A Pilot, First in Human Study of Autologous IFN-Gamma Stimulated Mesenchymal Stromal Cells for Treatment of Radiation-Induced Xerostomia

PURPOSE/OBJECTIVE(S)

There are no existing effective treatments for radiation-induced xerostomia (RIX), a common side effect of head and neck radiation. Mesenchymal stromal cells (MSCs) exhibit regenerative effects in multiple tissues and may represent an effective cell therapy for the treatment of RIX. Here we present the primary safety and secondary efficacy endpoints of a first-in-human pilot study of IFNγ-stimulated autologous bone marrow- derived MSCs [MSC(M)] for the treatment of RIX.

MATERIALS/METHODS

We conducted a single-center clinical trial investigating the safety and tolerability of autologous IFNγ-stimulated MSC(M). The study was conducted under an FDA-IND and approved by the local IRB. Patients underwent bone marrow aspiration, MSC(M) were then culture-expanded, stimulated with IFNγ, and cryopreserved. Banked IFNγ-stimulated MSC(M) were thawed, allowed to recover, and then 10 × 106 MSC(M) were injected transcutaneously via ultrasound guidance into one submandibular gland. The primary objective was safety and tolerability determined by dose-limiting toxicity (DLT) defined as submandibular pain > 5 on a standard 10-point pain scale or any serious adverse event (SAE) within one month after injection. Secondary objectives included analysis of efficacy as measured by salivary quantification and using 3 validated quality of life instruments. Quantitative results are reported as mean and standard deviation (SD).

RESULTS

Six radiation-induced xerostomia patients with head and neck cancer who had completed radiation at least 2 years earlier were enrolled. The median age was 71 (61-74) and 5 (83%) patients were male. Five patients (83%) were treated with chemoradiation and one patient (17%) with radiation alone. The average dose of radiation to the injected submandibular gland was 59.9 Gy. Three patients (50%) reported a pain score of 1 after submandibular gland injection, all pain resolved within 4 days. No patients reported pain 1 month after injection, with no SAEs or other DLTs reported 1 month after injection. The analysis of secondary endpoints demonstrated a trend of increased salivary production. The mean unstimulated saliva was 0.13 mL/min (SD 0.17) at baseline and increased to 0.14 mL/min (SD 0.12) at 1 month after injection and 0.19 mL/min (SD 0.21) at 3-months. Quality of life surveys also showed a trend towards improvement.

CONCLUSION

Injection of autologous IFNγ-stimulated MSC(M) into the submandibular gland of patients with RIX is safe and well tolerated. A trend towards an improvement in secondary endpoints of salivary quantity and quality of life was observed. This first-in-human pilot study provides support for further investigation into IFNγ-stimulated MSC(M) as an innovative, potentially curative, remedy to treat RIX. A phase I dose-escalation study injecting into bilateral submandibular glands is scheduled to begin accrual in the spring of 2023.

Evaluation of Bebtelovimab for Treatment of COVID-19 During the SARS-CoV-2 Omicron Variant Era

Background

Monoclonal antibody (mAb) treatment is associated with decreased risk of hospitalization and death in high-risk outpatients with mild to moderate coronavirus disease 2019 (COVID-19) caused by early severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. Bebtelovimab exhibits in vitro activity against the Omicron variant and its sublineages; however, clinical data are lacking.

Methods

A retrospective cohort study was conducted comparing bebtelovimab-treated patients with propensity score–adjusted and matched nontreated control groups. Participants included high-risk outpatients eligible for bebtelovimab treatment under Emergency Use Authorization with a positive SARS-CoV-2 test from March 30 to May 28, 2022. Treated patients received single-dose intravenous treatment with bebtelovimab. The primary outcome was hospitalization or death over 28 days.

Results

Before matching/statistical adjustment, mAb-treated patients were, on average, 10 years older than nontreated patients (61.6 vs 51.3 years) and had higher prevalence of obstructive sleep apnea, hypertension, chronic kidney disease, cancer, organ or cell transplant, and immunocompromised status (standardized mean differences ≥0.20). The adjusted odds ratio (OR) of hospitalization or death comparing 1006 treated with 2023 nontreated patients was 0.50 (95% CI, 0.31–0.80). Among 930 treated and 930 propensity score–matched nontreated patients, the incidence of hospitalization or death was 3.1% vs 5.5%, respectively (conditional OR, 0.53; 95% CI, 0.32–0.86). The lower odds ratio of hospitalization or death associated with bebtelovimab treatment was most evident in older patients, those with immunocompromised status, and fully vaccinated patients.

Conclusions

Monoclonal antibody treatment with bebtelovimab among COVID-19 outpatients is associated with lower odds of hospitalization or death, particularly among immunocompromised and older patients.

Effectiveness of Casirivimab-Imdevimab and Sotrovimab During a SARS-CoV-2 Delta Variant Surge: A Cohort Study and Randomized Comparative Effectiveness Trial

Importance

The effectiveness of monoclonal antibodies (mAbs), casirivimab-imdevimab and sotrovimab, is unknown in patients with mild to moderate COVID-19 caused by the SARS-CoV-2 Delta variant.

Objective

To evaluate the effectiveness of mAb against the Delta variant compared with no mAb treatment and to ascertain the comparative effectiveness of casirivimab-imdevimab and sotrovimab.

Design, Setting, and Participants

This study comprised 2 parallel studies: (1) a propensity score-matched cohort study of mAb treatment vs no mAb treatment and (2) a randomized comparative effectiveness trial of casirivimab-imdevimab and sotrovimab. The cohort consisted of patients who received mAb treatment at the University of Pittsburgh Medical Center outpatient infusion centers and emergency departments from July 14 to September 29, 2021. Participants were patients with a positive SARS-CoV-2 test result who were eligible to receive mAbs according to emergency use authorization criteria.

Exposure

For the trial, patients were randomized to either intravenous casirivimab-imdevimab or sotrovimab according to a system therapeutic interchange policy.

Main Outcomes and Measures

For the cohort study, risk ratio (RR) estimates for the primary outcome of hospitalization or death by 28 days were compared between mAb treatment and no mAb treatment using propensity score-matched models. For the comparative effectiveness trial, the primary outcome was hospital-free days (days alive and free of hospitalization) within 28 days after mAb treatment, where patients who died were assigned -1 day in a bayesian cumulative logistic model adjusted for treatment location, age, sex, and time. Inferiority was defined as a 99% posterior probability of an odds ratio (OR) less than 1. Equivalence was defined as a 95% posterior probability that the OR was within a given bound.

Results

A total of 3069 patients (1023 received mAb treatment: mean [SD] age, 53.2 [16.4] years; 569 women [56%]; 2046 had no mAb treatment: mean [SD] age, 52.8 [19.5] years; 1157 women [57%]) were included in the prospective cohort study, and 3558 patients (mean [SD] age, 54 [18] years; 1919 women [54%]) were included in the randomized comparative effectiveness trial. In propensity score-matched models, mAb treatment was associated with reduced risk of hospitalization or death (RR, 0.40; 95% CI, 0.28-0.57) compared with no treatment. Both casirivimab-imdevimab (RR, 0.31; 95% CI, 0.20-0.50) and sotrovimab (RR, 0.60; 95% CI, 0.37-1.00) were associated with reduced hospitalization or death compared with no mAb treatment. In the clinical trial, 2454 patients were randomized to receive casirivimab-imdevimab and 1104 patients were randomized to receive sotrovimab. The median (IQR) hospital-free days were 28 (28-28) for both mAb treatments, the 28-day mortality rate was less than 1% (n = 12) for casirivimab-imdevimab and less than 1% (n = 7) for sotrovimab, and the hospitalization rate by day 28 was 12% (n = 291) for casirivimab-imdevimab and 13% (n = 140) for sotrovimab. Compared with patients who received casirivimab-imdevimab, those who received sotrovimab had a median adjusted OR for hospital-free days of 0.88 (95% credible interval, 0.70-1.11). This OR yielded 86% probability of inferiority for sotrovimab vs casirivimab-imdevimab and 79% probability of equivalence.

Conclusions and Relevance

In this propensity score-matched cohort study and randomized comparative effectiveness trial, the effectiveness of casirivimab-imdevimab and sotrovimab against the Delta variant was similar, although the prespecified criteria for statistical inferiority or equivalence were not met. Both mAb treatments were associated with a reduced risk of hospitalization or death in nonhospitalized patients with mild to moderate COVID-19 caused by the Delta variant.

Trial Registration

ClinicalTrials.gov Identifier: NCT04790786.

The comparative effectiveness of COVID-19 monoclonal antibodies: A learning health system randomized clinical trial

Background

Monoclonal antibodies (mAb) that neutralize SARS-CoV-2 decrease hospitalization and death compared to placebo in patients with mild to moderate COVID-19; however, comparative effectiveness is unknown. We report the comparative effectiveness of bamlanivimab, bamlanivimab-etesevimab, and casirivimab-imdevimab.

Methods

A learning health system platform trial in a U.S. health system enrolled patients meeting mAb Emergency Use Authorization criteria. An electronic health record-embedded application linked local mAb inventory to patient encounters and provided random mAb allocation. Primary outcome was hospital-free days to day 28. Primary analysis was a Bayesian model adjusting for treatment location, age, sex, and time. Inferiority was defined as 99% posterior probability of an odds ratio < 1. Equivalence was defined as 95% posterior probability the odds ratio is within a given bound.

Findings

Between March 10 and June 25, 2021, 1935 patients received treatment. Median hospital-free days were 28 (IQR 28, 28) for each mAb. Mortality was 0.8% (1/128), 0.8% (7/885), and 0.7% (6/922) for bamlanivimab, bamlanivimab-etesevimab, and casirivimab-imdevimab, respectively. Relative to casirivimab-imdevimab (n = 922), median adjusted odds ratios were 0.58 (95% credible interval [CI] 0.30–1.16) and 0.94 (95% CI 0.72–1.24) for bamlanivimab (n = 128) and bamlanivimab-etesevimab (n = 885), respectively. These odds ratios yielded 91% and 94% probabilities of inferiority of bamlanivimab versus bamlanivimab-etesevimab and casirivimab-imdevimab, and an 86% probability of equivalence between bamlanivimab-etesevimab and casirivimab-imdevimab.

Interpretation

Among patients with mild to moderate COVID-19, bamlanivimab-etesevimab or casirivimab-imdevimab treatment resulted in 86% probability of equivalence. No treatment met prespecified criteria for statistical equivalence. Median hospital-free days to day 28 were 28 (IQR 28, 28) for each mAb.

Funding and registration

This work received no external funding. The U.S. government provided the reported mAb. This trial is registered at ClinicalTrials.gov, NCT04790786.

Association of Subcutaneous or Intravenous Administration of Casirivimab and Imdevimab Monoclonal Antibodies With Clinical Outcomes in Adults With COVID-19

IMPORTANCE

Monoclonal antibody (mAb) treatment decreases hospitalization and death in high-risk outpatients with mild to moderate COVID-19; however, only intravenous administration has been evaluated in randomized clinical trials of treatment. Subcutaneous administration may expand outpatient treatment capacity and qualified staff available to administer treatment, but the association with patient outcomes is understudied.

OBJECTIVES

To evaluate whether subcutaneous casirivimab and imdevimab treatment is associated with reduced 28-day hospitalization and death compared with nontreatment among mAb-eligible patients and whether subcutaneous casirivimab and imdevimab treatment is clinically and statistically similar to intravenous casirivimab and imdevimab treatment.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study evaluated high-risk outpatients in a learning health system in the US with mild to moderate COVID-19 symptoms from July 14 to October 26, 2021, who were eligible for mAb treatment under emergency use authorization. A nontreated control group of eligible patients was also studied.

EXPOSURES

Subcutaneous injection or intravenous administration of the combined single dose of 600 mg of casirivimab and 600 mg of imdevimab.

MAIN OUTCOMES AND MEASURES

The primary outcome was the 28-day adjusted risk ratio or adjusted risk difference for hospitalization or death. Secondary outcomes included 28-day adjusted risk ratios and differences in hospitalization, death, a composite end point of emergency department admission and hospitalization, and rates of adverse events. Among 1959 matched adults with mild to moderate COVID-19, 969 patients (mean [SD] age, 53.8 [16.7] years; 547 women [56.4%]) who received casirivimab and imdevimab subcutaneously had a 28-day rate of hospitalization or death of 3.4% (22 of 653 patients) compared with 7.0% (92 of 1306 patients) in nontreated controls (risk ratio, 0.48; 95% CI, 0.30-0.80; P = .002). Among 2185 patients treated with subcutaneous (n = 969) or intravenous (n = 1216; mean [SD] age, 54.3 [16.6] years; 672 women [54.4%]) casirivimab and imdevimab, the 28-day rate of hospitalization or death was 2.8% vs 1.7%, which resulted in an adjusted risk difference of 1.5% (95% CI, -0.6% to 3.5%; P = .16). Among all infusion patients, there was no difference in intensive care unit admission (adjusted risk difference, 0.7%; 95% CI, -3.5% to 5.0%) or need for mechanical ventilation (adjusted risk difference, 0.2%; 95% CI, -5.8% to 5.5%).

CONCLUSIONS AND RELEVANCE

In this cohort study of high-risk outpatients with mild to moderate COVID-19 symptoms, subcutaneously administered casirivimab and imdevimab was associated with reduced hospitalization and death when compared with no treatment. These results provide preliminary evidence of potential expanded use of subcutaneous mAb treatment, particularly in areas that are facing treatment capacity and/or staffing shortages.

Launching a comparative effectiveness adaptive platform trial of monoclonal antibodies for COVID-19 in 21 days

Outpatient treatments that limit progression to severe coronavirus disease 2019 (COVID-19) are of vital importance to optimise patient outcomes and public health. Monoclonal antibodies (mAb) demonstrated ability to decrease hospitalizations in randomized, clinical trials. However, there are many barriers to mAb treatment such as patient access and clinician education. There are no data comparing efficacy or safety of available mAbs. We sought to rapidly launch an adaptive platform trial with the goals of enhancing access to treatment, regardless of geography and socioeconomic status, and evaluating comparative efficacy and safety of available mAbs. Within 21 days from idea genesis, we allocated mAb treatment to all patients within the context of this clinical trial. Within 2 months, we closed the gap of the likelihood of receiving mAb, conditional on background positivity rate, between Black and White patients (Black patients 0.238; White patients 0.241). We describe trial infrastructure, lessons learned, and future directions for a culture of learning while doing.

The UPMC OPTIMISE-C19 (OPtimizing Treatment and Impact of Monoclonal antIbodieS through Evaluation for COVID-19) trial: a structured summary of a study protocol for an open-label, pragmatic, comparative effectiveness platform trial with response-adaptive randomization

Objectives

The primary objective is to evaluate the comparative effectiveness of COVID-19 specific monoclonal antibodies (mABs) with US Food and Drug Administration (FDA) Emergency Use Authorization (EUA), alongside UPMC Health System efforts to increase patient access to these mABs.

Trial design

Open-label, pragmatic, comparative effectiveness platform trial with response-adaptive randomization

Participants

We will evaluate patients who meet the eligibility criteria stipulated by the COVID-19 mAB EUAs who receive mABs within the UPMC Health System, including infusion centers and emergency departments. EUA eligibility criteria include patients with mild to moderate COVID-19, <10 days of symptoms, and who are at high risk for progressing to severe COVID-19 and/or hospitalization (elderly, obese, and/or with specific comorbidities). The EUA criteria exclude patients who require oxygen for the treatment of COVID-19 and patients already hospitalized for the treatment of COVID-19. We will use data collected for routine clinical care, including data entered into the electronic medical record and from follow-up calls.

Intervention and comparator

The interventions are the COVID-19 specific mABs authorized by the EUAs. All aspects of mAB treatment, including eligibility criteria, dosing, and post-infusion monitoring, are as per the EUAs. As a comparative effectiveness trial, all patients receive mAB treatment, and the interventions are compared against each other.

When U.S. government mAB policies change (e.g., FDA grants or revokes EUAs), UPMC Health System policies and the evaluated mAB interventions will accordingly change. From November 2020 to February 2021, FDA issued EUAs for three mAB treatments (bamlanivimab; bamlanivimab and etesevimab; and casirivimab and imdevimab), and at trial launch on March 10, 2021 we evaluated all three. Due to a sustained increase in SARS-CoV-2 variants in the United States resistant to bamlanivimab administered alone, on March 24, 2021 the U.S. Government halted distribution of bamlanivimab alone, and UPMC accordingly halted bamlanivimab monotherapy on March 31, 2021. On April 16, 2021, FDA revoked the EUA for bamlanivimab monotherapy. At the time of manuscript submission, we are therefore evaluating the two mAB treatments authorized by EUAs (bamlanivimab and etesevimab; and casirivimab and imdevimab).

Main outcomes

The primary outcome is total hospital free days (HFD) at 28 days after mAB administration,

calculated as 28 minus the number of days during the index stay (if applicable – e.g., for patients admitted to hospital after mAB administration in the emergency department) minus the number of days readmitted during the 28 days after treatment. This composite endpoint captures the number of days from the day of mAB administration to the 28 days thereafter, during which the patient is alive and free of hospitalization. Death within 28 days is recorded as -1 HFD, as the worst outcome.

Randomisation

We will start with equal allocation. Due to uncertainty in sample size, we will use a Bayesian adaptive design and response adaptive randomization to ensure ability to provide statistical inference despite variable sample size.

When mABs are ordered by UPMC physicians as a generic referral order, the order is filled by UPMC pharmacy via therapeutic interchange. OPTIMISE-C19 provides the therapeutic interchange via random allocation. Infusion center operations teams and pharmacists use a mAB assignment application embedded in the electronic medical record to determine the random allocation.

Blinding (masking)

This trial is open-label. However, outcome assessors conducting follow-up calls at day 28 are blinded to mAB assignment, and investigators are blinded to by-mAB aggregate outcome data until a statistical platform trial conclusion is reached.

Numbers to be randomised (sample size)

Sample size will be determined by case volume throughout the course of the pandemic, supply of FDA authorized mABs, and by that needed to reach a platform trial conclusion of inferiority, superiority, or futility of a given mAB. The trial will continue as long as more than one mAB type is available under EUA, and their comparative effectiveness is uncertain.

Trial Status

Protocol Version 1.0, February 24, 2021.

Recruitment began March 10, 2021 and is ongoing at the time of manuscript submission. The estimated recruitment end date is February 22, 2022, though the final end date is dependent on how the pandemic evolves, mAB availability, and when final platform trial conclusions are reached. As noted above, due to U.S. Government decisions, UPMC Health System halted bamlanivimab monotherapy on March 31, 2021.

Trial registration

ClinicalTrials.gov Identifier: NCT04790786. Registered March 10, 2021

Full protocol

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05316-3.

Evaluation of the effect of signalment and owner-reported impairment level on accelerometer-measured changes in activity in osteoarthritic dogs receiving a non-steroidal anti-inflammatory

In veterinary medicine, evaluation of osteoarthritis (OA) treatment efficacy remains challenging. Measurement of activity, utilizing accelerometers, provides a surrogate measure of pain through measuring effects on activity, and the objective data collected can be used to assess the efficacy of treatments. However, little is known about how dog characteristics impact the accelerometry-measured response to treatment. The objectives of this study were to evaluate the effect of signalment and initial impairment level on accelerometer-measured changes in activity in osteoarthritic dogs after receiving a non-steroidal anti-inflammatory (NSAID). Fifty-seven client-owned dogs with OA-associated pain and mobility impairment were administered meloxicam for 2 weeks, following a 2-week baseline, and spontaneous activity was measured using an Actical accelerometer unit. Signalment factors and disease variables were recorded (age, sex, weight, impairment level, forelimb or hindlimb pain). Initial degree of impairment had a significant effect on changes in weekly (P=0.009), weekday (P=0.044) activity following NSAID treatment. Greater initial impairment was associated with larger positive changes in activity. Degree of impairment should be taken into consideration during the development of a clinical trial. Appropriate selection of candidates based on initial degree of impairment may permit a greater treatment effect, therefore increasing the power of the study.

Magnetic Nanoparticles with High Specific Absorption Rate at Low Alternating Magnetic Field

This paper describes the synthesis and properties of a new type of magnetic nanoparticle (MNP) for use in the hyperthermia treatment of tumors. These particles consist of 2-4 nm crystals of gamma-Fe2O3 gathered in 20-40 nm aggregates with a coating of carboxymethyl-dextran, producing a zetasize of 110-120 nm. Despite their very low saturation magnetization (1.5-6.5 emu/g), the specific absorption rate (SAR) of the nanoparticles is 22-200 W/g at applied alternating magnetic field (AMF) with strengths of 100-500 Oe at a frequency of 160 kHz.

Comparative pharmacokinetic study of high-dose etoposide and etoposide phosphate in patients with lymphoid malignancy receiving autologous stem cell transplantation

The pharmacokinetics of two etoposide (E) formulations were evaluated in patients with refractory hematologic malignancies receiving high-dose conditioning with autologous stem cell transplantation. Patients were randomized to either E at 800 mg/m(2) (containing polysorbate 80 and polyethylene glycol) or etoposide phosphate (EP) at 910 mg/m(2) on days -7 and -5, prior to melphalan, 80 mg/m(2) on day -5. On day -3, EP was repeated. Plasma E was analyzed after each formulation on days -7 and -5 to compare intrapatient pharmacokinetics. In total, 10 patients were treated: four each with multiple myeloma or Hodgkin's disease and two with non-Hodgkin's lymphoma. Mucositis was the major toxicity with seven patients. EP first produced grade 3 mucositis. There was no procedure-related mortality and eight patients remained alive 1 year post-transplant. Cumulative etoposide exposure (AUC) was slightly greater with EP (P=0.056). Conversely, the volume of distribution was slightly, 33%, larger (P=0.052) and clearance was increased with the E infusion (P=0.14). As none of the differences reached statistical significance, both E formulations appear to be pharmacokinetically equivalent in the high-dose transplant setting. The combination of high-dose EP with melphalan is an active preparative regimen prior to ABMT for hematologic malignancies.

ARF mediates recruitment of PtdIns-4-OH kinase-beta and stimulates synthesis of PtdIns(4,5)P2 on the Golgi complex

The small GTPase ADP-ribosylation factor (ARF) regulates the structure and function of the Golgi complex through mechanisms that are understood only in part, and which include an ability to control the assembly of coat complexes and phospholipase D (PLD). Here we describe a new property of ARF, the ability to recruit phosphatidylinositol-4-OH kinase-beta and a still unidentified phosphatidylinositol-4-phosphate-5-OH kinase to the Golgi complex, resulting in a potent stimulation of synthesis of phosphatidylinositol-4-phosphate and phosphatidylinositol-4,5-bisphosphate; this ability is independent of its activities on coat proteins and PLD. Phosphatidylinositol-4-OH kinase-beta is required for the structural integrity of the Golgi complex: transfection of a dominant-negative mutant of the kinase markedly alters the organization of the organelle.

Thrombin peptide, TP508, induces differential gene expression in fibroblasts through a nonproteolytic activation pathway

Prior studies have shown that synthetic peptides representing the domain of thrombin responsible for high-affinity binding to fibroblasts stimulate chemotactic and cell proliferative signals through a nonproteolytic mechanism. One of these peptides, TP508, has recently been shown to be chemotactic for neutrophils, to enhance collagen accumulation in wounds, to enhance revascularization of wounds, and to accelerate the healing of incisional and open wounds in normal animals and in animals with impaired healing. To determine whether TP508 activates the proteolytically activated receptor for thrombin (PAR1), or the signals that are activated by PAR1, we treated human fibroblasts with TP508 and the PAR1-activating peptide, SFLLRNP, and analyzed the effects of these peptides on gene expression using differential display reverse transcriptase polymerase chain reaction. TP508 induces expression of a number of specific message fragments with short tyrosine kinase-like domains that are not induced by SFLLRNP. Sequencing full-length clones prepared by Marathon extension of TP508-induced fragments revealed that among the induced transcripts, there was a sequence with 88% homology to human annexin V. Northern analysis with authentic annexin V cDNA confirms that TP508, but not SFLLRNP, induces expression of annexin V in human fibroblasts. These results demonstrate that TP508 activates a cellular response separate from that activated through PAR1 and supports the hypothesis that TP508 acts through a separate nonproteolytically activated thrombin receptor that may be responsible for high-affinity thrombin binding and for nonproteolytic signals that are required for thrombin stimulation of cell proliferation.

A contextually relevant assessment of the impact of child maltreatment on the social competencies of low-income urban children

OBJECTIVE

A developmental-ecological model was used to explore the psychological adjustment and peer social competencies of maltreated preschool children.

METHOD

Enhanced research methods were used that included verification of maltreatment status, multiple-variable matching of comparison children, and contextually relevant assessment. One hundred eight Head Start children, of whom 54 were maltreated, participated. Assessment of social functioning included measurement of peer play interactions, global social skills, peer sociometrics, and teacher and parent ratings of behavior problems.

RESULTS

Findings indicated that maltreated children were significantly less interactive in peer play and overall exhibited less self-control and interpersonal skill in social interactions than nonmaltreated children. In addition, maltreated children were more likely than their nonmaltreated peers to receive low sociometric ratings and were found by both teachers and parents to display more internalizing behavior problems than comparison children.

CONCLUSIONS

These findings indicate the importance of using developmentally sensitive research methods to inform contextually relevant interventions.

Analytical and biological inequivalence of two commercial formulations of the antitumor agent bleomycin

Bleomycin is an antitumor agent which is a mixture of glycopeptides containing at least 55-75% bleomycin A2 and 25-32% bleomycin B2 fractional composition. Two bleomycin formulations, bleomycin sulfate, USP (Blenoxane, Bristol-Myers Squibb Oncology, Princeton, N.J.) and bleomycin HCI (Tianjin Hebei Pharmaceutical, Tianjin, China) were compared analytically and biologically. Reverse-phase high-performance liquid chromatography (HPLC) analyses using the USP methodology showed that Blenoxane contained primarily (69%) bleomycin A2 and 29.3% bleomycin B2. In contrast, Tianjin-supplied bleomycin HCI contained 97% bleomycin A5 fraction. In vitro tumor cell growth inhibition assays showed equivalent activity in human OVCAR-3 ovarian cancer cells and slightly greater potency in murine L-1210 leukemia cells for the Tianjin formulation. In C57/B1 mice bearing B-16 melanoma tumors, Tianjin-supplied bleomycin produced slightly greater tumor growth inhibition at the expense of greater drug-induced lethality at higher dose levels. These studies show there are significant differences in two international bleomycin formulations. These compositional differences lead to altered biologic effects.

In vivo phosphocreatine and ATP in piglet cerebral gray and white matter during seizures

The creatine kinase (CK) reaction is thought to be important in coupling ATP metabolism and regulating ADP concentration in tissues with high and variable ATP turnover, including cerebral gray matter (GM). There is low phosphocreatine (PCr), low CK reaction rates, and high mitochondrial CK (MiCK) isoenzyme activity in GM compared to white matter (WM). To compare the CK reaction in GM and WM when ATP metabolism is high, CK reactants and reaction rates were measured in predominantly GM and WM slices in vivo in 2 and 14-day old piglets during pentylenetetrazole (PTZ) seizures using 31P nuclear magnetic resonance (NMR) 1-dimensional chemical shift imaging (CSI). Arterial pressure, temperature, and blood gasses were stable at both ages. Before seizures, the PCr/nucleoside triphosphate (NTP) ratio was higher in WM than GM at both ages with a developmental increase seen in WM. The CK reaction rate constant increased in both regions between 2 and 14 days. During seizures, PCr/NTP increased in GM at 14 days due to increased PCr while the ratio and PCr decreased in WM. The NTP was more stable in WM and GM at both ages. The CK reaction rate decreased in both regions more at 2 than at 14 days. Thus, brain ATP, deduced from NTP, is stable during seizures in the piglet. In GM stable ATP is associated with a unique increase in PCR concentration.

Nutrition management of congenital glucose-galactose malabsorption: a case study

In this article we describe the clinical history, diagnostic evaluation, and management of an infant who had congenital glucose-galactose malabsorption (CGGM)--a rare disorder thought to be inherited as an autosomal recessive trait. Because of defective sodium-coupled cotransport of glucose and galactose in the intestinal mucosa, infants with CGGM suffer from chronic, profuse, watery diarrhea that often leads to hypertonic dehydration. This infant experienced persistent diarrhea and hypernatremic dehydration during the first 3 months of life. Despite management with elemental formulas and continuous nasogastric feedings during initial hospitalizations, worsening diarrhea and dehydration persisted and malnutrition occurred. Diagnostic evaluations ruled out cystic fibrosis and bacterial or viral gastroenteritis. Diagnostic tests also revealed normal pancreatic exocrine function and normal villus architecture. The persistence of glucose-positive, watery diarrhea, even when the infant was fed an oral electrolyte solution, led to the diagnosis of CGGM. The infant was treated successfully with a carbohydrate-free infant formula to which fructose was added incrementally to meet energy requirements. Parental education about dietary management of CGGM with specialized formula supplemented with fructose and solid food feedings was an important component of this infant's nutrition therapy. Aggressive nutrition intervention for the infants and judicious dietary counseling for parents can lead to normal growth and neurological development for an infant with CGGM.

Development and testing of a process measure of nursing home quality of care

OBJECTIVE

To develop and test quality of care process measures for three medical conditions of nursing home patients: fever, shortness of breath, and chest pain.

DESIGN

Flowsheets designed to capture the critical elements of care for the above conditions were developed by an expert panel. Nursing home residents charts were reviewed retrospectively using the flow sheets. The reviews were translated into clinical scenarios, and the quality of care the scenarios represented was rated by an expert panel.

SETTING

All nursing homes in Hennepin County, MN, that care for Medicaid patients.

PATIENTS

A random sample of 1405 Medicaid nursing home residents from 1984 and 1988.

MEASURES

Measures of quality of physician assessment and intervention, quality of nurse assessment and intervention, and global quality were developed and the intra- and interrater reliability were tested. The measures' validity was assessed by their ability to predict resident death.

RESULTS

Intrarater reliability was measured as the correlation of the ratings of blinded duplicates. The correlation for the global scale and the four subscales ranged from .74 to .88 (P < .001 for all). Interrater reliability was tested by examining what percentage of the quality ratings were within one unit (1-5 scale) for all three raters. All three raters were within one unit for more than 72% scenarios for all scales. The subscale of quality of physician assessment was able to predict resident death when the worst episode of care (OR = .47, 95% CI(.31-.74)) or the mean episode of care (OR .54, 95% CI(.30-.99)) was used. None of the other subscales or the global measure predicted death.

CONCLUSIONS

Through the use of an expert panel, measures of nursing home quality of care were developed for shortness of breath, fever, and chest pain. These measures have reasonable reliability and significant face validity. Their validity is supported further by the ability of one of the measures to predict resident death.

In vivo brain phosphocreatine and ATP regulation in mice fed a creatine analog

Mitochondrial and cytosolic creatine kinase (CK) isozymes are active in cells with high and variable ATP metabolic rates. beta-Guanidinopropionic acid (GPA), a competitive inhibitor of creatine transport, was used to study the hypothesis that the creatine-CK-phosphocreatine (PCr) system is important in regulating brain ATP metabolism. The CK-catalyzed reaction rate and reactant concentrations were measured in vivo with 31P nuclear magnetic resonance spectroscopy during energy deficit (hypoxia) or high-energy turnover (seizures) states in urethane-anesthetized mice fed GPA, creatine, or standard chow (controls). Brain phosphagen (i.e., cellular energy reserves) or PCr plus phosphorylated GPA (GPAP) concentrations were equal. The phosphagen-to-NTP ratio was lower than in controls. In vivo CK reaction rate decreased fourfold, whereas ex vivo CK activity that was biochemically measured was doubled. During seizures, CK-catalyzed fluxes increased only in GPA-fed mice. Phosphagen increased in GPA-fed mice, whereas PCr decreased in controls. Survival was higher and brain phosphagen and ATP losses were less for hypoxic GPA-fed mice than for controls. In contrast to mice fed GPA, hypoxic survival and CK reactant concentrations during hypoxia and seizures were the same in creatine-fed mice and controls. Thus GPA, GPAP, or adaptive changes in ATP metabolism stabilize brain ATP and enhance survival during hypoxia in mice.

Brain creatine kinase reaction rates and reactant concentrations during seizures in developing rats

Brain creatine kinase (CK) catalyzed phosphorus fluxes between phosphocreatine (PCr) and ATP and changes in reactant concentrations were measured using [31P] nuclear magnetic resonance spectroscopy ([31P]NMR) before and during pentylenetetrazole-induced seizures in 7 and 21 day old rats. The CK rate constants measured before seizures were three times higher in the older than in the younger rats. The rate constants increased 60% during seizures in the older rats but did not change or decreased in the younger. Small decreases in PCr were seen during seizures at both ages. A small decrease in ATP was seen at 7 days but not at 21 days.

Cloning and characterization of a wortmannin-sensitive human phosphatidylinositol 4-kinase

Phosphatidylinositol (PtdIns) 4-kinases catalyze the synthesis of PtdIns-4-P, the immediate precursor of PtdIns-4,5-P2. Here we report the cloning of a novel, ubiquitously expressed PtdIns 4-kinase (PI4Kbeta). The 2.4-kilobase pair cDNA encodes a putative translation product of 801 amino acids which shows greatest homology to the yeast PIK1 gene. The recombinant protein exhibits lipid kinase activity when expressed in Escherichia coli, and specific antibodies recognize a 110-kDa PtdIns 4-kinase in cell lysates. The biochemical properties of PI4Kbeta are characteristic of a type III enzyme. Interestingly, both recombinant PI4Kbeta and the endogenous protein are inhibited by 150 nM wortmannin, suggesting that we have cloned the previously described PtdIns 4-kinase that is responsible for regulating the synthesis of agonist-sensitive pools of polyphosphoinositides (Nakanishi, S., Catt, J. K., and Balla, T. (1995) Proc. Natl. Acad. Sci. U. S. A. 92, 5317-5321).

Community-based resilient peer treatment of withdrawn maltreated preschool children

The purpose of the present study was to evaluate differences in the social play of maltreated and nonmaltreated preschool children and the effectiveness of a resilient peer treatment (RPT) for socially withdrawn victims of physical abuse and neglect. RPT is a peer-mediated classroom intervention based on a developmental-ecological model. It involves pairing withdrawn children with resilient peers in the natural classroom under the supervision of a parent assistant. Forty-six Head Start children, of whom 22 were maltreated, were randomly assigned to RPT and control conditions. Outcome variables were observational categories of social play and standardized teacher ratings. Before treatment, maltreated children were significantly more isolated and less interactive in peer play than nonmaltreated children. RPT resulted in a significant increase in positive interactive peer play and a decrease in solitary play for maltreated and nonmaltreated, socially withdrawn children. Moreover, treatment gains in social interactions were validated 2 months following treatment. Findings are discussed in terms of a developmental-ecological model.

Safety of autotransplants with high-dose melphalan in renal failure: a pharmacokinetic and toxicity study

Melphalan (MEL) is probably the most effective chemotherapeutic agent in multiple myeloma (MM) with a clear dose-response effect. It can be escalated without excessive toxicity to 200 mg/m2, a myeloablative dose requiring hematopoietic stem cell support. Patients with marked renal insufficiency, not an infrequent finding in MM, have either received reduced doses or have been excluded from therapy with high-dose MEL. A prospective study was performed to evaluate the relationship between MEL pharmacokinetics and renal function in 20 patients with MM. Six patients had severe renal insufficiency (creatinine clearance, <40 ml/min), including five on chronic hemodialysis. Three patients with severe renal impairment first received a low test dose of MEL (16 mg/m2) for pharmacokinetic studies. All patients received 200 mg/m2 MEL divided into two equal doses of 100 mg/m2 i.v. on 2 consecutive days, followed by the administration of peripheral blood stem cells. MEL pharmacokinetics, performed after the first dose of 100 mg/m2, was not adversely affected by impaired renal function. The median half-life (t1/2), area under the concentration curve, and clearance of MEL were 1.1 h, 5.5 mg h/liter, and 27.5 liter/h, respectively, in patients with a creatinine clearance of <40 ml/min compared to 1.9, 7.9, and 23.6 for the others. Renal insufficiency also had no apparent negative impact on the quality of peripheral blood stem cell collections and did not adversely affect posttransplant engraftment, transfusion requirements, incidence of severe mucositis, or overall survival. However, it was associated with longer durations of fever (P = 0. 0005) and hospitalization (P = 0.004). No transplant-related deaths were observed. Plasma t1/2 and area under the concentration curve differed by a factor of 10 and MEL clearance by a factor of 5 between patients with the lowest and highest values. These large variations in MEL elimination could not be explained by patient or disease characteristics. We conclude that renal failure does not require dose reduction of MEL in autologous transplant. Due to marked interindividual variation in MEL elimination, pharmacokinetically guided dosing as well as cellular pharmacology studies may be helpful in achieving a more uniform antitumor effect.

Phosphocreatine and creatine kinase in piglet cerebral gray and white matter in situ

Rates of adenosine triphosphate (ATP) metabolism are higher in cerebral gray matter than in white matter. Like other excitable tissues, brain contains a phosphocreatine (PCr)/creatine kinase (CK)/ATP system including cytosolic (B-CK) and mitochondrial (Mi-CK) isozymes. High B-CK activity is present in white and gray matter while Mi-CK is mostly in gray matter. An in situ localizing 31P-NMR technique, one-dimensional chemical shift imaging (1D-CSI), has been used to study the PCr/CK/ATP system in these regions. In the metabolically mature 4-week-old piglet, the PCr/nucleoside triphosphate (NTP) ratio measured by the 1D-CSI technique is at least 50% higher in white than gray matter. Total creatine (Cr), ATP, and total NTP concentrations are the same in rapidly frozen rat white and gray matter, suggesting that PCr/Cr ratio is much higher in white matter. The PCr increases more in gray than white matter between 4 days and 4 weeks of age in piglet brain. The CK catalyzed reaction rate constant, measured by combining the saturation transfer experiment with the 1D-CSI, is also much higher in white than gray matter at both ages. The postnatal maturational increase in the CK rate constant is greater in gray matter. In summary, these differences in PCr concentration and CK reaction rates and isozymes characterize two physiologically different PCr/CK/ATP systems in gray and white matter.

Neutrophil recruitment after remote scald injury

Thermal injury is one trigger for pulmonary neutrophil recruitment. This article describes the time course of neutrophil recruitment after scald injury. Mice aged 8 to 10 weeks were anesthetized and subjected to 15% topical scald injury. Animals were put to death at 6 hours, 24 hours, 3 days, and 7 days after injury, and the pulmonary tissue harvested for staining with hematoxylin and eosin and neutrophil esterase. Cell counts for neutrophil accumulation were obtained. Control animals were handled in a comparable manner apart from the scald injury. Animals killed at 6 hours demonstrated significant neutrophil recruitment relative to the control. This difference had resolved at 24 hours. Animals killed at 3 and 7 days again demonstrated neutrophil accumulation despite normal behavior and absence of weight change from the control. Quantitative cultures of burn wounds failed to disclose infection. Scald injury was associated with significant pulmonary neutrophil recruitment that resolved at 24 hours. The presence of an untreated wound was associated with neutrophil recruitment beyond 24 hours despite outward normal behavior.

Issues in the development of subject recruitment strategies and eligibility criteria in multisite trials of matching

Decision-making in selecting and recruiting subjects for treatment matching research is a complex process involving conceptual, methodological and practical considerations. In selecting clients, concerns arise about whether the criteria will produce a subject population that is (1) relevant to the dimensions associated with the treatment matching, (2) representative of persons typically seen in alcohol treatment settings and, for practical purposes, (3) able or willing to comply with the requirements of the study protocol. Also, in order to fulfill sampling requirements, it may be necessary to employ a variety of creative outreach methods. However, these recruitment mechanisms can pose additional logistical and methodological problems for the research. This article focuses on various issues arising in the selection and recruitment of subjects in matching research. Project MATCH serves to highlight issues related to client eligibility and recruitment and to discuss effective strategies for resolving these matters.

Untying the elderly. 1989 to 1993 update

Research and public policy pertaining to the use of physical restraints has advanced since Evans' and Strumpfs' 1989 review. Research better delineates the harms caused by restraints, although not finding benefits. Federal law sharply restricts the use of restraints. Legal liability weighs against the use of restraints in most instances. Nursing homes have published substantial experience with programs to reduce and eliminate the use of physical restraints.

Cartilage chondrolysis by fibronectin fragments is associated with release of several proteinases: stromelysin plays a major role in chondrolysis

We have reported that three different Fn fragments (Fn-f) added to bovine articular cartilage cultured in serum-free DMEM cause marked elevation of proteoglycan (PG) degradation and release into the culture media. We report here that the PG release required the continual presence of Fn-f, that PG release still occurred when serum-free cultures were switched to bovine synovial fluid media, and that addition of recombinant IGF-1, TGF-beta, and recombinant interferon gamma to cultures did not affect Fn-f-mediated PG release. The Fn-f caused a 25-fold enhanced release of stromelysin-1 protein from cartilage by Day 1 and up to 120-fold by Day 3. The stromelysin form released was 43 kDa, the activated form of pro-stromelysin-1. This stromelysin form apparently played a major role in Fn-f-mediated PG release, since addition of Sepharose-bound anti-stromelysin-1 to cartilage cultures greatly slowed rates of PG release. Potential activators of pro-stromelysin-1, plasmin, and u-PA (urinary plasminogen activator), were also detected in conditioned media of Fn-f-treated cartilage. u-PA levels were increased in the presence of the Fn-f but by only a few fold. Addition of alpha-1-antiproteinase inhibitor, which can block enzymatic activity of u-PA, was found to inhibit about half the PG-releasing activity of the Fn-f. Levels of TIMP-1, the 30-kDa tissue inhibitor of metalloproteinases, which can inhibit stromelysin, doubled within 24 h when a Fn-f was added to culture. These data suggest that stromelysin-1 may be a major mediator of Fn-f-mediated PG release from cartilage.

Monotherapy with cyclosporine for chronic immunosuppression in pediatric liver transplant recipients

Children who survive liver transplantation (LT) suffer the adverse effects of life-long immunosuppression. In an attempt to minimize these effects, we have instituted a program of tapering immunosuppression, resulting in chronic monotherapy for children after LT. Seventy-three children ages 4 months to 19 years received LT between January 1987 and December 1992. Patient survival was 85% (62/73), with graft survival of 73%, at one year. Triple therapy with prednisone, cyclosporine, and azathioprine begun at transplant was tapered as follows: 1-2 mg/kg prednisone at discharge was reduced by .2 mg/kg every 2 months until a .2 mg/kg total was reached. Alternate-day steroids (.2 mg/kg) were begun at 1 year and discontinued at 1.5 years. AZA (1 mg/kg) was begun posttransplant and discontinued after any serious viral illness or by 1 year. Currently 37 survivors are > 18 months post-LT and were considered candidates for monotherapy. Monotherapy was attempted in 28 (76%), and 25 of these remain on monotherapy an average of 2 years later. All have normal liver function. After monotherapy and alternate-day steroids were achieved, 66% of children < 5th percentile for height at the time of transplant improved to greater than the 5th percentile. There were 3 (11%) patients who rejected while on monotherapy an average of 1.15 years after it was started. These patients had the following predisposing factors that decreased cyclosporine levels and led to rejection: common bile duct stricture, chronic and intermittent antibiotic administration for urinary tract infection, and noncompliance. In the 9 potential candidates not tapered to monotherapy, 6 have had recurrent acute or chronic rejection; 2 of these now receive FK506. We conclude that the majority of stable pediatric LT recipients may be safely tapered to chronic cyclosporine monotherapy. Increased growth is a major benefit of decreased steroid dosing in these children. Cyclosporine absorption and adequate levels are crucial for success of this approach.

Mineral balance and bone turnover in adolescents with anorexia nervosa

We evaluated seven female adolescents with anorexia nervosa to determine whether calcium metabolism was affected by their disorder. We measured calcium absorption, urinary calcium excretion, and calcium kinetics, using a dual-tracer, stable-isotope technique during the first weeks of an inpatient nutritional rehabilitation program. Results were compared with those from a control group of seven healthy adolescent girls of similar ages. The percentage of absorption of calcium was lower in subjects with anorexia nervosa than in control subjects (16.2% +/- 6.3% vs 24.6% +/- 7.2%; p < 0.05). Urinary calcium excretion was greater in subjects with anorexia nervosa than in control subjects (6.4 +/- 2.5 vs 1.6 +/- 0.7 mg.kg-1 x day-1; p < 0.01) and was associated with bone resorption rather than calcium hyper-absorption. Calcium kinetic studies demonstrated a decreased rate of bone formation and an increased rate of bone resorption. These results suggest marked abnormalities in mineral metabolism in patients with anorexia nervosa. From these results, we hypothesize that improvement in bone mineralization during recovery from anorexia nervosa will require resolution of hormonal abnormalities, including hypercortisolism, in addition to increased calcium intake.

Intraarticular injection of fibronectin fragments causes severe depletion of cartilage proteoglycans in vivo

We have reported that fibronectin fragments (Fn-f) cause cartilage damage in vitro by causing enhanced release of proteases. In order to determine whether the Fn-f can damage cartilage in vivo, we have injected native fibronectin (Fn) and Fn-f into adolescent rabbit knee joints. After 7 days, tissue was analyzed by histochemical and biochemical techniques and remaining proteoglycans quantified. Injection of 0.6 or 3 microM Fn-f caused up to a 70% loss in total cartilage proteoglycan while native Fn, rabbit serum albumin or an Arg-Gly-Asp-Ser synthetic peptide, derived from the cell-binding domain of Fn, did not cause damage. Our results suggest that this Fn-f/damage model may be useful for generating cartilage damage in vivo for other studies. Since Fn-f have been detected in synovial fluids from joints of patients with rheumatoid arthritis and osteoarthritis, our results are consistent with the notion that Fn-F mediated damage may occur in vivo.

Release of elastase from monocytes adherent to a fibronectin-gelatin surface

Fibronectin (Fn) is a circulating and extracellular matrix glycoprotein that may serve to facilitate phagocytosis because of its ability to bind many inflammatory ligands and to a monocyte receptor. Fn fragments have been shown in many systems to have augmented properties over those of native Fn. We show in this report that although Fn fragments did not cause elastase release from monocytes in suspension, fragments did cause elastase release from monocytes that were first bound to Fn-gelatin surfaces. An amino-terminal 29-Kd and a 140-Kd integrin-binding fragment were half-maximally active at 100 nmol/L, whereas the Arg-Gly-Asp-Ser integrin-recognition peptide was half-maximally active at 100 mumol/L. Fluid-phase Fn was ineffective yet blocked the activity of the Fn fragments. Complexing of Fn with gelatin or with heparin partially removed the blocking effect of Fn. Similar results were obtained with U-937 cells. Substitution of the Fn-gelatin surface with bovine articular cartilage also promoted elastase release. Therefore, in conditions in vivo in which monocytes bind to tissue surface, a high ratio of Fn fragments to native Fn may upregulate certain monocyte activities such as protease release.

Efficacy of preprocedural rinsing with an antiseptic in reducing viable bacteria in dental aerosols

This double-blind, controlled, cross-over, clinical study evaluated the effect of preprocedural rinsing with an antiseptic mouthrinse on the level of recoverable viable bacteria in an aerosol generated during a typical dental procedure. Eighteen subjects participated. Following 24 hours of abstention from all oral hygiene procedures, subjects received a 10-minute ultrasonic scaling of a randomly selected one-half of their mouth which served as the unrinsed control. They were then randomly assigned either antiseptic mouthwash or a control rinse and rinsed with 20 ml for 30 seconds, after which the remaining half mouth (experimental side) was scaled ultrasonically for 10 minutes. During each 10-minute scaling period aerosolized bacteria were collected on a sterile filter using a modified vacuum air-sampling device. Microbes captured on the sterile filter were quantitated by overlaying the filters onto trypticase soy agar, incubating the filters aerobically at 37 degrees C for 24 to 72 hours, and counting the resulting colony forming units (CFU). Preliminary experiments had confirmed that neither the collection method nor residual antiseptic mouthwash in the aerosol adversely affected the number of viable bacteria recovered from the filter. Rinsing with the antiseptic mouthwash produced a 94.1% reduction in recoverable CFUs compared to the non-rinsed control, while the control rinse produced a 33.9% reduction. The difference between the mouthwash and control was statistically significant (P < .001). This study indicates that preprocedural rinsing with an antiseptic mouthwash can significantly reduce the microbial content of aerosols generated during ultrasonic scaling and may have potential in-office use as part of an infection control regimen.

Fibronectin fragments in osteoarthritic synovial fluid

Fibronectin is an adhesive multifunctional glycoprotein found in the extracellular matrix of most types of cells and that exerts growth factor, differentiative and chemotactic activities toward many types of cells, including those cells found in knee joint tissue. Since fibronectin levels in the synovial fluid (SF) and on the cartilage surface of patients with osteoarthritis (OA) have been shown to be greatly increased over normal levels and since protease levels are also enhanced in diseased cartilage, we have investigated the presence of fibronectin fragments in the SF of patients with OA. We report that concentrations of at least 1 microM of 100 to 200 kDa fragments were found in all OA fluids examined. Since we have recently shown that fibronectin fragments can cause cartilage to release metalloproteinases, resulting in severe proteoglycan depletion, and others have shown that fragments also enhance metalloproteinase expression in synovial fibroblasts, the presence of these fragments suggests pathologic consequences in arthritis.

Amino acid gradients across the intestinal circulation in fetal lambs

Amino acids, including glutamine, glutamate and asparagine are major metabolic substrates for the adult enterocyte of several species. To determine whether circulating amino acids are utilized by the fetal intestine, we studied nine fetal sheep (mean gestational age 128 +/- 5 days; term: 147 days). Catheters were inserted into the descending aorta (DA) and the mesenteric vein (MV) to allow for simultaneous blood sampling across the intestine. Fetal blood gas, haemoglobin; O2 saturation and O2 tension were measured. Ammonia was determined by an enzymatic method and HPLC analysis was used to measure the content of all amino acids in DA (descending aorta) and MV (mesenteric vein). Intestinal blood flow measurements were obtained using the radionuclide microsphere method. Intestinal blood flow (81 +/- 28 ml/min/100g) and arterial pH (7.37 +/- 0.04) were within normal range for unstressed fetal lambs. Glutamine and glutamate were the only amino acids that were significantly taken up across the fetal intestinal circulation. The fetal intestine extracted approximately 21% of the delivered glutamine (6.8 +/- 4.5 mumol/min/100g), 7% of the delivered glutamate (1.3 +/- 1.1 mumol/min/100g) and 2.7% of the delivered oxygen (43.0 +/- 19.1 mumol/min/100g). These data suggest that glutamine and glutamate are major substrates for the intestine in unstressed fetal lambs.

Fibronectin fragments cause chondrolysis of bovine articular cartilage slices in culture

Elevated fibronectin (Fn) and Fn fragment concentrations are found in the synovial fluid of osteoarthritic and rheumatoid arthritic patients. Fn has been shown to affect expression of chondrocytic matrix proteins, and Fn fragments have been shown to elevate gene expression of neutral proteinases in synoviocytes. For these reasons, we tested the effects of Fn fragments on protease release and resultant proteoglycan release from cartilage in serum-free bovine articular cartilage explant cultures. We have found that 1 microM amino-terminal 29- and 50-kDa gelatin-binding Fn fragments caused over a 50-fold enhancement of gelatinolytic and collagenolytic proteinase release with a 23-fold enhancement of proteoglycan (PG) release. Release was significant at fragment concentrations as low as 20 nM. An integrin-binding 140-kDa fragment mixture was the least active fragment, whereas native Fn had little activity. The relative activities of the fragments correlated with their relative abilities to bind to cartilage. The RGDS integrin-recognition peptide also caused release, although sequence mutants did not. PG release was blocked by actinomycin D, cycloheximide, and deoxyglucose. Fn fragment-mediated PG release was decreased in 10% serum by over 10-fold but was still 2-fold greater than in controls. In the presence of insulin-like growth factor-1, PG release was as great as without serum. We suggest that Fn fragments, as found in diseased synovial fluid, may contribute to protease-mediated damage to cartilage.