Daily versus three times weekly dosing for treatment of iron deficiency nonanemia in NCAA Division 1 female athletes

OBJECTIVE

To compare the effectiveness, compliance, and side effect profile between daily or three times weekly (TIW) oral iron supplementation regimens in treating iron deficiency nonanemia (IDNA) in National Collegiate Athletic Association (NCAA) Division 1 female track and field or soccer athletes.

DESIGN

Prospective cohort study.

SETTING

Division 1 collegiate athletics.

PARTICIPANTS

Thirty-three NCAA Division 1 female athletes (18 track and field, 15 soccer).

INTERVENTIONS

Daily or TIW dosing of ferrous bisglycinate.

MAIN OUTCOME MEASURES

Serum ferritin (μg/L) was measured before and after 8 weeks of supplementation. Self-reported compliance and side effect profile was assessed by electronic survey every 2 weeks.

RESULTS

The average main effect for the TIW regimen was a significant increase of 5.17 μg/L (95% CI: 0.86-9.47) in serum ferritin (p = .02). The average main effect for the daily regimen was a significant increase of 12.88 μg/L (95% CI: 4.84-20.93) in serum ferritin (p = .003). The estimated average effect of the treatment on the treated between regimens was a nonsignificant decrease of -7.17 μg/L (95% CI: -19.02 - 3.59) in serum ferritin (p = .17). Thus, the TIW regimen increased serum ferritin 7.17 units less than the daily regimen on average after 8 weeks of supplementation. The athletes following the daily regimen experienced significantly more nausea (p = .04) and constipation (p = .002) compared to the TIW regimen. There was no statistical difference in compliance between the two groups (p = .14).

CONCLUSIONS

Both the daily and TIW regimens increased serum ferritin. Compared to the daily regimen, the TIW regimen produced a smaller increase in serum ferritin but less nausea and constipation.

Designing of spider silk proteins for human induced pluripotent stem cell-based cardiac tissue engineering

Materials made of recombinant spider silk proteins are promising candidates for cardiac tissue engineering, and their suitability has so far been investigated utilizing primary rat cardiomyocytes. Herein, we expanded the tool box of available spider silk variants and demonstrated for the first time that human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes attach, contract, and respond to pharmacological treatment using phenylephrine and verapamil on explicit spider silk films. The hiPSC-cardiomyocytes contracted for at least 14 days on films made of positively charged engineered Araneus diadematus fibroin 4 (eADF4(κ16)) and three different arginyl-glycyl-aspartic acid (RGD)-tagged spider silk variants (positively or negatively charged and uncharged). Notably, hiPSC-cardiomyocytes exhibited different morphologies depending on the spider silk variant used, with less spreading and being smaller on films made of eADF4(κ16) than on RGD-tagged spider silk films. These results indicate that spider silk engineering is a powerful tool to provide new materials suitable for hiPSC-based cardiac tissue engineering.

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hiPSC-cardiomyocytes attach and contract on positively charged and/or RGD-tagged spider silk variants.

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hiPSC-cardiomyocytes exhibit spider silk variant-dependent morphology upon adhesion.

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Explicit spider silk variants promote long-term contractility of hiPSC-cardiomyocytes.

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hiPSC-cardiomyocytes grown on spider silk materials respond to pharmacological treatment.

Prospective, multicenter study of postoperative deep-vein thrombosis in patients with haemophilia undergoing major orthopaedic surgery

Perioperative clotting factor replacement is administered to reverse the inherent haemostatic defect in persons with haemophilia (PWH), potentially increasing their risk for developing venous thromboembolism (VTE) postoperatively. It was our objective to determine the prevalence of VTE in PWH undergoing total hip or knee arthroplasty (THA, TKA). Patients with haemophilia A or B who underwent THA or TKA were enrolled in this prospective, multicentre observational cohort study. Lower extremity venous duplex ultrasound was performed prior to surgery and 4–6 weeks after surgery. Eleven centres enrolled 51 subjects, 46 of whom completed the study. Six subjects (13.0 %) were treated with bypass agents perioperatively; the remaining 40 subjects received factor VIII or IX replacement. Intermittent pneumatic compression devices were utilised postoperatively in 23 subjects (50 %), and four subjects (8.7 %) also received low-molecular-weight heparin prophylaxis. One subject (2.2 %) with moderate haemophilia A was diagnosed with symptomatic distal deep-vein thrombosis (DVT) on day 6 following TKA. One subject (2.2 %) with severe haemophilia A was diagnosed with pulmonary embolism on day 9 following bilateral TKA. No subjects had asymptomatic DVT. Eighteen subjects (39.1 %) had major bleeding, and three subjects (6.5 %) experienced minor bleeding. The observed prevalence of ultrasound-detectable, asymptomatic DVT in PWH following TKA or THA in this study was low, but the incidence of symptomatic VTE (4.3 %, 95 % CI, 0.5–14.8 %) appeared similar to the estimated incidence in the general population without thromboprophylaxis.

Abstract TP247: Impact of Helicopter Emergency Medical Services Flights on Recombinant Tissue Plasminogen Activator (rtpa) Integrity

Introduction: Inter-hospital transfer of ischemic stroke patients by Helicopter Emergency Medical Services (HEMS) is common in rural states. The administration of recombinant tissue plasminogen activator (rtPA) is often initiated at the outside hospital and continues during HEMS (drip and ship). Due to the unstable nature of rtPA after reconstitution in conjunction with strong, low frequency vibrations present during HEMS, there is potential for the physical integrity and thrombolytic activity of rtPA to be compromised during inter-hospital transfer.

Hypothesis: Air ambulance transfer alters the antigen integrity of rtPA in ischemic stroke patients.

Methods: Prospective cohort study of acute ischemic stroke patients receiving rtPA during air ambulance transfer to a comprehensive stroke center (CSC) (intervention group) compared to patients who presented directly to our CSC Emergency Department (control group). The duration of each flight was recorded to control for degree of exposure. To access the structural integrity and thrombolytic activity of rtPA, small residual samples (<0.5 mL) were taken from each patient’s vial after the infusion was completed. The structural integrity of rtPA antigen was evaluated with a specific rtPA protein ELISA.

Results: Thirteen patients received rtPA and were transferred to our CSC via our air ambulance service. The mean flight time was 30.6±5.5 minutes. The mean concentration of rtPA in the control sample was 1.035±0.42 mg/mL. The mean difference in the concentration of the rtPA in the intervention group compared to the control group was 1.59±1.28 mg/mL.

Conclusions: HEMS transfer appears to increase rtPA antigen concentrations possibly due to degradation. Future analysis will examine whether alteration in integrity of rtPA affects the thrombolytic activity.

Abstract 6: ADAMTS13 Reduces VWF-Mediated Acute Myocardial Ischemia/Reperfusion Injury in Mice

Background and objective: ADAMTS13 cleaves von Willebrand factor (VWF), a large multimeric protein that plays an important role in thrombus formation by binding to platelets following vascular injury. Epidemiological studies implicate elevated VWF levels and reduced ADAMTS13 activity in plasma as risk factors for myocardial infarction, but it remains unknown whether the ADAMTS13/VWF axis contributes to myocardial infarction pathogenesis. We tested the hypothesis that ADAMTS13 reduces VWF-mediated myocardial ischemia/reperfusion injury in mice.

Methods: Myocardial infarction was induced in male mice (8-10 weeks of age) by ligating the left anterior descending coronary artery for 30 minutes followed by 23.5 hours of reperfusion. The extent of myocardium damage was evaluated by measuring infarct size (%) in 2 mm serial sections stained with 2% triphenyl-2, 3, 4-tetrazolium-chloride.

Results: Adamts13 -/- mice had significantly larger infarcts (mean ± SEM: 21.4 ± 1.3%, P <0.05) than WT mice (16.9 ± 1.2%) after myocardial ischemia/reperfusion injury. Adamts13+/- mice, which have a 50% reduction in ADAMTS13 activity, had similar sized infarcts (16.6 ± 1.3%) compared to those in WT mice. Because VWF remains the only known substrate of ADAMTS13 in multiple experimental models, we hypothesized that ADAMTS13 reduces myocardial injury through its proteolytic effect on hyper adhesive ULVWF and /or VWF. To test this hypothesis, we used a VWF-blocking antibody. Interestingly, WT mice treated with the VWF-blocking antibody showed a marked reduction in infarct size (7.9 ± 0.6%, P < 0.001) compared with WT mice treated with control Ig (17.5 ± 1.5 %). Finally, Adamts13 -/- mice treated with the VWF-blocking antibody had infarct sizes (8.0 ± 1.5%) that were similar to those WT mice treated with VWF-blocking antibody, demonstrating that increased infarct size in the Adamts13 -/- mice in this acute myocardial ischemia/reperfusion injury model is VWF-dependent.

Conclusion: These findings reveal a new role for anti-thrombotic enzyme ADAMTS13 in reducing VWF-mediated myocardial ischemia/reperfusion injury.

[Mutation in factor II and factor V gene in patients with peripheral arterial occlusive disease]

Mutations in factor-V- and factor-II-genes are correlated with an increased risk for venous thrombosis according to the literature. The significance of the mutations in factor- II- and factor-V-genes for the development of the peripheral arterial occlusive disease is not known. Therefore, we investigated the presence of these mutations in 152 patients with documented peripheral arterial occlusive disease and 318 controls without peripheral arterial occlusive disease with polymerase chain reaction (PCR). There was no association between factor-II-mutation and peripheral arterial occlusive disease. The factor-V-mutation, however, was increased in patients with peripheral arterial occlusive disease double fold (12 positive cases in 318 controls, 12 positive cases in 152 patients with peripheral arterial occlusive disease). The significance level was reached (p = 0.05) in statistical analysis but the result did not fall below the significance level as necessary to reach statistical significance (odds ratio 2.19). Nevertheless, from these data we have to discuss a biological relevance of factor-V-mutation in the pathogenesis of peripheral arterial occlusive disease.

Chronisch-arterielle Verschlusskrankheit der Beine im Stadium IIb-IV

Die Faktor-V- und Faktor-II-Mutationen sind nach der Literatur mit einem erhöhten Risiko für venöse Thrombosen verbunden. Die Bedeutung der Mutationen im Faktor-IIund -V-Gen für die Entstehung und das Fortschreiten der arteriellen Verschlusskrankheit ist bislang nicht geklärt. Wir untersuchten das Vorhandensein dieser Mutationen bei 152 Patienten mit dokumentierter pAVK und 318 Kontrollen (ohne pAVK) mittels Polymerase-Kettenreaktion (PCR) und RFLP-Analyse. Die Ergebnisse erbrachten keinen Hinweis auf eine Assoziation zwischen einer Faktor-II-Mutation und der Entstehung einer pAVK. Dagegen waren Faktor- V-Mutationen bei pAVK-Patienten doppelt so häufig zu beobachten wie bei Gesunden (in der Kontrollgruppe ergaben sich 12 positive Fälle bei 318 Probanden, in der Patientengruppe ergaben sich 12 positive Fälle bei 152 Patienten). In der statistischen Analyse wurde das Signifikanzniveau (p = 0,05) zwar erreicht, aber nicht unterschritten. Das Chancenverhältnis (Odds-Ratio) betrug 2,19 (Konfidenzintervall 0,96-4,99). Schlussfolgerung: Die biologische Relevanz der Faktor-V-Mutation in der Pathogenese der pAVK kann aufgrund unserer Daten diskutiert werden.

[Chromogenic substrate as antidote against the thrombin inhibitor Melagatran?]

It could be shown in vitro that a chromogenic substrate (Chromozym TH, Roche Mannheim) acts at least partially as antidote against the new thrombin inhibitor Melagatran (AstraZeneca, Mölndal, Sweden). It is discussed that this antidote effect of a chromogenic substrate might be due to a substrate competition of fibrinogen, thrombin inhibitor, and chromogenic substrate for thrombin. Further animal experiments will clarify whether this in vitro observation is of practical relevance in vivo, too.

Chromogenes Substrat als Antidot gegen den Thrombininhibitor Melagatran?

Mit In-vitro-Untersuchungen wird gezeigt, dass ein chromogenes Substrat (Chromozym TH von Roche, Mannheim) die gerinnungshemmende Wirkung des neuen Thrombininhibitors Melagatran (AstraZeneca, Mölndal, Schweden) zumindest partiell antagonisieren kann. Der hier beschriebene Antidoteffekt eines chromogenen Substrats gegenüber einem Thrombininhibitor könnte seine Erklärung darin finden, dass eine Substratkompetition zwischen Thrombins im Testsystem und Fibrinogen, Thrombininhibitor und chromogenem Substrat vorliegt. Tierversuche unter Einbeziehung weiterer Thrombininhibitoren könnten klären, ob die beschriebene Antidotwirkung die beobachteten Blutungskomplikationen tatsächlich reduzieren kann oder ob ein In-vitro-Phänomen vorliegt, das in vivo wenig Relevanz besitzt.

Effect of gamma-interferon on binding of gliadin and other food peptides to the human intestinal cell line HT-29

gamma-Interferon is one of the main cytokines released during activation of intestinal lymphocytes in coeliac patients. The question has never been addressed whether gamma-interferon influences binding of gliadin and other food peptides to human enterocytes. Therefore, the human intestinal epithelial cell line HT-29 was cultured with gliadin, casein, beta-lactoglobulin and ovalbumin, with or without gamma-interferon, and peptide binding to cells was determined by flow cytometry and fluorescence microscopy. gamma-Interferon stimulated gliadin binding by a factor of 4. Binding was saturable with half maximal binding at 0.15 mg/ml. For maximal binding, an incubation of at least 24 h was necessary. gamma-Interferon increased binding of beta-lactoglobulin and casein, too, but inhibited that of ovalbumin. Binding of gliadin was inhibited by the other peptides. Under the conditions of ongoing mucosal inflammatory reactions and release of gamma-interferon, enhanced binding may trigger intestinal lymphocytes, increase secretion of cytokines and thus induce a vicious circle.

Reconstruction of pelvic exenterative wounds with transpelvic rectus abdominis flaps: a case series

Exenterative pelvic surgery is commonly performed for advanced carcinoma of the cervix and selected cases of locally advanced colorectal cancers. Low-lying lesions that are locally invasive in contiguous organs require resection of the perineal body en bloc with the resected specimen. The resulting defect, both in the pelvis and the perineum, creates a difficult management problem. Dead space in the pelvis, especially with adjunctive irradiation, leads to delayed wound healing and prolapse of small bowel into the pelvis. Small bowel obstruction and/or fistula formation are the greatest sources of morbidity in the operative group. Fifteen patients underwent exenterative pelvic procedures (total exenteration, 1 patient; posterior exenteration, 8 patients; abdominoperineal resection, 6 patients). All patients were reconstructed by transpelvic placement of the rectus abdominis muscle (muscle only, 4 patients; muscle with skin grafting, 8 patients; musculocutaneous, 3 patients). Eighty-seven percent received radiation therapy. One patient had Crohn's disease and all others had carcinoma. Healing was complete in 12 of 15 patients at discharge. There were no complications related to pelvic dead space (i.e., bowel obstruction, perineal fistula), with a mean follow-up time of 24.3 months. Small bowel was effectively excluded from the pelvis to the level of the acetabular roof by computerized axial tomography scan. The transpelvic rectus abdominis muscle flap is effective in preventing major morbidity after exenterative pelvic surgery.

"Medicine on wheels": an opportunity for outreach and housestaff education

Ambulatory-care teaching programs have been traditionally based in hospital settings. As many patients, in particular the homeless and underinsured, have never reached these settings, we describe a nontraditional outreach health-care program for medical residents. This multidisciplinary program places medical residents on a mobile van to deliver care to a population in New Haven where 18.2% of its families are below the poverty level and have limited or no access to health care at the teaching hospital. On-site urgent care is given along with HIV, pregnancy testing, and blood pressure screening. Health-care follow-up, dental care, alcohol detoxification, and drug counseling are scheduled. A total of 764 adult patients were seen between November 1991 and June 1993 by PGY2 residents on ambulatory rotations. One hundred forty-one patients consented to respond to a questionnaire. Thirty-seven (26%) were homeless with a mean length of homelessness of 15 months. Forty-one percent had been victimized within one year and 33% currently used illicit drugs. The benefits of this unique ambulatory teaching program for medical residents are described.

Cyclosporin enhancement of cisplatin chemotherapy in patients with refractory gynecologic cancer. A Gynecologic Oncology Group Study

BACKGROUND

Cyclosporin has been demonstrated to reverse resistance to several antineoplastic agents including cisplatin in vitro. The purpose of this Phase I trial was to study the potential clinical application of cyclosporin modulation of cisplatin and to establish a tolerable dose of cyclosporin when combined with a standard dose of cisplatin of 75 mg/m2.

METHODS

A course of therapy consisted of two cyclosporin infusions over 2 hours each, 24 hours apart, with cisplatin given 6 hours after the first dose. Treatment was repeated every 21 days. Cyclosporin was studied in a Phase I fashion at five different levels, from 1-5 mg/kg per dose. Twenty patients with refractory gynecologic cancer received 81 courses of therapy. All patients had received extensive prior chemotherapy containing cisplatin.

RESULTS

Grade 4 nephrotoxicity was seen in 4 of 20 patients: 1 treated at 1 mg/kg, 1 at 2 mg/kg, and 2 at 5 mg/kg of cyclosporin. The patient treated at the 1 mg/kg level was a partial clinical responder and tolerated six courses. The patient at the 2 mg/kg level had received 14 prior courses of cisplatin and tolerated only two additional courses before a Grade 4 renal toxicity developed. Grade 4 nephrotoxicity developed in the two patients receiving 5 mg after two courses of chemotherapy. Two of the 20 patients achieved a complete response (CR) and 3 patients achieved a partial response (PR), for a total response rate of 25% (5 of 20). The two women who achieved CR started treatment with symptomatic ascites; one of whom also had multiple pulmonary lesions that were no longer evident after three courses of therapy.

CONCLUSIONS

Cyclosporin at a dose of 4 mg/kg per day given for 2 consecutive days in association with 75 mg/m2 of cisplatin can be given with reasonable assurance of safety.