Second gas effect of N2O on oxygen uptake

PURPOSE: The concept of the second gas effect is well known, however, there have been no studies that showed the relationship between alveolar oxygen concentration and arterial oxygen tension (PaO2) after the inhalation of nitrous oxide (N2O) in humans. The purpose of this study was to examine the changes in both end-tidal oxygen fraction (F(ET)O2) and PaO2 after N2O inhalation in patients under general anesthesia. METHODS: Fifteen patients scheduled for elective orthopedic surgery were enrolled in this study. Anesthesia was maintained with the continuous infusion of propofol and with nitrogen (N2) and oxygen (O2) (6 L x min(-1), F1O2, 0.33). In all patients, the lungs were ventilated with a Servo 900C ventilator equipped with a gas mixer for O2, N2O, and N2. After obtaining baseline data, N2 was replaced with N2O maintaining FIO2 constant at 0.33. The changes in fractional concentration of O2, N2O, and N2 were continuously measured using mass spectrometer in a breath-by-breath basis. PaO2 and hemodynamic data were obtained at 1, 5, 10, 30 and 60 min after the start of N2O inhalation. RESULTS: Five minutes after N2O inhalation, F(ET)O2 increased from 0.27+/-0.01 to 0.31+/-0.02 (P<0.01) and PaO2 increased from 172.0+/-22.5 mm Hg to 201.0+/-10.3 mm Hg (P<0.01). These effects produced by N2O were observed for 30 min. CONCLUSIONS: These results confirm the concept of second gas effect of N2O on oxygen uptake in humans and provide evidence that the PaO2 increase correlated with the increase in F(ET)O2 after N2O inhalation.     

A case of relapse of C-ANCA-associated glomerulonephritis in post-transplant patients

We experienced a case of relapse of proteinase 3-specific antineutrophil cytoplasmic autoantibody (C-ANCA)-associated rapid progressive glomerulonephritis (RPGN) in a patient after renal transplantation. A 19-yr-old man, who underwent a living donor kidney transplantation, presented a rapid renal function deterioration along with a sign of infection. Initially he was treated as acute rejection, but renal function did not improve. Renal biopsy revealed crescentic glomerulonephritis, and C-ANCA titer was 12 EU/mL, resulting in the diagnosis of C-ANCA-associated RPGN. He was treated with three consecutive methylprednisolone pulses twice in addition to the basal immunosuppressive medications (cyclosporine A and mizoribine), then his renal function improved to normal. Bearing the possibility of recurrence of glomerulonephritis in mind, we re-evaluated the nature and disease course of renal failure of original kidney. He experienced a rapid deterioration of renal function in 1992, and eventually CAPD was started in 1992. His serum in 1992 revealed high titer of C-ANCA (24 EU/mL), and renal biopsy performed in 1992 showed a crescentic glomerulonephritis. Taken together, we diagnosed this event as a relapse of C-ANCA-associated GN. Lessons from our experience are: 1) steroid pulse and high-dose corticosteroid therapy may be useful for the treatment of relapse of C-ANCA-associated GN patients after renal transplantation; 2) the possibility of a relapse of C-ANCA-associated GN following renal transplantation has to be kept in mind, especially when infection precedes the deterioration of allograft kidney function.     

Association of the Low-density Lipoprotein Cholesterol/High-density Lipoprotein Cholesterol Ratio with Glecaprevir-pibrentasvir Treatment

Objective The change in serum lipid levels by direct-acting antiviral (DAA) treatment for chronic hepatitis C varies depending on the type of DAA. How the lipid level changes induced by glecaprevir-pibrentasvir (G/P) treatment contribute to the clinical outcome remains unclear. We conducted a prospective observational study to evaluate the effectiveness of G/P treatment and the lipid level changes. Methods The primary endpoint was a sustained virologic response at 12 weeks (SVR12). The total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels and LDL-C/HDL-C (L/H) ratio were measured every two weeks. Patients This study included 101 patients. Seventeen cases of liver cirrhosis and nine cases of DAA retreatment were registered. The G/P treatment period was 8 weeks in 74 cases and 12 weeks in 27 cases. Results SVR12 was evaluated in 96 patients. The rate of achievement of SVR12 in the evaluable cases was 100%. We found significantly elevated TC and LDL-C levels over the observation period compared to baseline. The serum levels of HDL-C did not change during treatment but were significantly increased after treatment compared to baseline. The L/H ratio was significantly increased two weeks after the start of treatment but returned to the baseline after treatment. Conclusion The primary endpoint of the SVR12 achievement rate was 100%. G/P treatment changed the serum lipid levels. Specifically, the TC and LDL-C levels increased during and after treatment, and the HDL-C levels increased after treatment. G/P treatment may be associated with a reduced thrombotic risk. Therefore, validation in large trials is recommended.     

Novel Therapeutic Method for Unresectable Pancreatic Cancer—The Impact of the Long-Term Research in Therapeutic Effect of High-Intensity Focused Ultrasound (HIFU) Therapy

High-intensity focused ultrasound (HIFU) is a novel advanced therapy for unresectable pancreatic cancer (PC). HIFU therapy with chemotherapy is being promoted as a novel method to control local advancement by tumor ablation. We evaluated the therapeutic effects of HIFU therapy in locally advanced and metastatic PC. PC patients were treated with HIFU as an optional local therapy and systemic chemotherapy. The FEP-BY02 (Yuande Bio-Medical Engineering) HIFU device was used under ultrasound guidance. Of 176 PC patients, 89 cases were Stage III and 87 were Stage IV. The rate of complete tumor ablation was 90.3%, while that of symptom relief was 66.7%. The effectiveness on the primary lesions were as follows: complete response (CR): n = 0, partial response (PR): n = 21, stable disease (SD): n = 106, and progressive disease (PD): n = 49; the primary disease control rate was 72.2%. Eight patients underwent surgery. The median survival time (MST) after diagnosis for HIFU with chemotherapy compared to chemotherapy alone (100 patients in our hospital) was 648 vs. 288 days (p < 0.001). Compared with chemotherapy alone, the combination of HIFU therapy and chemotherapy demonstrated significant prolongation of prognosis. This study suggests that HIFU therapy has the potential to be a novel combination therapy for unresectable PC.     

Fine structure of three types of olfactory organs in Xenopus laevis

There is no report on the fine structure of three types of olfactory organs in Xenopus laevis. Their functional assignments in olfaction are not yet established. The fine structure of three types of olfactory organs, olfactory epithelium (OE), vomeronasal organ (VNO), and middle chamber epithelium (MCE), was examined in Xenopus laevis by light and electron microscopy. The olfactory cells of the OE and the sensory cells of the VNO were equipped with cilia and microvilli, respectively, similar to terrestrial animals that possess both the OE and the VNO. On the other hand, the sensory cells of the MCE were classified into two types, the sensory cells with cilia and the sensory cells with microvilli, like those of the OE in fish. These findings suggest that the OE and the VNO in Xenopus laevis detect different kinds of odoriferous molecules in air, whereas the MCE is involved in the perception of odorants in water. Anat. Rec. 252:301–310, 1998. © 1998 Wiley-Liss, Inc.     

Successful Pre-Operative Local Control of Skin Invasion of Breast Cancer Using a Combination of Systemic Chemotherapy and Mohs Paste

Locally advanced breast cancer (tumor > 5 cm, widespread infiltration of the skin and muscle, or metastases to lymph nodes) is difficult to resect by surgery, and even when it is resectable, there is a high probability of local recurrence and distant metastasis. Therefore, systemic therapy should be administered first. However, as cutaneous infiltration progresses, the patient''s quality of life is impaired by pain, bleeding, presence of exudates, and a foul-smelling odor. Treatment with Mohs paste with systemic therapy can control symptoms associated with skin infiltration and can also be expected to decrease tumor volume. Herein, we report a case in which a tumor was resected following Mohs paste and systemic chemotherapy administration, and the skin defect was reconstructed with a latissimus dorsi myocutaneous flap. We also review the literature for previously reported cases of breast cancer involving Mohs paste.