[en] Among the various minimally invasive treatments, cryosurgery has been considered a potential methodology to treat solid cancerous tumors. The treatment involves using cryogenic temperatures to decrease the temperature of cancer tissues in order to destroy them. Low-pressure liquid nitrogen cooled cryoprobes have been employed to bring the temperature of tumor tissues below the lethal temperature (223 K). Experiments were performed with a liquid nitrogen cooled cryoprobe inserted in the biogel medium to simulate a single-cryoprobe freezing situation. The transient evolution of the freezing front was tracked using field-intensity maps obtained through processing the digital holograms. The longitudinal temperature along the cryoprobe tip was measured using three thermocouples. The recorded temperatures were used in the numerical simulations as a forcing function to simulate the freezing process. The freezing front (273 K) tracked using numerical simulations was observed to agree well with intensity-based experimental data. Upon realizing the accuracy of the numerical simulation, the transient temperature distribution was used to track the clinically significant lethal temperature isotherm and the region engulfed in it. Further, the experiments were repeated for higher operating pressures, viz., 3, 3.5, and 4 atm, and the effect of operating pressure on the advancement of lethal temperature isotherm is investigated. It was concluded that the cooldown time was reduced by 2 to 3 times with higher tank operating pressure. The investigation pertaining to the advancement of lethal temperature isotherm could assist the clinician in deciding the optimum operating pressure and operation time, thus increasing the efficacy of cryosurgical planning. (author)

[en] A new concept for cryosurgery control is presented in this paper, a concept which has the potential to dramatically change the outcome of cryosurgery. Unlike other cryosurgery control techniques, which are based on controlling the thermal performance of the cryoprobe, this new concept is based on heating the treated tissue as a means of shaping the frozen region. The new controlling heater is termed a 'cryoheater'. The cryoheater is a complementary device to the cryoprobe and can work with any cryosurgery cooling technique. In the current pilot study, the new cryoheater is demonstrated in a gelatin solution and, using heat transfer simulations, it is studied in simulated cases of prostate cryosurgery. It is suggested that cryosurgery planning tools and optimization techniques must be developed before the concept of the cryoheater can be applied in its full capacity

[en] Cryo preservation of cells, tissues or organisms (i.e. the storage at liquid-nitrogen or nitrogen vapour temperature) offers the most secure form of preservation, allowing cells to be maintained unaltered for a long time and preventing them from ageing. On the other hand, the multi-year exposure of cryo-preserved cells (like: stem and germ cells) to the environmental γ-ray background might induce a radiation-damage accumulation, due to the inhibition of cellular repair mechanisms, and contribute to cancer or non-cancer pathology risk assessment when such cells should be transplanted in individuals. To investigate the effect of the cryo preservation on the cell response to radiation exposures, the response of different biological systems (bacteria and mammalian cells) to γ-rays has been evaluated after irradiation in cryo-preserved and culture conditions, as a function of dose and dose rate, in terms of a variety of cellular and molecular end-points.

[en] Three electron microscopists were awarded the 2017 Nobel Prize in chemistry for their fundamental works and contributions in developing electron cryo-microscopy (cryoEM) technologies for determining the atomic structures of biological macromolecules in solution. All three laureates have a background in physics but win the prize for chemistry, which shows the importance of interdisciplinary researches involving biology, physics, mathematics and computer sciences. This review gives a brief review of the development of cryoEM, and explains how it can be used to observe life at the atomic level. (authors)

[en] Full text: For the last two decades, cryo-electron microscopy (cryo-em) of thin layers of vitrified biological suspensions has considerably extended applications in electron microscopy. Biomacromolecules or their assemblies can be observed in their fully hydrated native state, without any or few microscopy related preparation artefacts. Only electron beam damage still limits resolution, thus leaving room for specialists of image processing, capable of extracting the very last bit of information created by a limited number of electrons. They're skills and programs have been very good when applied to thin specimens but this method does not apply readily to bulk specimens. However over the last 20 years, cryo-em of vitreous bulk material and sections has also been under development. In principle, it is the dream method of structural cell biology. It consists in vitrifying a sample of tissue by rapid cooling, cutting into ultra-thin sections and cryo-em observation with all details perfectly preserved. Practically the technical problems are considerable. First of all, vitrification, which is relatively easy for sub-micron sample, must be extended to macroscopic dimensions. For this purpose, freezing under high pressure has proved very effective. Cutting a piece of vitreous material into < 100 nm sections is the second major challenge. Unlike resin, vitreous water does not behave well ^under the knife^. A compromise must be found between fracturing the brittle material or plastic deformation when it is more viscous. Here the recent development of an oscillating knife is promising. Finally, to become fluent with the various manipulations and adjustments leading to optimal observations requires time and experience. Copyright (2002) Australian Society for Electron Microscopy Inc

[en] Physical phenomena during biological freezing and thawing processes at the molecular, cellular, tissue, and organ levels are examined. The basics of cryosurgery and cryopreservation of cells and tissues are presented. Existing cryobiological models, including numerical ones, are reviewed. (reviews of topical problems)

[en] Heat deposition by interstitial routes, especially with ultrasound-based instruments, is becoming a valuable therapeutic option for the treatments of sites, which are difficult to access from outside of the body. The active part of most interstitial ultrasound applicators described in the literature is logically tubular to induce cylindrical volumes of coagulation necrosis. Because the pressure generated by such tubular transducers falls off rapidly with radial distance, we previously proposed using a rotating plane transducer. For a plane wave, the pressure fall-off is only due to attenuation, which makes deeper lesions and shorter treatment times possible. This work represents an advance in the development of ultrasound applicators designed for interstitial applications. This new applicator used a rotating slightly focused transducer. A brief theoretical analysis resulted in the choice of a long focal distance of 22 mm to obtain a nearly constant pressure all along the therapeutic depth. To experimentally validate this focal distance, pressure measurements were made in a tissue mimicking liquid phantom and the results were compared with those obtained with a plane transducer. In vitro experiments showed that necrosis could be induced at a depth of 15 mm. In the same conditions, the greatest depth attained with a plane transducer was only 10 mm. Because each individual lesion is narrower, more lesions and more time are required to necrose a cylindrical volume. The main advantage of this new type of applicator is that it can be used to induce necrosis at a greater depth without varying either the frequency, the intensity or the transducer cooling efficiency

[en] Objective: Demonstrate the effect of cryophacoemulsification in cataract surgery as a way to improve patient visual quality and quality of life. Methods: An analytical prospective study was conducted of a case series of 43 eyes with cataract. Statistical analysis was based on mean and standard deviation descriptive techniques. In results not compared, a chi-square test with 95% significance and p < 0.05 was considered to be statistically significant. Results: Of the patients studied, 67.44% did not feel any pain and reported very mild pain during blepharostat placement, clear corneal incision and intraocular lens placement; 62.79% were females aged over 70 years; 51.16% had NO3 nuclear hardness by LOCSIII; color vision improved in 90.70%; contrast sensitivity improved in 58.14%; in 72.09% the refractive cylinder was smaller than 0.5 diopters; in 93.02% best corrected visual acuity was 0.8-1.0; pachymetry showed significant differences at the end; mean endothelial cell loss was 274.16 cel/mm ; meanhexagonality was reduced 3.42%, and the VF-14 index was very good in 100% of the patients one month after surgery. Conclusions: Cryophacoemulsification is safe and effective, reduces the inflammatory effects of surgery on the cornea and achieves a high level of patient satisfaction.

[en] Along with the rapid development of modern medical sciences, cryoablation therapy, which has been regarded as a new minimally-invasive technique, has been widely practiced both at home and abroad, and at the same time is satisfactory effectiveness for the treatment of breast tumors has strongly attracted the medical workers' attention with each passing day. There is hope that this technique may become an important clinical therapeutic means for tumors in the 21th century. This paper aims to make a comprehensive review of the research progress in cryoablation therapy for breast tumor. (authors)

[en] Purpose: To investigate the role of external beam radiotherapy (EBRT) as salvage treatment of prostate cancer after cryosurgery failure. Methods and Materials: Between 1993 and 1998, 6 patients underwent EBRT with curative intent for local recurrence of prostate cancer after cryosurgery. All 6 patients had biopsy-proven recurrence and palpable disease on digital rectal examination at the time of EBRT. The median follow-up was 34 months (range 8-46). The median prostate-specific antigen level was 2.3 ng/mL (range 0.8-4.1). No patient had evidence of metastatic disease. Two patients received hormonal therapy before beginning EBRT. No patient received hormonal therapy after EBRT completion. The median elapsed time between cryosurgery and EBRT was 3 years (range 1.5-4). The median delivered dose was 66 Gy (range 62-70.2) using a 10-MeV photon beam. An in-house-developed three-dimensional treatment planning system was used to plan delivery of the prescribed dose with conformal radiotherapy techniques. Results: After EBRT, all patients had complete resolution of palpable disease. Four patients (66%) were disease free at the time of the last follow-up. Two patients developed biochemical failure as defined by the American Society for Therapeutic Radiology and Oncology consensus definition. One of these patients had a prostate-specific antigen level of 97 ng/mL before cryosurgery. No patient developed distant metastasis during follow-up. Two patients (33%) developed proctitis; 1 case resolved with Rowasa suppositories and 1 required blood transfusion. Conclusions: Our preliminary results suggest that EBRT can render a significant number of patients biochemically free of disease and can cause complete resolution of clinically palpable disease after initial cryosurgery. The results also showed that EBRT can be given without excessive morbidity. EBRT should be considered as a treatment option in these potentially curable cases