NON-INVASIVE MEASUREMENT OF DEEP TISSUE TEMPERATURE CHANGES CAUSED BY APOPTOSIS DURING BREAST CANCER NEOADJUVANT CHEMOTHERAPY:A CASE STUDY

Treatment-induced apoptosis of cancer cells is one goal of cancer therapy.Interestingly,more heat is generated by mitochondria during apoptosis,especially the uncoupled apoptotic state,^(1,2) compared to the resting state.In this case study,we explore these thermal effects by longitudinally measuring temperature variations in a breast lesion of a pathological complete responder during neoadjuvant chemotherapy(NAC).Diffuse Optical Spectroscopic Imaging(DOSI)was employed to derive absolute deep tissue temperature using subtle spectral features of the water peak at 975 nm.^(3)A significant temperature increase was observed in time windows during the anthracycline and cyclophosphamide(AC)regimen but not in the paclitaxel and bevacizumab regimen.Hemoglobin concentration changes generally did not follow temperature,suggesting the measured temperature increases were likely due to mitochondrial uncoupling rather than a direct vascular effect.A simultaneous increase of tissue oxygen saturation with temperature was observed,suggesting that oxidative stress also contributes to apoptosis.Although preliminary,this study indicates longitudinal DOSI tissue temperature monitoring provides information that can improve our understanding of the mechanisms of tissue response during NAC.

Monitoring tissue temperature during photothermal therapy for cancer

Phototherapies offer promising alternatives to traditional cancer therapies.Phototherapies mainly rely on manipulation of target tissue through photothermal,photochemical,or photomechanical interactions.Combining phototherapy with immunotherapy has the benefit of eliciting a systemic immune response.Specifically,photothermal therapy(PTT)has been shown to induce apoptosis and necrosis in cancer cells,releasing tumor associated antigenic peptides while sparing healthy host cells,through temperature increase in targeted tissue.However,the tissue temperature must be monitored and controlled to minimize adverse thermal effects on normal tissue and to avoid the destruction of tumor-specific antigens,in order to achieve the desired therapeutic effects of PTT.Techniques for monitoring PTT have evolved from post-treatment quantification methods like enzyme linked immunosorbent assay,western blot analysis,and flow cytometry to modern methods capable of real-time monitoring,such as magnetic resonance thermometry,computed tomography,and photoacoustic imaging.Monitoring methods are largely chosen based on the type of light delivery to the target tissue.Interstitial methods of thermometry,such as thermocouples and fiber-optic sensors,are able to monitor temperature of the local tumor environment.However,these methods can be challenging if the phototherapy itself is interstitially administered.Increasingly,non-invasive therapies call for non-invasive monitoring,which can be achieved through magnetic resonance thermometry,computed tomography,and photoacoustic imaging techniques.The purpose of this review is to introduce the feasible methods used to monitor tissue temperature during PTT.The descriptions of different techniques and the measurement examples can help the researchers and practitioners when using therapeutic PTT.

Characterization of T-complex polypeptide 1 (TCP-1) from the Chilo suppressalis HSP60 family and its expression in response to temperature stress

Many proteins require assistance from molecular chaperones at various stages to attain correctly folded states and functional conformations during protein synthesis. In this study, the gene encoding T-complex polypeptide 1（TCP-1）, which belongs to the heat shock protein 60（HSP60） family, was isolated and characterized from the rice stem borer, Chilo suppressalis, by RACE and q PCR, respectively. The full-length c DNA of Tcp-1 was 2 144 bp and encoded a 1 635-bp ORF; the deduced translational product contained 545 amino acids with 5′-and 3′-UTRs and an isoelectric point of 5.29. Cluster analysis confirmed that the deduced amino acid sequence shared high identity（60–99%） with TCP-1 from other insects. To investigate Tcp-1 expression in response to abiotic stress, q PCR was used to analyze expression levels of Tcp-1 m RNA in C. suppressalis larvae exposed to temperatures ranging from –11 to 43°C. With respect to heat shock, Tcp-1 expression was higher than the control after a 2-h exposure to 30 and 36°C and declined at 39 and 43°C. Difference in Tcp-1 expression was observed at temperatures ranging from –11 to 27°C. q PCR analyses revealed that Tcp-1 expression was the highest in hindgut tissue as compared to heads, epidermis, fat body, foregut, midgut, and malpighian tubules. Our results indicated that Tcp-1 expression was differentially expressed in C. suppressalis tissues, and was impacted by temperature stress.

Effect of viscoelasticity on skin pain sensation

Pain sensation may appear under long-lasting mechanical stimulation. Although people have the experience that pain sensation generally decreases with time while the stimulation remains, the underlying mechanism remains elusive. We experimentally studied the thermal and strain rate- dependent viscoelastic behavior of skin in uniaxial stretch and numerically investigated the effects of temperature and strain rate on pain sensation. The results indicate that the viscosity of skin tissue decreases with increasing temperature and reducing strain rate, which subsequently decreases the discharge frequency of skin nociceptor and thus relieves the pain sensation. The results would contribute to the understanding of pain relief mechanism and optimizing for mechanical treatment.

Interpretation of living tissue's temperature oscillations by thermal wave theory

The fact that the temperature of living tissue may respond oscillatorily to externalheating has been a classical difficulty in the field of bioheat transfer for a long time.Roemer et al. have carefully discussed this in their serial articles, but experiments did notsupport their conclusions, Tharp et al. have artificially made a time-delay differential equs-tion to describe this phenomenon, but their model is short of a strict theoretical founda-