Most of the filtered glucose is reabsorbed in the early proximal tubule by the sodium-glucose cotransporter SGLT2. The glycosuric effect of the SGLT2 inhibitor ipragliflozin is linked to a diuretic and natriuretic effect that activates compensatory increases in fluid and food intake to stabilize body fluid volume (BFV). However, the compensatory mechanisms that are activated on the level of renal tubules remain unclear. Type 2 diabetic Goto-Kakizaki (GK) rats were treated with vehicle or 0.01% (in diet) ipragliflozin with free access to fluid and food. After 8 weeks, GK rats were placed in metabolic cages for 24-hr. Ipragliflozin decreased body weight, serum glucose and systolic blood pressure, and increased fluid and food intake, urinary glucose and Na + excretion, urine volume, and renal osmolar clearance, as well as urine vasopressin and solute-free water reabsorption (TcH2O). BFV, measured by bioimpedance spectroscopy, and fluid balance were similar among the two groups. Urine vasopressin in ipragliflozin-treated rats was negatively and positively associated with fluid balance and TcH2O, respectively. Ipragliflozin increased the renal membrane protein expression of SGLT2, aquaporin (AQP) 2 phosphorylated at Ser269 and vasopressin V2 receptor. The expression of SGLT1, GLUT2, AQP1, and AQP2 was similar between the groups. In conclusion, the SGLT2 inhibitor ipragliflozin induced a sustained glucosuria, diuresis, and natriuresis, with compensatory increases in fluid intake and vasopressin-induced TcH2O in proportion to the reduced fluid balance to maintain BFV. These results indicate that the osmotic diuresis induced by SGLT2 inhibition stimulates compensatory fluid intake and renal water reabsorption to maintain BFV. K E Y W O R D Sbioimpedance analysis, glucosuria, SGLT2 inhibition, vasopressin, water reabsorption

Aim Sodium‐glucose cotransporter 2 (SGLT2) inhibitors are an antihyperglycemic drug with diuretic properties. We recently reported that an SGLT2 inhibitor ameliorated extracellular fluid expansion with a transient increase in urinary Na+ excretion. However, the effects of SGLT2 inhibitors on fluid distribution in comparison to conventional diuretics remain unclear. Methods Forty chronic kidney disease patients with fluid retention (average estimated glomerular filtration rate 29.2 ± 3.2 mL/min per 1.73 m2) were divided into the SGLT2 inhibitor dapagliflozin (DAPA), loop diuretic furosemide (FR) and vasopressin V2 receptor antagonist tolvaptan (TLV). The body fluid volume was measured on days 0 and 7 using a bioimpedance analysis device. Results In all three groups, body weight was significantly and similarly decreased, and urine volume numerically increased for 7 days. Bioimpedance analysis showed that the changes in intracellular water were similar, but that there were significant changes in the extracellular water (ECW) (DAPA −8.4 ± 1.7, FR −12.5 ± 1.3, TLV −7.4 ± 1.5%, P = 0.048). As a result, the change in the ratio of ECW to total body water in the DAPA group was significantly smaller than that in the FR group, but numerically larger than that in the TLV group (DAPA −1.5 ± 0.5, FR −3.6 ± 0.5, TLV −0.5 ± 0.4%, P < 0.001). Conclusion Sodium‐glucose cotransporter 2 inhibitor DAPA predominantly decreased the ECW with a mild increase in urine volume, but the change in the ECW/total body water was smaller than that in patients treated with FR, and larger than that in patients treated with TLV, suggesting that the effects of SGLT2 inhibitors on fluid distribution may differ from those of conventional diuretics.

The chronic intrinsic diuretic and natriuretic tone of sodium-glucose cotransporter 2 (SGLT2) inhibitors is incompletely understood because their effect on body fluid volume (BFV) has not been fully evaluated and because they often increase food and fluid intake at the same time. Here we first compared the effect of the SGLT2 inhibitor ipragliflozin (Ipra, 0.01% in diet for 8 wk) and vehicle (Veh) in Spontaneously Diabetic Torii rat, a nonobese type 2 diabetic model, and nondiabetic Sprague-Dawley rats. In nondiabetic rats, Ipra increased urinary excretion of Na (UNaV) and fluid (UV) associated with increased food and fluid intake. Diabetes increased these four parameters, but Ipra had no further effect, probably because of its antihyperglycemic effect, such that glucosuria and, as a consequence, food and fluid intake were unchanged. Fluid balance and BFV, determined by bioimpedance spectroscopy, were similar among the four groups. To study the impact of food and fluid intake, nondiabetic rats were treated for 7 days with Veh, Ipra, or Ipra+pair feeding+pair drinking (Pair-Ipra). Pair-Ipra maintained a small increase in UV and UNaV versus Veh despite similar food and fluid intake. Pair-Ipra induced a negative fluid balance and decreased BFV, whereas Ipra or Veh had no significant effect compared with basal values. In conclusion, SGLT2 inhibition induces a sustained diuretic and natriuretic tone. Homeostatic mechanisms are activated to stabilize BFV, including compensatory increases in fluid and food intake.

Background: Sodium-glucose cotransporter 2 (SGLT2) inhibitors are an antihyperglycemic drug with diuretic action. We recently reported that the SGLT2 inhibitor dapagliflozin ameliorates extracellular volume expansion with a mild increase in urine volume. However, the impact of the pretreatment extracellular volume status on the body fluid response to SGLT2 inhibitors remains unclear. Methods: Thirty-six diabetic kidney disease (DKD) patients were treated with dapagliflozin. The body fluid volume, including intracellular water (ICW), extracellular water (ECW) and total body water (TBW), were measured on baseline and day 7 using a bioimpedance analysis (BIA) device. The ECW/TBW and ECW were used as markers of the extracellular volume status. For a comparison, the extracellular volume status responses to loop diuretic furosemide (n = 16) and vasopressin V2 receptor antagonist tolvaptan (n = 13) were analyzed. Results: The body weight, brain natriuretic peptide and body fluid parameters measured by a BIA (ICW, ECW, TBW, and ECW/TBW) were significantly decreased for 1 week after dapagliflozin administration. The change in the ECW/ TBW in the high-ECW/TBW group (over the median value of 0.413) was significantly higher than in the low-ECW/TBW group (− 2.1 ± 0.4 vs. − 0.5 ± 0.4%, p = 0.006). Only with dapagliflozin treatment (not furosemide or tolvaptan treatment) was the baseline ECW/TBW significantly correlated with the changes in the ECW/TBW (r = − 0.590, p < 0.001) and ECW (r = − 0.374, p = 0.025). Conclusions: The pretreatment extracellular volume status predicts the body fluid response to the SGLT2 inhibitor dapagliflozin in DKD patients. The diminished extracellular fluid reduction effect of dapagliflozin in patients without severe extracellular fluid retention may contribute to maintaining a suitable body fluid status.

We investigated the effects of structured background noise on the detectability of stenotic lesions. Digital subtraction angiographic (DSA) images of stenotic blood vessels were simulated and superimposed onto uniform noise samples. Eighteen-alternative forced choice (18-AFC) experiments were employed to determine the detectability of the stenotic lesion in the structured-noise background of a blood vessel. In this study, the dependence of detectability on lesion size, vessel size, and incident x-ray exposure was examined. Our results indicate that the presence of structured noise in an image will reduce the detectability of a lesion. However, the relative performance of an observer when the lesion size and incident exposure were varied was the same with and without the presence of the structured background. Thus, conclusions obtained previously with regard to changes in the detectability of a lesion in the presence of uniform background noise can be applied directly to conditions in which simple structured anatomic background is present.

The authors report the results of internal irradiation with labeled chromic phosphate (32P) and gold-198 (198Au) colloid in eight cases of cystic craniopharyngiomas. They used a newly developed dosimetric formula, by which the radiation dose at the cyst wall and at any point far from the radioactive source can be calculated. Ten courses of irradiation in eight patients were carried out by injection of either 32P or 198Au colloid into the cyst through an Ommaya drainage system that had been placed at craniotomy. Follow-up studies ranging from 13 to 156 months revealed that all cysts were effectively treated, with elimination of fluid or collapse of the cyst. This was confirmed by Conray cystography and/or computerized tomography. Not only the dose delivered to the wall but also the thickness of the cyst wall and the location of the cyst are important factors in planning internal irradiation. A safe and adequate dose to the cyst wall could range between 9000 to 30,000 rads for craniopharyngioma. This treatment is suitable for large cysts that are thought to be difficult to remove radically, recurrent cysts resistant to previous treatment, or multiple cysts. Internal irradiation may also be applicable in other cystic intracranial tumors if dosimetry is calculated accurately.

BackgroundWhile ovarian mature cystic teratomas are benign ovarian germ-cell tumors and the most common type of all ovarian tumors, the formation of fistulas into surrounding organs such as the bladder and the intestinal tract is extremely rare. This report documents a case of ovarian mature cystic teratoma with a rectal fistula, thought to be caused by local inflammation.Case descriptionA pelvic mass was diagnosed as an ovarian mature cystic teratoma of approximately 10 cm in diameter on transvaginal ultrasound and magnetic resonance examinations. Endoscopic examination of the lower gastrointestinal tract to investigate diarrhea revealed an ulcerative lesion with hair in the rectal wall adjacent to the ovarian cyst, and formation of a fistula from the ovarian teratoma into the rectum was suspected. Laparotomy revealed extensive inflammatory adhesions between a left ovarian tumor and the rectum. Left salpingo-oophorectomy and upper anterior resection of the rectum were performed. The final pathological diagnosis was ovarian mature cystic teratoma with no malignant findings, together with severe rectal inflammation and fistula formation with no structural disorders such as diverticulitis of the colon or malignant signs.DiscussionThe formation of fistulas and invasion into the neighboring organs are extremely rare complications for ovarian mature cystic teratomas. The invasion of malignant cells into neighboring organs due to malignant transformation of the tumor is reported as the cause of fistula formation into the neighboring organs. A review of 17 cases including the present case revealed that fistula formation due to malignant transformation comprised only 4 cases (23.5 %), with inflammation as the actual cause in the majority of cases (13 cases, 76.5 %).ConclusionAlthough malignancy is the first consideration when fistula formation is observed between ovarian tumors and surrounding organs, in mature cystic teratoma, local inflammation is more likely than malignant transformation.

The maximum excretion rates of Iodine in exhalation, perspiration and salivation were measured in patients treated with I3'I for thyroid carcinoma and hyperthyroidism. The contamination of dishes, chopsticks, toothbrushes, linen (coversheets, sheets and towels), and underwear (shirts and drawers) were monitored and evaluated along wjth the air contamination level arising from these items.The maximum excretion rate of the administered dose on a n average was 3.2x per hr in exhalation, 2.45 x per hr in perspiration, and 6.3 x per ml. in salivation. The maximum contamination rate of items ranged from 1.1 x to lo-' of the administered dose. The predominant radio activity of the skin surface resulted from perspiration with a maximum of 1.8% evaporation into the air as water vapor. The air contamination level ranged 1.4 x lo-' to 1.2 x lo-' per hr of the administered dose.