An Equilibrium Constitutive Model of Anisotropic Cartilage Damage to Elucidate Mechanisms of Damage Initiation and Progression.

Traumatic injuries and gradual wear-and-tear of articular cartilage (AC) that can lead to osteoarthritis (OA) have been hypothesized to result from tissue damage to AC. In this study, a previous equilibrium constitutive model of AC was extended to a constitutive damage articular cartilage (CDAC) model. In particular, anisotropic collagen (COL) fibril damage and isotropic glycosaminoglycan (GAG) damage were considered in a 3D formulation. In the CDAC model, time-dependent effects, such as viscoelasticity and poroelasticity, were neglected, and thus all results represent the equilibrium response after all time-dependent effects have dissipated. The resulting CDAC model was implemented in two different finite-element models. The first simulated uniaxial tensile loading to failure, while the second simulated spherical indentation with a rigid indenter displaced into a bilayer AC sample. Uniaxial tension to failure simulations were performed for three COL fibril Lagrangian failure strain (i.e., the maximum elastic COL fibril strain) values of 15%, 30%, and 45%, while spherical indentation simulations were performed with a COL fibril Lagrangian failure strain of 15%. GAG damage parameters were held constant for all simulations. Our results indicated that the equilibrium postyield tensile response of AC and the macroscopic tissue failure strain are highly dependent on COL fibril Lagrangian failure strain. The uniaxial tensile response consisted of an initial nonlinear ramp region due to the recruitment of intact fibrils followed by a rapid decrease in tissue stress at initial COL fibril failure, as a result of COL fibril damage which continued until ultimate tissue failure. In the spherical indentation simulation, damage to both the COL fibril and GAG constituents was located only in the superficial zone (SZ) and near the articular surface with tissue thickening following unloading. Spherical indentation simulation results are in agreement with published experimental observations. Our results indicate that the proposed CDAC model is capable of simulating both initial small magnitude damage as well as complete failure of AC tissue. The results of this study may help to elucidate the mechanisms of AC tissue damage, which initiate and propagate OA.

Refractory Lactic Acidosis and Hypoglycemia in a Patient With Metastatic Esophageal Cancer Due to the Warburg Effect.

The Warburg effect describes a phenomenon in which tumor cells switch their metabolic machinery towards a glycolytic state even in the presence of normal oxygen concentration, resulting in excess lactate production. Lactic acidosis due to the Warburg effect in malignancy is a rare but potentially life-threatening emergency mainly described in hematological malignancies but can occur in non-hematological solid malignancies. To our knowledge, we present the first reported case of lactic acidosis due to the Warburg effect in metastatic esophageal cancer. A 44-year-old male was found to have an esophageal mass and likely hepatic metastases during his hospitalization for altered mental status due to severe hypercalcemia. He was re-admitted two days after discharge for persistent vomiting and an inability to tolerate an oral diet. The lab revealed elevated lactate levels (5.2 mmol/L), metabolic acidosis (pH 7.23), and hypoglycemia (48 mg/dL), all of which were persistent throughout hospitalization despite treatment with intravenous (IV) infusions of dextrose in sodium bicarbonate, IV boluses of dextrose, and IV thiamine. An esophagogastroduodenoscopy with a biopsy of the esophageal mass revealed squamous cell carcinoma of the esophagus. Given the presence of stage IV disease and poor functional status, the patient opted for in-patient hospice, where he passed away. Since prompt diagnosis and initiation of chemotherapy, if possible, are the only effective interventions for this potentially fatal complication, it is important to increase awareness of this underrecognized metabolic and oncologic emergency among physicians.

Therapeutic landscape of advanced HER2-positive breast cancer in 2022.

HER2-positive breast cancer is an aggressive subtype of breast cancer with five-year survival rates of 30% for the advanced stage. The development of anti-HER2 treatments has led to a paradigm shift in the management and clinical outcomes of advanced HER2-positive breast cancer patients. The standard first-line treatment consists of taxane-based chemotherapy plus dual anti-HER2 therapies with trastuzumab and pertuzumab. The antibody-drug conjugate (ADC) ado-trastuzumab emtansine (T-DM1) has been a second-line therapeutic standard, but the second-line treatment approach is rapidly evolving. Given a substantial advantage of another ADC, Fam-trastuzumab deruxtecan (T-DXd), compared to T-DM1 in a recent randomized trial in the second-line setting, T-DXd is currently the preferred second-line option. Optimal third-line treatment strategies are still not established, and multiple approaches have been used including combinations based on capecitabine, trastuzumab, or both with oral anti-HER2 tyrosine kinase inhibitors. Tucatinib plus capecitabine and trastuzumab, lapatinib plus trastuzumab, neratinib or lapatinib plus capecitabine are some of the FDA approved combinations. Another newer agent approved for third- or later-line therapy in the metastatic setting is margetuximab, an Fc-engineered anti-HER2 monoclonal antibody, in combination with chemotherapy. Other novel agents currently under clinical trials are the drugs that indirectly target HER2, including immune cell cycle inhibitors, PI3K/mTOR inhibitors, and immunotherapy agents.

NUT midline lung cancer: a rare case report with literature review.

Nuclear carcinoma of the testis (NUT) midline carcinoma are rare, poorly differentiated tumors resulting from t(15; 19) rearrangement, clinically characterized by aggressive and rapid progression to death. No optimal treatment regimen has been established for this rare malignancy. Surgery, chemotherapy, and radiation have been used for treatment alone or in combination, depending on location and staging of the disease, and may confer short periods of remission; however, re-emergence of the disease inevitably occurs. Targeted therapies such as bromodomain and extra-terminal domain protein (BET) inhibitors are currently in early phases of clinical trials. Here we describe a 49-year-old-male with no comorbidities who presented with acute worsening of chronic cough, new onset hemoptysis and left sided chest pain for 2 weeks. Workup revealed stage IIIB NUT midline carcinoma (NMC) of the lung with next-generation sequencing confirming the presence of a NUTM1-BRD4 fusion. The tumor was unresectable, and he began concurrent chemoradiation with weekly carboplatin and paclitaxel for 5 weeks. The follow-up CT scan showed partial response, so maintenance was continued with durvalumab. Two months later, he presented with metastasis to the posterior muscle compartment of the left arm, which was treated with local radiotherapy. Four months later he developed progression of lung disease with multiple pulmonary nodules. Durvalumab was discontinued and he was prescribed the BET inhibitor molibresib, 120 mg daily. After nearly 3 months of treatment with molibresib, he presented with brain metastasis for which he had a craniotomy with tumor resection and gamma knife radiation to solitary metastatic lesions. He was then prescribed chemo-immunotherapy with carboplatin plus pemetrexed and pembrolizumab. After two cycles of treatment his disease progressed, and he succumbed to it. Total survival was 18 months. In conclusion, NUT midline lung carcinoma is a rare but aggressive malignancy and patients have limited treatment options especially in advanced stages. Few targeted therapies have shown promising results in early clinical trials but more treatment options are awaited.

Inferior Vena Cava Filter Retrieval Trends: A Single-Center Experience.

Recognition of the adverse events of inferior vena cava filters (VCFs) has prompted the Food and Drug Administration (FDA) to issue safety warnings (2010 and 2014), advocating for removal, once the risk of pulmonary embolism has abated. Despite an initial increase in retrieval rates, these remain low (25-30% at 1 year in 2014). We retrospectively investigated retrieval trends in adults with VCFs placed between 2015 and 2018 at a single institution. The rate of retrievable VCF removal accounting for the competing risk of death was the main outcome. There were 494 VCFs placed (305 retrievable). The cumulative incidence of retrieval remained low (21% at 1 year), even after the second FDA warning (2014). Patients who resumed anticoagulation (AC) at any time were more likely to have retrieval (hazard ratio [HR] = 3.6, p < 0.01) and had higher retrieval rates at every time point (31.4 vs. 7.6% at 1 year). Advanced age (HR = 0.98 per year, p = 0.004), stroke (HR = 0.28, p = 0.028), and active malignancy (HR = 0.42, p = 0.006) predicted nonretrieval. Device-related complications were infrequent (<1%) but thrombotic complications occurred early and were more common for nonretrieved VCFs (17 vs. 12%, p = 0.29). Revision of guidelines to recommend active surveillance for the ability to tolerate AC in the immediate postimplantation period may improve retrieval rates.

Fungal infections in hematopoietic stem-cell transplant patients: a review of epidemiology, diagnosis, and management.

The advent of bone marrow transplant has opened doors to a different approach and offered a new treatment modality for various hematopoietic stem-cell-related disorders. Since the first bone marrow transplant in 1957, there has been significant progress in managing patients who undergo bone marrow transplants. Plasma-cell disorders, lymphoproliferative disorders, and myelodysplastic syndrome are the most common indications for hematopoietic stem-cell transplant. Despite the advances, invasive fungal infections remain a significant cause of morbidity and mortality in this high-risk population. The overall incidence of invasive fungal infection in patients with hematopoietic stem-cell transplant is around 4%, but the mortality in patients with allogeneic stem-cell transplant is as high as 13% in one study. Type of stem-cell transplant, conditioning regimen, and development of graft-versus-host disease are some of the risk factors that impact the risk and outcomes in patients with invasive fungal infections. Aspergillus and candida remain the two most common organisms causing invasive fungal infections. Molecular diagnostic methods have replaced some traditional methods due to their simplicity of use and rapid turnaround time. Primary prophylaxis has undoubtedly shown to improve outcomes even though breakthrough infection rates remain high. The directed treatment has seen a significant shift from amphotericin B to itraconazole, voriconazole, and echinocandins, which have shown better efficacy and fewer adverse effects. In this comprehensive review, we aim to detail epidemiology, risk factors, diagnosis, and management, including prophylaxis, empiric and directed management of invasive fungal infections in patients with hematopoietic stem-cell transplant.

When leucocytosis is not leukaemia.

A female aged 84 years with a history of Clostridium difficile-associated diarrhoea presented from an extended care facility with altered mental status and respiratory distress. She was haemodynamically unstable and initial laboratory results revealed hyperleucocytosis (110.3×109/L). The presence of immature myeloid precursors, thrombocytopenia and respiratory distress, raised concern for an acute leukaemic process requiring emergent leucapheresis. However, on evaluation of the peripheral smear, prominent left shift and toxic granulation were noted, along with absence of blast cells. Considering her history of C. difficile infection, a CT scan of the abdomen and pelvis was obtained, which was suggestive of toxic megacolon. She was taken to the operating room for emergent colectomy. The pathology specimen showed pseudomembrane formation consistent with fulminant C. difficile infection. She was treated with oral vancomycin and intravenous metronidazole, followed by clinical improvement and resolution of leucocytosis and thrombocytopenia.

A poroelastic finite element model of the bone-cartilage unit to determine the effects of changes in permeability with osteoarthritis.

The changes experienced in synovial joints with osteoarthritis involve coupled chemical, biological, and mechanical processes. The aim of this study was to investigate the consequences of increasing permeability in articular cartilage (AC), calcified cartilage (CC), subchondral cortical bone (SCB), and subchondral trabecular bone (STB) as observed with osteoarthritis. Two poroelastic finite element models were developed using a depth-dependent anisotropic model of AC with strain-dependent permeability and poroelastic models of calcified tissues (CC, SCB, and STB). The first model simulated a bone-cartilage unit (BCU) in uniaxial unconfined compression, while the second model simulated spherical indentation of the AC surface. Results indicate that the permeability of AC is the primary determinant of the BCU's poromechanical response while the permeability of calcified tissues exerts no appreciable effect on the force-indentation response of the BCU. In spherical indentation simulations with osteoarthritic permeability properties, fluid velocities were larger in magnitude and distributed over a smaller area compared to normal tissues. In vivo, this phenomenon would likely lead to chondrocyte death, tissue remodeling, alterations in joint lubrication, and the progression of osteoarthritis. For osteoarthritic and normal tissue permeability values, fluid flow was predicted to occur across the osteochondral interface. These results help elucidate the consequences of increases in the permeability of the BCU that occur with osteoarthritis. Furthermore, this study may guide future treatments to counteract osteoarthritis.

Breast Implant-Associated Anaplastic Large Cell Lymphoma: A Case Report and Review of the Literature.

Breast implant-associated anaplastic large T-cell lymphoma has recently been recognized as an entity, with few reports describing the two common subtypes: in situ (indolent) and infiltrative. Recently, the infiltrative subtypes have been shown to be more aggressive requiring adjuvant chemotherapy. We report a rare case of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) in a 65-year-old Caucasian female following silicone breast implantation and multiple capsulectomies. We discuss the rare presentation of this disease, histopathologic features of the indolent and infiltrative subtypes of ALCL, and their clinical significance. We also review the literature for up-to-date information on the diagnosis and clinical management. Treatment modalities including targeted therapy are also discussed. Although BIA-ALCL is rare, it should always be considered as part of the differential diagnosis especially in women with breast implants. Given the increasing rate of breast reconstruction and cosmetic surgeries, we anticipate a continuous rise in incidence rates of this rare disease; thus, caution must be taken to avoid misdiagnosis.

Ibrutinib as a Bruton Kinase Inhibitor in the Management of Chronic Lymphocytic Leukemia: A New Agent With Great Promise.

The recent discovery of the role of the B-cell antigen receptor (BCR) signaling pathway in the propagation and maintenance of both normal B-cell function and in B-cell malignancies has highlighted the importance of many protein kinases involved in BCR signal propagation. Considerable research attention has focused on the Bruton tyrosine kinase (BTK) as a potential therapeutic target in B-cell malignancies. Treatment paradigms including ibrutinib, a potent inhibitor of the BTK recently approved by the US Food and Drug Administration, have significantly improved disease outcome among high-risk and relapsed/refractory cases of chronic lymphocytic leukemia. This has provided additional treatment options, especially among the elderly, where improved disease response has been accompanied by more manageable treatment-associated toxicity than commonly found with chemoimmunotherapy. In this review, we provide a synopsis of the current data on the efficacy and clinical utilization of ibrutinib and management of its resistance in the treatment of chronic lymphocytic leukemia.

An evolutionary model of osteoarthritis including articular cartilage damage, and bone remodeling in a computational study.

With osteoarthritis, a complex set of progressive chemical, biological, and mechanical changes occur in both cartilage and bone. The aim of this study is to develop a high-fidelity computational model of the complete bone-cartilage unit to study the evolution of osterarthritis-induced articular cartilage (AC) damage and remodeling of subchondral cortical bone (SCB) and subchondral trabecular bone (STB). A finite element model of spherical indentation was developed with a depth-dependent anisotropic model of degenerating articular cartilage, a calcified cartilage (CC) zone, and SCB and STB remodeling regions. Calcified tissue (CC, SCB, and STB) and AC material regions were integrated to form an evolutionary bone-cartilage unit model. Results indicate that with indentation loading, articular cartilage damage occurs at the articular surface. Furthermore, bone remodeling was predicted to occur with a net stiffening of the subchondral bone plate. Changes in indentation force were minimal (<2%) between initial and final peak indentation loading. However, additional degradation and wear of AC and/or alterations in loading may have more pronounced effects on the mechanical response of the bone-cartilage unit. Bone remodeling and articular cartilage damage predictions are consistent with experimental observations that cartilage damage begins at the articular surface and subchondral bone experiences a thickening (i.e., stiffening) response with osteoarthritis. Our results provide insight into the early-term initiation behavior of osteoarthritis; the potential consequences of evolutions in AC, SCB, and STB with disease progression; and may guide future experimental and computational studies to elucidate mechanisms of osteoarthritis progression.

Is it time for preemptive drug treatment of asymptomatic (smoldering) multiple myeloma?

Asymptomatic (smoldering) multiple myeloma is a heterogeneous plasma cell proliferative disorder with a variable rate of progression to active multiple myeloma or related disorders. Hypercalcemia, renal insufficiency, anemia, bone lesions or recurrent bacterial infections characterize active multiple myeloma. Some patients with asymptomatic myeloma develop active disease rapidly, and others can stay asymptomatic for many years. Those who are likely to progress within the first 2 years of diagnosis have been categorized as having high-risk disease. The availability of novel agents in the treatment of active multiple myeloma and our better understanding of the heterogeneity of asymptomatic multiple myeloma have spurred interest in the early treatment of these patients. We have reviewed the current proposed definitions of high-risk asymptomatic multiple myeloma, the concerns about future therapy in view of the transient nature, remissions and toxicities of the therapies, and the eventual relapses that characterize this incurable disease.

A Hertzian contact mechanics based formulation to improve ultrasound elastography assessment of uterine cervical tissue stiffness.

Clinical practice requires improved techniques to assess human cervical tissue properties, especially at the internal os, or orifice, of the uterine cervix. Ultrasound elastography (UE) holds promise for non-invasively monitoring cervical stiffness throughout pregnancy. However, this technique provides qualitative strain images that cannot be linked to a material property (e.g., Young's modulus) without knowledge of the contact pressure under a rounded transvaginal transducer probe and correction for the resulting non-uniform strain dissipation. One technique to standardize elastogram images incorporates a material of known properties and uses one-dimensional, uniaxial Hooke's law to calculate Young's modulus within the compressed material half-space. However, this method does not account for strain dissipation and the strains that evolve in three-dimensional space. We demonstrate that an analytical approach based on 3D Hertzian contact mechanics provides a reasonable first approximation to correct for UE strain dissipation underneath a round transvaginal transducer probe and thus improves UE-derived estimates of tissue modulus. We validate the proposed analytical solution and evaluate sources of error using a finite element model. As compared to 1D uniaxial Hooke's law, the Hertzian contact-based solution yields significantly improved Young's modulus predictions in three homogeneous gelatin tissue phantoms possessing different moduli. We also demonstrate the feasibility of using this technique to image human cervical tissue, where UE-derived moduli estimations for the uterine cervix anterior lip agreed well with published, experimentally obtained values. Overall, UE with an attached reference standard and a Hertzian contact-based correction holds promise for improving quantitative estimates of cervical tissue modulus.

Phase II study of low-dose topotecan in myelodysplastic syndromes: a Hoosier Oncology Group (HOG) study.

Topotecan has demonstrable activity in high-risk MDS and CMMoL. However, the significant toxicity of topotecan administered at a dose of 2mg/m2 i.v. daily for 5 days as a continuous infusion limits its use in older patients. Therefore, we studied topotecan 1.5mg/m2 per day i.v. over 2 h for three consecutive days in 20 patients with high-risk MDS (12 RAEB; 4 RAEB-T; 4 CMMoL). Cycles were given every 4-6 weeks. Fifteen patients were evaluable for response. Only one patient achieved a durable complete remission (CR). There were three deaths within the first cycle of therapy. Severe myelosuppression was the most common toxicity. Grades 3-4 infections were documented in four patients. We conclude that topotecan administered at this dose and schedule has no clinically significant activity.

Metastatic ovarian sex-cord stromal tumor with annular tubules in a patient without Peutz-Jeghers syndrome.

Sex-cord stromal tumors (SCSTs) with annular tubules (SCTATs) are a small class of ovarian lesions that possess histologic features of both Sertoli and granulosa cells. Approximately one-third of patients with SCTAT also have Peutz-Jaghers syndreome, which makes these cases especially rare. Patients with non-PJS-associated SCTAT make up the remaining two-thirds; 20% of these cases have a metastatic presentation. Metastasis of these tumors to the head and neck region has only been reported in a few instances. In this article we report a case of a 25-year-old woman who presented with "a lump in her throat" and was ultimately diagnosed with SCTAT. We also discuss the current protocols in the diagnosis and treatment of this entity.

Integrating qPLM and biomechanical test data with an anisotropic fiber distribution model and predictions of TGF-ß1 and IGF-1 regulation of articular cartilage fiber modulus.

A continuum mixture model with distinct collagen (COL) and glycosaminoglycan elastic constituents was developed for the solid matrix of immature bovine articular cartilage. A continuous COL fiber volume fraction distribution function and a true COL fiber elastic modulus ([Formula: see text] were used. Quantitative polarized light microscopy (qPLM) methods were developed to account for the relatively high cell density of immature articular cartilage and used with a novel algorithm that constructs a 3D distribution function from 2D qPLM data. For specimens untreated and cultured in vitro, most model parameters were specified from qPLM analysis and biochemical assay results; consequently, [Formula: see text] was predicted using an optimization to measured mechanical properties in uniaxial tension and unconfined compression. Analysis of qPLM data revealed a highly anisotropic fiber distribution, with principal fiber orientation parallel to the surface layer. For untreated samples, predicted [Formula: see text] values were 175 and 422 MPa for superficial (S) and middle (M) zone layers, respectively. TGF-[Formula: see text]1 treatment was predicted to increase and decrease [Formula: see text] values for the S and M layers to 281 and 309 MPa, respectively. IGF-1 treatment was predicted to decrease [Formula: see text] values for the S and M layers to 22 and 26 MPa, respectively. A novel finding was that distinct native depth-dependent fiber modulus properties were modulated to nearly homogeneous values by TGF-[Formula: see text]1 and IGF-1 treatments, with modulated values strongly dependent on treatment.

Differential regulation of immature articular cartilage compressive moduli and Poisson's ratios by in vitro stimulation with IGF-1 and TGF-beta1.

Mechanisms of articular cartilage growth and maturation have been elucidated by studying composition-function dynamics during in vivo development and in vitro culture with stimuli such as insulin-like growth factor-1 (IGF-1) and transforming growth factor-beta 1 (TGF-beta1). This study tested the hypothesis that IGF-1 and TGF-beta1 regulate immature cartilage compressive moduli and Poisson's ratios in a manner consistent with known effects on tensile properties. Bovine calf articular cartilage from superficial-articular (S) and middle-growth (M) regions were analyzed fresh or following culture in medium with IGF-1 or TGF-beta1. Mechanical properties in confined (CC) and unconfined (UCC) compression, cartilage matrix composition, and explant size were assessed. Culture with IGF-1 resulted in softening in CC and UCC, increased Poisson's ratios, substantially increased tissue volume, and accumulation of glycosaminoglycan (GAG) and collagen (COL). Culture with TGF-beta1 promoted maturational changes in the S layer, including stiffening in CC and UCC and increased concentrations of GAG, COL, and pyridinoline crosslinks (PYR), but little growth. Culture of M layer explants with TGF-beta1 was nearly homeostatic. Across treatment groups, compressive moduli in CC and UCC were positively related to GAG, COL, and PYR concentrations, while Poisson's ratios were negatively related to concentrations of these matrix components. Thus, IGF-1 and TGF-beta1 differentially regulate the compressive mechanical properties and size of immature articular cartilage in vitro. Prescribing tissue growth, maturation, or homeostasis by controlling the in vitro biochemical environment with such growth factors may have applications in cartilage repair and tissue engineering.

Phase II study of ifosfamide plus daily oral etoposide in previously treated ovarian cancer: a Hoosier Oncology Group (HOG) study.

Advanced epithelial ovarian carcinoma is a chemosensitive tumor to platinum plus paclitaxel combination chemotherapy. However, most patients develop recurrences following their initial platinum-based regimen and are candidates for subsequent chemotherapy. Several chemotherapeutic drugs have been tested as single therapeutic agents or in combination for relapsed epithelial ovarian carcinoma. The response rate has been modest with no obvious advantage to combination chemotherapy versus single agents. Both oral etoposide and ifosfamide have shown activity as single agents in pretreated patients. We completed a phase II study at the Hoosier Oncology Group utilizing oral etoposide plus ifosfamide in patients with relapsed ovarian epithelial carcinoma. Fourteen patients entered the study. Ifosfamide was given intravenously (IV) at a dose of 1.2 g/m2/d on days 1 to 4 with mesna 300 mg/m2 IV 15 minutes prior to and 4 and 8 hours after ifosfamide infusion. Etoposide was administered as 37.5 mg/m2/d orally on days 1 to 14. This regimen was repeated every 28 days until disease progression or for a maximum of 6 cycles. Grade III to IV granulocytopenia occurred in 9 patients (64%), with 2 neutropenic infections, but with no therapy-related deaths. Grade III to IV thrombocytopenia occurred in 3 patients (21%), and grade III to IV nausea and vomiting in 1 patient. No renal, pulmonary, hepatic, cardiac, or serious neurotoxicity was observed. Two patients (14%) achieved partial response, and additional 5 (35%) patients had stable disease. The 1-year survival probability using Kaplan-Meier analysis was 0.8. In this small sample-size trial, we did not demonstrate an advantage to this combination regimen compared to these or other single agents.