A concept of dual-responsive prodrugs based on oligomerization-controlled reactivity of ester groups: an improvement of cancer cells versus neutrophils selectivity of camptothecin

Many known chemotherapeutic anticancer agents exhibit neutropenia as a dose-limiting side effect. In this paper we suggest a prodrug concept solving this problem for camptothecin (HO-cpt). The prodrug is programmed according to Boolean "AND" logic. In the absence of H2O2 (trigger T1), e.g. in the majority of normal cells, it exists as an inactive oligomer. In cancer cells and in primed neutrophils (high H2O2), the oligomer is disrupted forming intermediate (inactive) lipophilic cationic species. These are accumulated in mitochondria (Mit) of cancer cells, where they are activated by hydrolysis at mitochondrial pH 8 (trigger T2) with formation of camptothecin. In contrast, the intermediates remain stable in neutrophils lacking Mit and therefore a source of T2. In this paper we demonstrated a proof-of-concept. Our prodrug exhibits antitumor activity both in vitro and in vivo, but is not toxic to normal cell and neutrophils in contrast to known single trigger prodrugs and the parent drug HO-cpt.

Tumor-specific radiosensitizing effect of the ATM inhibitor AZD0156 in melanoma cells with low toxicity to healthy fibroblasts

PURPOSE

Despite new treatment options, melanoma continues to have an unfavorable prognosis. DNA damage response (DDR) inhibitors are a promising drug class, especially in combination with chemotherapy (CT) or radiotherapy (RT). Manipulating DNA damage repair during RT is an opportunity to exploit the genomic instability of cancer cells and may lead to radiosensitizing effects in tumors that could improve cancer therapy.

METHODS

A panel of melanoma-derived cell lines of different origin were used to investigate toxicity-related clonogenic survival, cell death, and cell cycle distribution after treatment with a kinase inhibitor (KI) against ATM (AZD0156) or ATR (VE-822, berzosertib), irradiation with 2 Gy, or a combination of KI plus ionizing radiation (IR). Two fibroblast cell lines generated from healthy skin tissue were used as controls.

RESULTS

Clonogenic survival indicated a clear radiosensitizing effect of the ATM inhibitor (ATMi) AZD0156 in all melanoma cells in a synergistic manner, but not in healthy tissue fibroblasts. In contrast, the ATR inhibitor (ATRi) VE-822 led to additive enhancement of IR-related toxicity in most of the melanoma cells. Both inhibitors mainly increased cell death induction in combination with IR. In healthy fibroblasts, VE-822 plus IR led to higher cell death rates compared to AZD0156. A significant G2/M block was particularly induced in cancer cells when combining AZD0156 with IR.

CONCLUSION

ATMi, in contrast to ATRi, resulted in synergistic radiosensitization regarding colony formation in melanoma cancer cells, while healthy tissue fibroblasts were merely affected with respect to cell death induction. In connection with an increased number of melanoma cells in the G2/M phase after ATMi plus IR treatment, ATMi seems to be superior to ATRi in melanoma cancer cell treatments when combined with RT.

DNA as the main target in radiotherapy-a historical overview from first isolation to anti-tumour immune response

DNA damage is one of the foremost mechanisms of irradiation at the biological level. After the first isolation of DNA by Friedrich Miescher in the 19th century, the structure of DNA was described by Watson and Crick. Several Nobel Prizes have been awarded for DNA-related discoveries. This review aims to describe the historical perspective of DNA in radiation biology. Over the decades, DNA damage has been identified and quantified after irradiation. Depending on the type of sensing, different proteins are involved in sensing DNA damage and repairing the damage, if possible. For double-strand breaks, the main repair mechanisms are non-homologous end joining and homologous recombination. Additional mechanisms are the Fanconi anaemia pathway and base excision repair. Different methods have been developed for the detection of DNA double-strand breaks. Several drugs have been developed that interfere with different DNA repair mechanisms, e.g., PARP inhibitors. These drugs have been established in the standard treatment of different tumour entities and are being applied in several clinical trials in combination with radiotherapy. Over the past decades, it has become apparent that DNA damage mechanisms are also directly linked to the immune response in tumours. For example, cytosolic DNA fragments activate the innate immune system via the cGAS STING pathway.

Radiotherapy combined with docetaxel alters the immune phenotype of HNSCC cells and results in increased surface expression of CD137 and release of HMGB1 of specifically HPV-positive tumor cells

PURPOSE

Human papilloma virus (HPV) positive head and neck squamous cell carcinoma (HNSCC) tumors respond significantly better to anticancer treatments. It is assumed to be due to a better response to radiotherapy (RT), and presumably to an increased immunogenicity. However, little is known how the immune phenotype of HNSCC tumor cells is modulated by standard treatment, namely by radiochemotherapy (RCT).

METHODS

Therefore, we aimed to examine the impact of the HPV status on the immune phenotype of HNSCC cell lines following RCT with 5 × 3Gy or 1 × 19.3Gy and/or docetaxel, by analyzing cell death, release of damage-associated molecular patterns (DAMPs), surface expression of immune checkpoint molecules (ICMs) and the impact on activation of human monocyte-derived dendritic cells (hmDCs).

RESULTS

Cell death induction and Hsp70 release following RCT was independent of the HPV status, and RCT significantly increased the expression of the immune suppressive ICMs PD-L1, PD-L2 and HVEM. An immune stimulatory ICM, CD137, was significantly increased following RCT only on HPV-positive cell lines, as well as the release of HMGB1. Although the treatment increased cell death and modulated ICM expression in HNSCC, the hmDCs were not activated after co-incubation with treated tumor cells.

CONCLUSION

Our data with the HPV-dependent release of HMGB1 and increased expression of CD137 following RCT provide a hint for increased immunogenicity underlining the better prognosis for HPV positive tumors following RCT.

Fisetin induces DNA double-strand break and interferes with the repair of radiation-induced damage to radiosensitize triple negative breast cancer cells

Background

Triple-negative breast cancer (TNBC) is associated with aggressiveness and a poor prognosis. Besides surgery, radiotherapy serves as the major treatment modality for TNBC. However, response to radiotherapy is limited in many patients, most likely because of DNA damage response (DDR) signaling mediated radioresistance. Y-box binding protein-1 (YB-1) is a multifunctional protein that regulates the cancer hallmarks among them resisting to radiotherapy-induced cell death. Fisetin, is a plant flavonol of the flavonoid family of plant polyphenols that has anticancer properties, partially through inhibition of p90 ribosomal S6 kinase (RSK)-mediated YB-1 phosphorylation. The combination of fisetin with radiotherapy has not yet been investigated.

Methods

Activation status of the RSK signaling pathway in total cell lysate and in the subcellular fractions was analyzed by Western blotting. Standard clonogenic assay was applied to test post-irradiation cell survival. γH2AX foci assay and 3 color fluorescence in situ hybridization analyses were performed to study frequency of double-strand breaks (DSB) and chromosomal aberrations, respectively. The underlying repair pathways targeted by fisetin were studied in cells expressing genomically integrated reporter constructs for the DSB repair pathways via quantifying the expression of green fluorescence protein by flow cytometry. Flow cytometric quantification of sub-G1 cells and the protein expression of LC3-II were employed to measure apoptosis and autophagy, respectively. Kinase array and phosphoproteomics were performed to study the effect of fisetin on DDR response signaling.

Results

We showed that the effect of fisetin on YB-1 phosphorylation in TNBC cells is comparable to the effect of the RSK pharmacological inhibitors. Similar to ionizing radiation (IR), fisetin induces DSB. Additionally, fisetin impairs repair of IR-induced DSB through suppressing the classical non-homologous end-joining and homologous recombination repair pathways, leading to chromosomal aberration as tested by metaphase analysis. Effect of fisetin on DSB repair was partially dependent on YB-1 expression. Phosphoproteomic analysis revealed that fisetin inhibits DDR signaling, which leads to radiosensitization in TNBC cells, as shown in combination with single dose or fractionated doses irradiation.

Conclusion

Fisetin acts as a DSB-inducing agent and simultaneously inhibits repair of IR-induced DSB. Thus, fisetin may serve as an effective therapeutic strategy to improve TNBC radiotherapy outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02442-x.

An In Vitro Approach for Investigating the Safety of Lipotransfer after Breast-Conserving Therapy

The application of lipotransfer after breast-conserving therapy (BCT) and irradiation in breast cancer patients is an already widespread procedure for reconstructing volume deficits of the diseased breast. Nevertheless, the safety of lipotransfer has still not been clarified yet due to contradictory data. The goal of this in vitro study was to further elucidate the potential effects of lipotransfer on the irradiated remaining breast tissue. The mammary epithelial cell line MCF-10A was co-cultured with the fibroblast cell line MRC-5 and irradiated with 2 and 5 Gy. Afterwards, cells were treated with conditioned medium (CM) from adipose-derived stem cells (ADSC), and the effects on the cellular functions of MCF-10A cells and on gene expression at the mRNA level in MCF-10A and MRC-5 cells were analyzed. Treatment with ADSC CM stimulated transmigration and invasion and decreased the surviving fraction of MCF-10A cells. Further, the expression of cytokines, extracellular, and mesenchymal markers was enhanced in mammary epithelial cells. Only an effect of ADSC CM on irradiated fibroblasts could be observed. The present data suggest epithelial–mesenchymal transition-like changes in the epithelial mammary breast cell line. Thus, the benefits of lipotransfer after BCT should be critically weighed against its possible risks for the affected patients.

Kinase inhibitors increase individual radiation sensitivity in normal cells of cancer patients

Purpose

Kinase inhibitors (KI) are known to increase radiosensitivity, which can lead to increased risk of side effects. Data about interactions of commonly used KI with ionizing radiation on healthy tissue are rare.

Patients and methods

Freshly drawn blood samples were analyzed using three-color FISH (fluorescence in situ hybridization) to measure individual radiosensitivity via chromosomal aberrations after irradiation (2 Gy). Thresholds of 0.5 and 0.6 breaks/metaphase (B/M) indicate moderate or clearly increased radiosensitivity.

Results

The cohorts consisted of healthy individuals (NEG, n = 219), radiosensitive patients (POS, n = 24), cancer patients (n = 452) and cancer patients during KI therapy (n = 49). In healthy individuals radiosensitivity (≥ 0.6 B/M) was clearly increased in 5% of all cases, while in the radiosensitive cohort 79% were elevated. KI therapy increased the rate of sensitive patients (≥ 0.6 B/M) to 35% significantly compared to 19% in cancer patients without KI (p = 0.014). Increased radiosensitivity of peripheral blood mononuclear cells (PBMCs) among patients occurred in six of seven KI subgroups. The mean B/M values significantly increased during KI therapy (0.47 ± 0.20 B/M without compared to 0.50 ± 0.19 B/M with KI, p = 0.047).

Conclusions

Kinase inhibitors can intensify individual radiosensitivity of PBMCs distinctly in 85% of tested drugs.

Influence of alectinib and crizotinib on ionizing radiation - in vitro analysis of ALK/ROS1-wildtype lung tissue cells

(1) Background: Just little is known about the interaction of ALK/ROS1-targeting kinase inhibitors with ionizing radiation (IR), particularly regarding side effects. We investigated the toxicity in two different lung cell lines both ALK/ROS1 wildtype (healthy and tumor origin) as representatives for normal lung tissue; (2) Methods: Human lung cell line BEAS-2B and malignant A549 lung cancer cells (ALK/ROS1 wt) were treated with alectinib or crizotinib, 2 Gy irradiation or a combination of KI and IR. Cell toxicity was analyzed by cell death (Annexin, 7AAD), colony forming, migration assay and live-cell imaging (TMRM, DRAQ7, Caspase3/7). Cell cycle (Hoechst) were analyzed by flow cytometry; (3) Results: Crizotinib led to higher cell death rates than alectinib, when cells were treated with 10 µM KI. Alectinib induced a more intense growth inhibition of colonies. Both inhibitors showed additive effects in combination with irradiation. Combination treatment (IR + KI) does not lead to synergistic effect on neither cell death nor colony forming; (4) Conclusions: The influence of simultaneous KI and IR was studied in non-mutated ALK/ROS1 cell lines. Both KIs seems to be well tolerated in combination with thoracic radiotherapy and lacked synergistic reinforcement in cellular toxicity. This supports the feasibility of ALK/ROS1 inhibition in combination with thoracic irradiation in future clinical trials.

Influence of Gender on Radiosensitivity during Radiochemotherapy of Advanced Rectal Cancer

Simple Summary

In radiotherapy for rectal cancer, the treatment is identical for women and men. In recent years, the question has arisen whether there are gender differences in radiochemotherapy. We have investigated, in detail, differences between men and women, especially with regard to radiation sensitivity. We found no evidence for a difference in radiosensitivity between the sexes. Nevertheless, during radiochemotherapy, women experienced increased impairments in the quality of life, which, however, are restored in the subsequent period. One possibility is an increased sensitivity of women to chemotherapy.

Abstract

Gender is increasingly recognized as an important factor in medicine, although it has long been neglected in medical research in many areas. We have studied the influence of gender in advanced rectal cancer with a special focus on radiosensitivity. For this purpose, we studied a cohort of 495 men (84.1% ≥ T3, 63.6% N1, 17.6%, M1) and 215 women (84.2% ≥ T3, 56.7% N1, 22.8%, M1) who all suffered from advanced rectal cancer and were treated with radiochemotherapy. The energy deposited, DNA double-strand break (dsb) repair, occurrence of chromosomal aberrations, duration of therapy, tumor regression and tumor-infiltrating lymphocytes, laboratory parameters, quality of life and survival were assessed. The residual DNA dsb damage 24 h after irradiation in lymphocytes was identical in both sexes. Furthermore, chromosomal aberrations accurately reflecting radiosensitivity, were similar in both sexes. There were no gender-dependent differences in tumor regression, tumor-infiltrating lymphocytes and outcome indicating no differences in the radiosensitivity of cancer cells. The irradiated tumor volume in women was slightly lower than in men, related to body weight, no difference was observed. However, when the total energy deposited was calculated and related to the body weight, women were exposed to higher amounts of ionizing radiation. During radiochemotherapy, decreases in blood lymphocyte counts and albumin and several quality-of-life parameters such as nausea and vomiting, loss of appetite, and diarrhea were significantly worse in women. There is no difference in radiation sensitivity between men and women in both normal tissue and tumors. During radiochemotherapy, the quality of life deteriorates more in women than in men. However, women also recover quickly and there are no long-term differences in quality of life.

Palbociclib Induces Senescence in Melanoma and Breast Cancer Cells and Leads to Additive Growth Arrest in Combination With Irradiation

Introduction

Several kinase inhibitors (KI) bear the potential to act as radiosensitizers. Little is known of the radiosensitizing effects of a wide range of other KI like palbociclib, which is approved in ER+/HER2- metastatic breast cancer.

Method

In our study, we used healthy donor fibroblasts and breast cancer and skin cancer cells to investigate the influence of a concomitant KI + radiation therapy. Cell death and cell cycle distribution were studied by flow cytometry after Annexin-V/7-AAD and Hoechst staining. Cellular growth arrest was studied in colony-forming assays. Furthermore, we used C12-FDG staining (senescence) and mRNA expression analysis (qPCR) to clarify cellular mechanisms.

Results

The CDK4/6 inhibitor palbociclib induced a cell cycle arrest in the G0/G1 phase. Cellular toxicity (cell death) was only slightly increased by palbociclib and not enhanced by additional radiotherapy. As the main outcome of the colony formation assays, we found that cellular growth arrest was induced by palbociclib and improved by radiotherapy in an additive manner. Noticeably, palbociclib treatment clearly induced senescence not only in breast cancer and partly in melanoma cells, but also in healthy fibroblasts. According to these findings, the downregulation of senescence-related FOXM1 might be an involved mechanism of the senescence-induction potential of palbociclib.

Conclusion

The effect on cellular growth arrest of palbociclib and radiotherapy is additive. Palbociclib induces permanent G0/G1 cell cycle arrest by inducing senescence in fibroblasts, breast cancer, and melanoma cells. Direct cell death induction is only a minor secondary mechanism of action. Concomitant KI and radiotherapy is a strategy worth studying in clinical trials.

Kinase Inhibitors of DNA-PK, ATM and ATR in Combination with Ionizing Radiation Can Increase Tumor Cell Death in HNSCC Cells While Sparing Normal Tissue Cells

(1) Kinase inhibitors (KI) targeting components of the DNA damage repair pathway are a promising new type of drug. Combining them with ionizing radiation therapy (IR), which is commonly used for treatment of head and neck tumors, could improve tumor control, but could also increase negative side effects on surrounding normal tissue. (2) The effect of KI of the DDR (ATMi: AZD0156; ATRi: VE-822, dual DNA-PKi/mTORi: CC-115) in combination with IR on HPV-positive and HPV-negative HNSCC and healthy skin cells was analyzed. Cell death and cell cycle arrest were determined using flow cytometry. Additionally, clonogenic survival and migration were analyzed. (3) Studied HNSCC cell lines reacted differently to DDRi. An increase in cell death for all of the malignant cells could be observed when combining IR and KI. Healthy fibroblasts were not affected by simultaneous treatment. Migration was partially impaired. Influence on the cell cycle varied between the cell lines and inhibitors; (4) In conclusion, a combination of DDRi with IR could be feasible for patients with HNSCC. Side effects on healthy cells are expected to be limited to normal radiation-induced response. Formation of metastases could be decreased because cell migration is impaired partially. The treatment outcome for HPV-negative tumors tends to be improved by combined treatment.

Dual mTOR/DNA-PK Inhibitor CC-115 Induces Cell Death in Melanoma Cells and Has Radiosensitizing Potential

CC-115 is a dual inhibitor of the mechanistic target of rapamycin (mTOR) kinase and the DNA-dependent protein kinase (DNA-PK) that is currently being studied in phase I/II clinical trials. DNA-PK is essential for the repair of DNA-double strand breaks (DSB). Radiotherapy is frequently used in the palliative treatment of metastatic melanoma patients and induces DSBs. Melanoma cell lines and healthy-donor skin fibroblast cell lines were treated with CC‑115 and ionizing irradiation (IR). Apoptosis, necrosis, and cell cycle distribution were analyzed. Colony forming assays were conducted to study radiosensitizing effects. Immunofluorescence microscopy was performed to determine the activity of homologous recombination (HR). In most of the malign cell lines, an increasing concentration of CC-115 resulted in increased cell death. Furthermore, strong cytotoxic effects were only observed in malignant cell lines. Regarding clonogenicity, all cell lines displayed decreased survival fractions during combined inhibitor and IR treatment and supra-additive effects of the combination were observable in 5 out of 9 melanoma cell lines. CC-115 showed radiosensitizing potential in 7 out of 9 melanoma cell lines, but not in healthy skin fibroblasts. Based on our data CC-115 treatment could be a promising approach for patients with metastatic melanoma, particularly in the combination with radiotherapy.

Ex vivo radiosensitivity is increased in non-cancer patients taking valproate

Background

Valproate (VPA) is a commonly prescribed antiepileptic drug for patients experiencing epileptic seizures due to brain tumors. VPA increases radiation sensitivity in various tumor cells in vitro due to complex mechanisms. This could make tumors more vulnerable to ionizing radiation or overcome radioresistance. Yet, clinical data on possible improvement of tumor control by adding VPA to tumor therapy is controversial. Potentially radiosensitizing effects of VPA on healthy tissue remain unclear. To determine individual radiosensitivity, we analyzed blood samples of individuals taking VPA.

Methods

Ex vivo irradiated blood samples of 31 adult individuals with epilepsy were studied using 3-color fluorescence in situ hybridization. Aberrations in chromosomes 1, 2 and 4 were analyzed. Radiosensitivity was determined by the mean breaks per metaphase (B/M) and compared to age-matched (2:1) healthy donors.

Results

The patient cohort (n = 31; female: 38.7%) showed an increase of their average B/M value compared to healthy individuals (n = 61; female: 56.9%; B/M: 0.480 ± 0.09 vs. 0.415 ± 0.07; p = .001). The portion of radiosensitive (B/M >  0.500) and distinctly radiosensitive individuals (B/M >  0.600) was increased in the VPA group (54.9% vs. 11.3 and 9.7% vs. 0.0%; p < .001). In 3/31 patients, radiosensitivity was determined prior to and after VPA treatment and radiosensitivity was increased by VPA-treatment.

Conclusions

In our study, we confirmed that patients treated with VPA had an increased radiosensitivity compared to the control group. This could be considered in patients taking VPA prior to the beginning of radiotherapy to avoid toxic side effects of VPA-treatment.

Senescence Induction by Combined Ionizing Radiation and DNA Damage Response Inhibitors in Head and Neck Squamous Cell Carcinoma Cells

DNA damage response inhibitors (DDRi) may selectively enhance the inactivation of tumor cells in combination with ionizing radiation (IR). The induction of senescence may be the key mechanism of tumor cell inactivation in this combinatorial treatment. In the current study the effect of combined IR with DDRi on the induction of senescence was studied in head and neck squamous cell carcinoma (HNSCC) cells with different human papilloma virus (HPV) status. The integrity of homologous recombination (HR) was assessed in two HPV positive, two HPV negative HNSCC, and two healthy fibroblast cell cultures. Cells were treated with the DDRi CC-115 (DNA-dependent protein kinase, DNA-pK; dual mammalian target of rapamycin, mTor), VE-822 (ATR; ataxia telangiectasia and Rad3-related kinase), and AZD0156 (ATM; ataxia telangiectasia mutated kinase) combined with IR. Effects on senescence, apoptosis, necrosis, and cell cycle were analyzed by flow cytometry. The fibroblast cell lines generally tolerated IR or combined treatment better than the tumor cell lines. The ATM and ATR inhibitors were effectively inducing senescence when combined with IR. The DNA-PK inhibitor was not an important inductor of senescence. HPV status and HR activity had a limited influence on the efficacy of DDRi. Induction of senescence and necrosis varied individually among the cell lines due to molecular heterogeneity and the involvement of DNA damage response pathways in senescence induction.

PARP inhibitors combined with ionizing radiation induce different effects in melanoma cells and healthy fibroblasts

Background

PARP inhibitors niraparib and talazoparib are FDA approved for special cases of breast cancer. PARP is an interesting repair protein which is frequently affected in cancer cells. We studied the combined action of talazoparib or niraparib with ionizing radiation in melanoma cells and healthy fibroblasts.

Methods

Homologous recombination (HR) status in six different melanoma cell lines and healthy fibroblasts was assessed. Cell cultures were treated with PARP inhibitors talazoparib or niraparib and ionizing radiation (IR). Apoptosis, necrosis and cell cycle distribution was analyzed via flow cytometry. Cell migration was studied by scratch assays.

Results

Studied melanoma cell cultures are HR deficient. Studied healthy fibroblasts are HR proficient. Talazoparib and niraparib have congruent effects within the same cell cultures. In all cell cultures, combined treatment increases cell death and G2/M arrest compared to IR. Combined treatment in melanoma cells distinctly increases G2/M arrest. Healthy fibroblasts are less affected by G2/M arrest. Treatment predominantly decelerates or does not modify migration. In two cell cultures migration is enhanced under the inhibitors.

Conclusions

Although the two PARP inhibitors talazoparib and niraparib appear to be suitable for a combination treatment with ionizing radiation in our in vitro studies, a combination treatment cannot generally be recommended. There are clear interindividual differences in the effect of the inhibitors on different melanoma cells. Therefore, the effect on the cancer cells should be studied prior to a combination therapy. Since melanoma cells increase more strongly than fibroblasts in G2/M arrest, the fractional application of combined treatment should be further investigated.

Generation of a zinc and rhodium containing metallomacrocycle by rearrangement of a six-coordinate precursor complex

Two pentadentate N3,P2 ligands coordinate zinc(ii) by their N3 pocket. Four free phosphine donors allow the coordination of four AuCl moieties leading to a pentanuclear ZnAu4 complex. In contrast, the attempt to use the phosphines for chelating coordination of two Rh(CO)Cl units results in a well-organized rearrangement that ends up with the formation of a metallomacrocycle in high yields.

Endovascular Cooling Catheter for Selective Brain Hypothermia: An Animal Feasibility Study of Cooling Performance

BACKGROUND AND PURPOSE

Therapeutic hypothermia represents a promising neuroprotective treatment in acute ischemic stroke. Selective cerebral hypothermia applied early, prior to and during endovascular mechanical recanalization therapy, may be beneficial in the critical phase of reperfusion. We aimed to assess the feasibility of a new intracarotid cooling catheter in an animal model.

MATERIALS AND METHODS

Nine adult sheep were included. Temperature probes were introduced into the frontal and temporal brain cortices bilaterally. The cooling catheter system was introduced into a common carotid artery. Selective blood cooling was applied for 180 minutes. Systemic and local brain temperatures were measured during cooling and rewarming. Common carotid artery diameters and flow were measured angiographically and by Doppler sonography.

RESULTS

The common carotid artery diameter was between 6.7 and 7.3 mm. Common carotid artery blood flow velocities increased moderately during cooling and after catheter removal. Maximum cerebral cooling in the ipsilateral temporal cortex was -4.7°C (95% CI, -5.1 to -4.0°C). Ipsilateral brain temperatures dropped significantly faster and became lower compared with the contralateral cortex with maximum temperature difference of -1.3°C (95% CI, -1.5 to -1.0°C; P < .0001) and compared with systemic temperature (-1.4°C; 95% CI, -1.7 to -1.0°C; P < .0001).

CONCLUSIONS

Sheep proved a feasible animal model for the intracarotid cooling catheter. Fast induction of selective mild hypothermia was achieved within the cooled cerebral hemisphere, with stable temperature gradients in the contralateral brain and systemic blood. Further studies are required to demonstrate any therapeutic benefit of selective cerebral cooling in a stroke model.

Combined Selective Cerebral Hypothermia and Mechanical Artery Recanalization in Acute Ischemic Stroke: In Vitro Study of Cooling Performance

BACKGROUND AND PURPOSE

Therapeutic hypothermia represents a promising neuroprotective treatment for patients with ischemic stroke. Selective, intracarotid blood cooling may initiate rapid and early brain hypothermia, reduce systemic effects, and allow combined endovascular mechanical thrombectomy. For this approach, a balloon cooling catheter system was designed and studied in vitro to optimize its cooling performance.

MATERIALS AND METHODS

Computational fluid dynamics of blood cooling was performed within the common carotid artery lumen by using 3 different catheter designs (1-, 2-, and 4-balloon array). On the basis of these results, a first catheter prototype was manufactured, and its heat-exchange performance was tested in an artificial in vitro circulation simulating the common carotid artery lumen at different flow rates (inflow temperature of 37°C).

RESULTS

In the computational fluid dynamics model, the catheter with the 4-balloon array achieved the highest cooling rate of -1.6°C, which may be attributed to disruption of the thermal boundary layers. In the in vitro study, cooling of the blood substitute at flow rates of 400 mL/min (normal common carotid artery flow) and 250 mL/min (reduced common carotid artery flow due to distal MCA occlusion) achieved a temperature drop inside the blood substitute along the cooling balloons of -1.6°C and -2.2°C, respectively.

CONCLUSIONS

The feasibility of intracarotid blood cooling using a new catheter system was demonstrated in vitro. A serial 4-balloon array led to an optimized cooling capacity approaching optimum target temperatures of mild therapeutic hypothermia. To determine the therapeutic efficacy of combined selective therapeutic hypothermia and mechanical thrombectomy, further in vivo studies by using a model of temporary ischemia with large-vessel occlusion and recanalization are required.

Internal Field Distribution in Organic Light Emitting Diodes with Double Layer Structure

Double layer organic light emitting devices (OLED) are constructed by evaporating tris(8 -hydroxy) quinoline aluminum (Alq3) on a spin cast thin film of a methyl substituted ladder type poly -para -phenylene (m -LPPP). A thick layer of Mg:Ag is used as the cathode material. These organic materials are very suitable for application in OLEDs both, as transporting materials as well as active layers. Alq3 predominantly transports electrons while m - LPPP is a conjugated polymer having higher hole mobilities. Due to these transport properties the formation and radiative recombination of the excitons in ITO/m -LPPP/Alq3/Mg:Ag devices occur close to the m -LPPP/Alq3 interface. We compare the device performance of OLEDs with varying Alq3 layer thickness (0, 50, 150, 300, 500Å) and constant m -LPPP layer thickness (900Å). A difference in the device parameters and performance as a function of the Alq3 layer thickness is observed. We analyze these results with respect to the internal electric field distribution of the double layer devices derived from electroabsorption measurements.

The Dielectric Response Of 8-Hydroxyquinoline Aluminum used in Multilayer Organic Devices

We present optical measurements of 8-hydroxyquinoline aluminum (Alq3) a metal-chelate complex which is an important material used for multilayer light emitting diodes. Thin films of Alq3 produced by vacuum deposition were investigated by transmission and reflectance spectroscopy, and the dielectric coefficients in the near IR to UV-Vis energy range were calculated. Kramers-Kronig analysis was used to determine the real and imaginary dielectric spectral dependence of the thin films. Values obtained by internal field distribution measurements in organic double layer LED's are compared to those determined from optical data. A near-IR value of epsilon (real component) close to 3 was obtained from optical measurements.

Protein multiplex sandwich immunoassay: A reliable and objective method for complete molecular characterization of breast cancer from core needle biopsies

20025

Background: Within the last years, protein microarrays have been developed to quantify a large number of parameters present in a given sample simultaneously. Such miniaturised and parallelised sandwich immunoassays are of general interest for all proteomic and diagnostic approaches in which several parameters have to be determined from small samples. We describe the development of a bead-based flow cytometry that represents a convenient approach for rapid multiplex detection of functional target molecules from breast cancer biopsies. Methods: Briefly, sonographically guided core needle biopsies (CNB) were performed from 120 breast cancer masses from different patients. All biopsies were carried out with an automated core biopsy device fitted with 14-gauge (22 mm excursion) needles. Tumor samples were frozen on at −70 Celsius and pulverized. Proteins were extracted, allowing the simultaneous quantification of more than hundred proteins by a bead-based multiplex sandwich immunoassay. Results: The total amount of extracted protein from tumor tissues (mean weight of 20 mg) ranged from 300 to 1000 μg. We demonstrate appropriate sensitivity, reproducibility, and robustness for this protein microarray technology to characterize clinical samples and generate reliable data sets. A set of multiplexed sandwich immunoassays based on Luminex beads were developed that identify marker proteins indicative of prognosis or response to therapeutic options. Up to almost hundred parameters were identified and quantified simultaneously of which estrogen, progesterone and HER2 status in the multiplex assay was highly significant correlated to results obtained by immunohistochemistry (IHC) (p < 0.01). Conclusions: Our results demonstrate that this new bead-based protein microarray technology rapidly and reliably characterizes tissue samples to generate data sets of molecular marker. Therefore, this technology may once replace traditional IHC in determining marker proteins indicative of prognosis or response to therapeutic options.

No significant financial relationships to disclose.

Influence of median sternotomy on the psychosomatic outcome in coronary artery single-vessel bypass grafting

OBJECTIVES

New less invasive surgical techniques for the treatment of coronary artery single-vessel disease have been developed by either avoiding median sternotomy or cardiopulmonary bypass or both, however, until now no prospective randomized trial has been carried out to compare these techniques to the conventional approach with special respect to the psychosomatical effects.

METHODS

In a prospective randomized trial four different surgical techniques were compared. Group 1: conventional technique (median sternotomy, cardiopulmonary bypass) in ten patients (eight male, two female, age 59.6 +/- 11.0 years); Group 2: off-pump coronary artery bypass with median sternotomy in nine patients (six male, three female, age 65.7 +/- 11.1 years); Group 3: lateral minithoracotomy and cardiopulmonary bypass in eight patients (five male, three female, age 62.3 +/- 9.9 years). Group 4: off-pump procedure and lateral minithoracotomy in nine patients (eight male, one female, age 63.8 +/- 11.3 years). All patients due to coronary artery single-vessel disease. The tests used for psychosomatic situation were post-traumatic stress disorders scale, pain behavior rating scale, pain visual analog scale, and 6' walking-distance. For detection of false results due to surgical technical failures 3-month follow-up was undertaken including echocardiography and coronary angiogram.

RESULTS

There were no deaths or major complications. Operative time was longer in lateral minithoracotomy procedures, but intensive care unit stay and hospitalization were equal in all groups. Pain visual analog scale and pain behavior rating scale showed a peak on post-operative day 4 in median sternotomy procedures. Post-traumatic stress disorder scale revealed higher values on post-operative day 4 and equalizing with lateral minithoracotomy procedures 1 month post-operatively. Six-minutes walking distance on post-operative day 4 was longer in the group with lateral minithoracotomy. Three-month follow-up revealed patency of all grafts.

CONCLUSIONS

Even if surgery is successful in all procedures, operative time is longer in lateral minithoracotomy procedures without compromising intensive care unit stay and hospital stay. More pain with multiple post-traumatic stress disorders is related to median sternotomy, and post-operative convalescence is superior for lateral minithoracotomy procedures.

[Minimal invasive surgical treatment of coronary multi-vessel disease]

To reduce surgical trauma and median sternotomy related complications in cardiac surgery, a new minimally invasive surgical technique has been developed for the treatment of coronary artery multivessel disease using a small left lateral chest incision in the 3rd intercostal space. This technique enables direct LIMA harvesting and performance of bypass surgery upon all coronary vessels with cardiopulmonary bypass and cardioplegic arrest. So far, 123 patients have been treated with this procedure and survived with fewer complications, and we believe that routine application of this procedure will lead to reduced morbidity in patients receiving coronary artery bypass surgery, short hospital stay and early convalescence, combined with good cosmetic results.

Minimally invasive surgical treatment of coronary artery multivessel disease

BACKGROUND

If coronary artery multivessel disease is the target of a minimally invasive procedure, either median sternotomy or cardiopulmonary bypass can be avoided.

METHODS

We used an alternate technique instead of minithoracotomy and cardiopulmonary bypass to treat 102 patients (82 men, 20 women; age range, 39 to 82 years; median, 61.0 +/- 8.9 years) for coronary artery single-vessel, double-vessel, or multivessel disease between November 1996 and January 1998. Twenty-nine patients (22 men, 7 women; age range, 46 to 78 years; median, 69.0 +/- 8.4 years), who were in a high-risk group for the development of perioperative complications because of the use of cardiopulmonary bypass, received median sternotomy and a beating heart procedure using the Octopus stabilizing technique. The left anterior descending coronary artery was the target vessel in all patients except for 1, in whom the left internal mammary artery was used.

RESULTS

There was no intraoperative death in either series. In the beating heart group (Octopus) 2 patients died on postoperative day 31 and 35, respectively, of postoperative pneumonia.

CONCLUSIONS

Both techniques present safe alternative procedures to conventional coronary artery bypass grafting in patients with coronary artery multivessel disease.

German health care reform: the next steps

From the U.S. perspective, the German health care system offers much to be desired: universal access, moderate costs, and freedom of choice. The Germans consider their health care system to be in crisis, however, because the mechanisms on which they currently rely for financing and paying for health care, as well as the structures through which medical care is delivered, seem increasingly less viable. Germany has recently adopted modest reforms to partially address these problems. For longer term solutions, however, some in Germany are looking to U.S. managed care models, for better or for worse.

Contact allergy to Manilla resin. Nomenclature and physico-chemistry of Manilla, kauri, damar and copal resins

16 cases of allergic eczema from a resin used in a surgical adhesive (Alphacopal) are described. Because of the extreme confusion regarding the nomenclature and origin of the resins called copals and damars, this report attempts to give a terminological, botanical, physico-chemical and allergological restatement of this problem. Copals and damars are produced by trees belonging to the Araucariaceae, Caesalpiniaceae, Dipterocarpaceae and Burseraceae families. We suggest that the word "copal" be reserved for the resins of the Caesalpiniaceae and that of "damar" for the resins of the Dipterocarpaceae. The resins of the Araucariaceae are special products that may be called Manilla resin and kauri resin, which are relatively different from each other. As far as the soft resins of the Burseraceae are concerned, it would be appropriate to use the word "elemi". The component resin of the surgical adhesive implicated (Alphacopal) is a Manilla resin, produced by a variety of Agathis dammara (Lamb.) Rich., native to the Philippines. We suggest 3 allergen screening series. Finally 2 pseudo-cross-sensitivities are mentioned.

Production and characterization of monoclonal antibodies against recombinant human tumor necrosis factor/cachectin

Tumor necrosis factor is a monokine, which causes cytolysis of many transformed cells. In this study we have found that in addition to cytotoxicity recombinant Escherichia coli-derived human tumor necrosis factor, like cachectin, inhibited the lipoprotein lipase of 3T3-L1 preadipocytes. Both effects were inhibited by monoclonal anti-tumor necrosis factor antibodies. Monoclonal antibodies against recombinant human tumor necrosis factor were produced by fusing splenocytes of immune mice with P3X63Ag8 653 myeloma cells. The monoclonal antibodies, namely BG 2-4, were of IgG2a, IgG, and IgG2a subclasses. These monoclonal antibodies neutralized the cytotoxicity of natural and recombinant human tumor necrosis factor but not that of rabbit or mouse tumor necrosis factor. They also neutralized the cachectin activity of human tumor necrosis factor in the 3T3-L1 embryonic cell assay. These results indicate that the functional structure(s) of human tumor necrosis factor responsible for the cytotoxicity and cachectin activities are likely to be closely related.

Study of antigenic epitopes recognized by monoclonal antibodies to recombinant interferon-gamma

Seven hybridomas (BG 1-7) which secreted monoclonal antibodies against recombinant interferon-gamma were produced. The ascites fluids containing four of the seven monoclonal antibodies (BG 1-4) neutralized the antiviral activity of both natural and recombinant interferon-gamma. Competition between labeled and unlabeled monoclonal antibodies for interferon-gamma in a solid phase immunoassay showed that BG 1 was competed by both BG 3 and BG 4 but not by BG 2; BG 2 was competed by BG 3 but not by BG 1 nor by BG 4. These results suggest that human interferon-gamma has at least two antigenic epitopes; one of the epitopes reacted with BG 1 & BG 4 while the other reacted with BG 2; BG 3 either binds to a region overlapping with the other two epitopes or reacts with both epitopes. The antigenic epitopes recognized by these four neutralizing monoclonal antibodies are likely at or closely related to the active sites of interferon-gamma.

Bone grafts with surface decalcified allogeneic and particulate autologous bone: report of cases

A method for mandibular bone grafting that uses a combination of SDAB and particulate autologous cancellous bone and marrow is presented. The results of this treatment in four patients are described. Two additional maxillary bone grafts that use only SDAB are also reported. Grafts that are a combination of SDAB and cancellous autologous bone and marrow are biocompatible, anatomically contoured, easily adapted at surgery, and the allogeneic component is biodegradable. They do not require elaborate internal metallic devices for structural support.