Generation of mouse models for type 1 diabetes by selective depletion of pancreatic beta cells using toxin receptor-mediated cell knockout

AbstractBy using the toxin receptor-mediated cell knockout (TRECK) method, we have generated two transgenic (Tg) murine lines that model type 1 (insulin-dependent) diabetes. The first strain, C.B-17/Icr-Prkdcscid/Prkdcscid-INS-TRECK-Tg, carries the diphtheria toxin receptor (hDTR) driven by the human insulin gene promoter, while the other strain, C57BL/6-ins2(BAC)-TRECK-Tg, expresses hDTR cDNA under the control of the mouse insulin II gene promoter. With regard to the C.B-17/Icr-Prkdcscid/Prkdcscid-INS-TRECK-Tg strain, only one of three Tg strains exhibited proper expression of hDTR in pancreatic β cells. By contrast, hDTR was expressed in the pancreatic β cells of all four of the generated C57BL/6-ins2(BAC)-TRECK-Tg strains. Hyperglycemia, severe ablation of pancreatic β cells and depletion of serum insulin were observed within 3days after the administration of diphtheria toxin (DT) in these Tg mice. Subcutaneous injection of a suitable dosage of insulin was sufficient for recovery from hyperglycemia in all of the examined strains. Using the C.B-17/Icr-Prkdcscid/Prkdcscid-INS-TRECK-Tg model, we tried to perform regenerative therapeutic approaches: allogeneic transplantation of pancreatic islet cells from C57BL/6 and xenogeneic transplantation of CD34+ human umbilical cord blood cells. Both approaches successfully rescued C.B-17/Icr-Prkdcscid/Prkdcscid-INS-TRECK-Tg mice from hyperglycemia caused by DT administration. The high specificity with which DT causes depletion in pancreatic β cells of these Tg mice is highly useful for diabetogenic research

The acute effects of mianserin hydrochloride and sodium valproate on the human AEP (Auditory Evoked Potential) and EEG

The acute effects of mianserin hydrochloride (MSR) and sodium valproate (VPA) were studied by auditory evoked potential (AEP), with 16 healthy male subjects (26~43 y. o.). In the two experimental session on different days, MSR (0.3 mg/kg) or VPA (5 mg/ kg) were orally administered for each subjects. EEGs containing AEPs evoked by click stimuli once every 5 sec were derived from the two derivations (3 ch : Cz→A1+2, 6 ch : Cz →T 5 ) and recorded into magnetic tape. Reproducing the tape, AEPs with 1024 msec of analysis time were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. In the experimental session, EEG containing AEPs were recorded befored and 60, 120, and 180 min after the administration of MSR, and before and 30, 60, and 90 min after VPA. Consecutive changes of group mean AEP were studied. Individual AEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The followig results were obtained. 1. After the administration of MSR, P2 and P3 latenies of the middle latency components and those of long latency components (P6~) of AEP significantly increased. All of significant changes were decrease for the peak-to-peak amplitudes of the AEP components. These inhibitory effects of MSR on AEP were attributed to the antihistaminergic effect of MSR. Moreover, significant positive correlation was found between δ and θ power % of EEG and P2 and P3 latencies, significant negative correlation between α2 and β2 power % of EEG and P2 latency, and between α2 power % of EEG and P3 latency. These results indicate that not only P2 but also P3 reflect the activities of the reticular formation and thalamocortical systems. 2. After the administration of VPA, latencies of long latency components (P6~) significantly increased, but those of middle latency components (Pl~P3) did not significantly change. These results were attributed to the inhibitory effects of VPA on the cerebral cortex through GABA neuron system. 3. From these results, it was considered that MSR has more inhibitory effect on the reticular formation and thalamocortical systems, and VPA has main inhibitory effect on the cerebral cortex

Effects of a novel method of anesthesia combining propofol and volatile anesthesia on the incidence of postoperative nausea and vomiting in patients undergoing laparoscopic gynecological surgery

AbstractBackgroundWe investigated the effects of a novel method of anesthesia combining propofol and volatile anesthesia on the incidence of postoperative nausea and vomiting in patients undergoing laparoscopic gynecological surgery.MethodsPatients were randomly divided into three groups: those maintained with sevoflurane (Group S, n=42), propofol (Group P, n=42), or combined propofol and sevoflurane (Group PS, n=42). We assessed complete response (no postoperative nausea and vomiting and no rescue antiemetic use), incidence of nausea and vomiting, nausea severity score, vomiting frequency, rescue antiemetic use, and postoperative pain at 2 and 24h after surgery.ResultsThe number of patients who exhibited a complete response was greater in Groups P and PS than in Group S at 0–2h (74%, 76% and 43%, respectively, p=0.001) and 0–24h (71%, 76% and 38%, respectively, p<0.0005). The incidence of nausea at 0–2h (Group S=57%, Group P=26% and Group PS=21%, p=0.001) and 0–24h (Group S=62%, Group P=29% and Group PS=21%, p<0.0005) was also significantly different among groups. However, there were no significant differences among groups in the incidence or frequency of vomiting or rescue antiemetic use at 0–24h.ConclusionCombined propofol and volatile anesthesia during laparoscopic gynecological surgery effectively decreases the incidence of postoperative nausea. We term this novel method of anesthesia “combined intravenous-volatile anesthesia (CIVA)”

The acute effects of antidepressant on the human SEP (Somatosensory Evoked Potential) and EEG

The acute effects of clomipramine hydrochloride (CMI) and mianserin hydrochloride (MSR) on somatosensory evoked potential (SEP) were studied with each 12 and 16 healthy male subjects, respectively. In the two experimental sessions, CMI (0.5mg/kg) or MSR (0.3mg/ kg) was orally administered for each subject. EEGs containing SEPs evoked by electric stimuli, once every 5 sec, were derived from the two derivations (monopolar : C3'→A1+2, bipolar : C3'→F3'), and recorded into magnetic tape. Reproducing the tape, SEPs before and 120 min after the administration of these drugs, with 1024 msec of analysis time, were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. The changes of the waveform of group mean SEP were studied. Individual SEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The following, statistically significant (P<0.01, P<0.05), results were obtained. 1. After the administration of CMI, the latencies were significantly decreased for the early middle latency component (P2 and N2), and significantly increased for the long latency component (monopolar : P6~, bipolar : P7~). While those of late middle latency component (P4~P5) did not change significantly. The amplitudes of middle latency component (P3 and P4) increased significantly. In EEG, the power % were significantly increased for α1. In conclusion, stimulatory properties of CMI was verified by SEP. 2. After the administration of MSR, the latencies were significantly increased for the almost all middle and long latency component. The amplitudes of middle and long latency components (N4, P5 and P6) decreased significantly. In EEG, the power % were significantly increased for δ and θ, and significantly decreased for α2 and β2. In conclusion, sedative properties of MSR was verified by SEP

Characterisation of Ppy-lineage cells clarifies the functional heterogeneity of pancreatic beta cells in mice

Aims/hypothesis Pancreatic polypeptide (PP) cells, which secrete PP (encoded by the Ppy gene), are a minor population of pancreatic endocrine cells. Although it has been reported that the loss of beta cell identity might be associated with beta-to-PP cell-fate conversion, at present, little is known regarding the characteristics of Ppy-lineage cells. Methods We used Ppy-Cre driver mice and a PP-specific monoclonal antibody to investigate the association between Ppy-lineage cells and beta cells. The molecular profiles of endocrine cells were investigated by single-cell transcriptome analysis and the glucose responsiveness of beta cells was assessed by Ca2+ imaging. Diabetic conditions were experimentally induced in mice by either streptozotocin or diphtheria toxin. Results Ppy-lineage cells were found to contribute to the four major types of endocrine cells, including beta cells. Ppy-lineage beta cells are a minor subpopulation, accounting for 12–15% of total beta cells, and are mostly (81.2%) localised at the islet periphery. Unbiased single-cell analysis with a Ppy-lineage tracer demonstrated that beta cells are composed of seven clusters, which are categorised into two groups (i.e. Ppy-lineage and non-Ppy-lineage beta cells). These subpopulations of beta cells demonstrated distinct characteristics regarding their functionality and gene expression profiles. Ppy-lineage beta cells had a reduced glucose-stimulated Ca2+ signalling response and were increased in number in experimental diabetes models. Conclusions/interpretation Our results indicate that an unexpected degree of beta cell heterogeneity is defined by Ppy gene activation, providing valuable insight into the homeostatic regulation of pancreatic islets and future therapeutic strategies against diabetes

大阪教育大学附属池田小学校 (仮校舎) の防犯体制

In June 2001 a middle-aged man murdered several children at Ikeda Elementary School associated with Osaka University of Education. After the murder case, a temporary school was constructed at a place near the original site. In the temporary school facilities and equipment were carefully designed to protect children against crimes of offenders intruding into school. A security guard at the school gate, observation video cameras on school sites, a teachers\u27 room looking onto the playground, checking guests at the front desk, emergency buttons in classrooms, safety rules and manuals, and other measures were considered to be extremely important for protection against crimes

チュウスイ ゲンパツ フクゴウガタ セン シンケイ ナイブンピツ ガン ノ イチチケンレイ

A５２-year-old man visited our hospital because of epigastralgia. The colonoscopic examination revealed an about ４cm-protruded lesion like SMT on the appendix and findings of the biopsy specimen were compatible with the disgnosis of signet ring cell carcinoma. The primary lesion was unknown by upper gastrointestinal endoscopy, CT and PET, and the tumor markers were normal revel. At laparotomy, severe peritoneal metastasis was revealed in the abdominal cavity, especially appendix. Severe stenosis of ileocecum was found, so we conducted ileocecal resection. The histopathological diagnosis was primary signet ring cell caicinoma of appendix, SE, N２, M０, P３, pStage Ⅳ. Postoperatively mFOLFOX was started, but allergic reaction was seen after１cycle. We started Panitumumab/CPT-１１and the patient attended our emergency department with shivering chill and fever on treatment day１０. The next day he became shock state and CT revealed free air. Operation might not save his life and we started supportive care. He died on the day. The cause of his death was peritonitis by cancer perforation

Selective depletion of mouse kidney proximal straight tubule cells causes acute kidney injury

The proximal straight tubule (S3 segment) of the kidney is highly susceptible to ischemia and toxic insults but has a remarkable capacity to repair its structure and function. In response to such injuries, complex processes take place to regenerate the epithelial cells of the S3 segment; however, the precise molecular mechanisms of this regeneration are still being investigated. By applying the “toxin receptor mediated cell knockout” method under the control of the S3 segment-specific promoter/enhancer, Gsl5, which drives core 2 β-1,6-N-acetylglucosaminyltransferase gene expression, we established a transgenic mouse line expressing the human diphtheria toxin (DT) receptor only in the S3 segment. The administration of DT to these transgenic mice caused the selective ablation of S3 segment cells in a dose-dependent manner, and transgenic mice exhibited polyuria containing serum albumin and subsequently developed oliguria. An increase in the concentration of blood urea nitrogen was also observed, and the peak BUN levels occurred 3–7 days after DT administration. Histological analysis revealed that the most severe injury occurred in the S3 segments of the proximal tubule, in which tubular cells were exfoliated into the tubular lumen. In addition, aquaporin 7, which is localized exclusively to the S3 segment, was diminished. These results indicate that this transgenic mouse can suffer acute kidney injury (AKI) caused by S3 segment-specific damage after DT administration. This transgenic line offers an excellent model to uncover the mechanisms of AKI and its rapid recovery