Mode of regulation of the ACh-sensitive K-channel by the muscarinic receptor in rabbit atrial cells

The mechanism underlying the regulation of the K-channel by the muscarinic receptor was examined with patch-clamp experiments in atrial cells isolated enzymatically from the rabbit heart. The patch-electrode and the recording chamber were perfused with various solutions while the activity of the K-channels in the membrane-patch was recorded continuously. In the absence of muscarinic agonists, opening of K-channels occurred at a low frequency (basal activity). Application of ACh to the bath did not affect the basal activity, but perfusion of the patch electrode with ACh markedly increased the channel activity in the "cell-attached" patch. Application of oxotremorine, i.e. a specific muscarinic agonist, via the pipette also opened K-channels. When the membrane patch was isolated from the cell body ("inside-out" patch), ACh-induced single K-channel currents were still observed, but the frequency was reduced. Perfusion of atropine or scopolamine, two muscarinic antagonists, through the patch-electrode depressed the basal activity. In the case of scopolamine, channel-activity recovered after washing out the drug. The current voltage relationship determined from the basal activity was similar to that of ACh-induced single K-channel currents. The mean open time was 0.49 ms at basal activity and 1.35 ms during the application of 0.1 microM ACh via the patch electrode. Application of oxotremorine via the pipette hardly affected the open-time, it remained at 99 +/- 4% (n = 7) of the control.(ABSTRACT TRUNCATED AT 250 WORDS)     

Shared amino acid sequences in the NDβN and Nα regions of the T cell receptors of tumor-infiltrating lymphocytes within malignant glioma

The purpose of this study was to assess the V-(D)-J junctional region of the T cell receptor (TCR), the CDR3 region, which is responsible for glioma-specific antigen contact in αβ TCR-mediated recognition. We sequenced the TCR α and β chians of Vα7, and Vβ13.1 cDNA derived from tumor-infiltrating lymphocytes (TIL) of 12 glioma patients and also the corresponding clones from the patients' peripheral blood lymphocytes (PBL). A shared Vβ13.1 DJ sequence of the CDR3 region, NDβN, was demonstrated in 49 of 66 Vβ13.1⁺ clones (74.2 %) from the glioma TIL, whereas only 4 of 33 clones (12.1 %) were observed in the Vβ13.1⁺ clones from the PBL (p < 0.001). A common VDJ sequence, FCASS (Vβ13.1)-YRLPWGTSDS (NDβN)-GELFF(Jβ2.2), was observed not only in the gliomas from each patient, but also among all the patients with a preference for Vβ13.1. In contrast, the amino acid sequences of the Vβ13.1⁺ PBL clones were diverse and random. Next, we sequenced subclones from other Vβ subfamilies randomly selected to compare their VDJ region rearrangements (Vβ3 and Vβ5.1). In contrast to Vβ13.1, the amino acid sequences of these junctional regions were completely different in these subclones. The V-J junctional region of the α chain is dominated by a few clones in some patients, and no shared amino acid sequences were detected in the TCR Vα junctional region. However, in the Nα region of the Vα7-bearing TIL clones, arginine was used in 27 of 44 clones (61.4%) compared to only 3 of 12 clones from the PBL (p < 0.05). These results are consistent with the hypothesis that a clonal expansion/accumulation of glioma lineage-specific T cells occurred in vivo at the tumor site and that these T cells may be recognizing glioma-specific antigens.     

In vivo efficacy of a novel double liposome as an oral dosage form of salmon calcitonin

A simple method for the preparation of the inner liposomes for double liposomes (DL) was developed. The encapsulation efficiency of erythrosine in liposomes prepared by this new method is superior to that of the previous method because of the concentration of the drug in the lipid membrane. To evaluate the usefulness of DL prepared by the glass‐filter method modified in this study as an oral dosage form of salmon calcitonin (SCT), a suspension of liposomes containing SCT was administered to rats at a dose of 10 μg SCT/kg. Each type of DL showed better efficacy than its inner liposomes alone. The decrease in plasma calcium level was dependent on the electrical charge and particle size of the inner liposomes. The hypocalcemic efficacy of DL encapsulating SCT‐loading cationic liposomes relative to that after subcutaneous administration of SCT at a dose of 1 μg/kg was 6.47%, which was the largest value obtained. These results indicated that not only the particle size but also the electrical charge of inner liposomes affect intestinal absorption. This study verified that the efficacy was increased because of the decrease in diameter of the inner liposomes and the use of lipid with a positive charge. These findings concluded that DL might be useful as an oral dosage form of SCT. Drug Dev. Res. 58:253–257, 2003. © 2003 Wiley‐Liss, Inc.     

Comparing outcomes of nonoperative treatment for adhesive small bowel obstruction with and without antibiotics

IntroductionSome clinicians administer antibiotics in adhesive SBO treatment to prevent bacterial translocation without evidence confirming reduced sepsis and mortality. We aimed to evaluate the effectiveness of preventive antibiotic administration in nonoperative treatment of adhesive small bowel obstruction (SBO) in a retrospective study.MethodsUsing a Japanese national inpatient database, we identified 114,786 eligible patients with adhesive SBO and divided patients into a group who did not receive intravenous antibiotics in the initial 2 consecutive days after admission (control group, n = 71,666) and a group who received intravenous antibiotics ≥2 days after admission (antibiotic group, n = 43,120). To compare the in-hospital mortality, occurrence of sepsis, septic shock, Clostridioides difficile colitis, length of stay, and total costs between the two groups, we performed instrumental variable analyses to adjust for measured and unmeasured confounding factors.ResultsOverall, in-hospital mortality was 2.2%, and the occurrence of sepsis was 0.8%. In the instrumental variable analyses, no significant differences were found for in-hospital mortality, occurrence of sepsis, septic shock, Clostridioides difficile colitis, or total hospitalization costs. The antibiotic group showed a longer length of stay than the control group (coefficient, 1.9 days; 95% confidence interval, 0.6–3.2).ConclusionsIn this large nationwide cohort of patients with adhesive SBO, we found no benefit regarding preventive antibiotic administration in nonoperative treatment; however, antibiotic administration was associated with a longer hospital stay. These results did not support routine administration of antibiotics at admission to prevent bacterial translocation.     

Contraindications and image-defined risk factors in laparoscopic resection of abdominal neuroblastoma

Purpose

Minimally invasive surgery (MIS) has become widely accepted as a technique for abdominal neuroblastoma resection. However, the indications for MIS are still controversial. The aim of this study was to evaluate image-defined risk factors (IDRFs), complications, and oncologic outcomes in patients with abdominal neuroblastomas treated with MIS.

Methods

Between August 1998 and February 2016, MIS was planned for 20 children with abdominal neuroblastomas. Clinical data were retrospectively reviewed and compared between the IDRF-negative and IDRF-positive patients.

Results

On the basis of the latest IDRF guidelines, five patients were classified as IDRF-positive and four of them had operative complications; namely, partial infarction of the ipsilateral kidney or open conversion. Concerning the two patients who needed open conversion, the primary reason for open conversion was difficulty in dissection of the tumor from the vena cava. Preoperative images of these cases showed either deformation or subtotal encasement of the vena cava. Relapse occurred in three high-risk patients and in none of the low/intermediate-risk patients. No complication occurred in the IDRF-negative cases.

Conclusions

IDRF-negative might be a good indication for MIS for abdominal neuroblastoma. However, deformation or subtotal encasement of the vena cava should be considered as IDRF-positive for MIS.

     

Spontaneous closure of macular hole after posterior vitreous detachment

Macular holes can be treated with surgically-induced vitreous detachment and gas tamponade. The authors report a case of a macular hole that closed spontaneously after the development of posterior vitreous detachment (PVD). Optical coherence tomography (OCT) revealed a small full-thickness macular hole with perifoveal cystic changes in a 25-year-old female with a central scotoma at her initial visit. There was no evidence of PVD. Five months later, PVD was observed and the macular hole disappeared. OCT performed three months later showed macular hole closure and resolution of the perifoveal cystic changes. The physiologic pit was restored in the fovea. OCT is useful to detect and monitor the morphologic changes of a macular hole.     

MRI findings on healing process of vertebral fracture in osteoporosis

The healing process of vertebral fracture was investigated in 37 senile osteoporotic patients on serial magnetic resonance imagings (MRIs), including enhancement study with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA). The healing process was classified retrospectively into six categories in terms of the changes and recovery of T1 and T2 signal intensity and in terms of the local vascularity. Two types of damage foci were identified, and, in each type, three patterns of healing were noted. In the partial collapse type, the focus of damage in the fractured vertebral body was located near the cranial or caudal endplates; in the total collapse type, the focus was located at the center of the body. In each of these two types, fracture healing was smooth, belated, or resulted in nonunion. In the partial collapse type, vertebral fractures healed smoothly (smooth pattern) in 8 cases, belatedly (belated pattern) in 11, and resulted in nonunion (nonunion pattern) in 5. In the total collapse type, vertebral fractures healed smoothly (smooth pattern) in 6 cases, belatedly (belated pattern) in 4, and resulted in nonunion (nonunion pattern) in 3. The percent height of the anterior wall, central portion, and posterior wall was defined to allow accurate calculatation of the collapse of the fractured vertebral body. Chronological changes in the vertebral body height were investigated. Progressive collapse of the vertebral body was minimal in the smooth pattern cases, and most severe in the nonunion pattern cases. Statistical analysis indicated that prediction of the course of the fracture was difficult only with the height of the fractured vertebral body in acute phase. Enhancement study with Gd-DTPA showed that, in fractures with favorable prognosis, the ischemic area in the body tended to be smaller from the beginning, and restoration of vascularity was prompt. On the contrary, in fractures with unfavorable prognosis, the ischemic area was wider, and restoration of vascularity was poor.