Breakthrough pain in cancer patients: new therapeutic approaches to an old challenge

Breakthrough pain is a well recognized but ill-defined phenomenon that occurs commonly in the presence of otherwise stable, persistent pain. It is defined now as a "transient pain episode that occurs, or breaks through from the otherwise stable background pain." Breakthrough pain is usually associated with moderate to severe pain and may form a predictor of poor response to treatment with routine pharmacotherapy. Breakthrough pain is also associated with functional impairment and psychological distress. The assessment and treatment should be multidimensional. Although primary therapies such as chemotherapy, radiation treatment, and surgical options are explored, the mainstay of treatment is pharmacotherapy. Nonpharmacologic methods, such as orthotic devices and joint stabilizations along with behavioral methods, should be explored. Anesthetic and neurosurgical procedures are performed on a limited number of patients based on the prognosis, intractable nature of pain, and favorable risk/benefit ratio. Newer oral transmucosal fentanyl offers a favorable pharmacokinetic and pharmacodynamic profile and ease of administration.     

Outcome of thoracoabdominal aortic operations using deep hypothermia and distal exsanguination

BACKGROUND: Operation of the descending and thoracoabdominal aorta may be affected by a significant perioperative morbidity, mainly because of ischemic damage of the spinal cord and malperfusion of the abdominal organs. METHODS: A comparative analysis was performed on two consecutive series of patients operated between 1982 and 1998. Group 1 consisted of 90 patients operated with moderate hypothermic left heart bypass. Group 2 included 38 patients operated using deep hypothermic cardiopulmonary bypass and a period of circulatory arrest while performing the proximal anastomosis and distal exsanguination during confection of the distal anastomosis. RESULTS: Main demographic factors and causes of the aortic disease were similar in both groups. Early mortality was significantly higher in the group of patients with aortic cross-clamping (15 of 90, 16%) than in those operated with circulatory arrest (2 of 38, 5.2%), p < 0.001. Paraplegia occurred in 8 patients in the group operated with mild hypothermia (8.8%) but in only 1 patient (2.6%) when deep hypothermia had been used. CONCLUSIONS: In our experience, deep hypothermia combined with distal exsanguination significantly improved the early postoperative outcome after operation of the descending and thoracoabdominal aorta. This technique allowed easy confection of proximal and distal anastomoses, and the duration of the operation was not prolonged significantly through this approach.     

Moxonidine, a selective imidazoline-alpha2 -adrenergic receptor agonist, produces spinal synergistic antihyperalgesia with morphine in nerve-injured mice

BACKGROUND: Moxonidine, a novel imidazoline-alpha2-adrenergic receptor-selective analgesic, was recently identified as antinociceptive but has yet to be evaluated in neuropathic pain models. alpha2-adrenergic receptor-selective analgesics, and high-efficacy opioids, effectively inhibit neuropathic pain behaviors in rodents. In contrast, morphine potency and efficacy decreases in states of neuropathic pain, both in rodents and in humans, but may be restored or enhanced by coadministration of morphine with alpha2-adrenergic receptor-selective analgesics. The current experiments extend the evaluation of opioid-coadjuvant interactions in neuropathic subjects by testing the respective antihyperalgesic interactions of moxonidine and clonidine with morphine in a test of mechanical hyperalgesia. METHODS: Nerve-injured mice (Chung model) were spinally administered moxonidine, clonidine, morphine, and the combinations moxonidine-morphine and clonidine-morphine. Hyperalgesia was detected by von Frey monofilament stimulation (3.3 mN) to the hind paws (plantar surface). The ED50 values were calculated and the interactions tested by isobolographic analysis. RESULTS: In nerve-injured mice, moxonidine, clonidine, and morphine all dose-dependently inhibited mechanical hyperalgesia. Furthermore, the combinations of moxonidine-morphine and clonidine-morphine resulted in substantial leftward shifts in the dose-response curves compared with those of each agonist administered separately. The calculated ED50 values of the dose-response curves of these combinations were significantly lower than their corresponding theoretical additive ED50 values. These results confirmed that both interactions were synergistic. CONCLUSIONS: Moxonidine and clonidine both synergize with morphine to inhibit paw withdrawal from nociceptive mechanical stimuli in nerve-injured mice.     

Detection of spontaneous CD4+ T-cell responses in melanoma patients against a tyrosinase-related protein-2-derived epitope identified in HLA-DRB1*0301 transgenic mice.

PURPOSE: The frequently expressed differentiation antigen tyrosinase-related protein-2 (TRP-2) has repeatedly been described as a target of spontaneous cytotoxic T-cell responses in melanoma patients, suggesting that it might be an ideal candidate antigen for T cell-based immunotherapy. As a prerequisite for immunization, T-cell epitopes have to be identified. Whereas a number of HLA class I-presented TRP-2-derived epitopes are known, information about HLA class II-presented antigenic ligands recognized by CD4+ T helper (Th) cells is limited. EXPERIMENTAL DESIGN: The search for TRP-2-derived Th epitopes was carried out by competitive in vitro peptide binding studies with predicted HLA-DRB1*0301 ligands in combination with peptide and protein immunizations of HLA-DRB1*0301 transgenic mice. In vivo selected candidate epitopes were subsequently verified for their immunogenicity in human T-cell cultures. RESULTS: This strategy led to the characterization of TRP-2(60-74) as an HLA-DRB1*0301-restricted Th epitope. Importantly, TRP-2(60-74)-reactive human CD4+ Th cell lines, specifically recognizing target cells loaded with recombinant TRP-2 protein, could be established by repeated peptide stimulation of peripheral blood lymphocytes from several HLA-DRB1*03+ melanoma patients. Even short-term peptide stimulation of patients' peripheral blood lymphocytes showed the presence of TRP-2(60-74)-reactive T cells, suggesting that these T cells were already activated in vivo. CONCLUSION: Peptide TRP-2(60-74) might be a useful tool for the improvement of immunotherapy and immune monitoring of melanoma patients.     

SARS-CoV-2 Variants in Paraguay: Detection and Surveillance with an Economical and Scalable Molecular Protocol

SARS-CoV-2 variant detection relies on resource-intensive whole-genome sequencing methods. We sought to develop a scalable protocol for variant detection and surveillance in Paraguay, pairing rRT-PCR for spike mutations with Nanopore sequencing. A total of 201 acute-phase nasopharyngeal samples were included. Samples were positive for the SARS-CoV-2 N2 target and tested with the Spike SNP assay to detect mutations associated with the following variants: alpha (501Y), beta/gamma (417variant/484K/501Y), delta (452R/478K), and lambda (452Q/490S). Spike SNP calls were confirmed using amplicon (Sanger) sequencing and whole-genome (Nanopore) sequencing on a subset of samples with confirmed variant lineages. Samples had a mean N2 Ct of 20.8 (SD 5.6); 198/201 samples (98.5%) tested positive in the Spike SNP assay. The most common genotype was 417variant/484K/501Y, detected in 102/198 samples (51.5%), which was consistent with the P.1 lineage (gamma variant) in Paraguay. No mutations (K417 only) were found in 64/198 (32.3%), and K417/484K was identified in 22/198 (11.1%), consistent with P.2 (zeta). Seven samples (3.5%) tested positive for 452R without 478K, and one sample with genotype K417/501Y was confirmed as B.1.1.7 (alpha). The results were confirmed using Sanger sequencing in 181/181 samples, and variant calls were consistent with Nanopore sequencing in 29/29 samples. The Spike SNP assay could improve population-level surveillance for mutations associated with SARS-CoV-2 variants and inform the judicious use of sequencing resources.     

Understanding and clinical application of acute dilation of the left ventricle on ventricular arrhythmias

In this issue of the Journal of Geriatric Cardiology,Yin et al discussed the effects of calcium preconditioning (CPC) and streptomycin (S) on acute dilation of the left ventricle.……