purification, and characterization of the human receptor activator of NF-kappaB ligand (RANKL) extracellular domain

Receptor activator of NF-kappaB ligand (RANKL) is a type II transmembrane protein found on osteoblasts which functions as a major determinant of osteoclast differentiation and activation. RANKL mediates bone homeostasis through binding to the cognate ligand on osteoclasts, RANK, and a soluble decoy receptor, osteoprotegerin (OPG). We designed a construct encoding the extracellular domain of human RANKL that conformed to reports of native processing. To encourage folding and posttranslational modification of a normally membrane-inserted moiety, we expressed the RANKL truncate as a secreted protein using the signal sequence from OPG in a Trichoplusia ni cell line using a baculovirus expression vector. RANKL was purified by a three-step process including an OPG-Fc affinity column. SDS-PAGE and mass spectral analysis indicated that the protein was >99% pure and glycosylated. Circular dichroism spectra revealed that the protein exhibited structural elements similar to tumor necrosis factor-alpha. By BIAcore analysis, RANKL bound to OPG with an affinity of 6.7 nM. Sedimentation equilibrium analytical ultracentrifugation analyses established that our protein existed as a trimer. We conclude that our expressed human RANKL truncate is folded, is functional, and exhibits self-association consistent with other family members.

The association of the menstrual cycle with the laxity of the anterior cruciate ligament in adolescent female athletes

OBJECTIVE

To identify a significant change in the laxity of the anterior cruciate ligament (ACL) in the competitive adolescent female athlete throughout the different phases of the menstrual cycle.

DESIGN

Prospective, single-blinded 8-week study set during a winter sports season.

SETTING

Suburban Ohio Division I high school.

PARTICIPANTS

26 members of gymnastics, soccer, track, tennis, and basketball teams. All participants were screened for normal menstrual cycles (26-30 days, menses 4-7 days long).

MAIN OUTCOME MEASURES

KT-1000 arthrometer was used to measure laxity by performing repeated measures throughout an 8-week period. Measurements were taken before the athletes' workouts. The athlete charted the menstrual periods on a monthly calendar. The measurements were then grouped into the three phases of the menstrual cycle (follicular, ovulatory, and luteal) and averaged.

RESULTS

Right knee laxity measured 4.98 mm follicular phase, 5.24 mm ovulatory, and 5.09 mm luteal. Left knee laxity measured 4.51 mm follicular, 4.43 mm ovulatory, and 4.62 mm luteal. There was no statistical difference among the three phases in the left (p = 0.9) and right (p = 0.7977). Additionally, left ACL laxity was significantly less in all three phases. We found no statistically significant variability in laxity among the five sports sampled (p > 0.63 to 0.10) and different ages (p = 0.404).

CONCLUSIONS

We found an insignificant change in ACL laxity from follicular to luteal phases of the menstrual cycle. This indicates that no single phase of the menstrual cycle clinically affects the ACL more than the next. Although the presence of sex hormones-particularly estrogen-may indeed predispose females to higher ACL injury rates, we did not find any evidence that hormonal level changes equate with significant ACL laxity changes. We conclude that the menstrual cycle does not significantly affect ACL laxity in the competitive adolescent female athlete.

The surface conformation of Sindbis virus glycoproteins E1 and E2 at neutral and low pH, as determined by mass spectrometry-based mapping

Sindbis virus contains two membrane glycoproteins, E1 and E2, which are organized into 80 trimers of heterodimers (spikes). These trimers form a precise T=4 icosahedral protein lattice on the surface of the virus. Very little is known about the organization of the E1 and E2 glycoproteins within the spike trimer. To gain a better understanding of how the proteins E1 and E2 are arranged in the virus membrane, we have used the techniques of limited proteolysis and amino acid chemical modification in combination with mass spectrometry. We have determined that at neutral pH the E1 protein regions that are accessible to proteases include domains 1-21 (region encompassing amino acids 1 to 21), 161-176, and 212-220, while the E2 regions that are accessible include domains 31-84, 134-148, 158-186, 231-260, 299-314, and 324-337. When Sindbis virus is exposed to low pH, E2 amino acid domains 99-102 and 262-309 became exposed while other domains became inaccessible. Many new E1 regions became accessible after exposure to low pH, including region 86-91, which is in the putative fusion domain of E1 of Semliki Forest virus (SFV) (M. C. Kielian et al., J. Cell Biol. 134:863-872, 1996). E1 273-287 and region 145-158 were also exposed at low pH. These data support a model for the structure of the alphavirus spike in which the E1 glycoproteins are centrally located as trimers which are surrounded and protected by the E2 glycoprotein. These data improve our understanding of the structure of the virus membrane and have implications for understanding the protein conformational changes which accompany the process of virus-cell membrane fusion.

Identification of a mammalian mitochondrial homolog of ribosomal protein S7

Bovine mitochondrial small subunit ribosomal proteins were separated by two-dimensional electrophoresis. The region containing the most basic protein(s) was excised and the protein(s) present subjected to in-gel digestion with trypsin. Electrospray tandem mass spectrometry was used to provide sequence information on some of the peptide products. Searches of the human EST database using the sequence of the longest peptide analyzed indicated that this peptide was from the mammalian mitochondrial homolog of prokaryotic ribosomal protein S7 (MRP S7(human)). MRP S7(human) is a 28-kDa protein with a pI of 10. Significant homology to bacterial S7 is observed especially in the C-terminal half of the protein. Surprisingly, MRP S7(human) shows less homology to the corresponding mitochondrial proteins from plants and fungi than to bacterial S7.

Changi: a place of personal pilgrimages and collective histories

This article investigates the meaning that the Changi historical site has had for its visitors. The study traces how the landmarks and relics of the former prisoner-of-war camp at Changi in Singapore have been re-created and, in some cases, relocated for the public since the end of World War II. Changi's meaning as a place is derived not only from the significance that it has for the ex-prisoners of war and their relatives, who frequently revisit the site: many visitors for whom Changi represents a major historical event in their own national history also attach considerable importance to the site.

Endogenous fertility, mortality and growth

This paper presents a model that illustrates the joint determination of population and development. "Economic and demographic outcomes are determined jointly in a choice-theoretic model of fertility, mortality and capital accumulation.... In addition to choosing savings and births, parents may reduce (infant) deaths by incurring expenditures on health-care which is also provided by the government. A generalised production technology accounts for long-run endogenous growth with short-run transitional dynamics. The analysis yields testable time series and cross-section implications which accord with the empirical evidence on the relationship between demography and development."

High-pressure Liquid Injection of Isazofos for Management of Hoplolaimus galeatus and Tylenchorhynchus dubius Infesting Turfgrasses

Three high-pressure liquid injection machines were used to inject isazofos into the root zone of tuff;grass plots to evaluate its potential for control of Hoplolaimus galeatus and Tylenchorhynchus dubius. A Rogers root zone injector delivering isazofos at 2.3 kg a.i./ha through 30 degrees and 60 degrees spray tips at 5,000 psi (3.45 x 10 Pascals) significantly reduced nematode populations at 32 days after a single application and 33 days after a second application. In a second experiment with the Rogers injector at 2.3 kg a.i./ha, H. galeatus populations were significantly lower at 16 days after a single application and at 42 and 61 days after a second application with the 60 degrees spray angle tips. An Envirojet turfgrass injector used to inject isazofos at 1.15 kg a.i./ha and 2.88 kg a.i./ha at 3,000 psi (1.38 x 107 Pascals) significantly reduced nematode populations at 7 days after treatment at the low rate and at 63 days after treatment with both application rates. A Landpride material injector applying isazofos at 6.9 and 13.8 kg a.i./ha at 2,000 psi (1.38 x 10 Pascals) significantly reduced nematode populations at 7, 14, and 63 days after treatment at the high rate and at 63 days after the low-rate application. Although suppression of nematodes with isazofos was found, the degree of suppression is probably not enough to warrant recommendation of high-pressure delivery of isazofos for control of H. galeatus and T. dubius populations infesting turfgrasses.

Redesigning the care of carotid endarterectomy patients

Recent studies have supported the effectiveness of carotid endarterectomy (CEA) as a treatment for significant carotid stenosis. While the efficacy of CEA has been established, it is important to review the processes and outcomes of care to ensure high-quality, cost-effective care. As part of a quality-improvement process, our hospital's Vascular Surgery Quality Improvement Team redesigned the care for patients having CEA surgery. Practice changes, implemented in January 1995, included routine discharge on the first postoperative day; a new critical pathway supported by a computerized order set, a switch from general anesthesia to a regional block approach, and the use of an algorithm in treating postoperative hypertension. The impact of these changes on cost and quality were then analyzed. A retrospective chart audit was completed on 185 CEA surgeries performed in 1995. Length of stay decreased by 1.15 days, and costs were reduced by $1900 per case, with no change in postoperative morbidity or mortality rates. The incidence and severity of postoperative hypertension, bradycardia, and hypotension were also analyzed, supporting the practice changes and the current level of nursing care.

Avermectin B1, Isazofos, and Fenamiphos for Control of Hoplolaimus galeatus and Tylenchorhynchus dubius Infesting Poa annua

Avermectin B, isazofos, and fenamiphos were evaluated in greenhouse experiments for efficacy against two common turfgrass parasites, Hoplolaimus galeatus and Tylenchorhynchus dubius. Treatments in all experiments were arranged in a completely randomized design and replicated four times. In the first experiment, avermectin B at rates of 0.2 and 0.4 kg a.i./ha and isazofos at rates of 2.3 and 23 kg a.i./ha significantly reduced populations of both species of parasitic nematodes compared to controls at 14 and 28 days after treatment (P </= 0.01). In the second experiment, the greatest reductions in both nematode populations occurred at 28 and 56 days after treatment, where 23 kg a.i./ha of isazofos was applied (P </= 0.01). These reductions, however, were not different from reductions of H. galeatus at 28 and 56 days after treatment (P </= 0.01) or T. dubius at 56 days after treatment (P </= 0.01), where 0.2- and 0.4-kg a.i./ha rates of avermectin B were mixed throughout the soil. In the third experiment, the greatest population reduction of H. galeatus was observed with a 0.4-kg a.i./ha treatment of avermectin B at 56 days after treatment (P </= 0.05). T. dubius populations were reduced by the 0.4-kg a.i./ha rate of avermectin B at 28 (P </= 0.01), 56 (P </= 0.05), and 70 (P </= 0.01) days after treatment. In the fourth and fifth experiments, avermectin B at rates of 7.5 and 15.2 kg a.i./ha consistently reduced nematode populations compared to controls and performed as well or better than fenamiphos (P </= 0.01).

Dealing with border issues the primary healthcare way

Border issues are commonly conceptualised as concerns about inequities in health care for people living near State boundaries or borders. This paper examines how border issues have been addressed in the implementation of primary healthcare at the community level. The paper focuses on the implementation of primary healthcare principles in two towns, Wallangarra in Queensland and Jennings in New South Wales. The primary healthcare approach employed by Stanthorpe Health Services addressed border issues by providing the residents of Wallangarra and Jennings with equitable access to health service provision. The structure of health service delivery, the funding differences in each State and the impact of State policies on the residents of these two towns are discussed. The paper demonstrates how application of primary healthcare principles has reduced the impact of some of the border issues faced by the residents of Wallangarra and Jennings.

Nickel inhibits endothelin-induced contractions of vascular smooth muscle

Endothelin (ET)-induced contractions of vascular smooth muscle (VSM) are dependent on extracellular Ca2+ yet display only partial sensitivity to L-type Ca2+ antagonists. The purpose of this study was to evaluate the effect of nickel (Ni2+), a Ca2+ channel antagonist with clearly documented differential potency toward L- vs. T-type Ca2+ currents on ET-mediated contractions in VSM. Treatment of rings of left anterior descending porcine coronary artery (LAD) with Ni2+ produced a profound dose-dependent inhibition of isometric force development in response to porcine ET (ET-1). At a concentration of 360 microM, Ni2+ exerted a significant inhibitory effect on contracture in response to doses of ET-1 ranging from 3 to 100 nM. In contrast, the same concentration of Ni2+ failed to significantly affect peak force development in response to KCl depolarization (5-77 mM) or to phenylephrine (0.3-30 mM). In addition, 360 microM Ni2+ significantly inhibited the contractile response of rat aorta to 10 nM ET-1. We conclude that ET-1 activates a Ni2(+)-sensitive process in VSM which may signal an additional Ca2+ influx pathway that appears to be functionally distinct from the L-type Ca2+ channel.

Can implanted cyst pieces of Echinococcus granulosus regenerate?

Small piece of ovine hydatid cysts devoid of brood capsules and protoscoleces, and half or quarter pieces of secondary sterile murine cysts of equine origin failed, over a six-month period, to regenerate when passaged into the peritoneal cavity of BALB/c mice. The majority of similar pieces placed in microdiffusion chambers prior to insertion into mice also failed to regenerate, suggesting that the passage of cyst pieces may not be totally reliable in the assessment of the viability of germinal layer tissue after chemotherapy.

The peritrophic membrane of the female sandfly Phlebotomus papatasi

The ultrastructure of the peritrophic membrane of the female sandfly Phlebotomus papatasi has been studied at various times after blood meals. The membrane begins to form within four hours of the blood meal with the secretion by the entire midgut epithelium of an electron-dense amorphous material. Subsequently, the membrane is stabilized and strengthened by the production of a layer of irregular chitinous microfibres, the whole membrane then forming a complete and resilient sac apparently unaffected by boiling 9 M potassium hydroxide. The membrane appears redundant 48 hours after the blood meal and fragments, possibly as a result of chitinase activity. The membrane's main functions are probably the prevention of clogging of the microvillous brush border by the blood meal and the confinement of large proteins, particularly serum trypsin inhibitors, to the endoperitrophic space while allowing sandfly proteases access to the blood meal periphery. Blood is not required to stimulate membrane production. Saline taken by blood feeding into the midgut also stimulates membrane formation. Phlebotomus papatasi females may lack an efficient anticoagulant, at least in the midgut, as blood meals frequently include fibrin clots.

Evaluation of the reproductive toxicology of 2,4,6-trichlorophenol in male and female rats

The toxicity of chlorinated organic compounds which may be generated as a by-product of drinking water chlorination has been an issue of increasing concern. Relatively few data are available concerning their reproductive toxicity. The present study was designed to evaluate the reproductive effects of one of these compounds, 2,4,6-trichlorophenol (TCP), in male and female rats. Adult males were treated with either 0, 100, 500, or 1000 mg/kg of TCP (po) for 10 weeks, at which time semen evaluations were conducted on ejaculates recovered from the genital tract of receptive females. Fertility was assessed in the 0- and 1000-mg/kg groups. Females were treated with identical doses for 2 weeks prior to pregnancy then throughout gestation. Dams were allowed to litter and pup development was monitored until Day 42 postpartum. TCP had no effect on any sperm parameter or male fertility. Treatment of females with 1000 mg/kg of TCP produced gross maternal toxicity as reflected in increased lethality and decreased weight gains in the dams. However, no treatment-related differences were seen in litter sizes or pup survival. Male and female birth weights were significantly depressed in the 500- and 1000-mg/kg groups; these differences disappeared by Day 4 postpartum, suggesting that they were a reflection of maternal toxicity. To this extent, the reproductive processes of male and female rats do not appear to be a primary target for the effects of TCP.

Novel methods for the estimation of acceptable daily intake

This paper describes two general methods for estimating ADIs that circumvent some of the limitations inherent in current approaches. The first method is based on a graphic presentation of toxicity data and is also shown to be useful for estimating acceptable intakes for durations of toxicant exposure other than the entire lifetime. The second method uses dose-response or dose-effect data to calculate lower CLs on the dose rate associated with specified response or effect levels. These approaches should lead to firmer, better established ADIs through increased use of the entire spectrum of toxicity data.

The development of young infants' ability to detect stimuli in the nasal visual field

We compared infants' ability to detect single lines of varying width in the temporal and nasal visual fields. The smallest lines detected by 1-month-olds at 20 degrees in the nasal visual field were more than eight times wider than those detected at 30 degrees in the temporal visual field. In contrast, 2-month-olds detected smaller lines at 20 degrees in the nasal visual field than at 30 degrees in the temporal visual field. Converging evidence suggests that the observed improvement between 1 and 2 months in detection in the nasal visual field reflects the maturation of a projection from the retina through the visual cortex to the superior colliculus.

Effects of trichloroethylene exposure on male reproductive function in rats

The present study was designed to evaluate the influences of trichloroethylene (TCE) on the reproductive system of male rats. In addition, information was obtained on the distribution and metabolism of TCE. At 100 days of age, male rats were allowed to copulate with ovariectomized, hormonally primed females and copulatory behaviors scored. Fifteen minutes post-ejaculation, females were sacrificed and ejaculate and semen plug recovered from the uterus and vagina for evaluation. These data served as a pre-exposure baseline for each animal. TCE exposure was then initiated with animals intubated with either 0, 10, 100, or 1000 mg/kg of TCE (10 males/group) for 5 days/week for 6 weeks. Copulatory behaviors and semen evaluations were conducted at Weeks 1 and 5 as well as 4 weeks post-exposure. Three males/group were sacrificed at the end of the sixth week of exposure and levels of TCE and its metabolites measured in various organs and blood. The remaining animals were sacrificed at the end of Week 10. TCE-related effects were seen primarily in the 1000 mg/kg group as reduced body weight gain, elevated liver/body weight ratios, and impaired copulatory behavior. However, the copulatory performance of the "affected" males had returned to normal by the fifth week of exposure. Although TCE and its metabolites concentrated to a significant extent in the male reproductive organs, semen evaluations failed to reveal any indices of spermatotoxicity. The initial alterations in copulatory behavior may be attributed to the narcotic properties of TCE. Tolerance to this pharmacological effect may explain the absence of these effects by the fifth week of exposure.

An evaluation of the copulatory, endocrinologic, and spermatotoxic effects of carbon disulfide in the rat

The present study was undertaken to evaluate the endocrinologic and spermatogenic effects of carbon disulfide (CS2) exposure in the rat. Adult, male rats were exposed to either 600 ppm CS2 or filtered air for 6 hr/day for 5 days/week for 10 weeks. One week prior to exposure and then at Weeks 1, 4, 7, and 10, males were placed with ovariectomized, hormonally primed females, and copulatory behaviors were scored. Fifteen minutes postcopulation, the female was killed and the ejaculate was recovered from the excised uterine tract along with the semen plug. Sperm counts, sperm motility, and morphology were determined. A blood sample was obtained for analyses of testosterone, follicle-stimulating (FSH), and luteinizing hormone (LH). At the end of the 10th week, five animals in each group were challenged with either human chorionic gonadotropin (HCG, 50 IU/animal, iv) or gonadotropin-releasing hormone (GnRH, 100 ng/animal, iv), and the testosterone or gonadotropin responses were monitored over time. Animals were subsequently killed with one epididymis and testis processed for histology and a sperm count determined from the other epididymis. Analysis revealed that CS2 exposure produced significant alterations in copulatory behavior and a decrease in ejaculated sperm counts by the fourth and seventh weeks of exposure, respectively. No endocrinologic alterations were observed. Moreover, caudal epididymal sperm counts were not depressed and the testes appeared histologically normal. These data suggest that CS2 does not exert a direct effect on the testes, but rather may interfere with the processes regulating sperm transport and ejaculation.