The effects of esketamine on blood pressure and hypotension incidence during induction of bariatric surgery: A randomized controlled trial

BACKGROUND

The prevalence of obesity is high. Bariatric surgery is an effective treatment for severe obesity; however, the induction phase of anesthesia in these patients poses a risk of hypotension. Esketamine, known for its sympathetic nervous system stimulation, may stabilize blood pressure during induction. This study aimed to investigate the effects of esketamine on blood pressure in bariatric surgery patients.

METHODS

This randomized controlled trial included 145 patients undergoing bariatric surgery. Patients were randomly assigned to receive esketamine or a control intervention during induction. Blood pressure and other vital signs were measured and compared between the 2 groups using statistical analyses.

RESULTS

Administration of esketamine increased blood pressure before intubation (T2). The incidence of hypotension was lower in the esketamine group at multiple time points during induction. Postoperatively, the esketamine group exhibited lower pain scores at 24 hours and a reduced need for rescue analgesics.

CONCLUSION

A single dose of 0.2 mg/kg esketamine during the induction phase of bariatric surgery can improve blood pressure stability and decrease the incidence of hypotension. Furthermore, it is associated with reduced postoperative pain. Future studies could explore the effects of higher esketamine doses and validate these findings in a larger and more diverse patient population.

Distinctive Neuroanatomic Regions Involved in Cocaine-Induced Behavioral Sensitization in Mice

The present study aimed to characterize the phenomenon of behavioral sensitization to cocaine and to identify neuroanatomical structures involved in the induction and expression phases of this phenomenon. For this, in experiment 1 (induction phase), mice were treated with saline or cocaine every second day for 15 days (conditioning period), in the open-field or in their home-cages. In experiment 2 (expression phase), the same protocol was followed, except that after the conditioning period the animals were not manipulated for 10 days, and after this interval, animals were challenged with cocaine. Neuroanatomical structures involved in the induction and expression phases were identified by stereological quantification of c-Fos staining in the dorsomedial prefrontal cortex (dmPFC), nucleus accumbens core (NAc core and shell (NAc shell), basolateral amygdala (BLA), and ventral tegmental area (VTA). Neuroanatomical analysis indicated that in the induction phase, cocaine-conditioned animals had higher expression of c-Fos in the dmPFC, NAc core, BLA, and VTA, whereas in the expression phase, almost all areas had higher expression except for the VTA. Therefore, environmental context plays a major role in the induction and expression of behavioral sensitization, although not all structures that compose the mesolimbic system contribute to this phenomenon.

Induction-phase treatment costs for cryptococcal meningitis in high HIV-burden African countries: New opportunities with lower costs

Introduction: Access to and the cost of induction treatment for cryptococcal meningitis (CM) is rapidly changing. The newly-announced price for flucytosine ($0.75 per 500 mg pill) and possibly lower prices for liposomal amphotericin B (AmB-L) create opportunities to reduce CM treatment costs compared to the current standard treatment in low- and middle-income countries. Methods: We developed an Excel-based cost model to estimate health system treatment costs for CM over a two-week induction phase for multiple treatment combinations, newly feasible with improved access to flucytosine and AmB-L. CM treatment costs include medications, laboratory tests and other hospital-based costs (bed-day costs and healthcare worker time). We report results from applying the model using country-specific information for South Africa, Uganda, Nigeria, and Botswana. Results: A 14-day induction-phase of seven days of inpatient AmB-D with flucytosine, followed by seven days of high-dose fluconazole as an outpatient, will cost health systems less than a 14-day hospital stay with AmB-D and fluconazole. If daily AmB-L replaces AmB-D for those with baseline renal dysfunction, with a cost of $50 or less per 50 mg vial, incremental costs would still be less than the AmB-D with fluconazole regimen. Simple oral combinations (e.g., seven days of flucytosine with fluconazole as an inpatient) are practical when AmB-D is not available, and treatment costs would remain less than the current standard treatment. Conclusions: Improved access to and lower prices for flucytosine and AmB-L create opportunities for improving CM treatment regimens. An induction regimen of flucytosine and AmB-D for seven days is less costly than standard care in the settings studied here. As this regimen has also been shown to be more effective than current standard care, countries should prioritize scaling up flucytosine access. The cost of AmB-L based regimens is highly dependent on the price of AmB-L, which currently remains unclear.

Induction-phase treatment costs for cryptococcal meningitis in high HIV-burden African countries: New opportunities with lower costs

Introduction: Access to and the cost of induction treatment for cryptococcal meningitis (CM) is rapidly changing. The newly-announced price for flucytosine ($0.75 per 500 mg pill) and possibly lower prices for liposomal amphotericin B (AmB-L) create opportunities to reduce CM treatment costs compared to the current standard treatment in low- and middle-income countries. Methods: We developed an Excel-based cost model to estimate health system treatment costs for CM over a two-week induction phase for multiple treatment combinations, newly feasible with improved access to flucytosine and AmB-L. CM treatment costs include medications, laboratory tests and other hospital-based costs (bed-day costs and healthcare worker time). We report results from applying the model using country-specific information for South Africa, Uganda, Nigeria, and Botswana. Results: A 14-day induction-phase of seven days of inpatient AmB-D with flucytosine, followed by seven days of high-dose fluconazole as an outpatient, will cost health systems less than a 14-day hospital stay with AmB-D and fluconazole. If daily AmB-L replaces AmB-D for those with baseline renal dysfunction, with a cost of $50 or less per 50 mg vial, incremental costs would still be less than the AmB-D with fluconazole regimen. Simple oral combinations (e.g., seven days of flucytosine with fluconazole as an inpatient) are practical when AmB-D is not available, and treatment costs would remain less than the current standard treatment. Conclusions: Improved access to, and lower prices for flucytosine and AmB-L create opportunities for improving CM treatment regimens. An induction regimen of flucytosine and AmB-D for seven days is less costly than standard care in the settings studied here. As this regimen has also been shown to be more effective than current standard care, countries should prioritize scaling up flucytosine access. The cost of AmB-L based regimens is highly dependent on the price of AmB-L, which currently remains unclear.

Induction-phase treatment costs for cryptococcal meningitis in high HIV-burden African countries: New opportunities with lower costs

Introduction: Access to and the cost of induction treatment for cryptococcal meningitis (CM) is rapidly changing. The newly-announced price for flucytosine ($0.75 per 500 mg pill) and possibly lower prices for liposomal amphotericin B (AmB-L) create opportunities to reduce CM treatment costs compared to the current standard treatment in low- and middle-income countries. Methods: We developed an Excel-based cost model to estimate health system treatment costs for CM over a two-week induction phase for multiple treatment combinations, newly feasible with improved access to flucytosine and AmB-L. CM treatment costs include medications, laboratory tests and other hospital-based costs (bed-day costs and healthcare worker time). We report results from applying the model using country-specific information for South Africa, Uganda, Nigeria, and Botswana. Results: A 14-day induction-phase of seven days of inpatient AmB-D with flucytosine, followed by seven days of high-dose fluconazole as an outpatient, will cost health systems less than a 14-day hospital stay with AmB-D and fluconazole. If daily AmB-L replaces AmB-D for those with baseline renal dysfunction, with a cost of $50 or less per 50 mg vial, incremental costs would still be less than the AmB-D with fluconazole regimen. Simple oral combinations (e.g., seven days of flucytosine with fluconazole as an inpatient) are practical when AmB-D is not available, and treatment costs would remain less than the current standard treatment. Conclusions: Improved access to, and lower prices for flucytosine and AmB-L create opportunities for improving CM treatment regimens. An induction regimen of flucytosine and AmB-D for seven days is less costly than standard care in the settings studied here. As this regimen has also been shown to be more effective than current standard care, countries should prioritize scaling up flucytosine access. The cost of AmB-L based regimens is highly dependent on the price of AmB-L, which currently remains unclear.

The Contribution of PEG Molecular Weights in PEGylated Emulsions to the Various Phases in the Accelerated Blood Clearance (ABC) Phenomenon in Rats

PEGylated preparations will be cleared rapidly from blood circulation when they are administrated twice in the same animal at a time interval, referred to as the "accelerated blood clearance" (ABC) phenomenon. Commonly, the study of the ABC phenomenon was investigated in two aspects: induction phase and effectuation phase. Herein, we report the influence of physicochemical properties (PEG molecular weights) in the induction phase and effectuation phase on the ABC phenomenon. In the experiment, on one hand, PEGylated emulsions with different molecular weights of PEG (refer to PEn, n = 400, 600, 800, 1000, 2000, and 5000) were injected for the first dose (induction phase) and induced PE2000 to produce ABC phenomenon. On the other hand, after PE2000 injected, PEn was injected for the second dose (effectuation phase). The results indicated that PE2000 and PE5000 induced an intense ABC phenomenon by their long-circulating characteristic. Interestingly, PE400, PE600, PE800, and PE1000 produced a consistent ABC phenomenon but different circulation time. Apparently, the induction of the ABC phenomenon is not only determined by the circulation time but also by the PEG molecular weights. When PEn is in the effectuation phase, the extent of the ABC phenomenon was not positively related to the molecular weights of PEG, increasing first and then weaken with the increase of molecular weights of PEG. These suggest that the number of -(CH₂CH₂O)_n- repeat units of PE2000 was more conducive to interact with anti-PEG IgM. The results reported here clearly indicate that both the PEG molecular weights of prior dose and the subsequent dose of emulsion strongly influence the extent of the ABC phenomenon. Taken together, our observations in this study complete the effect of PEG molecular weights at a different phase of the ABC phenomenon. Furthermore, our findings have a significant impact on the choice of molecular weights for PEGylated formulations for use in cross-administration.

The role of major histocompatibility complex expression on head and neck cancer cells in the induction of autologous cytotoxic T lymphocytes

Using head and neck tumors, we studied the role of HLA class I and DR antigens on tumor cells in cytotoxic T lymphocyte (CTL) induction. Expression of major histocompatibility complex (MHC) antigens was investigated by two-color flow cytometry analysis and for this study we used the tumor cells, over 50% of which expressed both HLA class I and DR antigens on their surface. In seven cases, tumor cells were divided into three groups according to the specificity of monoclonal antibodies (mAb) to MHC to study the role of MHC antigens on tumor cells in CTL induction: one was not blocked (MHC double-positive tumor), a second was blocked by anti-class I mAb (class-I-negative DR-positive tumor) and third was blocked by anti-DR mAb (class-I-positive DR-negative tumor). Subsequently, these tumors were used to stimulate an autologous mixed lymphocyte/tumor cell culture for 5 days (MLTC) followed by further cultivation with interleukin-2 for 12 days. The induced autologous tumor killer cells were most cytotoxic when non-treated tumors, which consist mainly of cells that are both HLA-class I and DR-positive, were used as stimulator cells. When the tumor cells blocked by anti-DR mAb were used as stimulators, autologous tumor killer activity was lower than that induced by tumor cells blocked by anti-class-I mAb. Moreover, cytolysis by autologous tumor killer cells induced by stimulation of non-treated tumor cells was blocked during the effector phase, 26.6%-42.3% and 32.7%-53.8% by anti-class-I and anti-DR mAb respectively, suggesting that majority of the autologous tumor killer cells are MHC-restricted CD8+ or CD4+ CTL. These results suggest that both MHC class I and class II antigens on head and neck tumor cells play a critical role in inducing CTL.