Genetic characterization of intramuscular myxomas.

Introduction: Intramuscular myxomas are benign tumors that are challenging to diagnose, especially on core needle biopsies. Acquired chromosomal aberrations and pathogenic variants in codon 201 or codon 227 in GNAS complex locus gene (GNAS) have been reported in these tumors. Here we present our genetic findings in a series of 22 intramuscular myxomas. Materials and methods: The tumors were investigated for the presence of acquired chromosomal aberrations using G-banding and karyotyping. Pathogenic variants in codon 201 or codon 227 of GNAS were assessed using direct cycle Sanger sequencing and Ion AmpliSeq Cancer Hotspot Panel v2 methodologies. Results: Eleven tumors carried chromosomal abnormalities. Six tumors had numerical, four had structural, and one had both numerical and structural chromosomal aberrations. Gains of chromosomes 7 and 8 were the most common abnormalities being found in five and four tumors respectively. Pathogenic variants in GNAS were detected in 19 myxomas (86%) with both methodologies. The detected pathogenic variants were p.R201H in nine cases (seven with abnormal and two with normal karyotypes), p.R201C in five cases, all with normal karyotypes, p.R201S in three cases (two with abnormal and one with normal karyotype), p.R201G in one case with a normal karyotype, and p.Q227E in one case with a normal karyotype. Conclusion: Firstly, our data indicate a possible association between chromosomal abnormalities and GNAS pathogenic variants in intramuscular myxomas. Secondly, the presence of the rare pathogenic variants R201S, p.R201G and p.Q227E in 26% (5 out of 19) of myxomas with GNAS pathogenic variants shows that methodologies designed to detect only the common "hotspot" of p.R201C and p.R201H will give false negative results. Finally, a comparison between Ion AmpliSeq Cancer Hotspot Panel v2 and direct cycle Sanger sequencing showed that direct cycle Sanger sequencing provides a quick, reliable, and relatively cheap method to detect GNAS pathogenic variants, matching even the most cutting-edge sequencing methods.

The efficacy of a combination of naproxen and fexofenadine (SJP - 002) to inhibit the symptoms that are associated with viral upper respiratory tract infection: Four case reports of individuals with common cold.

Key Clinical Message: There is no effective treatment that reduces both the severity and duration of a common cold episode. SJP - 002 (naproxen and fexofenadine) reduced symptom severity by two-third, and the duration of the common cold episode approximately by half. Abstract: The common cold is one of the most frequently experienced immune-related complaints. At present, available treatments have limited efficacy in inhibiting symptoms associated with upper respiratory tract infection, nor do they significantly shorten the duration of common cold episodes. Four case reports are presented of individuals with a common cold. Three of them self-administered the combination of naproxen and fexofenadine (SJP - 002). Results of one individual were compared to her spouse, who did not take SJP - 002 to treat common cold, while two other individuals took SJP - 002 and compared symptom severity with another common cold episode they experienced previously without taking SJP - 002. SJP - 002 reduced the severity of symptoms associated with upper respiratory tract infection by two-third and reduced the duration of the common cold episode approximately by half. In conclusion, SJP - 002 reduced the severity and duration of common cold episodes. These findings warrant further investigation of SJP - 002 in double-blind, placebo-controlled clinical trials.

Efficacy of Naproxen/Fexofenadine (SJP-003) in the Prevention of Side Effects of Influenza Vaccination: Four Case Studies.

The influenza virus is associated with sickness, and in particular among vulnerable populations such as elderly and those with underlying disease with hospitalization and increased mortality rates. Vaccination is an effective way to prevent infection with influenza. However, undesirable side effects of the vaccination are commonly experienced, and comprise one of the primary reasons for a substantial group of individuals to refrain from vaccination. An effective treatment against vaccination side effects could increase the overall willingness to vaccinate against influenza. Here, four cases are presented that self-administered SJP-003 (a combination of 220 mg naproxen sodium, directly followed by a single oral dose of 60 mg fexofenadine HCL), 2 h before and 10 h after influenza vaccination. No flu-like symptoms and pain at the injection site were reported. These observations warrant further investigation of SJP-003 in double-blind, placebo-controlled clinical trials.

Efficacy of the triple-combination SM-1 in a 5-h phase advance transient insomnia model.

Thomas Dahl, PO Box 404, Guilford, CT 06437 USA. Email: tadahl@outlook.com. The objectives of the study were to demonstrate the efficacy and safety of SM-1 in a circadian challenge model of transient insomnia. Randomized, double-blind, placebo-controlled cross-over study utilizing a 5-h phase advance model of transient insomnia. Subjects were 85 healthy adults reporting a history of transient insomnia, with an average age of 38.9 years. Both SM-1 and placebo were administered to all subjects in a randomly assigned sequence, with at least 1 week between treatments. The primary endpoint was total sleep time determined by polysomnography. Secondary endpoints included wakefulness after sleep onset, latency to persistent sleep, number of awakenings, subjective total sleep time and subjective sleep onset latency, total sleep time by quarters of the night, subjective number of awakenings, and sleep quality. Safety endpoints included adverse events, Karolinska Sleepiness Scale, Digit Symbol Substitution Test, and predischarge evaluation (tandem gait and Romberg tests). SM-1 provided an increase of 94.4 min in total sleep time over placebo (p < 0.0001). Wakefulness after sleep onset, subjective total sleep time, subjective sleep onset latency, and total sleep time in the first quarter of the night also showed significant improvement. SM-1 was well-tolerated with both type and frequency of adverse events being comparable to placebo, and no residual sleepiness upon awakening (i.e., after 8 h). SM-1 provided a robust and statistically significant increase in total sleep time compared to placebo in a circadian model of transient insomnia, without evidence of next-day impairment.

In Vitro Assessment of the Antiviral Activity of Ketotifen, Indomethacin and Naproxen, Alone and in Combination, against SARS-CoV-2.

The 2019 coronavirus infectious disease (COVID-19) is caused by infection with the new severe acute respiratory syndrome coronavirus (SARS-CoV-2). Currently, the treatment options for COVID-19 are limited. The purpose of the experiments presented here was to investigate the effectiveness of ketotifen, naproxen and indomethacin, alone or in combination, in reducing SARS-CoV-2 replication. In addition, the cytotoxicity of the drugs was evaluated. The findings showed that the combination of ketotifen with indomethacin (SJP-002C) or naproxen both reduce viral yield. Compared to ketotifen alone (60% inhibition at EC50), an increase in percentage inhibition of SARS-CoV-2 to 79%, 83% and 93% was found when co-administered with 25, 50 and 100 µM indomethacin, respectively. Compared to ketotifen alone, an increase in percentage inhibition of SARS-CoV-2 to 68%, 68% and 92% was found when co-administered with 25, 50 and 100 µM naproxen, respectively. For both drug combinations the observations suggest an additive or synergistic effect, compared to administering the drugs alone. No cytotoxic effects were observed for the administered dosages of ketotifen, naproxen, and indomethacin. Further research is warranted to investigate the efficacy of the combination of ketotifen with indomethacin (SJP-002C) or naproxen in the treatment of SARS-CoV-2 infection in humans.

Functional observation after morphine withdrawal: effects of SJP-005.

RATIONALE AND OBJECTIVE: SJP-005 (ketotifen and ibuprofen) is being developed as a potential new treatment for opioid withdrawal. Three studies were conducted to evaluate the early phase (acute, day 1) and late phase (days 2-12) effects of SJP-005 on discontinuation-induced morphine withdrawal. METHODS: Sprague-Dawley rats received subcutaneous morphine twice daily for 18 days and ceased on day 19. Twice daily, oral dosages of placebo or SJP-005 (1 mg/kg ketotifen and 15 mg/kg ibuprofen) were administered starting 4 days before (study 1), 2 days before (study 2), or immediately after (study 3) morphine cessation. Functional observations were made up to 12 h after treatment cessation on day 19 (early phase), and immediately after treatment on days 20-30 (late phase). Treatment effects (mean overall score, and individual symptoms) were compared with placebo using ANOVA, and Tukey's tests in case of multiple comparisons. RESULTS: Across the studies, the number of withdrawal signs on day 19 (early phase) and days 20-30 (late phase) was lower with SJP-005 compared with placebo. The effects of SJP-005 when treatment was initiated 2 days before morphine cessation by discontinuation were most pronounced and statistically significant in the late phase (F(1,18) = 14.10, p = 0.001). In particular, a significant reduction was observed in hypersensitivity to touch (F(1,18) = 13.65, p = 0.002). A 50% reduction in withdrawal symptoms was observed 9.0 days after placebo versus 4.5 days after SJP-005. After 9.0 days, all withdrawal symptoms were absent in the SJP-005 group, while symptoms in the placebo group were still evident on day 18. CONCLUSION: Compared to placebo, SJP-005 significantly reduced the incidence and duration of discontinuation-induced morphine withdrawal symptoms when treatment was initiated 2 days before morphine cessation.

A Comparison of the Antinociceptive Properties of SJP-005 and Morphine in Rats.

SJP-005 (a combination of ketotifen and ibuprofen) is being developed as a potential treatment for pain and for opioid use disorder. It is therefore important to investigate the potential antinociceptive properties of SJP-005. Two studies were conducted to evaluate the potential effects of SJP-005 in rats. Study 1 applied the von Frey test to examine the antinociceptive effect of morphine with and without SJP-005 in adjuvant-induced hypersensitivity to tactile stimulation. In a double-blind, between-groups design, groups of rats (n = 10 each) received morphine at 3, 10, or 30 mg/kg bodyweight (bw) (subcutaneous injection) with or without SJP-005 (oral). Mechanic allodynia and paw volume were assessed before and after treatment. Study 2 utilized the hot plate test. Using a crossover design, groups of rats (n = 10 each) received either morphine at 3, 10, or 30 mg/kg bw (subcutaneous injection) preceded by oral administration of placebo (Week 1) or SJP-005 (Week 2). In Study 1, in the von Frey up-and-down test, Δ paw withdrawal responses in Group 1 (3 mg/kg bw morphine) were significantly lower compared to those in Group 4 (3 mg/kg bw morphine plus SJP-005), whereas the differences in Δ paw withdrawal between Group 2 and Group 5 (10 mg/kg bw morphine with and without SJP-005) and between Group 3 and Group 6 (10 mg/kg bw morphine with and without SJP-005) did not reach statistical difference. Trendline analysis of the dose-response relationship for the morphine + placebo groups and morphine + SJP-005 groups revealed no significant differences in the intercepts and slopes. In Study 2, no significant differences were observed on hot plate performance between morphine and morphine in combination with SJP-005. In conclusion, the findings in the von Frey up-and-down test (Study 1) suggest that animals can withstand higher levels of painful stimuli when SJP-005 is co-administered. This may also suggest a possible opioid sparing effect. However, in the hot plate test (Study 2), animals did not respond more adaptively to stronger painful stimuli after co-administering SJP-005. These observations warrant further investigation of the antinociceptive properties of SJP-005.

The Effects of SJP-001 on Alcohol Hangover Severity: A Pilot Study.

BACKGROUND: Despite a clear market need and many hangover products available, currently there is no hangover treatment that is supported by substantial scientific evidence demonstrating its efficacy and safety. A pilot study was conducted to investigate the effects of a potential new hangover treatment, SJP-001, and its constituents (220 mg naproxen and 60 mg fexofenadine) on hangover severity. METHODS: N = 13 healthy social drinkers (36.3 ± 8.9 years old) participated in a double-blind, factorial design, cross-over study. On each test day, they consumed their own choice of alcohol up to a self-reported level sufficient to elicit a next-day hangover. Treatments were administered prior to onset of drinking. Next morning, hangover severity was assessed with the Acute Hangover Scale (AHS). Subjects were included in the efficacy analysis only if they reported a hangover after placebo. RESULTS: N = 5 subjects (60% male, 35.2 ± 9.0 years old) were included in the analysis. They consumed a mean (SD) of 4.6 ± 1.1 units of alcohol and had an average peak breath alcohol concentration (BrAC) of 0.065% across conditions. Compared to placebo, SJP-001 significantly improved the AHS overall hangover severity score (0.8 ± 0.3 versus 1.5 ± 0.9, p = 0.042). Compared to placebo, SJP-001 also reduced scores on the individual item 'hangover', although the observed improvement (-1.6) did not reach statistical significance (p = 0.102). The differences from placebo after naproxen alone and fexofenadine alone were not statistically significant. SJP-001 also improved scores for the individual hangover symptoms tired, thirsty, headache, dizziness, nausea, and loss of appetite, but these effects did not reach statistical significance. DISCUSSION: Compared to placebo, SJP-001 significantly reduced overall hangover severity. The effects of SJP-001 should be further examined in a double-blind, placebo-controlled trial with a larger sample size and controlled administration of sufficient amounts of alcohol to provoke a more substantial alcohol hangover.

Efficacy of SM-1 in a transient insomnia model.

OBJECTIVES: The objectives of this study were primarily to assess the efficacy and safety of SM-1 in a circadian challenge model of transient insomnia and secondarily, to assess the contribution of diphenhydramine to the combination. METHODS: Randomized, double-blind, placebo-controlled three-way cross-over study with a 5-hr phase advance. Subjects were 39 healthy adults reporting a history of transient insomnia. All treatments (SM-1, SM-1 without diphenhydramine, or placebo) were administered to all subjects in a randomly assigned sequence, with at least 1 week between treatments. The primary endpoint was total sleep time (TST) determined by polysomnography. Secondary endpoints included wakefulness after sleep onset (WASO), latency to persistent sleep, number of awakenings (NAW), subjective TST (sTST) and sleep latency (sSL), TST, and NAW by quarters of the night and sleep quality. Safety endpoints included adverse events, Karolinska Sleepiness Scale digit symbol substitution test, and subject-reported alertness level. RESULTS: SM-1 provided an increase of 126.7 min in TST over placebo (p < .001). WASO, sTST, sleep quality, and sSL also showed significant improvement. Diphenhydramine demonstrated a significant (p = .014) contribution of 43.7 min to TST. SM-1 was well-tolerated with type and frequency of adverse events comparable with placebo, and no residual sleepiness upon awakening after 8 hr. CONCLUSIONS: SM-1 provided a robust and statistically significant increase in TST compared with placebo in a circadian model of transient insomnia, without evidence of next-day impairment. Diphenhydramine contributed to the effect.

Pharmacodynamic and pharmacokinetic profile of SM-1, a triple-drug combination to increase total sleep time.

OBJECTIVE: The primary objective was to characterize the pharmacokinetics and pharmacodynamics of SM-1 after administration of a single oral dose to healthy volunteers in a placebo-controlled double-blind trial of daytime sedation. Secondary objectives were to determine the onset, duration, and offset of the sedative effects using subjective and objective measures of sedation. Safety and tolerability of SM-1 were also investigated. METHODS: Males and females 18-45 years of age received SM-1, a combination drug product comprised of diphenhydramine, zolpidem (delayed release), and lorazepam (delayed release). The pharmacokinetic profile of each drug was determined from blood samples. Sedative effects were assessed by visual analog scale, digit symbol substitution test, memory test, and quantitative electroencephalography. RESULTS: Similar number and severity of adverse events were observed following administration of SM-1 and placebo. Onset of sedation, as determined by subjective, performance, and electroencephalography measures, occurred 0.5-1 hr postdose, lasting about 7-7.5 hr. Plasma concentration curves for the two delayed-release components were altered compared with published data for unmodified drugs. Exposure values obtained with the combination product were in good agreement with published values of the drugs given individually. CONCLUSIONS: SM-1 was well tolerated and has pharmacologic activity starting within an hour of ingestion, lasting approximately 7-8 hr. Sedative activity was seen with subjective, psychomotor, and electroencephalography assays.

Potentiation of azole antifungals by 2-adamantanamine.

Azoles are among the most successful classes of antifungals. They act by inhibiting α-14 lanosterol demethylase in the ergosterol biosynthesis pathway. Oropharyngeal candidiasis (OPC) occurs in about 90% of HIV-infected individuals, and 4 to 5% are refractory to current therapies, including azoles, due to the formation of resistant biofilms produced in the course of OPC. We reasoned that compounds affecting a different target may potentiate azoles to produce increased killing and an antibiofilm therapeutic. 2-Adamantanamine (AC17) was identified in a screen for compounds potentiating the action of miconazole against biofilms of Candida albicans. AC17, a close structural analog to the antiviral amantadine, did not affect the viability of C. albicans but caused the normally fungistatic azoles to become fungicidal. Transcriptome analysis of cells treated with AC17 revealed that the ergosterol and filamentation pathways were affected. Indeed, cells exposed to AC17 had decreased ergosterol contents and were unable to invade agar. In vivo, the combination of AC17 and fluconazole produced a significant reduction in fungal tissue burden in a guinea pig model of cutaneous candidiasis, while each treatment alone did not have a significant effect. The combination of fluconazole and AC17 also showed improved efficacy (P value of 0.018) compared to fluconazole alone when fungal lesions were evaluated. AC17 is a promising lead in the search for more effective antifungal therapeutics.

The effects of individual factors and school environment on mental health and prejudiced attitudes among Norwegian adolescents.

INTRODUCTION: The aim was to examine the prevalence of mental health difficulties and prejudices toward mental illness among adolescents, and to analyze possible school and school class effects on these issues. METHODS: The sample comprised 4,046 pupils (16-19 years) in 257 school classes from 45 Norwegian upper secondary schools. The estimated response rate among the pupils was about 96%. Self-reported mental health difficulties were measured with a four-item scale that covered emotional and behavioral difficulties. Prejudiced attitudes toward mental illness were assessed using a nine-item scale. Multilevel regression analysis was used to estimate the contribution of factors at the individual level, and at the school and class levels. RESULTS: Most of the variance in self-reported mental health difficulties and prejudices was accounted for by individual level factors (92-94%). However, there were statistically significant school and class level effects (P < 0.01), confounded by socioeconomic factors. Mental health difficulties were commonly reported, more often by females than males (P < 0.01). Difficulties with emotions and attention were the two main problem areas, with definite to severe difficulties being reported by 19 and 21% of the females, and by 9 and 16% of the males, respectively. Prejudices were reported more often by males than females (P < 0.01). Both self-reported mental health difficulties and prejudiced attitudes were related to educational program, living situation, and parental education (P < 0.01). CONCLUSION: The relatively high prevalences of mental health difficulties and prejudiced attitudes toward mental illness among adolescents indicate a need for effective mental health intervention programs. Targeted intervention strategies should be considered when there is evidence of a high number of risk factors in schools and school classes. Furthermore, the gender differences found in self-reported mental health difficulties and prejudices suggest a need for gender-differentiated programs.

Phase I clinical trial of STA-4783 in combination with paclitaxel in patients with refractory solid tumors.

PURPOSE: STA-4783 is a new compound that markedly enhances the therapeutic index of paclitaxel against human tumor xenograft models. A phase I clinical trial was undertaken to determine the maximum tolerated dose, toxicity profile, and pharmacokinetics of STA-4783 in combination with paclitaxel. EXPERIMENTAL DESIGN: Adults with refractory solid tumors concurrently received STA-4783 and paclitaxel as a 3-h i.v. infusion at starting doses of 44 and 135 mg/m(2), respectively. After increasing paclitaxel to 175 mg/m(2), the STA-4783 dose was escalated as permitted by dose-limiting toxicity during the first 21-day cycle. RESULTS: Thirty-five patients were treated with eight dose levels of STA-4783/paclitaxel. In patients receiving 175 mg/m(2) paclitaxel, the incidence of severe toxicity increased with escalation of the STA-4783 dose above 263 mg/m(2), and 438 mg/m(2) was the maximum tolerated dose. All toxicities were typical of paclitaxel, with neutropenia, mucositis, and myalgia/arthralgia being dose limiting. Partial responses were achieved in one patient with Kaposi's sarcoma and another with ovarian cancer that progressed during prior treatment with paclitaxel. STA-4783 exhibited linear pharmacokinetics characterized by rapid elimination from plasma (biological half-life, 1.06 +/- 0.24 h) and a low steady-state apparent volume of distribution (25.1 +/- 8.1 L/m(2)). The total body clearance of paclitaxel decreased significantly with escalation of the STA-4783 dose. CONCLUSIONS: The STA-4783/paclitaxel combination was well tolerated with a toxicity profile similar to single-agent paclitaxel. Enhanced systemic exposure to paclitaxel resulting from a dose-dependent interaction with STA-4783 was associated with increased toxicity. Objective responses in two heavily pretreated patients, both with taxane exposure, have encouraged further clinical evaluation of this regimen.

Capravirine, a nonnucleoside reverse-transcriptase inhibitor in patients infected with HIV-1: a phase 1 study.

Capravirine is a nonnucleoside reverse-transcriptase inhibitor (NNRTI) with a unique resistance profile. Although single mutations allow resistance to established NNRTIs, human immunodeficiency virus (HIV)-1 must undergo multiple mutations to achieve resistance to capravirine. In the present phase 1 study, capravirine was administered orally for up to 28 days to 55 HIV-1-infected individuals with CD4+ T lymphocyte counts of 50-500 cells/microL. The most frequent adverse events were diarrhea (5%) and nausea (4%), with no drug-related rashes observed. The day 15 median (mean) HIV-1 load decreased by 1.34 (1.45) log(10) copies/mL in the patients receiving 25 mg/kg/day. Capravirine demonstrated potent antiviral activity, even in antiretroviral-experienced patients.

Safety, pharmacokinetics, and biological pharmacodynamics of the immunocytokine EMD 273066 (huKS-IL2): results of a phase I trial in patients with prostate cancer.

This phase 1 clinical trial was conducted to evaluate the safety and to determine the maximum tolerated dose (MTD) of the immunocytokine EMD 273066 huKS-IL2 and, secondarily, to assess its pharmacokinetics, immunogenic potential, and immunologic activity in patients with androgen-independent prostate cancer (n = 22). EMD 273066 was administered in 3-day cycles (separated by 4 weeks) of once-daily, 4-hour intravenous infusions at a dose determined by an escalation protocol (0.4, 0.7, 1.4, 2.8, 4.3, 6.4, or 8.5 mg/m/d). Approximately 2/3 of patients received a second cycle of treatment. The results show that the MTD of EMD 273066 [ie, one dose level below that producing dose-limiting toxicity (DLT) in at least 33% of patients in a dosing group] was 6.4 mg/m/d. EMD 273066 was generally well tolerated up to a dose of 4.3 mg/m/d. No DLTs, defined as drug-related toxicities >OR= Grade 3 occurring during the first treatment cycle, were observed among patients in the 0.4-, 0.7-, 1.4-, or 4.3-mg/m/d dosing groups. Four patients treated with 2.8, 6.4, or 8.5 mg/m/d EMD 273066 experienced DLTs. Titers of both antiimmunocytokine and anti-FcIL-2 antibody responses were observed after the first dose cycle and either decreased or remained stable during a second course of treatment. No hypersensitivity reactions were observed. EMD 273066 exhibited immunologic activity as demonstrated by increases in lymphocyte counts, natural killer cell number and specific activity, and antibody-dependent cellular cytotoxicity activity. On average, Cmax, which was dose-dependent, was achieved within 1 hour after infusion. Mean t(1/2) which was independent of dose, ranged from 4.0 to 6.7 hours across doses. A zero-compartment body model with one-order kinetics best described the concentration-time profiles. These data demonstrate that the novel immunocytokine EMD 273066 is well tolerated at doses above a level of observed systemic biologic activity in patients with androgen-independent prostate cancer.

Electrostatic interactions lead to the formation of asymmetric collagen-phosphophoryn aggregates.

In bone and dentin the formation and mineralization of the extra cellular matrix structure is a complex process highly dependent on intermolecular interactions. In dentin, the phosphophoryns (PP) and type I collagen (COL1) are the major constituents implicated in mineralization. Thus, as a first step in understanding the tissue organization, we have initiated a study of their interaction as a function of pH, ionic strength, and relative concentrations or mixing ratios. Complex formation has been analyzed by dynamic light scattering to detect aggregate formation and by rotary shadowing electron microscopy (EM) to determine aggregate shape. The EM data showed that at the pH values studied, the PP-COL1 interaction leads to the formation of large fibrillar aggregates in which the PP are present along the fibril surfaces. The quantitative phase distribution data showed a 1/1 molar equivalence at the maximum aggregation point, not at electrostatic PP-COL1 equivalence. As the ionic strength was raised, the PP-COL1 aggregates became smaller but the binding and asymmetric fibrillar aggregation persisted. In EM, the PP appear as dense spheres. Along the surfaces of the collagen aggregates, the PP are larger and more open or extended, suggesting that COL1-bound PP may undergo a conformational change, opening up so that a single PP molecule might interact with and electrostatically link several COL1 molecules. This might have important implications for dentin structure, stability, and mineralization.

Dentin matrix protein 1 initiates hydroxyapatite formation in vitro.

Bone and dentin formation are interesting examples of matrix-mediated mineralization. However, factors and mechanisms regulating this process are poorly understood. Dentin matrix protein 1 (DMP1) is an acidic extracellular matrix protein found in dentin and bone, and based on its amino acid composition it could be postulated to play an important role in mineralization. Our present study examines the ability of recombinant DMP1 to initiate apatite formation in vitro. A 45Ca-binding assay demonstrated that recombinant DMP1 (rDMP1) possesses calcium-binding ability under physiological conditions. The in vitro nucleation experiments when conducted with rDMP1-coated glass plates demonstrated hydroxyapatite nucleation, while amorphous mineral was deposited on blank or BSA-coated surface. This mineral deposition was found to be 10-fold higher on rDMP1-coated glass surface when compared with the control glass plates. These findings suggest that DMP1 could be considered as a nucleator for apatite deposition in vitro.

Mineral-related proteins of sea urchin teeth: Lytechinus variegatus.

Sea urchins have a set of five continuously growing teeth, each of which has a very complex structure. The mineral phase is calcite of varying Mg content, depending on the location within a tooth. The calcium carbonate is present in amorphous, plate-like and rod-like forms. It has been hypothesized that the mineral deposition is a matrix-mediated process, similar to that in vertebrate bone and tooth, wherein certain macromolecules within the organic matrix of the mineralized tissue play an important role in nucleating and controlling the growth habit of the mineral crystals. It has also been hypothesized that the mineral-related macromolecules involved in urchin teeth might bear a direct evolutionary relationship to those of the vertebrate tooth. These hypotheses are explored here by examining the pattern and nature of the mineral distribution, using microCT of intact teeth, and the nature of the mineral-related matrix proteins. The mineral-related proteins were extracted and fractionated by anion exchange chromatography. The relationship of certain fractions to vertebrate matrix proteins was established by immunoblots using antibodies to vertebrate tooth proteins. The antibodies were then used to localize the proteins within the teeth, by immunocytochemistry and histology with specific staining. The microCT data on mineral density has been correlated with the patterns of cellular migration and mineral deposition within the tooth as it grows. It appears that the mineralization within the different tooth compartments might take place under the influence of different matrix proteins. Further studies are in progress to more completely describe the vertebrate-invertebrate immunologically cross-reactive proteins of the urchin teeth.

Improved circulating half-life and efficacy of an antibody-interleukin 2 immunocytokine based on reduced intracellular proteolysis.

PURPOSE: Previous studies showed that reducing the interaction of antibody-interleukin 2 immunocytokines with Fc receptors improved their circulating half-life in mice and increased their antitumor activity. We sought to modify sequences that would increase half-life but retain the ability to activate Fc receptor-mediated effector functions. EXPERIMENTAL DESIGN: Modified immunocytokines were assessed in vitro for effector function and protease sensitivity and in vivo for pharmacokinetic and antitumor activities in an syngeneic tumor regression model. RESULTS: Single amino acid changes in the junction sequence between the antibody and interleukin-2 components had dramatic effects on circulating half-life and antitumor activity. This effect was independent of Fc receptor binding to either Fcgamma receptors or the Fc protection receptor, but was associated with changes in susceptibility to intracellular proteases. CONCLUSIONS: We have identified modifications that dramatically improve the circulating half-life of immunocytokines based on increased resistance to intracellular degradation and thus have demonstrated how these molecules can be recycled in and out of an intracellular compartment. Use of these improved immunocytokines with highly favorable pharmacokinetic properties and retained effector functions should lead to more effective treatment of epithelial cancers.