Skeletal and Cardiac Muscle Defects in a Murine Model of Emery-Dreifuss Muscular Dystrophy

Previous histological findings, physiological data, and behavioral observations on the A-type lamin knockout mouse (Lmna(-/-)) suggest that important aspects of this model resemble the human Emery-Dreifuss muscular dystrophy (EDMD) phenotype. The main goal of our experiments was to study skeletal and cardiac muscle function in this murine model to obtain the semiquantitative data needed for more detailed comparisons with human EDMD defects. Measurements of the mechanical properties of preparations from two different skeletal muscle groups, the soleus and the diaphragm, were made in vitro. In addition, records of the electrocardiogram, and measurements of heart rate variability were obtained; and phasic contractions (unloaded shortening) of enzymatically isolated ventricular myocytes were monitored. Soleus muscles from Lmna(-/-) mice produced less force and work than control preparations. In contrast, force and work production in strips of diaphragm were not changed significantly. Lead II electrocardiograms from conscious, restrained Lmna(-/-) mice revealed slightly decreased heart rates, with significant prolongations of PQ, QRS, and 'QT' intervals compared with those from control recordings. These ECG changes resemble some aspects of the ECG records from humans with EDMD; however, the cardiac phenotype in this Lmna(-/-) mouse model appears to be less well-defined/developed. Ventricular myocytes isolated from Lmna(-/-) mice exhibited impaired contractile responses, particularly when superfused with the beta-adrenergic agonist, isoproterenol (1 microM). This deficit was more pronounced in myocytes isolated from the left ventricle(s) than in myocytes from the right ventricle(s). In summary, tissues from the Lmna(-/-) mouse exhibit a number of skeletal and cardiac muscle deficiencies, some of which are similar to those which have been reported in studies of human EDMD.

An investigation of the action of the hamstring muscles during standing in crouch using functional electrical stimulation (FES)

The hamstring muscle moment arms indicate that they act as hip extensors and knee flexors. Previous work using induced acceleration (IA) analysis and functional electrical stimulation (FES) has, however, revealed counter-intuitive muscle actions, particularly for biarticular muscles during the stance phase of normal gait. In conditions such as cerebral palsy the hamstrings have been associated with the development of pathological gait patterns, particularly crouch gait. This study examines the role of these muscles in the control of crouched standing postures. Five unimpaired adult subjects had their muscles stimulated during quiet standing in different degrees of crouch. Kinematic and kinetic changes were observed and measured using a 3D motion analysis system. The hamstring muscles were shown to act strongly to retrovert the pelvis and extend the hip. The action at the knee changes as crouch increases, moving from flexing to extending.

Symptomatic nutritional rickets in a teenager with autistic spectrum disorder

Selectivity with food and food related behavioural difficulties are relatively common in children on the Autistic Spectrum. This may result in an inadequate nutritional status. Integration of sensory signals in the brain associated with textures, tastes and smells has been postulated as a possible cause.

Structure and function of enzymes involved in the biosynthesis of phenylpropanoids

As a major component of plant specialized metabolism, phenylpropanoid biosynthetic pathways provide anthocyanins for pigmentation, flavonoids such as flavones for protection against UV photodamage, various flavonoid and isoflavonoid inducers of Rhizobium nodulation genes, polymeric lignin for structural support and assorted antimicrobial phytoalexins. As constituents of plant-rich diets and an assortment of herbal medicinal agents, the phenylpropanoids exhibit measurable cancer chemopreventive, antimitotic, estrogenic, antimalarial, antioxidant and antiasthmatic activities. The health benefits of consuming red wine, which contains significant amounts of 3,4',5-trihydroxystilbene (resveratrol) and other phenylpropanoids, highlight the increasing awareness in the medical community and the public at large as to the potential dietary importance of these plant derived compounds. As recently as a decade ago, little was known about the three-dimensional structure of the enzymes involved in these highly branched biosynthetic pathways. Ten years ago, we initiated X-ray crystallographic analyses of key enzymes of this pathway, complemented by biochemical and enzyme engineering studies. We first investigated chalcone synthase (CHS), the entry point of the flavonoid pathway, and its close relative stilbene synthase (STS). Work soon followed on the O-methyl transferases (OMTs) involved in modifications of chalcone, isoflavonoids and metabolic precursors of lignin. More recently, our groups and others have extended the range of phenylpropanoid pathway structural investigations to include the upstream enzymes responsible for the initial recruitment of phenylalanine and tyrosine, as well as a number of reductases, acyltransferases and ancillary tailoring enzymes of phenylpropanoid-derived metabolites. These structure-function studies collectively provide a comprehensive view of an important aspect of phenylpropanoid metabolism. More specifically, these atomic resolution insights into the architecture and mechanistic underpinnings of phenylpropanoid metabolizing enzymes contribute to our understanding of the emergence and on-going evolution of specialized phenylpropanoid products, and underscore the molecular basis of metabolic biodiversity at the chemical level. Finally, the detailed knowledge of the structure, function and evolution of these enzymes of specialized metabolism provide a set of experimental templates for the enzyme and metabolic engineering of production platforms for diverse novel compounds with desirable dietary and medicinal properties.

Creation and characterization of E-selectin- and VCAM-1-deficient mice

A variety of adhesion molecules have been identified which mediate the interaction of leukocytes with endothelial cells. In order to define the role of individual molecules in inflammation we have produced lines of mice which are deficient in the synthesis of specific adhesion molecules. Null mutations were introduced into the genes encoding E-selectin or vascular cell adhesion molecule-1 (VCAM-1) in embryonic stem cells and these cells were used to produce lines of mice carrying the mutation. E-selectin-deficient mice were viable and exhibited no developmental defects. The roles of E- and P-selectin in the influx of neutrophils were examined using these mice. The data suggest that the two selectins are functionally redundant in mediating neutrophil emigration in a model of chemically induced peritonitis. VCAM-1-deficient mice are not viable. Analysis of VCAM-1 gene expression in wild-type embryos and phenotypic analysis of VCAM-1 -/- embryos suggests that VCAM-1 is required for development of the extraembryonic circulatory system and the embryonic heart.

Two steps forward, one step back: advance care planning, Australian regulatory frameworks and the Australian Medical Association

The Australian Medical Association has recently adopted a policy position concerning advance care planning, which is generally supportive of extending patient self-determination beyond the loss of decision-making capacity. It calls for uniform national legislation for legally enforceable advance health directives (AHD), and statutory protection for practitioners who comply with valid AHD, or who do not comply on several grounds. Analysis of the grounds for non-compliance indicate that they undermine patient autonomy, and aspects of the policy are inconsistent with current common law and statutory regimes that allow an adult to complete a legally binding AHD. The policy therefore threatens the patient self-determination, which it endorses, and places doctors who participate in advance care planning at legal risk.

Selective dorsal rhizotomy for children with cerebral palsy: the Oswestry experience

BACKGROUND

Although three randomised control trials have shown that selective dorsal rhizotomy (SDR) reduces spasticity in children with cerebral palsy, a meta-analysis of the results demonstrated that the procedure conferred only small functional benefit on the patient.

AIM

To determine whether applying strict criteria for patient selection as practised in Oswestry leads to improved outcomes, using gait analysis as an outcome measure.

METHODS

Ambulant children with cerebral palsy were selected for SDR using very strict clinical criteria. Instrumented gait analysis was used as the main outcome measure.

RESULTS

Of 53 children referred for the procedure, only 19 (35%) fulfilled our strict criteria for selection. These children underwent surgery and when pre- and post-SDR data were compared, they showed improvement in cosmesis of gait, clinical examination and temporal, kinetic and kinematic parameters of gait. After SDR the children walked, on average, 0.15 m/s faster, with a step length improvement of 0.11 m. Changes were seen at hip, knee and ankle, with those at the knee being most marked. A 0.3 grade improvement in knee extensor power on clinical examination led to a 13 degrees improvement in stance phase knee extension. Knees also became less stiff, with an 82 degrees /s improvement in the rate of flexion into swing phase. A functional tool (the GMFCS) applied retrospectively also confirmed post-operative improvement, with 15 of the 19 children improving by at least one level.

CONCLUSION

Application of strict selection criteria when considering children for SDR leads to encouraging results as demonstrated by gait analysis and other measures.

The changing face of phase I protocols: A closer look at study requirements

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Background: We have studied our recent experience in the MDACC Clinical Translational Research Center (CTRC), the Phase I Program, and the Dept. of Thoracic/Head & Neck Medical Oncology to compare the extent of regulatory and other requirements for current phase I and II cancer clinical trials. Methods: We developed a comprehensive database, together with a Microsoft Excel spreadsheet matrix to analyze the number and extent of diagnostic and therapeutic requirements for each protocol. We then examined the demands for pharmacokinetic (PK) sampling as well as electrocardiography (ECG) in the first cycle of a protocol as a surrogate for study complexity. Results: Since October, 2002, 250 protocols have been conducted in the CTRC; 54.6% were Phase I clinical trials. We reviewed 65 trials, approximately one quarter of the total. Of these, 48 were phase I trials carried out by the Phase I Program. For comparison, we identified 17 phase II trials managed by the Dept. of Thoracic/Head & Neck Medical Oncology during the same time period. In the phase I trials there were significantly more PKs (mean ± SE = 16.69 ± 1.93) than in the phase II trials (mean ± SE = 1.82 ± 1.17) (p<0.0001). Similarly, there were more ECGs in the phase I versus phase II trials (4.46 ± 1.18 vs. 1.41 ± 0.35; p=0.017). Conclusions: Pharmacokinetic collection and ECG monitoring in Phase I trials are complex and labor-intensive. In addition, they represent only a small portion of time-intensive requirements, with increasingly complicated correlates and monitoring (physical exams, imaging, etc.). Successful and accurate Phase I clinical trials require resources and commitment for research infrastructure considerably greater than later phase studies.

No significant financial relationships to disclose.

The challenge of patients' unmet palliative care needs in the final stages of chronic illness

BACKGROUND

There is consensus in the literature that the end of life care for patients with chronic illness is suboptimal, but research on the specific needs of this population is limited.

AIM

This study aimed to use a mixed methodology and case study approach to explore the palliative care needs of patients with a non-cancer diagnosis from the perspectives of the patient, their significant other and the clinical team responsible for their care. Patients (n = 18) had a diagnosis of either end-stage heart failure, renal failure or respiratory disease.

METHODS

The Short Form 36 and Hospital and Anxiety and Depression Questionnaire were completed by all patients. Unstructured interviews were (n = 35) were conducted separately with each patient and then their significant other. These were followed by a focus group discussion (n = 18) with the multiprofessional clinical team. Quantitative data were analysed using simple descriptive statistics and simple descriptive statistics. All qualitative data were taped, transcribed and analysed using Colaizzi's approach to qualitative analysis.

FINDINGS

Deteriorating health status was the central theme derived from this analysis. It led to decreased independence, social isolation and family burden. These problems were mitigated by the limited resources at the individual's disposal and the availability of support from hospital and community services. Generally resources and support were perceived as lacking. All participants in this study expressed concerns regarding the patients' future and some patients described feelings of depression or acceptance of the inevitability of imminent death.

CONCLUSION

Patients dying from chronic illness in this study had many concerns and unmet clinical needs. Care teams were frustrated by the lack of resources available to them and admitted they were ill-equipped to provide for the individual's holistic needs. Some clinicians described difficulty in talking openly with the patient and family regarding the palliative nature of their treatment. An earlier and more effective implementation of the palliative care approach is necessary if the needs of patients in the final stages of chronic illness are to be adequately addressed.

Electroporation of a multicellular system: asymptotic model analysis

Quantitative understanding of electroporation in a multicellular system has been limited. The transient aqueous pore theory describes electroporation as the stochastic formation of hydrophilic pores in the presence of an applied electric field. We have used an asymptotic model for local membrane electroporation in a transport lattice system model to predict effects of a electrical pulse on a didactic multicellular model. We show that pulses of amplitude 0.2 to 2 kV/cm and duration 100 micros can cause extensive electroporation resulting in significant redistribution of transmembrane voltages.

Muromonab-CD3 (Orthoclone OKT3), methylprednisolone and cyclosporine for acute graft-versus-host disease prophylaxis in allogeneic bone marrow transplantation

We report the results of a prospective non-randomized phase II study of Muromonab-CD3 (Orthoclone OKT3), an anti-CD3 monoclonal antibody, with methylprednisolone (MP) and cyclosporine (CSA) for acute GVHD (aGVHD) prophylaxis in 22 hematologic malignancy patients. OKT3 was given at 0.1 mg/kg/day with a maximum dose of 5 mg/day. Initial MP dose was 1000 mg before OKT3, with subsequent doses at 1 mg/kg/day before each OKT3 infusion with a planned taper beginning at day +28. CSA (3 mg/kg/day) was given as a continuous infusion at day -1 and adjusted to maintain serum levels between 250 and 399 ng/ml. Allogeneic BMT donors were HLA-matched siblings (n = 17), single HLA-mismatched-related (n = 1) and HLA-matched unrelated (n = 4). All patients achieved neutrophil engraftment at a median 11 days (range, 8-25 days). By intent-to-treat, the cumulative incidence of grade II-IV aGVHD was 33% (95% CI 13-53%) at a median 26 days post-BMT (range, 14-84 days). Chronic GVHD developed in 11/12 evaluable patients. Eight patients (36%) developed OKT3 first dose reactions; no cases of post-transplant lymphoproliferative disorder were observed. OKT3 depleted peripheral CD3+ cells in vivo as measured by flow cytometry. OKT3+MP+CSA combination is moderately effective aGVHD prophylaxis, however, it is unlikely to be superior to CSA+MTX.

Immediate adverse reactions to chemotherapy: Experience of a large ambulatory treatment center

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Background: In recent years there has been a proliferation of Ambulatory Chemotherapy Treatment Centers (ATC). The incidence of hypersensitivity and other immediate adverse drug reactions (IADR) in these ATC units have not been well studied. We aim to describe our experience with IADR in our ATC. Methods: Retrospective chart review was conducted for all patients in the Adverse Drug Reaction Report database (Maxsys II) for the year 2004. Data was abstracted for demographics, risk factors, clinical characteristics, and outcomes of IADR. Overall frequency of different chemotherapeutic and monoclonal agents infused was obtained for the same period through the pharmacy database. Results: In 2004, 81,580 chemotherapy infusions were given and 256 IADR (0.31%) were reported. The mean age was 55 years and 45% were males. The most common drugs used were fluorouracil (12.9%), paclitaxel (9.4%), docetaxel (6.1%), carboplatin (5.9%), and gemcitabine (5.8%). The table shows the most prevalent agents that led to IADR. Common symptoms included flushing (52.3%), dyspnea (27.3%), chest discomfort (27%), pruritus (22.7%), and hypertension (18.4%). Diphenhydramine (85.5%), hydrocortisone (37.1%), and dexamethasone (17.2%) were the most common drugs used for treatment of IADR. Common risk factors included previous allergy to medications (43.4%), previous IADR (19.5%), previous reactions to iodide (7.8%), allergies to seafood (1.6%), allergic rhinitis (1.2%), urticaria (1.2%), and asthma (0.8%). Most patients had their chemotherapy resumed and completed (87.9%) on the same day. Discussion: IADR were rare. Most cases were easily treated and chemotherapy was restarted and completed in the same day. However, they still pose a significant burden to cancer patients. Prospective studies are needed to further evaluate the identified risk factors and most common offending agents in outpatient settings. This will help develop pathways for more effective prevention and treatment of these IADR.

[Table: see text]

No significant financial relationships to disclose.

Role of amifostine as a cytoprotectant in children ≥ 3 years with average risk (AR) medulloblastoma (MB) treated with craniospinal irradiation (CSI) and 4 courses of cisplatin (CDDP)-based high dose chemotherapy

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Background: Therapy for MB (CSI and CDDP-based chemotherapy) results in hearing loss before completion of therapy in 30%-50% of patients, who consequently require a reduced cisplatin dose. Cytoprotection against cisplatin-induced ototoxicity may be provided by amifostine, a thiol prodrug that protects many normal tissues against therapy-induced damage without diminishing antitumor effects. Method: This study was designed to detect a 20% decrease (80% power) in CDDP induced ototoxicity (defined as needing hearing aids) in AR MB patients with the use of amifostine (n=62) compared to historical controls (n=35) one year from diagnosis. An interim analysis was conducted after accrual of 32 pts on the experimental arm. A total of 67 AR MB patients received CSI (23.4 Gy) followed by 3-dimensional conformal boost to the tumor bed (total 55.8 Gy) and 4 cycles of high-dose cyclophsophamide (4,000 mg/m2 per cycle), cisplatin (75 mg/m2 per cycle), and vincristine (two 1.5 mg/m2 doses per cycle). When used, amifostine (600 mg/m2 per cycle) was given before and 3 hours into the cisplatin infusion. Results: The median age of the 40 male, 27 female patients was 8.7 (range, 3.2–20.2) yrs. The 2 groups had similar median ages (amifostine, 9.1; control, 7.8 years) and gender (male: amifostine, 66%; control, 54%). One year after the start of treatment, the objective criteria for needing a hearing aid in at least 1 ear were met by 13 (37%) of control-group patients and 6 (18.8%) of those who received amifostine. Conclusion: The interim analysis has demonstrated that the need for hearing aids in AR MB children treated with the above-described regimen is halved by using amifostine during CDDP administration.

No significant financial relationships to disclose.

Rituximab in Combination With Fludarabine Chemotherapy in Low-Grade or Follicular Lymphoma

Purpose

To evaluate the safety and efficacy of fludarabine plus rituximab in treatment-naïve or relapsed patients with low-grade and/or follicular non-Hodgkin's lymphoma.

Patients and Methods

This was an open-label, single-arm, single-center phase II study enrolling 40 patients. During the first week of the study, patients received two infusions of rituximab 375 mg/m2 administered 4 days apart. Seventy-two hours after the second infusion of rituximab, patients received the first of six cycles of fludarabine chemotherapy (25 mg/m2/d for 5 days on a 28-day cycle). Single infusions of rituximab were administered 72 hours before the second, fourth, and sixth cycles of fludarabine, and two infusions of rituximab were given 4 weeks after the last cycle of fludarabine. Treatment duration was 26 weeks.

Results

An overall response rate of 90% (80% complete response rate) was achieved in the intent-to-treat population. Similar response rates were seen in treatment-naïve and previously treated patients. The median duration of response has not been reached at 40+ months. The median follow-up time in this study is 44 months (range, 15 to 66 months). In patients positive for the 14;18 translocation in blood and/or marrow at enrollment, molecular remission was achieved in 88% of cases, with patients remaining negative for up to 4 years to date. Hematologic toxicity was manageable, and except for a 15% incidence of herpes simplex/zoster infections, infectious complications were rare. Nonhematologic toxicities were minimal.

Conclusion

Rituximab plus fludarabine was well tolerated and associated with an excellent complete response rate, including molecular remissions, in patients with low-grade or follicular lymphoma.

A laser speckle imaging technique for measuring tissue perfusion

Laser Doppler imaging (LDI) has become a standard method for optical measurement of tissue perfusion, but is limited by low resolution and long measurement times. We have developed an analysis technique based on a laser speckle imaging method that generates rapid, high-resolution perfusion images. We have called it laser speckle perfusion imaging (LSPI). This paper investigates LSPI output and compares it to LDI using blood flow models designed to simulate human skin at various levels of pigmentation. Results show that LSPI parameters can be chosen such that the instrumentation exhibits a similar response to changes in red blood cell concentration (0.1%-5%, 200 microL/min) and velocity (0-800 microL/min, 1% concentration) and, given its higher resolution and quicker response time, could provide a significant advantage over LDI for some applications. Differences were observed in the LDI and LSPI response to tissue optical properties. LDI perfusion values increased with increasing tissue absorption, while LSPI perfusion values showed a slight decrease. This dependence is predictable, owing to the perfusion algorithms specific to each instrument, and, if properly compensated for, should not influence each instrument's ability to measure relative changes in tissue perfusion.

Receptor of advanced glycation end product (RAGE) expression in the minor salivary glands of patients with Sjögren's syndrome: a preliminary study

OBJECTIVE

Receptor for advanced glycation end product (RAGE) is a cell-surface receptor with ligands capable of inducing proinflammatory responses in autoimmunity. We investigated the immunohistochemical expression and immunoblotting of RAGE in labial salivary glands from Sjögren's syndrome (SS) patients.

MATERIAL AND METHODS

Ten minor salivary glands from SS and 15 from normal salivary tissue adjacent to mucocele were stained immunohistochemically using an antibody to RAGE. Immunoblotting was performed on four SS biopsies and four controls from normal gland.

RESULTS

Immunohistochemistry showed all sections positive for RAGE. The SS sections did not statistically differ from controls. In immunoblotting, SS samples expressed approximately 100% more RAGE than controls [probability (p)<0.03, Student's t-test].

CONCLUSIONS

RAGE is present in the labial salivary glands of both normal and SS patients, with preliminary data suggesting over-expression in SS tissues. The role of RAGE in the pathogenesis of SS has yet to be determined.

Long uvula: an unusual cause of chronic cough

Chronic cough is a distressing symptom for patients and parents in paediatric practice. Investigations of the child with persistent cough can be simple or complex depending on the underlying cause. There are some unusual reasons for chronic cough, which need to be kept in mind when investigating the cause. A case of a long, floppy uvula causing chronic cough through mechanical irritation of upper airway is reported.

Endoscopic laser imaging of tissue perfusion: new instrumentation and technique

BACKGROUND AND OBJECTIVES

New instrumentation, based on a previously established laser speckle perfusion imaging (LSI) technique is evaluated for its ability to capture and generate blood flow images during endoscopic surgery.

STUDY DESIGN/MATERIALS AND METHODS

Investigations are detailed in an in-vitro blood flow model simulating physiological properties of vascularized tissue, and in-vivo in rabbit joint capsule tissue.

RESULTS

In-vitro measurements showed a linear response of the instrument to blood flow in the range of 0-800 microl/minute, where data points were significantly correlated with an r(2) value of 0.96. In-vivo measurements showed a 58.7% decrease to the medial collateral ligament during occlusion of the femoral artery.

CONCLUSIONS

Blood flow images demonstrate that the endoscopic LSI technique is capable of measuring relative tissue blood flow changes at high resolutions and rapid response times and incorporates well with endoscopic surgeries.