Long-Term Effectiveness of a Nonsurgical BPH Treatment System in Prostate Radiation Patients with Medication-Refractory Lower Urinary Tract Symptoms

PURPOSE/OBJECTIVE(S)

To evaluate the long-term outcomes and toxicity of a nonsurgical prostatic urethral lift system in patients with prior prostate cancer radiation therapy (RT).

MATERIALS/METHODS

From 2018 to 2020, nineteen patients with a history of prior prostate RT underwent a nonsurgical prostatic urethral lift (PUL) procedure for lower urinary track symptoms (LUTS) refractory to alpha blocker medications. Prostate cancer RT was completed a median of 17.8 months (IQR 13.4-27.4) prior to PUL procedure. All patients were assessed with IPSS/quality of life (QOL) scores and urinary post void residual (PVR) ultrasound before and after PUL. Patients were also assessed for ability to discontinue alpha blockade medications for their LUTS and any post PUL toxicity based on CTCAE v5.0 criteria.

RESULTS

All patients underwent successful placement of the PUL implants. Median pre-PUL IPSS score was 20 (IOR 17.5-22.5) and the median prostate volume was 41cc (IQR 33-49). Median follow up was 22 months (IQR 5-30). The average improvement in IPSS score was 8.5 points (IRQ 5.5-11) at 3 months and 7.5 points (IQR 6-10) at last follow-up. Two patients (10%) initially had improvement in IPSS score at 3 months with subsequent significant increase in IPSS (>5 points) at last follow-up. Overall, there was minimal change in reported QOL scores (median 0, IQR 0-1.75). The average reduction in PVR was 90cc. The percentage of patients able to discontinue alpha blockade at last follow-up was 68%. There was no grade 3 or higher GU toxicity in either group.

CONCLUSION

Use of a nonsurgical prostatic urethral lift system in patients with prior prostate RT refractory to alpha blocker medications results in significant long-term improvement of LUTS after radiation therapy for the majority of patients with minimal toxicity.

Pinene-Based Oxidative Synthetic Toolbox for Scalable Polyester Synthesis

Generation of renewable polymers is a long-standing goal toward reaching a more sustainable society, but building blocks in biomass can be incompatible with desired polymerization type, hampering the full implementation potential of biomaterials. Herein, we show how conceptually simple oxidative transformations can be used to unlock the inherent reactivity of terpene synthons in generating polyesters by two different mechanisms starting from the same α-pinene substrate. In the first pathway, α-pinene was oxidized into the bicyclic verbanone-based lactone and subsequently polymerized into star-shaped polymers via ring-opening polymerization, resulting in a biobased semicrystalline polyester with tunable glass transition and melting temperatures. In a second pathway, polyesters were synthesized via polycondensation, utilizing the diol 1-(1'-hydroxyethyl)-3-(2'-hydroxy-ethyl)-2,2-dimethylcyclobutane (HHDC) synthesized by oxidative cleavage of the double bond of α-pinene, together with unsaturated biobased diesters such as dimethyl maleate (DMM) and dimethyl itaconate (DMI). The resulting families of terpene-based polyesters were thereafter successfully cross-linked by either transetherification, utilizing the terminal hydroxyl groups of the synthesized verbanone-based materials, or by UV irradiation, utilizing the unsaturation provided by the DMM or DMI moieties within the HHDC-based copolymers. This work highlights the potential to apply an oxidative toolbox to valorize inert terpene metabolites enabling generation of biosourced polyesters and coatings thereof by complementary mechanisms.

Toughening of a Soft Polar Polythiophene through Copolymerization with Hard Urethane Segments

Polar polythiophenes with oligoethylene glycol side chains are exceedingly soft materials. A low glass transition temperature and low degree of crystallinity prevents their use as a bulk material. The synthesis of a copolymer comprising 1) soft polythiophene blocks with tetraethylene glycol side chains, and 2) hard urethane segments is reported. The molecular design is contrary to that of other semiconductor-insulator copolymers, which typically combine a soft nonconjugated spacer with hard conjugated segments. Copolymerization of polar polythiophenes and urethane segments results in a ductile material that can be used as a free-standing solid. The copolymer displays a storage modulus of 25 MPa at room temperature, elongation at break of 95%, and a reduced degree of swelling due to hydrogen bonding. Both chemical doping and electrochemical oxidation reveal that the introduction of urethane segments does not unduly reduce the hole charge-carrier mobility and ability to take up charge. Further, stable operation is observed when the copolymer is used as the active layer of organic electrochemical transistors.

Structures and internal dynamics of diphenylether and its aggregates with water

We report on a detailed multi-spectroscopic analysis of the structures and internal dynamics of diphenylether and its aggregates with up to three water molecules by employing molecular beam experiments.

Biocatalysis for terpene-based polymers

Accelerated generation of bio-based materials is vital to replace current synthetic polymers obtained from petroleum with more sustainable options. However, many building blocks available from renewable resources mainly contain unreactive carbon-carbon bonds, which obstructs their efficient polymerization. Herein, we highlight the potential of applying biocatalysis to afford tailored functionalization of the inert carbocyclic core of multicyclic terpenes toward advanced materials. As a showcase, we unlock the inherent monomer reactivity of norcamphor, a bicyclic ketone used as a monoterpene model system in this study, to afford polyesters with unprecedented backbones. The efficiencies of the chemical and enzymatic Baeyer-Villiger transformation in generating key lactone intermediates are compared. The concepts discussed herein are widely applicable for the valorization of terpenes and other cyclic building blocks using chemoenzymatic strategies.

A Retro-biosynthesis-Based Route to Generate Pinene-Derived Polyesters

Significantly increased production of biobased polymers is a prerequisite to replace petroleum‐based materials towards reaching a circular bioeconomy. However, many renewable building blocks from wood and other plant material are not directly amenable for polymerization, due to their inert backbones and/or lack of functional group compatibility with the desired polymerization type. Based on a retro‐biosynthetic analysis of polyesters, a chemoenzymatic route from (−)‐α‐pinene towards a verbanone‐based lactone, which is further used in ring‐opening polymerization, is presented. Generated pinene‐derived polyesters showed elevated degradation and glass transition temperatures, compared with poly(ϵ‐decalactone), which lacks a ring structure in its backbone. Semirational enzyme engineering of the cyclohexanone monooxygenase from Acinetobacter calcoaceticus enabled the biosynthesis of the key lactone intermediate for the targeted polyester. As a proof of principle, one enzyme variant identified from screening in a microtiter plate was used in biocatalytic upscaling, which afforded the bicyclic lactone in 39 % conversion in shake flask scale reactions.

The triolein/aqueous interface and lipase activity studied by spectroscopic ellipsometry and coarse grained simulations

In spite of the importance of the triglyceride aqueous interface for processes like emulsification, surfactant interactions and lipase activity, relatively little is known about this interface compared to that between alkanes and water. Here, the contact between triolein and water was investigated in terms of water inclusion in the oil phase and orientation of the molecules at the interface. Coarse grained models of triglycerides in contact with water were constructed and correlated with experimental results of the changes in thickness and refractive index, obtained using spectroscopic ellipsometry of spin-coated triolein films. The topography of the layer was revealed by atomic force microscopy. Dry triolein and a triolein sample after equilibration with water were also compared structurally using small-angle X-ray scattering. Additionally, the kinetics of adsorption/activity of three different variants of the Thermomyces lanuginosus lipase (TLL) were investigated. The results show that uptake of water in the triolein phase leads to increase in thickness of the layer. The observed increase of thickness was further enhanced by an active lipase but reduced when an inactive mutant of the enzyme was applied.

Structural analyses of isolated cyclic tetrapeptides with varying amino acid residues

Structural analyses of isolated cyclic tetrapeptides with varying amino acid residues were performed by applying combined IR/UV spectroscopy in the molecular beam and DFT calculations. The intrinsic structural properties especially with regard to the influence of different amino acid residues are fundamental for optimizing their binding ability.

Structural investigations on a linear isolated depsipeptide: the importance of dispersion interactions

The first molecular beam investigations of an isolated linear depsipeptide are presented. By applying IR/UV spectroscopic methods and DFT calculations three structural arrangements are identified with the most stable structure being only stable by including dispersion interactions.

Enhancement of ferroelectric polarization stability by interface engineering

By using theoretical predictions based on first-principle calculations, we explore an interface engineering approach to stabilize polarization states in ferroelectric heterostructures with a thickness of just several nanometers.

New model for in vivo quantification of microvascular embolization, thrombus formation, and recanalization in composite flaps

BACKGROUND

Microthrombi are suggested to be involved in the pathogenesis of composite flap failure. Due to the lack of appropriate experimental models, however, the significance of microvascular thrombus formation and microthromboembolization in free flap failure remains poorly understood. The purpose of this study was therefore to develop a rat hindlimb model that allows tissue-confined in vivo analysis of thrombus formation, thromboembolization, and recanalization within the microcirculation of osteomyocutaneous flaps using intravital fluorescence microscopy.

MATERIALS AND METHODS

Thrombus formation was induced photochemically in individual arterioles and venules of muscle, subcutis, and periosteum. To study thromboembolization, autologous arterial thrombi (40 microm) were preformed in vitro and were injected into the femoral artery supplying the osteomyocutaneous flap.

RESULTS

First platelet deposition was found independent from microvascular red blood cell velocity, while the subsequent growth of thrombus correlated inversely with red blood cell flow measured in the respective microvessel. Time required for complete thrombotic arteriolar occlusion exceeded 700 s, whereas thrombus growth in venules was found to be significantly accelerated ( approximately 300 s) without differences between the individual tissues analyzed. The embolization resulted in a complete shutdown of capillary perfusion in muscle, subcutis, skin, and periosteum. During subsequent spontaneous recanalization, capillary perfusion increased in all tissues to approximately half of baseline, however, without further recovery during the 4-h postembolization period.

CONCLUSIONS

The model presented is suitable to quantitatively study the pathophysiology of microvascular thrombus formation, thromboembolization, and recanalization in composite flaps, and may thus be used to evaluate the effectiveness of novel therapeutic strategies to prevent flap failure.

Childhood leukemia and electromagnetic fields: results of a population-based case-control study in Germany

The investigation of an association between increased exposure to residential extremely-low frequency electromagnetic fields (ELF-EMF) and childhood leukemia was part of a population-based case-control study carried out between 1992 and 1995 in the northwestern part of Germany. A total of 129 children with leukemia and 328 controls participated in the EMF-study. Exposure assessment comprised measurements of the magnetic field over 24 hours in the child's bedroom at the residence where the child had been living for the longest period before the date of diagnosis, and spot measurements at all residences where the child had been living for more than one year. The median of the 24h-measurement in the child's bedroom was regarded as the most valid exposure variable. For children exposed to more than 0.2 microT, an elevated but not significant odds ratio (OR) was observed (OR = 3.2, 95 percent confidence interval = 0.7-14.9). These figures are based on only four leukemia cases and three controls since only 1.5 percent of the study population was classified as highly exposed. Exploratory analyses revealed ORs that were not statistically significantly increased for other characteristics of the magnetic field at varying cut-points. The results are comparable with those from other studies. Although not statistically significant, they may indicate a positive association between EMF and childhood leukemia.

In situ activation of mouse alveolar macrophages by aerosolized liposomal IFN-gamma and muramyl tripeptide

Interferon-gamma (IFN-gamma) was entrapped with an efficiency of 30-40% in muramyl tripeptide-containing liposomes by a freeze-thawing procedure. A microcytotoxicity assay was developed to measure the tumoricidal activity of mouse alveolar macrophages (AM) against tumoral target cells with a colorimetric viability test. Free IFN-gamma and liposomal muramyl tripeptide phosphatidylethanolamine (MTP-PE) were found to be only slightly effective to activate in vitro AM, whereas encapsulation of both INF-gamma and MTP-PE within the same liposomes produced higher activation of AM. Aerosolized IFN-gamma and liposomal immunomodulators enhanced antitumor properties of AM recovered in mice 24 h postinhalation. Whereas free IFN-gamma also induced a substantial activation of peritoneal macrophages, liposomal encapsulation significantly reduced the systemic activity of inhaled immunomodulators. This approach provides a useful model for the compartmentalized organ-specific activation of AM in mice.

Cytological effects of 50 Hz electromagnetic fields on human lymphocytes in vitro

Incubation of human peripheral blood cultures in the presence of an electromagnetic field (EMF) of 50 Hz and 5 mT leads to stimulation of the cell cycle of dividing lymphocytes but has no influence on the frequencies of sister-chromatid exchanges. Comparative studies with two different exposure systems and with different culture temperatures indicate that the effect on the cell cycle results from the EMF and is not a thermal effect. These data support the assumption that with respect to their suspected carcinogenic effects EMFs have no initiating but probably promoting effects.

Effects of weak alternating magnetic fields on nocturnal melatonin production and mammary carcinogenesis in rats

Since extremely low frequency (i.e., 50- or 60-Hz) magnetic fields (MFs) from overhead power lines and other electromagnetic sources are ubiquitous in modern societies, the possible carcinogenic effect of such fields recently suggested by epidemiological studies has engendered much concern. However, in view of various unknown and uncontrolled variables which may bias epidemiological studies on MF interactions, a causal relationship between MFs and tumorigenesis can only be determined precisely in animal experiments. The goal of the study reported here was to determine if low frequency MFs at the low flux densities which are relevant for human populations induce tumor-promoting or copromoting effects in a model of breast cancer. Furthermore, since reduction in pineal production of melatonin has been implicated as a cause of tumor promotion by electromagnetic fields, determinations of nocturnal melatonin peak levels in serum were performed during MF exposure. Mammary tumors were induced by intragastric administration of 20 mg (5 mg/week) 7,12-dimethylbenz(a)anthracene (DMBA) in female Sprague-Dawley rats. Groups of 36 rats were either sham-exposed or exposed for 91 days at a 50-Hz gradient MF of 0.3-1 microT, which is a relevant range for elevated domestic MF exposure as arising from neighboring power lines. Nocturnal melatonin levels were significantly reduced by exposure to this weak alternating MF. However, histopathological evaluation of mammary lesions did not disclose any significant difference between MF- and sham-exposed animals. Incidence of mammary tumors was 61% in controls versus 67% in MF-exposed rats. The predominant tumor type was the invasive adenocarcinoma, which was found in 21 rats of both groups. Examination of tumor size did not indicate significant differences in tumor burden between both groups. Furthermore, the incidence of preneoplastic lesions was not altered by MF exposure. Thus, the data of this study indicate that alternating MF do not exert significant tumor promoting or copromoting effects at environmentally relevant flux densities in the rat mammary cancer system.

Accelerated stability of Ibuprofen-Eudragit RSPM sustained release tablets, IR and DSC solid stability testing

Preformulated Ibuprofen-Eudragit RSPM sustained release tablets were subjected to accelerated stability testing at 25, 37 and 45 degrees C for 6 months. The stored tablets were evaluated for the intact drug in the formula, drug-polymer interaction and compatibility of the drug with the formulated excipients using infra red spectroscopy (IR) and differential scanning calorimetry (DSC). The IR spectrum of Ibuprofen in the tablets prepared by 15% w/v Eudragit RSPM as a granulating agent and containing 23% w/v Avicel pH 102 as an excipient is similar to the IR of standard Ibuprofen. There is no change in the IR spectra of the tablet components before and after storage of those tablets at the different investigated temperatures for 1, 3 and 6 months. The DSC thermograms of the Ibuprofen stored tablets show that the drug was still in the highly pure (> 98%) crystalline form and there was no significant degradation after storage indicating the stability of the drug on storage. In detecting Ibuprofen purity in the stored tablets, plotting of the sample temperature versus the reciprocal of the fraction of Ibuprofen melted showed deviation from Van 't Hoff linear plot.

Tumor promotion in a breast cancer model by exposure to a weak alternating magnetic field

In view of the methodological problems of epidemiological studies on associations between exposures to 50/60 Hz magnetic fields (MF) and increased incidence of cancers, laboratory studies are necessary to determine if 50/60 Hz MF are cancer promoters or can progress cancers. The objective of the present study was to determine if an alternating MF of low flux density exerts tumor-promoting or co-promoting effects in a model of breast cancer in female rats. Mammary tumors were induced by the chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). A group of 99 rats was exposed to a homogeneous MF of 50 Hz, 100 microT (microtesla), for 24 h/day 7 day/week for a period of 91 days; another group of 99 rats was sham-exposed under the same environmental conditions as the MF-exposed rats. The exposure chambers were identical for MF-exposed and sham-exposed animals. DMBA was administered orally at a dose of 5 mg/kg at the first day of exposure and at weekly intervals thereafter up to a total dose of 20 mg per rat. The animals were palpated once weekly to assess the development of mammary tumors. In controls, DMBA induced tumors in about 40% of the animals within three months of first application. Eight weeks after DMBA application the MF-exposed rats exhibited significantly more tumors than sham-exposed animals. This difference in the rate of tumor development was observed throughout the period of exposure. At the end of the three-month period of MF exposure the tumor incidence in MF-exposed rats was 50% higher than in sham-exposed rats, the difference being statistically significant. Furthermore, the size of tumors as estimated by palpation was significantly larger in the MF-exposed compared to sham-exposed rats. The data demonstrates that long-term exposure of DMBA-treated female rats to an alternating MF of low flux density promotes the growth and increases the incidence of mammary tumors, thus strongly indicating that MF exposure exerts tumor-promoting and/or copromoting effects.

Effects of magnetic fields on mammary tumor development induced by 7,12-dimethylbenz(a)anthracene in rats

A series of epidemiological studies have indicated associations between exposure to magnetic fields (MFs) and a variety of cancers, including breast cancer. In order to test the possibility that MF acts as a cancer promoter or copromoter, four separate experiments have been conducted in rats in which the effects of chronic exposure to MFs on the development of mammary tumors induced by 7,12-dimethylbenz(a)anthracene (DMBA) were determined. Female rats were exposed in magnetic coils for 91 days (24 h/day) to either alternating current (AC; 50 Hz)-MF or direct current (DC)-MF. Magnetic flux density of the DC-MF was 15 mT. Two AC-MF exposures used a homogeneous field with a flux density of 30 mT (rms); one used a gradient field with flux density ranging from 0.3-1 microT. DMBA (5 mg) was administered orally at the onset of MF exposure and was repeated thrice at intervals of 1 week. In each experiment, 18-36 animals were exposed in 6 magnetic coils. The same number of rats were used as sham-exposed control. These control animals were treated with DMBA and were placed in dummy coils in the same room as the MF-exposed rats. Furthermore, groups of age-matched rats (reference controls) were treated with DMBA but housed in another room to exclude any MF exposure due to the magnetic stray field from the MF produced by coils. At the end of the exposure or sham-exposure period, tumor number and weight or size of tumors were determined at necropsy. Results were as follows: In sham-exposed animals or reference controls, the tumor incidence varied between 50 and 78% in the 4 experiments. The average number of mammary tumors per tumor-bearing animal varied between 1.6 and 2.9. In none of the experiments did MFs significantly alter tumor incidence, but in one of the experiments with AC-MF exposure at 30 mT, the number of tumors per tumor-bearing animal was significantly increased. Furthermore, exposure to a DC-MF at 15 mT significantly enhanced the tumor weight. Exposure to a gradient AC-MF at 0.3-1 microT exerted no significant effects. These experiments seem to indicate that MFs at high flux densities may act as a promoter or copromoter of breast cancer. However, this interpretation must be considered only a tentative conclusion because of the limitations of this study, particularly the small sample size used for MF exposure and the lack of repetition of data.