A constriction channel analysis of astrocytoma stiffness and disease progression.

Studies have demonstrated that cancer cells tend to have reduced stiffness (Young's modulus) compared to their healthy counterparts. The mechanical properties of primary brain cancer cells, however, have remained largely unstudied. To investigate whether the stiffness of primary brain cancer cells decreases as malignancy increases, we used a microfluidic constriction channel device to deform healthy astrocytes and astrocytoma cells of grade II, III, and IV and measured the entry time, transit time, and elongation. Calculating cell stiffness directly from the experimental measurements is not possible. To overcome this challenge, finite element simulations of the cell entry into the constriction channel were used to train a neural network to calculate the stiffness of the analyzed cells based on their experimentally measured diameter, entry time, and elongation in the channel. Our study provides the first calculation of stiffness for grades II and III astrocytoma and is the first to apply a neural network analysis to determine cell mechanical properties from a constriction channel device. Our results suggest that the stiffness of astrocytoma cells is not well-correlated with the cell grade. Furthermore, while other non-central-nervous-system cell types typically show reduced stiffness of malignant cells, we found that most astrocytoma cell lines had increased stiffness compared to healthy astrocytes, with lower-grade astrocytoma having higher stiffness values than grade IV glioblastoma. Differences in nucleus-to-cytoplasm ratio only partly explain differences in stiffness values. Although our study does have limitations, our results do not show a strong correlation of stiffness with cell grade, suggesting that other factors may play important roles in determining the invasive capability of astrocytoma. Future studies are warranted to further elucidate the mechanical properties of astrocytoma across various pathological grades.

Real-time prediction of patient immune cell modulation during irreversible electroporation therapy.

Immunotherapies have demonstrated limited efficacy in pancreatic ductal adenocarcinoma (PDAC) patients despite their success in treating other tumor types. This limitation is largely due to the relatively immunosuppressive environment surrounding the tumor. A focal ablative technique called irreversible electroporation (IRE) has been shown to modulate this environment, enhancing the efficacy of immunotherapy. One enhancing factor related to improved prognosis is a decrease in regulatory T cells (Treg). This decrease has been previously unpredictable for clinicians using IRE, who currently have limited real-time metrics for determining the activation of the patient's immune response. Here, we report that larger overall changes in output current are correlated with larger decreases in T cell populations 24 hours post-treatment. This result suggests that clinicians can make real-time decisions regarding optimal follow-up therapy based on the range of output current delivered during treatment. This capability could maximize the immunomodulating effect of IRE in synergy with follow-up immunotherapy. Additionally, these results suggest that feedback from a preliminary IRE treatment of the local tumor may help inform clinicians regarding the timing and choice of subsequent therapies, such as resection, immunotherapy, chemotherapy, or follow-up thermal or non-thermal ablation.

Characterization of Ablation Thresholds for 3D-Cultured Patient-Derived Glioma Stem Cells in Response to High-Frequency Irreversible Electroporation.

High-frequency irreversible electroporation (H-FIRE) is a technique that uses pulsed electric fields that have been shown to ablate malignant cells. In order to evaluate the clinical potential of H-FIRE to treat glioblastoma (GBM), a primary brain tumor, we have studied the effects of high-frequency waveforms on therapy-resistant glioma stem-like cell (GSC) populations. We demonstrate that patient-derived GSCs are more susceptible to H-FIRE damage than primary normal astrocytes. This selectivity presents an opportunity for a degree of malignant cell targeting as bulk tumor cells and tumor stem cells are seen to exhibit similar lethal electric field thresholds, significantly lower than that of healthy astrocytes. However, neural stem cell (NSC) populations also exhibit a similar sensitivity to these pulses. This observation may suggest that different considerations be taken when applying these therapies in younger versus older patients, where the importance of preserving NSC populations may impose different restrictions on use. We also demonstrate variability in threshold among the three patient-derived GSC lines studied, suggesting the need for personalized cell-specific characterization in the development of potential clinical procedures. Future work may provide further useful insights regarding this patient-dependent variability observed that could inform targeted and personalized treatment.

Polypharmacy in a hospitalized psychiatric population: risk estimation and damage quantification.

BACKGROUND: Polypharmacy increases the risk of pharmacological interactions, prevalence of secondary effects and with this the lack of adherence to treatment. It is estimated that between 10 and 40% of patients hospitalized in psychiatric institutions are prescribed more than one antipsychotic. The objective of the present study was to identify the prevalence of polypharmacy, evaluate adverse effects associated to the use of psych drugs and to estimate the risk in specific groups. METHODS: We carried out a longitudinal, retrospective study that included the analysis of all discharged patients (n = 140) in the first trimester of the year in a psychiatric hospital in Mexico. The information was classified into 7 sections: sociodemographic, diagnosis, clinical follow-up information, prescribed drugs, adverse reactions, substance abuse, laboratory and complementary results. Risk estimation was obtained with Odds Ratios, to correlate continuous variables Pearson's correlation was used. Student's T and Mann Whitney's U were used to compare 2 independent samples; multiple and linear regressions were carried out. RESULTS: The mean number of drugs used during hospitalization was 7.8 drugs per patient. The mean prescribed psych drugs was 4.07. The mean antipsychotic dose was the risperidone equivalent of 5.08 mg. 29.2% of patients had at least one secondary effect associated to the use of drugs, 17.8% presented extrapyramidal symptoms. 81.4% of patients were prescribed 6 or more drugs (polypharmacy) and were 5 times more likely to suffer a secondary effects (OR 6.24). 14.2% had polypharmacy while receiving antipsychotics and had more than twice the risk of presenting extrapyramidal symptoms (OR 3.05). For each added psych drug, hospital stay increased by 6.56 days. CONCLUSIONS: Despite international guideline recommendations where reasoned and conciliatory prescription of psych drugs is advised, there is still a high prevalence of polypharmacy in patients hospitalized in psychiatric institutions. In the present study 4 out of 5 patients received polypharmacy decreasing tolerability, treatment adherence and increasing the risk and costs secondary to an increased hospital stay.

High-frequency irreversible electroporation targets resilient tumor-initiating cells in ovarian cancer.

We explored the use of irreversible electroporation (IRE) and high-frequency irreversible electroporation (H-FIRE) to induce cell death of tumor-initiating cells using a mouse ovarian surface epithelial (MOSE) cancer model. Tumor-initiating cells (TICs) can be successfully destroyed using pulsed electric field parameters common to irreversible electroporation protocols. Additionally, high-frequency pulses seem to induce cell death of TICs at significantly lower electric fields suggesting H-FIRE can be used to selectively target TICs and malignant late-stage cells while sparing the non-malignant cells in the surrounding tissue. We evaluate the relationship between threshold for cell death from H-FIRE pulses and the capacitance of cells as well as other properties that may play a role on the differences in the response to conventional IRE versus H-FIRE treatment protocols.

A microfluidic model of the blood-brain barrier to study permeabilization by pulsed electric fields.

Pulsed electric fields interact with the blood-brain barrier (BBB) and have been shown to increase the BBB permeability under some pulsing regimes. Pulsed electric fields may enhance drug delivery to the brain by disrupting the integrity of the BBB and allowing otherwise impermeable drugs to reach target areas. Microfluidic, in vitro models offer an alternative platform for exploring the impact of pulsed electric fields on the BBB because they create physiologically relevant microenvironments and eliminate the confounding variables of animal studies. We developed a microfluidic platform for real-time measurement of BBB permeability pre- and post-treatment with pulsed electric fields. Permeability is measured optically by the diffusion of fluorescent tracers across a monolayer of human cerebral microcapillary endothelial cells (hCMECs) cultured on a permeable membrane. We found that this device is able to capture real-time permeability of hCMEC monolayers for both reversible and irreversible electroporation pulsing regimes. Furthermore, preliminary testing of deep brain stimulation pulsing regimes reveals possible impacts on BBB integrity. This device will enable future studies of pulsed electric field regimes for improved understanding of BBB permeabilization.

In vitro and numerical support for combinatorial irreversible electroporation and electrochemotherapy glioma treatment.

Irreversible electroporation (IRE) achieves targeted volume non-thermal focal ablation using a series of brief electric pulses to kill cells by disrupting membrane integrity. Electrochemotherapy (ECT) uses lower numbers of sub-lethal electric pulses to disrupt membranes for improved drug uptake. Malignant glioma (MG) brain tumors are difficult to treat due to diffuse peripheral margins into healthy neural tissue. Here, in vitro experimental data and numerical simulations investigate the feasibility for IRE-relevant pulse protocols with adjuvant ECT drugs to enhance MG treatment. Cytotoxicity curves were produced on two glioma cell lines in vitro at multiple pulse strengths and drug doses with Bleomycin or Carboplatin. Pulses alone increased cytotoxicity with higher pulse numbers and strengths, reaching >90% by 800 V/cm with 90 pulses. Chemotherapeutic addition increased cytotoxicity by >50% for 1 ng/mL concentrations of either drug relative to 80 pulses alone with J3T cells at electric fields ≥400 V/cm. In addition to necrosis, transmission electron microscopy visualizes apoptotic morphological changes and Hoescht 33342 staining shows apoptotic cell fractions varying with electric field and drug dose relative to controls. Numerically simulated treatment volumes in a canine brain show IRE combined with ECT expands therapeutic volume by 2.1-3.2 times compared to IRE alone.

Non-thermal irreversible electroporation (N-TIRE) and adjuvant fractionated radiotherapeutic multimodal therapy for intracranial malignant glioma in a canine patient.

Non-thermal irreversible electroporation (N-TIRE) has shown promise as an ablative therapy for a variety of soft-tissue neoplasms. Here we describe the therapeutic planning aspects and first clinical application of N-TIRE for the treatment of an inoperable, spontaneous malignant intracranial glioma in a canine patient. The N-TIRE ablation was performed safely, effectively reduced the tumor volume and associated intracranial hypertension, and provided sufficient improvement in neurological function of the patient to safely undergo adjunctive fractionated radiotherapy (RT) according to current standards of care. Complete remission was achieved based on serial magnetic resonance imaging examinations of the brain, although progressive radiation encephalopathy resulted in the death of the dog 149 days after N-TIRE therapy. The length of survival of this patient was comparable to dogs with intracranial tumors treated via standard excisional surgery and adjunctive fractionated external beam RT. Our results illustrate the potential benefits of N-TIRE for in vivo ablation of undesirable brain tissue, especially when traditional methods of cytoreductive surgery are not possible or ideal, and highlight the potential radiosensitizing effects of N-TIRE on the brain.

A study of the immunological response to tumor ablation with irreversible electroporation.

Immune cell recruitment during the treatment of sarcoma tumors in mice with irreversible electroporation was studied by immunohistochemistry. Irreversible electroporation is a non-thermal tissue ablation technique in which certain short duration electrical fields are used to permanently permeabilize the cell membrane, presumably through the formation of nanoscale defects in the membrane. Employing irreversible electroporation parameters known to completely ablate the tumors without thermal effects we did not find infiltration of immune cells probably because of the destruction of infiltration routes. We confirm here that immune response is not instrumental in irreversible electroporation efficacy, and we propose that irreversible electroporation may be, therefore, a treatment modality of interest to immunodepressed cancer patients.

Tissue ablation with irreversible electroporation.

This study introduces a new method for minimally invasive treatment of cancer-the ablation of undesirable tissue through the use of irreversible electroporation. Electroporation is the permeabilization of the cell membrane due to an applied electric field. As a function of the field amplitude and duration, the permeabilization can be reversible or irreversible. Over the last decade, reversible electroporation has been intensively pursued as a very promising technique for the treatment of cancer. It is used in combination with cytotoxic drugs, such as bleomycin, in a technique known as electrochemotherapy. However, irreversible electroporation was completely ignored in cancer therapy. We show through mathematical analysis that irreversible electroporation can ablate substantial volumes of tissue, comparable to those achieved with other ablation techniques, without causing any detrimental thermal effects and without the need of adjuvant drugs. This study suggests that irreversible electroporation may become an important and innovative tool in the armamentarium of surgeons treating cancer.

Long-distance transportation of patients with a paracorporeal left ventricular assist device.

Patients in cardiogenic shock refractory to basic medical therapy may require specialised assistance in a multispeciality environment distant to the institution where they are first admitted. In such situations, transportation of these critical patients may be difficult and involve many risks. Here we describe the case histories of two patients who underwent implantation of a paracorporeal left ventricular assist device and were transferred to specialised institutions for extended treatment. The distance of transportation was 400 km and the patients were transported by ambulance and helicopter. Some aspects of logistics and complexity of long-distance transportation are also commented on.

Literacy levels of ophthalmic patient education materials.

Health care providers have become increasingly aware of poor patient understanding of their illnesses and their treatments. A major, increasingly recognized factor in poor understanding and compliance is the low literacy skills of 90 million Americans. This article reviews the literature on the relationship between patients' literacy skills and the literacy levels required to read educational health care materials, and applies a similar analysis to commonly used ophthalmic patient-educational materials. Understanding the relationships between patient literacy skills and health care utilization will be critical in improving the efficiency of the health care system.

Energetic consequences of mild Giardia intestinalis infestation in Mexican children.

This study explored the effects of mild infestation with Giardia on energy intake and expenditure at rest and in activity in an urban Mexican population. Ten boys aged 6-10 y living in low-income sectors in northwest Mexico who had Giardia infestation were recruited. Energy intake, basal metabolic rate (BMR), and total free-living expenditure (TEE) measured by the doubly labeled water method were determined for 7 d during both infestation and after treatment. There was no significant difference in recorded energy intake between the two periods (7.76 and 7.70 MJ/d; P = 0.847). BMR showed no significant change in response to treatment; values were 4.79 and 4.86 MJ/d (P = 0.03). The mean TEE increased by almost 1 MJ/d in the Giardia-free period. This increase was observed in 8 of the 10 subjects; however, the overall change was not statistically significant (P = 0.08).

Effect of insulin-glipizide combination on skeletal muscle capillary basement membrane width in diabetic patients.

This study investigated the long-term effect of insulin or the combination of insulin and an oral hypoglycemic compound (glipizide) on the skeletal muscle capillary basement membrane width in insulin-requiring diabetic patients. Seventy diabetic patients were randomized to treatment with either insulin-placebo or insulin-glipizide (5 mg/d) for 3 years. Of these, only 61 patients completed the study; 27 patients received insulin-placebo and 34 patients received insulin-glipizide. Three skeletal muscle (quadriceps femoris) biopsies were performed in all patients over a 3-year period. Glycosylated hemoglobin A1 was determined every 100 +/- 20 days, including plasma glucose levels. Muscle capillary basement membrane width was quantitated by a previously described method. After approximately 16 months, glycosylated hemoglobin A1 decreased significantly in each group from its baseline (P < 0.001 insulin-glipizide group and P < 0.025 insulin-placebo), although no statistically significant difference was seen between the two groups. After 3 years this decrease was statistically significant (P < 0.001) only in the insulin-glipizide group. At baseline, no statistically significant difference was found in the muscle capillary basement membrane width between the two groups. In spite of the significant decrease in glycosylated hemoglobin A1 in both groups after 14 to 16 months, only muscle capillary basement membrane width in the insulin-glipizide group decreased significantly compared with baseline. Patients receiving insulin-placebo showed a gradual increase in the muscle capillary basement membrane width, which after 3 years was significantly higher than baseline (P < 0.02). Although the mechanisms by which the addition of glipizide to insulin treatment reduced the thickening of the muscle capillary basement membrane are not clearly understood, the current findings suggest that diabetic microangiopathy is not necessarily progressive and that prophylaxis may be attained.

Effects of pimobendan on isolated human right atria strips and on isolated left atria of the rat.

The present study describes the effects of pimobendan on isolated human right atrial strips and on isolated left atria of the rat. Pimobendan induces a positive inotropic effect both in human and rat preparations. The maximal increase (28 +/- 2.0%) obtained with pimobendan in the strips from human right atria was similar to that obtained in left atria of the rat (31 +/- 1.8%). These observations may have some clinical relevance as pimobendan might prove to be an alternative to catecholamines for inotropic support in patients who undergo general anaesthesia.

Diabetic microangiopathy in KK mice. VI. Effect of glycemic control on renal glycoprotein metabolism and established glomerulosclerosis.

Twenty-three nonobese KK mice with abnormal tolerance to glucose, hyperinsulinemia with insulin resistance and human diabetic-like nephropathy were treated with either saline (12 mice) or glipizide, an oral hypoglycemic compound, 1 mg/kg, (11 mice) from 120 to 360 days of age. These mice develop significant increases in mesangial volume and matrix by 40 days of age. Oral glucose tolerance (OGTT), glucosyltransferase and N-acetyl-beta-glucosaminidase (enzymes involved in synthesis and degradation of kidney glycoproteins, respectively) in the kidney and serum, 24-hr proteinuria, and light microscopy studies of the kidney were performed. Glipizide-treated mice improved their OGTT. There was no difference in body weight; however, a 16% decrease (P less than 0.05) in kidney weight was observed in glipizide-treated mice. Both enzymes were significantly increased in the kidneys of mice treated with glipizide. No difference in serum enzymes was found between the two groups of mice. About 58% of the saline-treated mice had moderate glomerulosclerosis. By contrast, only 27% of glipizide-treated mice had moderate glomerulosclerosis. Also, a significant decrease in proteinuria was found in glipizide-treated mice. These data suggest that glipizide improves glucose metabolism, decreases kidney size, prevents kidney glycoprotein and mesangial matrix accumulation, and reduces proteinuria in type II diabetic KK mice. This indicates that good glycemic control prevents further progression of established diabetic nephropathy in animals.

Diabetic nephropathy. An update.

Nephropathy is a serious microvascular complication in patients with insulin-dependent diabetes mellitus. In the United States, diabetes accounts for one fourth of new cases of end-stage renal disease each year. Complication rates and costs are much higher for diabetic than for nondiabetic patients with end-stage renal disease. Despite numerous studies, the pathophysiology of diabetic renal disease is not completely understood. We reviewed the current status of the structural, functional, biochemical, pathogenetic, and treatment modalities of diabetic renal disease and examined future therapeutic interventions.

Sulfonylurea-induced decrease of muscle capillary basement membrane thickness in diabetes.

Three muscle biopsies were performed in 53 overt type 2 diabetics over a period of approximately 2 years. At baseline, 21 (40%) had an increased capillary basement membrane width in muscle. Thirty-five patients received glipizide and 18 received placebo. In the patients receiving placebo, the mean of the muscle capillary basement membrane width increased from 158.7 +/- 11.5 nm (SEM) to 170.9 +/- 14.7 nm (P = NS), but in those receiving glipizide the value decreased from 192.9 +/- 13.2 nm to 161.0 +/- 10.2 nm (P = 0.02). Plasma glucose and glycosylated hemoglobin A1 decreased significantly (P less than 0.001) after 2 years in patients receiving glipizide. In 15, mean glycosylated hemoglobin A1 reached a normal range, and mean basement membrane width decreased to a level close to that found in subjects without diabetes (P = NS). These findings are consistent with the hypothesis that effective response to oral medication can decrease the basement membrane thickening, suggesting that diabetic microangiopathy is not necessarily progressive.

Disminución inducida por drogas del espesor de la membrana basal capilar en diabetes / Drug-induced decrease of muscle capillary basement membrane thickness in diabetes

Se realizaron tres biopsias musculares en 53 diabéticos no insulinodependientes durante un período de aproximadamente dos años. Al inicio 21 (40%) tuvieron un aumento en el espesor de la membrana basal capilar de músculo; 35 pacientes recibieron glipizida y 18 recibieron placebo. En los pacientes que recibieron placebo, la medida de espesor de la membrana basal capilar de músculo aumentó de 158,7 ñ 11,5 nm (SEM) a 170,9 ñ 14,7 nm (P = NS), pero en aquéllos que recibieron glipizida el valor disminuyó de 192,9 ñ 13,2 nm a 161,0 ñ 10,2 nm (P = 0,02). La glucosa plasmática y la hemoglobina glucosilada disminuyeron significativamente (P < 0,001) después de dos años en los pacientes que recibieron glicpizida. En 15, la media de la hemoglobina glucosilada A1 alcanzó un rango normal, mientras que el espesor medio de la membrana basal disminuyó a un nivel cercano al encontrado en sujetos sin diabetes (P = NS). Estos hallazgos concuerdan con la hipótesis de uqe la respuesta efectiva a la medicación oral puede disminuir el espesor de la membrana basal, sugiriendo que la microangiopatía diabética no es necesariamente progresiva

Disminución inducida por drogas del espesor de la membrana basal capilar en diabetes / Drug-induced decrease of muscle capillary basement membrane thickness in diabetes

Se realizaron tres biopsias musculares en 53 diabéticos no insulinodependientes durante un período de aproximadamente dos años. Al inicio 21 (40%) tuvieron un aumento en el espesor de la membrana basal capilar de músculo; 35 pacientes recibieron glipizida y 18 recibieron placebo. En los pacientes que recibieron placebo, la medida de espesor de la membrana basal capilar de músculo aumentó de 158,7 ñ 11,5 nm (SEM) a 170,9 ñ 14,7 nm (P = NS), pero en aquéllos que recibieron glipizida el valor disminuyó de 192,9 ñ 13,2 nm a 161,0 ñ 10,2 nm (P = 0,02). La glucosa plasmática y la hemoglobina glucosilada disminuyeron significativamente (P < 0,001) después de dos años en los pacientes que recibieron glicpizida. En 15, la media de la hemoglobina glucosilada A1 alcanzó un rango normal, mientras que el espesor medio de la membrana basal disminuyó a un nivel cercano al encontrado en sujetos sin diabetes (P = NS). Estos hallazgos concuerdan con la hipótesis de uqe la respuesta efectiva a la medicación oral puede disminuir el espesor de la membrana basal, sugiriendo que la microangiopatía diabética no es necesariamente progresiva (AU)