Evaluation of Fixed Intrathecal Bupivacaine Infusion Doses in the Oncologic Population.

OBJECTIVES: Intrathecal drug delivery systems (IDDS) are an important method of pain control for patients with refractory oncologic pain. Local anesthetics such as bupivacaine have been infused either alone or with opioids. While effective, bupivacaine can cause adverse effects such as numbness, weakness, and urinary retention. This study looks to establish a safe and efficacious fixed bupivacaine dosing algorithm in intrathecal pumps for cancer patients. MATERIALS AND METHODS: A bupivacaine dosing algorithm was developed using data from 120 previous patients who underwent IDDS placement at Memorial Sloan Kettering Cancer Center. The outcomes were then evaluated for 43 subsequent patients who were treated with bupivacaine IDDS according to our aforementioned algorithm. RESULTS: Our data show that in patients treated with our bupivacaine guideline, visual analog pain scale scores decreased by 59% and oral morphine equivalence decreased by 70% from the period between IDDS implantation until discharge from the MSKCC hospital. However, 16.3% of our patients had bupivacaine-related side effects. CONCLUSIONS: For oncological patients, our data and experience support the initiation of intrathecal bupivacaine at the following doses: 5 mg/day for catheter tips in the cervical spine, 8 mg/day for catheter tips at T1-4, and 10 mg/day for catheter tips at T5-8. Given the higher likelihood of adverse effects in catheters at T9-12 and the lumbar spine, we start at 8 mg/day with close follow-up of the patient. Initiating these doses allow our patients to safely reach adequate analgesia faster, with a shorter hospitalization and quicker return to anti-cancer therapy.

Distinct signature type I interferon responses are determined by the infecting virus and the target cell.

BACKGROUND: Type I interferons (IFN) include multiple IFN-alpha subtypes which exhibit considerable amino acid identity and activate the same cell-surface receptor. The promoter regions of the IFN-alpha genes, however, have different transcription factor binding sites, implying differential transcriptional activation. Evolutionary conservation of multiple subtypes may have resulted from external pressures associated with the crucial nature of an IFN response, namely that different viruses that are tropic for different target tissues determine the nature and extent of an IFN response, specifically the IFN-alpha subtype profile. METHODS: Studies were undertaken to examine inducible IFN gene expression profiles in response to infection with single-stranded RNA viruses: Sendai virus (SeV), murine hepatitis virus (MHV-1) and coxsackie virus B3 (CVB3). RESULTS: In vitro, distinct signature profiles of SeV and MHV-1-inducible gene expression for IFN-alpha2, IFN-alpha4 and IFN-alpha5 subtypes in L2 and L929 mouse fibroblast cells, in relation to the extent and kinetics of their induction, were identified. In vivo, whereas A/J mice are highly permissive for both MHV-1 and CVB3 infections and mount a poor IFN response, C57B1/6 mice are relatively resistant to both virus infections and mount a vigorous IFN response. CONCLUSIONS: These data suggest that the infecting virus and the target cell type dictate the extent and signature of inducible type I IFN gene expression. The extent of IFN response to viral infection influences the subsequent biological outcome: a robust IFN response prescribes a level of resistance, whereas a poor IFN response contributes towards a permissive phenotype for infection.

Anatomical Study of the Innervation of Anterior Knee Joint Capsule: Implication for Image-Guided Intervention.

BACKGROUND AND OBJECTIVES: The knee joint is the most common site of osteoarthritis. While joint replacement is considered an ultimate solution, radiofrequency denervation may be contemplated in some cases. Radiofrequency ablation requires precise localization of the articular branches innervating the joint capsule. The objective of this cadaveric study was to determine the source, course, relationships, and frequency of articular branches innervating the anterior knee joint capsule. METHODS: Fifteen knees were meticulously dissected. The number and origin of the articular branches were recorded, and their distribution defined by quadrants. Their relationships to anatomical landmarks were identified. RESULTS: The articular branches terminated in 1 of the 4 quadrants with minimal overlap. In all specimens, the superolateral quadrant was innervated by the nerve to vastus lateralis, nerve to vastus intermedius, superior lateral genicular and common fibular nerves; inferolateral by the inferior lateral genicular and recurrent fibular nerves; superomedial by the nerve to vastus medialis, nerve to vastus intermedius and superior medial genicular nerve; and inferomedial by the inferior medial genicular nerve. In 3 specimens, the inferomedial quadrant also received innervation from the infrapatellar branch of saphenous nerve. All articular branches except the nerves to vastus lateralis and medialis course at the periosteal level. CONCLUSIONS: The frequency map of the articular branches provides an anatomical basis for the development of new clinical protocols for knee radiofrequency denervation and perioperative pain management.

Anatomic Study of Innervation of the Anterior Hip Capsule: Implication for Image-Guided Intervention.

BACKGROUND AND OBJECTIVES: The purpose of this cadaveric study was to determine the pattern of anterior hip capsule innervation and the associated bony landmarks for image-guided radiofrequency denervation. METHODS: Thirteen hemipelvises were dissected to identify innervation of the anterior hip capsule. The femoral (FN), obturator (ON), and accessory obturator (AON) nerves were traced distally, and branches supplying the anterior capsule documented. The relationships of the branches to bony landmarks potentially visible with ultrasound were identified. RESULTS: The anterior hip capsule received innervation from the FNs and ONs in all specimens and the AON in 7 of 13 specimens. High branches of the FN (originating above the inguinal ligament) were found exclusively in 12 specimens and passed between the anterior inferior iliac spine and the iliopubic eminence. The ONs were innervated exclusively by high branches (proximal to the division), by low branches (from the posterior branch), and by both in 4, 5, and 4 specimens, respectively. The most consistent landmark was the inferomedial acetabulum (radiographic "teardrop"). When present, the AON coursed over the iliopubic eminence before innervating the anterior hip capsule. CONCLUSIONS: Branches of the FNs and ONs consistently provided innervation to the anterior hip capsule. The AON also contributed innervation in many specimens. The relationship of the articular branches from these 3 nerves to the inferomedial acetabulum and the space between the anterior inferior iliac spine and iliopubic eminence may suggest potential sites for radiofrequency ablation.

Diversity and relatedness among the type I interferons.

Type I interferons (IFNs) include the IFN-alpha family of subtypes, IFN-beta, IFN-omega, IFN-tau, IFN-kappa, IFN-lambda, and IFN-zeta. IFN genes lack introns and encode secretory signal peptide sequences that are proteolytically cleaved prior to secretion from the cell. In contrast to the approximately 50% amino acid sequence identity among the human IFN-alpha subtypes, human IFN-alphas share approximately 22% identity with human IFN-beta and 37% identity with human IFN-omega. Many of the conserved residues among the type I IFNs are implicated in receptor recognition and structural integrity. This report provides an update on the gene annotations for the mouse and human IFN gene clusters on chromosome 4 and 9, respectively, with accompanying amino acid sequence alignments. Based on sequence identities, a phylogenic tree analysis for the different mammalian Type I IFNs is also presented, showing the high degree of relatedness among these IFNs. Notably, sequence alignment of the different human and mouse IFN promoter regions reveals different signature patterns for transcription factor binding sites, implying different inducers might differentially activate the transcription of the different IFNs.

The effects of an automatic, low pressure and constant flow ventilation device versus manual ventilation during cardiovascular resuscitation in a porcine model of cardiac arrest.

BACKGROUND: Cardiac arrest is an important cause of mortality. Cardiopulmonary resuscitation (CPR) improves survival, however, delivery of effective CPR can be challenging and combining effective chest compressions with ventilation, while avoiding over-ventilation is difficult. We hypothesized that ventilation with a pneumatically powered, automatic ventilator (Oxylator(®)) can provide adequate ventilation in a model of cardiac arrest and improve the consistency of ventilations during CPR. METHODS/RESULTS: Twelve pigs (∼40 kg, either sex) underwent 3 episodes each of cardiac arrest and resuscitation consisting of 30s of untreated ventricular fibrillation, followed by 5 min of CPR, defibrillation, and ∼30 min of recovery. During CPR in each episode, pigs were ventilated in 1 of 3 ways in random balanced order: manual ventilation using AMBU bag (12 breaths/min), low pressure Oxylator(®) (maximum airway pressure 15 cm H2O with 20 L/min constant flow in automatic mode [Ox15/20]), or high pressure Oxylator(®) (maximum airway pressure 20 cm H2O with 30 L/min constant flow in automatic mode [Ox20/30]). During CPR, both Ox15/20 and Ox20/30 resulted in higher levels of positive end expiratory pressure than manual ventilation. Ox15/20 ventilation also resulted in higher arterial pCO2 than manual ventilation. Ox20/30 ventilation yielded higher arterial pO2 and a lower arterial-alveolar gradient than manual ventilation. All pigs were successfully defibrillated, and no measured haemodynamic variables were different between the groups. CONCLUSION: Ventilation with an automatic ventilation device during CPR is feasible and provides adequate ventilation and comparable haemodynamics when compared to manual bag ventilation.

Functions of ERp57 in the folding and assembly of major histocompatibility complex class I molecules.

ERp57 is a thiol oxidoreductase of the endoplasmic reticulum that appears to be recruited to substrates indirectly through its association with the molecular chaperones calnexin and calreticulin. However, its functions in living cells have been difficult to demonstrate. During the biogenesis of class I histocompatibility molecules, ERp57 has been detected in association with free class I heavy chains and, at a later stage, with a large complex termed the peptide loading complex. This implicates ERp57 in heavy chain disulfide formation, isomerization, or reduction as well as in the loading of peptides onto class I molecules. In this study, we show that ERp57 does indeed participate in oxidative folding of the heavy chain. Depletion of ERp57 by RNA interference delayed heavy chain disulfide bond formation, slowed folding of the heavy chain alpha(3) domain, and caused slight delays in the transport of class I molecules from the endoplasmic reticulum to the Golgi apparatus. In contrast, heavy chain-beta(2)-microglobulin association kinetics were normal, suggesting that the interaction between heavy chain and beta(2) -microglobulin does not depend on an oxidized alpha(3) domain. Likewise, the peptide loading complex assembled properly, and peptide loading appeared normal upon depletion of ERp57. These studies demonstrate that ERp57 is involved in disulfide formation in vivo but do not support a role for ERp57 in peptide loading of class I molecules. Interestingly, depletion of another thiol oxidoreductase, ERp72, had no detectable effect on class I biogenesis, consistent with a specialized role for ERp57 in this process.

Murine hepatitis virus strain 1 produces a clinically relevant model of severe acute respiratory syndrome in A/J mice.

Severe acute respiratory syndrome (SARS) is a life-threatening infectious disease which has been difficult to study and treat because of the lack of a readily available animal model. Intranasal infection of A/J mice with the coronavirus murine hepatitis virus strain 1 (MHV-1) produced pulmonary pathological features of SARS. All MHV-1-infected A/J mice developed progressive interstitial pneumonitis, including dense macrophage infiltrates, giant cells, and hyaline membranes, resulting in death of all animals. In contrast, other mouse strains developed only mild transitory disease. Infected A/J mice had significantly higher cytokine levels, particularly macrophage chemoattractant protein 1 (MCP-1/CCL-2), gamma interferon, and tumor necrosis factor alpha. Furthermore, FGL2/fibroleukin mRNA transcripts and protein and fibrin deposits were markedly increased in the lungs of infected A/J mice. These animals developed a less robust type I interferon response to MHV-1 infection than resistant C57BL/6J mice, and treatment with recombinant beta interferon improved survival. This study describes a potentially useful small animal model of human SARS, defines its pathogenesis, and suggests treatment strategies.

The avian B-cell receptor complex: distinct roles of Igalpha and Igbeta in B-cell development.

The bursa of Fabricius has evolved in birds as a gut-associated site of B-cell lymphopoiesis that is segregated from the development of other hematopoietic lineages. Despite differences in the developmental progression of chicken as compared to murine B-cell lymphopoiesis, cell-surface immunoglobulin (sIg) expression has been conserved in birds as an essential checkpoint in B-cell development. B-cell precursors that express an sIg complex that includes the evolutionarily conserved Igalpha/beta heterodimer colonize lymphoid follicles in the bursa, whereas B-cell precursors that fail to express sIg due to non-productive V(D)J recombination are eliminated. Productive retroviral gene transfer has allowed us to introduce chimeric receptor constructs into developing B-cell precursors in vivo. Chimeric proteins comprising the extracellular and transmembrane regions of murine CD8alpha fused to the cytoplasmic domain of chicken Igalpha efficiently supported B-cell development in precursors that lacked endogenous sIg expression. By contrast, expression of an equivalent chimeric receptor containing the cytoplasmic domain of Igbeta actively inhibited B-cell development. Consequently, the cytoplasmic domains of Igalpha and Igbeta play functionally distinct roles in chicken B-cell development.