Abstract
Renal medullary carcinoma (RMC) and fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) are rare but highly aggressive malignancies that are often refractory to the therapies used ...for the more common RCCs. FH-deficient RCC most often occurs in individuals with hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC) and is characterized by loss of FH activity, a key metabolic enzyme. Bevacizumab plus erlotinib (B+E) is a preferred first-line therapy for FH-deficient RCC. RMC is characterized by loss of SMARCB1, which is involved in ATP-dependent chromatin remodeling. Platinum-based chemotherapy consisting of either cisplatin or carboplatin plus paclitaxel is the preferred first-line therapy for RMC. We developed patient-derived xenograft (PDX) models of tumors exposed to the commonly used first-line therapies to allow functional characterization of the metabolic hallmarks of treatment-experienced RMC and FH-deficient RCC. Methods: Resected tumor tissue was immediately implanted into NSG male and female mice. After tumor engraftment, animals were euthanized, and the tumor tissue implanted into another set of NSG mice. PDX tissues were confirmed to be genetically identical to the original patient tissue by short tandem repeat analysis. Histology was confirmed to be identical between original patient tumor and PDX by a trained clinical pathologist. Four tumors from each PDX model and four normal human kidney tissue samples were analyzed using reverse phase protein array (RPPA). Expression of proteins shown to be highly expressed by RPPA were further validated by Western blots. Results: We successfully generated one PDX model for RMC and one for FH-deficient RCC, respectively. The RMC model was generated from a 28-year old male with sickle cell trait, who had previously received cisplatin plus paclitaxel followed carboplatin plus paclitaxel. His lesion was characterized as ypT3apN1pMx and histology was consistent with RMC. The FH-deficient RCC model was generated from a 24-year-old female with HLRCC, who had been previously treated with B+E. Her lesion was characterized as pT3apN1pM1 and histology consistent with FH-deficient RCC. Germline testing revealed a R233H pathogenic mutation in the FH gene. RPPA revealed higher expression of hexokinase II (10x HLRCC, 16x RMC), lactate dehydrogenase A (27x HLRCC, 17x RMC), and glutaminase (4x HLRCC) in PDX tissue compared to normal kidney tissue. Western blots confirmed higher expression of glutaminase 1 in both HLRCC and RMC compared to normal kidney. Furthermore, we observed substantially higher hypoxia inducible factor 2α (HIF2α) protein expression in PDX tissue from FH-deficient RCC compared to RMC PDX tumors and normal kidney. Conclusions: Our study revealed distinct metabolic features in PDX models of FH-deficient RCC following treatment with B+E, and of platinum-experienced RMC, these differences may confer targetable vulnerabilities.
Citation Format: Manuel Ozambela, Alberto Pieretti, Graciela M. Nogueras Gonzalez, Tapati Maity, Lei Wang, Carolyn De La Cerda, Breanna Alonzo, Luis Segarra, Angelita Alaniz, Priya Rao, Nizar Tannir, Jose A. Karam, Christopher G. Wood, Pavlos Msaouel, Niki M. Zacharias. Metabolic hallmarks of rare renal cell carcinoma patient-derived xenograft models abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3112.
A number of methods have been used to try to protect kidney function in patients undergoing surgery. These include the administration of dopamine, diuretics, calcium channel blockers, angiotensin ...converting enzyme inhibitors and hydration fluids.
For this review, we selected randomized controlled trials, which employed different methods to protect renal function during the perioperative period. In examining these trials, we looked at outcomes such as renal failure and mortality, as well as changes in the renal function tests, including urine output, creatinine clearance, free water clearance, fractional excretion of sodium and renal plasma flow.
We searched the Cochrane Central register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2004), MEDLINE (1966 to 2004) and EMBASE (1988 to 2004) and hand searched six journals (British Journal of Anaesthesia; Anesthesia and Analgesia; Anesthesiology; Annals of Surgery; Journal of Thoracic and Cardiovascular Surgery and Journal of Vascular Surgery).
We selected all randomized controlled trials in adult population undergoing surgery where a treatment measure was used for the purpose of renal protection in the perioperative period.
We selected 37 studies for inclusion in this review. As well as analysis of the data from all the studies, we also performed subgroup analysis for type of interventions, types of surgical procedures and those with pre-existing renal dysfunction. We undertook sensitivity analysis on studies with high methodological quality.
The review included data from 37 studies, comprising a total of 1227 patients. Of these, 658 received some form of treatment and 569 acted as controls. The interventions were mostly employing different pharmaceutical agents such as dopamine, diuretics, calcium channel blockers. ACE inhibitors or selected hydration fluids. The results indicated that certain interventions showed some benefits, but all the results suffered from significant heterogeneity. Hence we can draw no conclusions about the effectiveness of these interventions in protecting the kidneys during surgery.
There is no reliable evidence from available literature to suggest that interventions during surgery can protect the kidneys from damage. However, there is a need for more studies of high methodological quality. One particular area for further studies may be on patients with pre-existing renal dysfunction undergoing surgery.
The ability of a fast-twitch dystrophic muscle to regenerate was compared at two ages to control muscle regeneration. Myofiber growth, and the distribution of nuclei in fibers were used to ...characterize the muscle regeneration 3 and 6 weeks after injury. In control and mdx muscles, myosatellite cell proliferation was completed by 3 weeks after injury. Mdx muscle regenerated as well as controls, based on similar distribution of myofiber cross sectional area, and the percent of centronucleation, typical of regenerated fibers. In addition, muscle from the younger dystrophic mdx mice grew to unoperated levels with no net change in fiber area distribution, while older muscles did not regenerate as well. There were also more peripheral (satellite cell) nuclei observed in younger mdx muscle than in older muscles, after the most active phase of dystrophy.
Abstract
Background: Penile Cancer (PeCa) is a rare cancer with over 90% squamous cell carcinoma (SCC)histology. Risk factors include human papillomavirus (HPV) infection and phimosis. Molecular ...oncogenic pathways between HPV-Positive and HPV-Negative PeCa are difficult to validate because there are few preclinical models of PeCa and no models of HPV-Positive PeCa. Our goal was to establish PeCA patient-derived xenograft (PDX) models to elucidate the molecular signature of HPV-Positive and HPV-Negative PeCa for therapeutic benefit.
Methods: PeCa specimens from penectomies and inguinal lymph node dissections (ILND) were collected from 2019-2021. Tumor specimens were dissected and tissue coated in Matrigel and transplanted subcutaneously into NOD SCID gamma (NSG™) mice. Tumor growth was monitored and was harvested at ≈ 1500m3 for subsequent propagation. Short tandem repeat fingerprinting (STR) analysis was performed on genomic DNA from PDX tissue and parental patient tumor tissue. Immunohistochemistry was performed on all PDX models and original patient primary tumors to validate the expression of p16 protein, a surrogate marker for HPV-Positive disease. p16 positivity was determined using a 0-3 scoring where a score of 3 was assessed as positive and a score of ≤2 as negative. For HPV genotyping: PCR was performed using DNA ELISA kit HPV, followed by RHA Kit HPV SPF10-LiPA25.
Results: 8 PDXs were established from tissue from 7 patients. Age, race, and type of surgery were determined. SCC histology was confirmed in all the patients. Basaloid variant was present in 3 patients, and Verrucous variant was present in 1 patient. For pathological staging, 2 patients were staged as pT3N3Mx, 2 patients as pT2N1M0, 1 patient as pT3N0 and 3 patients as pT3Nx. One ILND had no evidence of disease. 2 PDX models (MDAPe3 and MDAPe7) were derived from two specimens from the same patient (1 pretreatment, 1 post-treatment). All models were matched to the patient's primary tumor by STR fingerprinting analysis. Squamous cell carcinoma histology was confirmed in all PDXs. 6 PDX models are currently in passage 3 and 6 PDXs were p16 positive. HPV genotyping in p16 positive PDXs detected high-risk HPV 16 and p16 negative xenografts were also HPV negative.
Conclusion: In our study, we established PeCa PDX models that recapitulated the patients' histology. We report to our knowledge the first HPV-positive penile cancer xenografts. Plans for comprehensive characterization and future targeted therapy experiments are in development.
Citation Format: Luis A. Segarra, Niki M. Zacharias, Alberto Pieretti, Angelita Alaniz, Tapati Maity, Sue Martinez, Priya Rao, Natalie Fowlkes, Jad Chahoud, Xin Lu, Magaly Martinez Ferrer, Christopher Wood, Curtis Pettaway. Establishment of patient-derived xenografts in penile cancer abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3111.
Pain relief in children Zacharias, Mathew; Watts, Duncan
BMJ. British medical journal (International ed.),
05/1998, Letnik:
316, Številka:
7144
Journal Article
Recenzirano
Pediatric pain management is discussed in an editorial. The difficulty of objectively assessing pain has been a longstanding problem in pediatric pain management.
Molecular dynamics simulations have been applied to the DNA octamer d(GCGCA-GAAC) · d(GTTCGCGC), which has an adenine bulge at the center to determine the pathway for interconversion between the ...stacked and extended forms. These forms are known to be important in the molecular recognition of bulges. From a total of ∼35
ns of simulation time with the most recent CHARMM27 force field a variety of distinct conformations and subconformations are found. Stacked and fully looped-out forms are in excellent agreement with experimental data from NMR and x-ray crystallography. Furthermore, in a number of conformations the bulge base associates with the minor groove to varying degrees. Transitions between many of the conformations are observed in the simulations and used to propose a complete transition pathway between the stacked and fully extended conformations. The effect on the surrounding DNA sequence is investigated and biological implications of the accessible conformational space and the suggested transition pathway are discussed, in particular for the interaction of the MS2 replicase operator RNA with its coat protein.
To describe the fluidic events that occur in a test chamber during phacoemulsification with longitudinal and torsional ultrasound (US) modalities.
Pasteur Ophthalmic Clinic Phacodynamics Laboratory, ...Santiago, Chile, and Nanyang Technological University, Singapore.
Experimental study.
Ultra-high-speed videos of a phacoemulsifying tip were recorded while the tip operated in longitudinal and torsional US modalities using variable US power. Two high-speed video cameras were used to record videos up to 625,000 frames per second. A high-intensity spotlight source was used for illumination to engage shadowgraphy techniques. Particle image velocimetry was used to evaluate fluidic patterns while a hyperbaric environmental system allowed the evaluation of cavitation effects. Tip-to-tissue interaction at high speed was evaluated using human cataract fragments.
Particle imaging velocimetry showed the following flow patterns for longitudinal and torsional modes at high US powers: forward-directed streaming with longitudinal mode and backward-directed streaming with torsional mode. The ultrasound power threshold for the appearance of cavitation was 60% for longitudinal mode and 80% for torsional mode. Cavitation was suppressed with pressure of 1.0 bar for longitudinal mode and 0.3 bar for torsional mode. Generation of previously unseen stable gaseous microbubbles was noted. Tip-to-tissue interaction analysis showed the presence of cavitation bubbles close to the site of fragmentation with no apparent effect on cutting.
High-speed imaging and particle image velocimetry yielded a better understanding and differentiated the fluidic pattern behavior between longitudinal and torsional US during phacoemulsification. These recordings also showed more detailed aspects of cavitation that clarified its role in lens material cutting for both modalities.
The regulation of the synthesis of ribosomal RNA is a key problem for the understanding of bacterial growth. Many different regulatory mechanisms involving cis and trans acting components participate ...in a concerted way to achieve the very efficient, flexible and coordinated production of this class of molecules. We have studied three different sequence regions within a ribosomal RNA transcription unit which are believed to control different stages of ribosomal RNA expression. In the first part of the study the function of AT-rich sequences upstream of the -35 hexamer of rRNA promoter P1 in the activation of rRNA transcription was analyzed. We confirm that a sequence dependent bend upstream of P1 is responsible for the high promoter activity. Experiments employing linker scanning mutations demonstrated that the distance as well as the angular orientation of the bent DNA is crucial for the degree of activation. In addition, the effect of the trans activating protein Fis on the transcription initiation of promoter P1 was investigated. We can show, using the abortive initiation assay, that the predominant effect of Fis is due to an increase in the affinity of RNA polymerase for the promoter (binding constant KB) while the isomerisation rate (kf) from a closed to an open RNA polymerase promoter complex is not altered significantly. We also describe the characterization of sequence determinants important for stringent regulation and growth rate control. Evidence is provided that the discriminator motif GCGC is a necessary but not sufficient element for both types of control. Furthermore we show that not simply a particular DNA primary structure but the higher order conformation of the complete promoter region is recognized and triggers the two regulatory mechanisms, both of which are apparently mediated by the effector molecule guanosine tetraphosphate (ppGpp). Finally, we have carried out a systematic mutational analysis of the rrnB leader region preceding the structural gene for 16S RNA. We could demonstrate that highly conserved sequence elements within the rrnB leader, which were believed to be involved in transcription antitermination have post-transcriptional functions. We present evidence that these sequence elements direct the biogenesis of active ribosomal particles.
Methods A 5-question survey was given to a cohort of asthmatics to assess their perception of their weight, its role in their asthma control, and their willingness to pursue weight loss.
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