Liquid profiling of circulating tumor DNA in colorectal cancer: steps needed to achieve its full clinical value as standard care

The analysis of circulating tumor DNA (ctDNA) is at the threshold of implementation into standard care for colorectal cancer (CRC) patients. However, data about the clinical utility of liquid profiling (LP), its acceptance by clinicians, and its integration into clinical workflows in real‐world settings remain limited. Here, LP tests requested as part of routine care since 2016 were retrospectively evaluated. Results show restrained request behavior that improved moderately over time, as well as reliable diagnostic performance comparable to translational studies, with an overall agreement of 91.7%. Extremely low ctDNA levels at < 0.1% in over 20% of cases, a high frequency of concomitant driver mutations (in up to 14% of cases), and ctDNA levels reflecting the clinical course of disease were revealed. However, certain limitations hampering successful translation of ctDNA into clinical practice were uncovered, including the lack of clinically relevant ctDNA thresholds, appropriate time points of LP requests, and integrative evaluation of ctDNA, imaging, and clinical findings. In conclusion, these results highlight the potential clinical value of LP for CRC patient management and demonstrate issues that need to be addressed for successful long‐term implementation in clinical workflows.     

Autologous and alloplastic breast reconstruction--overview of techniques, indications and results

It is important for any woman undergoing mastectomy to make an informed decision about reconstruction and to be provided with information about the technique, advantages and disadvantages. There is a high degree of patient satisfaction with breast reconstruction, but high levels of preoperative information and psychological support are necessary. Close collaboration between oncological and reconstructive surgeons or management by an oncoplastic breast surgeon, careful patient selection and counseling, and refinements in surgical techniques can provide a range of safe and predictable techniques for breast reconstruction. After modified radical mastectomy breast reconstruction involves replacement of breast skin and breast volume; after skin-sparing mastectomy only the replacement of breast volume is necessary. The most commonly used surgical techniques are tissue expansion, latissimus dorsi myocutaneous flap with or without implants, and the use of lower abdominal tissue. Until today, the pedicled TRAM flap is the standard method for autologous breast reconstruction.     

Structure of the processive rubber oxygenase RoxA from Xanthomonas sp

Rubber oxygenase A (RoxA) is one of only two known enzymes able to catalyze the oxidative cleavage of latex for biodegradation. RoxA acts as a processive dioxygenase to yield the predominant product 12-oxo-4,8-dimethyl-trideca-4,8-diene-1-al (ODTD), a tri-isoprene unit. Here we present a structural analysis of RoxA from Xanthomonas sp. strain 35Y at a resolution of 1.8 Å. The enzyme is a 75-kDa diheme c-type cytochrome with an unusually low degree of secondary structure. Analysis of the heme group arrangement and peptide chain topology of RoxA confirmed a distant kinship with diheme peroxidases of the CcpA family, but the proteins are functionally distinct, and the extracellular RoxA has evolved to have twice the molecular mass by successively accumulating extensions of peripheral loops. RoxA incorporates both oxygen atoms of its cosubstrate dioxygen into the rubber cleavage product ODTD, and we show that RoxA is isolated with O₂ stably bound to the active site heme iron. Activation and cleavage of O₂ require binding of polyisoprene, and thus the substrate needs to use hydrophobic access channels to reach the deeply buried active site of RoxA. The location and nature of these channels support a processive mechanism of latex cleavage.     

Effective treatment of malignant pleural effusion by minimal invasive thoracic surgery: thoracoscopic talc pleurodesis and pleuroperitoneal shunts in 101 patients

Background. For effective palliation of patients with malignant pleural effusion due to advanced neoplastic disease, any proposed treatment should have low procedure-related mortality and morbidity.

Methods. The clinical outcome of 119 thoracoscopies in 101 patients (56 women, 45 men), from 42 to 91 years of age (mean, 68 ± 9 years) with malignant pleural effusions was evaluated in a retrospective study. Video-assisted thoracoscopy (VATS) talc pleurodesis was done in 105 instances, and a pleuroperitoneal shunt was performed 14 times as an alternative when complete expansion of the lung could not be achieved due to tumor implants on the visceral pleura.

Results. The VATS talc pleurodesis resulted in clinically significant improvement of dyspnea in 92.2% of the patients. Thirty-day mortality was 2.8% and morbidity was 2.8%. The mean duration of postoperative survival was 6.7 months. Recurrent pleural effusion occurred in 5.7% of patients after a mean interval of 6 months. Clinical relief of dyspnea was obtained in 73% of the patients treated with pleuroperitoneal shunts. Thirty-day mortality in this group was 21% and morbidity was 14.3%. The mean duration of survival was 4.2 months.

Conclusions. The VATS talc pleurodesis is appropriate for palliation of patients with malignant pleural effusions and should be performed once the diagnosis has been confirmed. Patients with lungs trapped by visceral carcinomatosis may benefit from placement of a pleuroperitoneal shunt as an alternative.     

Thermal injury resulting from application of a granular mineral hemostatic agent

BACKGROUND: Uncontrolled hemorrhage accounts for the majority of deaths in combat. Effective topical hemostatic agents suitable for use on the battlefield may be valuable in controlling hemorrhage until definitive surgical intervention is possible. In an effort to identify a hemostatic agent suitable for battlefield use, we evaluated several potential hemostatic agents in a swine injury model and noted thermal injury to tissues with a granular mineral hemostatic agent (QuikClot). METHODS: Anesthetized swine were maintained with a mean arterial pressure in excess of 60 mm Hg. Cutaneous, muscular, hepatic, splenic, venous, and arterial wounds were created in a standardized fashion. Topical hemostatic agents were immediately applied to the wounds and the amount of bleeding and time to hemostasis were noted. RESULTS: The results reported here are part of a larger study in which a variety of hemostatic agents were evaluated. Only the findings related to the granular mineral hemostatic agent are discussed here. Application of the agent resulted in elevated tissue surface temperatures in excess of 95 degrees C and internal tissue temperatures exceeding 50 degrees C, 3 mm deep to the bleeding surface. Necrosis of fat and muscle were noted as well as full and partial thickness cutaneous burns. CONCLUSIONS: Topical administration of a granular mineral hemostatic agent to a variety of wounds in an experimental swine model resulted in thermal tissue injury and necrosis. Suggestions for reducing the extent of injury with this product are offered.     

Steady-state free precession projection MRI as a potential alternative to the conventional chest X-ray in pediatric patients with suspected pneumonia

Magnetic resonance imaging of the lung tissue is thought to be hardly possible due to physical limitations especially the low proton density, susceptibility, and motion artifacts. The objective of our study was to evaluate and refine a very fast MR technique at a low field strength which overcomes the limitations in MR lung imaging. Thirty-five investigations were performed in 30 pediatric patients with suspected pneumonia. The MR investigations were performed in coronal slice orientation without cardiac or respiratory triggering in a low-field MR system. An optimized true fast imaging with steady precession sequence was applied. The MR images and the corresponding conventional chest radiographs were evaluated. The examination time per slice was 1.6 s. No motion artifacts could be observed. The signal-to-noise ratio for pulmonary parenchyma ranged from 4.9 to 7.1. All pathological findings of the chest X-ray images were correctly identified by the MRI (κ=0.82–0.85). Effusions as well as small pneumonic infiltrates were more precisely detected by the MRI investigation (κ=0.82) as compared with X-ray. Low-field projection MRI is a promising alternative to pediatric chest X-ray. Due to its short examination time, it overcomes the physical limits of usual MRI methods and provides comparable diagnostic information. Electronic Publication     

Low-volume resuscitation with a polymerized bovine hemoglobin-based oxygen-carrying solution (HBOC-201) provides adequate tissue oxygenation for survival in a porcine model of controlled hemorrhage

BACKGROUND: We have shown in a previous work that HBOC-201 is able to reverse anaerobic metabolism at low volumes in a porcine model of controlled hemorrhage. On the basis of these results, we hypothesize that low-volume resuscitation with HBOC-201 in a porcine model of controlled hemorrhage provides adequate tissue oxygenation to limit end-organ damage and allow for survival of the animal. METHODS: Twenty-four Yorkshire swine (55-65 kg) were rapidly hemorrhaged to a mean arterial pressure (MAP) of 30 mm Hg, maintained hypotensive for 45 minutes, and then divided into four groups. The first group, Shed Blood (BL), was resuscitated with shed blood to baseline MAP. A second group, Shed Blood (60), underwent resuscitation for four hours at an MAP of 60 mm Hg with shed blood. The third group, LR + Blood, was resuscitated with lactated Ringer's (maximum, 40 mL/kg) followed by shed blood to baseline MAP. The final group, HBOC (60), underwent resuscitation for 4 hours at an MAP of 60 mm Hg with HBOC-201. Hemodynamic variables, urine output, blood gas analyses, lactate levels, and jejunal oximetry were followed throughout the experiment. Animals were allowed to survive and underwent necropsy on postinjury day 3. Histologic comparisons were made. Data were analyzed using analysis of variance/Duncan's multiple range test. RESULTS: All animals survived the hemorrhage/resuscitation. One animal in the LR + Blood group died on postinjury day 1. Heart rate, MAP, and arterial pH were similar between groups. Cardiac output was significantly lower throughout resuscitation in the HBOC (60) group. Jejunal oximetry was similar throughout the experiment in all groups, revealing a decline in Po2 during hemorrhage and return to baseline or near baseline during resuscitation. There was no evidence of renal dysfunction. Histologically, one animal in the LR + Blood group and four of six animals in the HBOC (60) group demonstrated mild hepatocellular damage. All other tissues examined were found to have no significant abnormalities. Elevations in serum aspartate aminotransferase levels were noted when comparing the HBOC (60) group to the Shed Blood (BL) and Shed Blood (60) groups on day 2. Significant decreases in hemoglobin levels were noted in the HBOC (60) group compared with all other groups beginning on day 2. CONCLUSION: Low-volume resuscitation with HBOC-201 provides adequate tissue oxygenation for survival in a porcine model of controlled hemorrhagic shock with no long-term organ dysfunction identified. Although some animals did show mild hepatocellular damage with elevations of aspartate aminotransferase at day 2, these findings did not appear to have clinical relevance, and the enzyme elevations were trending toward normal by the third postoperative day. Decreases in hemoglobin levels at the later time points were expected, given the half-life of the product.