Noninvasive evaluation of donor and native pancreases following simultaneous pancreas-kidney transplantation using positron emission tomography/computed tomography

It is crucial to develop practical and noninvasive methods to assess the functional beta-cell mass in a donor pancreas, in which monitoring and precise evaluation is challenging. A patient with type 1 diabetes underwent noninvasive imaging following simultaneous kidney-pancreas transplantation with positron emission tomography/computed tomography (PET/CT) using an exendin-based probe, [18 F]FB(ePEG12)12-exendin-4. Following transplantation, PET imaging with [18 F]FB(ePEG12)12-exendin-4 revealed simultaneous and distinct accumulations in the donor and native pancreases. The pancreases were outlined at a reasonable distance from the surrounding organs using [18 F]FB(ePEG12)12-exendin-4 whole-body maximum intensity projection and axial PET images. At 1 and 2 h after [18 F]FB(ePEG12)12-exendin-4 administration, the mean standardized uptake values were 2.96 and 3.08, respectively, in the donor pancreas and 1.97 and 2.25, respectively, in the native pancreas. [18 F]FB(ePEG12)12-exendin-4 positron emission tomography imaging allowed repeatable and quantitative assessment of beta-cell mass following simultaneous kidney-pancreas transplantation.

18F-labeled PEGylated exendin-4 imaging noninvasively differentiates insulinoma from an accessory spleen: the first case report of [18F]FB(ePEG12)12-exendin-4 positron emission tomography/computed tomography for insulinoma

Background

Insulinomas are the most common functioning pancreatic neuroendocrine neoplasms, and these tumors induce hypoglycemia due to hyperinsulinemia. Hypoglycemia caused by insulinomas can cause seizures, coma or death due to the delayed diagnosis. The only curative treatment is surgical resection. To perform curative surgical resection of insulinomas, preoperative localization is crucial. However, localization of insulinomas is often challenging using conventional imaging methods such as computed tomography (CT) and magnetic resonance imaging. Although endoscopic ultrasound (EUS) fine-needle aspiration and selective arterial calcium stimulation test, which can reflect the endocrine character of the tumor, are performed in such cases, these modalities are invasive and require operator-dependent techniques. Additionally, somatostatin receptor (SSTR)-targeted imaging has a relatively low sensitivity for detecting insulinomas due to its low SSTR type 2 expression. Thus, there is an urgent need for developing a noninvasive diagnostic technique which is specific for detecting insulinomas. Consequently, glucagon-like peptide-1 receptor-targeted imaging has recently emerged and gained a wide interest. Recently, we have developed a novel 18F-labeled exendin-4-based probe conjugated with polyethylene glycol, [18F]FB(ePEG12)12-exendin-4 (18F-exendin-4), for positron emission tomography (PET) imaging. Here we report a case of insulinoma in which 18F-exendin-4 PET/CT noninvasively provided critical information for localization.

Case description

This is a case of a 58-year-old male with symptomatic hypoglycemia for 10 years; however, a preoperative diagnosis of insulinoma was not established due to the difficulty in differentiating it from an accessory spleen using conventional imaging. Moreover, the patient requested to avoid invasive diagnostic procedures including EUS. 18F-exendin-4 PET/CT revealed significant uptakes in the pancreatic tail whereas no apparent uptakes were observed in the spleen; thus, curative laparoscopic enucleation of the pancreatic tail was performed. The diagnosis of insulinoma was confirmed via histopathological examination. This is the first case report of insulinoma diagnosed using 18F-exendin-4 PET/CT.

Conclusion

In this case, PET information led to curative resection through enucleation of the pancreas. 18F-exendin-4 PET/CT may serve as a useful noninvasive clinical tool for insulinoma localization.

Preservation effect of imeglimin on pancreatic β-cell mass: Noninvasive evaluation using 111In-exendin-4 SPECT/CT imaging and the perspective of mitochondrial involvements

Progressive loss of β-cell mass (BCM) has a pernicious influence on type 2 diabetes mellitus (T2DM); evaluation of BCM has conventionally required an invasive method that provides only cross-sectional data. However, a noninvasive approach to longitudinal assessment of BCM in living subjects using an indium 111-labeled exendin-4 derivative ([Lys12(¹¹¹In-BnDTPA-Ahx)]exendin-4) (¹¹¹In-exendin-4) has been developed recently. Imeglimin is a novel antidiabetic agent that is reported to improve glycemic control and glucose-stimulated insulin secretion (GSIS) via augmentation of mitochondrial function. However, the influence of imeglimin on BCM is not fully understood. We have investigated the effects of imeglimin on BCM in vivo in prediabetic db/db mice using a noninvasive ¹¹¹In-exendin-4 single-photon emission computed tomography/computed tomography (SPECT/CT) technique. During the 5-week study period, imeglimin treatment attenuated the progression of glucose intolerance, and imeglimin-treated mice retained greater BCM than control, which was consistent with the results of ¹¹¹In-exendin-4 SPECT/CT scans. Furthermore, immunohistochemical analysis revealed reduced β-cell apoptosis in the imeglimin-treated db/db mice, and also lowered release of cytosolic cytochrome c protein in the β cells. Furthermore, electron microscopy observation and membrane potential measurement revealed improved structural integrity and membrane potential of the mitochondria of imeglimin-treated islets, respectively. These results demonstrate attenuation of progression of BCM loss in prediabetic db/db mice partly via inhibition of mitochondria-mediated apoptosis.

Two Cases of Anti-PIT-1 Hypophysitis Exhibited as a Form of Paraneoplastic Syndrome

Background: Anti-pituitary-specific transcription factor 1 (PIT-1) hypophysitis (anti-PIT-1 antibody syndrome) is a newly defined clinical entity, demonstrating an adult-onset hypopituitarism, and is a thymoma-associated autoimmune disease characterized by acquired GH, PRL, and TSH deficiencies due to autoimmunity against PIT-1 (1, 2). This disease is defined by an acquired specific GH, PRL, and TSH deficiencies and the presence of circulating anti-PIT-1 antibody and/or PIT-1-specific T cells (2). As the etiology, ectopic expression of PIT-1 in thymoma plays a causal role in the development of the disease (3); however, it is unknown whether this disease is involved in other conditions. Here, we report two PIT-1 hypophysitis cases, exhibiting as a form of paraneoplastic syndrome with malignancies other than thymoma. Clinical Case: A 79-year-old woman (case 1) and an 86-year-old man (case 2) were referred to us on suspicion of anti-PIT-1 hypophysitis because of acquired GH, PRL, and TSH deficiencies. In both patients, the endocrinological evaluation revealed extremely low basal levels and blunted responses of GH, PRL, and TSH to the provocative stimuli. In contrast, the secretion of HPA and HPG axis were preserved in both patients. Magnetic resonance imaging of the pituitary gland showed slight atrophy in case 1 and normal size in case 2. Interestingly, computed tomography imaging revealed no evidence for thymomas in both patients. On the other hand, case 1 was complicated with diffuse large B-cell lymphoma (DLBCL) of the bladder with multiple bilateral cervicals, axillary, para-aorta, and internal and external peri iliac lymphadenopathies. Case 2 was diagnosed with malignancy with multiple metastases of unknown origin with para-aortic and para-gastric lymphadenopathies, and vertebral body infiltrates. Because circulating anti-PIT-1 antibody was detected, both patients were diagnosed with anti-PIT-1 hypophysitis. Circulating PIT-1-reactive T cells were detected in case 1 using Enzyme-Linked Immunospot assay. Interestingly, the PIT-1 protein was ectopically expressed in the DLBCL tissue of case 1, while DLBCL tissues derived from control patients without anti-PIT-1 hypophysitis were negative for PIT-1. In case 2, the materials were not available because of the situation of the best supportive care. Conclusion: These data show that anti-PIT-1 hypophysitis is associated not only with thymoma but also with other malignancies. Additionally, the ectopic expression of PIT-1 in the DLBCL tissues and presence of PIT-1-

reactive T cells suggested that the underlying mechanisms were similar to those observed in thymoma (3). Thus, anti-PIT-1 hypophysitis is defined as a form of paraneoplastic syndrome. Reference: (1) J Clin Invest. 2011;121(1):113-119., (2) Endocr Rev. 2020;41(2)., (3) Sci Rep. 2017;7:43060.

Two Cases of anti-PIT-1 Hypophysitis Exhibited as a Form of Paraneoplastic Syndrome not Associated With Thymoma

Anti–pituitary-specific transcription factor 1 (PIT-1) hypophysitis (anti–PIT-1 antibody syndrome) is a thymoma-associated autoimmune disease characterized by acquired growth hormone (GH), prolactin (PRL), and thyrotropin (TSH) deficiencies due to autoimmunity against PIT-1. Ectopic expression of PIT-1 in the thymoma plays a causal role in development of the disease. Here, we report 2 cases of anti–PIT-1 hypophysitis exhibiting as a form of paraneoplastic syndrome with conditions other than thymoma. A 79-year-old woman (case 1) and an 86-year-old man (case 2) were referred with a suspicion of anti–PIT-1 hypophysitis because of acquired GH, PRL, and TSH deficiencies. Case 1 was complicated by diffuse large B-cell lymphoma (DLBCL) of the bladder and case 2 was diagnosed with malignancy with multiple metastases of unknown origin. Because circulating anti–PIT-1 antibody was detected, both patients were diagnosed with anti–PIT-1 hypophysitis. Circulating PIT-1–reactive T cells were detected in case 1 via enzyme-linked immunospot (ELISPOT) assay. Interestingly, the PIT-1 protein was ectopically expressed in the DLBCL cells of case 1, whereas DLBCL tissues derived from patients without anti–PIT-1 hypophysitis were negative for PIT-1. In case 2, the materials were not available because of best supportive care was under way. These data show that anti–PIT-1 hypophysitis is associated not only with thymoma but also with other malignancies. Additionally, the ectopic expression of PIT-1 in the DLBCL tissues and presence of PIT-1–reactive T cells suggested that the underlying mechanisms were similar to those observed in thymoma. Thus, anti–PIT-1 hypophysitis is defined as a form of paraneoplastic syndrome.

Anteroposterior weight-bearing radiography of the knee with both knees in semiflexion, using new equipment

In order to obtain high reproducibility and sensitivity in the evaluation of joint space in osteoarthritic knees, we used new equipment, and established an anteroposterior weight-bearing radiograph with both knees in semiflexion taking into account our investigation of the posterior slope angle. We compared our method with the Rosenberg method, and the coefficient of variation of our method showed higher reproducibility than that of the Rosenberg method. The most essential issue is whether the bilateral leg loading radiograph can show the same sensitivity as the homolateral leg loading radiograph. We compared standing radiographs of the knee in 26 degrees flexion with those of 26 degrees flexion in both knees. We assessed the widths of the narrowest points of the joint spaces in the medial and lateral compartments, the condylar plateau angle, and the femorotibial angle, in 47 knees in 24 patients. The data were analyzed statistically by single regression and each correlation was of statistical significance. Our method has better reproducibility and is more comfortable for the subject than conventional methods.

Membrane perturbing factor in reticulocyte lysate, which is transiently activated by proteases

Proteases have been used to examine the topology of proteins on various membranes. We reexamined the conditions of protease treatment for rough microsomal membranes and found that proteinase K degraded the lumenal proteins in the presence of reticulocyte lysate. The lysate treated with either heat or N-ethylmaleimide no longer promoted the degradation. The reticulocyte dependent degradation was also observed with papain, trypsin, and elastase. This activity was transiently generated by treating reticulocyte lysate short-term with trypsin. We thus concluded that a membrane perturbing factor(s) must exist in reticulocyte which is transiently activated by protease treatment.

[Inhibition of 5-fluorouracil-cisplatin-induced stomatitis by oral cryotherapy: use of an ice-bar containing fibrinolysin and deoxyribonuclease combine (Elase)]

Stomatitis caused by a combined chemotherapy with 5-fluorouracil (5-FU) and cisplatin (CDDP) is a serious problem in the course of treatment for patients with oral carcinoma. In the present study, we proposed a form of cryotherapy using an ice-bar containing fibrinolysin and deoxyribonuclease (Elase) to inhibit the stomatitis. The therapeutic effect of the ice-bar cryotherapy was evaluated in 20 patients with oral squamous cell carcinoma who were undergoing 5-FU-CDDP chemotherapy. Nine of the 20 patients were given the ice-bar cryotherapy while the remaining patients were not. As a result, although there was no significant difference between the incidence of stomatitis in the groups with and without the ice-bar cryotherapy, the incidence of severe stomatitis with ulcers and/or eating disturbance in the 11 cases without the ice-bar cryotherapy (90%) was significantly higher than that in the 9 cases with the cryotherapy (44%) (p < 0.05). However, no significant difference in the clinical response rate of the 5-FU-CDDP chemotherapy was observed between the two groups.

New serine protease inhibitors with leukotriene B4 (LTB4) receptor binding affinity

A series of new trypsin-like serine protease inhibitors, 1, 2 and 7-23, containing amidinobenzene moiety was found to show potent LTB4-receptor affinity. Among them, compounds 1 and 2 were found to be LTB4 receptor antagonists based on an inhibition assay of human polymorphonuclear neutrophil (PMN) intracellular calcium mobilization induced by LTB4. Compounds 1 and 2, which satisfy the reported structural requirements for good oral activity, are expected to show a balanced dual mode of action, i.e., protease inhibitory activity and LTB4 receptor antagonist activity, in vivo.

New orally active serine protease inhibitors: structural requirements for their good oral activity

Synthesis and structural requirements for good oral activity of a series of para-substituted benzoyl esters of 4-hydroxybenzamidine serine protease inhibitors are described. The structure required for good oral activity was found to be general formula II whose corresponding ester has to be hydrolyzed in the intestine before absorption through the mucous membranes or in plasma after absorption. Biological evaluation of oral absorption using plasma anti-trypsin activity was useful for rapid evaluation. By measuring their actual plasma concentrations after oral administration, compounds 14 and 16b were confirmed to show good area under the plasma concentration-time curves (AUC). Their plasma concentrations corresponded to their plasma anti-trypsin activity. Structure-oral activity relationships are discussed.

Development of a highly cardioselective ultra short-acting beta-blocker, ONO-1101

A novel, highly cardioselective ultra short-acting beta-blocker, ONO-1101, has been developed for application in the emergency treatment of tachycardia and better control of heart rate in surgery. This agent is approximately nine times more potent in beta-blocking activity in vivo and eight times more cardioselective in vitro than esmolol. This beta-blocking drug has a short duration of activity, enabling rapid recovery after cessation of administration if side effects occur. It can be used safely in patients suffering from acute heart disease and represents a major therapeutic advance in the treatment of heart disease.

Synthesis and antitumor activity of tropolone derivatives. 7. Bistropolones containing connecting methylene chains

Bistropolone derivatives (4-12) containing differing lengths of linkage between the two tropolone rings were prepared and examined for their antitumor activity in in vitro (KB cell) and in vivo (leukemia P388 in mice) systems. Parent compound 3, related compounds previously prepared, and the new compounds 4-12 were evaluated for inhibitory activity against ribonucleotide reductase by indirect means to measure their effects on the dNTP pool imbalance. Present structure-activity relationship results would suggest that potently active bistropolones in vivo inhibit intracellular ribonucleotide reductase through chelating with the two irons at the two active sites of the enzyme.