Competency of iPSC-derived retinas in MHC-mismatched transplantation in non-human primates.

Transplantation of embryonic/induced pluripotent stem cell-derived retina (ESC/iPSC-retina) restores host retinal ganglion cell light responses in end-stage retinal degeneration models with host-graft synapse formation. We studied the immunological features of iPSC-retina transplantation using major histocompatibility complex (MHC)-homozygote monkey iPSC-retinas in monkeys with laser-induced retinal degeneration in MHC-matched and -mismatched transplantation. MHC-mismatched transplantation without immune suppression showed no evident clinical signs of rejection and histologically showed graft maturation without lymphocytic infiltration, although immunological tests using peripheral blood monocytes suggested subclinical rejection in three of four MHC-mismatched monkeys. Although extensive photoreceptor rosette formation was observed on histology, evaluation of functional integration using mouse models such as mouse ESC-retina (C57BL/6) transplanted into rd1(C3H/HeJ, MHC-mismatched model) elicited light responses in the host retinal ganglion cells after transplantation but with less responsiveness than that in rd1-2J mice (C57BL/6, MHC-matched model). These results suggest the reasonable use of ESC/iPSC-retina in MHC-mismatched transplantation, albeit with caution.

Medium- to long-term survival and functional examination of human iPSC-derived retinas in rat and primate models of retinal degeneration.

BACKGROUND: We have previously reported that xeno-transplanted human ESC-derived retinas are able to mature in the immunodeficient retinal degeneration rodent models, similar to allo-transplantations using mouse iPSC-derived retina. The photoreceptors in the latter developed outer segments and formed synapses with host bipolar cells, driving light responses of host retinal ganglion cells. In view of clinical application, here we further confirmed the competency of human iPSC-derived retina (hiPSC-retina) to mature in the degenerated retinas of rat and monkey models. METHODS: Human iPSC-retinas were transplanted in rhodopsin mutant SD-Foxn1 Tg(S334ter)3LavRrrc nude rats and two monkeys with laser-induced photoreceptor degeneration. Graft maturation was studied by immunohistochemistry and its function was examined by multi-electrode array (MEA) recording in rat retinas and visually-guided saccade (VGS) in a monkey. FINDINGS: A substantial amount of mature photoreceptors in hiPSC-retina graft survived well in the host retinas for at least 5 months (rat) to over 2 years (monkey). In 4 of 7 transplanted rat retinas, RGC light responses were detected at the grafted area. A mild recovery of light perception was also suggested by the VGS performance 1.5 years after transplantation in that monkey. INTERPRETATION: Our results support the competency of hiPSC-derived retinas to be clinically applied for transplantation therapy in retinal degeneration, although the light responses observed in the present models were not conclusively distinguishable from residual functions of degenerating host retinas. The functional analysis may be further elaborated using other models with more advanced retinal degeneration.

Establishment of Immunodeficient Retinal Degeneration Model Mice and Functional Maturation of Human ESC-Derived Retinal Sheets after Transplantation.

Increasing demand for clinical retinal degeneration therapies featuring human ESC/iPSC-derived retinal tissue and cells warrants proof-of-concept studies. Here, we established two mouse models of end-stage retinal degeneration with immunodeficiency, NOG-rd1-2J and NOG-rd10, and characterized disease progress and immunodeficient status. We also transplanted human ESC-derived retinal sheets into NOG-rd1-2J and confirmed their long-term survival and maturation of the structured graft photoreceptor layer, without rejection or tumorigenesis. We recorded light responses from the host ganglion cells using a multi-electrode array system; this result was consistent with whole-mount immunostaining suggestive of host-graft synapse formation at the responding sites. This study demonstrates an application of our mouse models and provides a proof of concept for the clinical use of human ESC-derived retinal sheets.

Corneal Erosion With Pigments Derived From a Cosmetic Contact Lens: A Case Report.

PURPOSE: To report a case of corneal erosion with pigments derived from a cosmetic contact lens (CCL). METHODS: A 29-year-old woman complained of foreign body sensation after wearing CCL. Slit-lamp examination of her left eye revealed corneal erosion with yellow pigment at its edges. The surface of the CCLs was examined using the rub-off test and scanning electron microscopy (SEM). An elementary analysis using SEM with energy-dispersive x-ray (SEM-EDX) was also performed. RESULTS: On the back surface of the CCL, the pigments easily came off during the rub-off test. An SEM examination found exposed pigments with needle-like construction on the back surface. SEM-EDX revealed the presence of carbon, oxygen, iron, titanium, and chlorine in the pigments. CONCLUSION: Direct contact between the bare pigments on a CCL and the corneal surface can cause corneal damage.

One year follow-up after a randomized controlled trial of a 130 g/day low-carbohydrate diet in patients with type 2 diabetes mellitus and poor glycemic control.

BACKGROUND & AIMS: Recently, we conducted a prospective randomized controlled trial (RCT) showing that a 6-month 130g/day low-carbohydrate diet (LCD) reduced HbA1c and BMI more than a calorie restricted diet (CRD). [1] To assess whether the benefits of the LCD persisted after the intensive intervention, we compared HbA1c and BMI between the LCD and CRD groups at 1 year after the end of the 6-month RCT. METHODS: Following the end of the 6-month RCT, patients were allowed to manage their own diets with periodic outpatient visits. One year later, we analyzed clinical and nutrition data. RESULTS: Of the 66 participants in the original study, 27 in the CRD group and 22 in the LCD group completed this trial. One year after the end of the original RCT, the carbohydrate intake was comparable between the groups (215 [189-243]/day in the CRD group and 214 (176-262) g/day in the LCD group). Compared with the baseline data, HbA1c and BMI were decreased in both groups (CRD: HbA1c -0.4 [-0.9 to 0.3] % and BMI -0.63 [-1.20 to 0.18] kg/m2; LCD: HbA1c -0.35 [-1.0 to 0.35] % and BMI -0.77 [-1.15 to -0.12] kg/m2). There were no significant differences in HbA1c and BMI between the groups. CONCLUSIONS: One year after the diet therapy intervention, the beneficial effect of the LCD on reduction of HbA1c and BMI did not persist in comparison with CRD. However, combining the data of both groups, significant improvements in HbA1c and BMI from baseline were observed. Although the superiority of the LCD disappeared 1 year after the intensive intervention, these data suggest that well-constructed nutrition therapy programs, both CRD and LCD, were equally effective in improving HbA1c for at least 1 year. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN) ID000010663.

A randomized controlled trial of 130 g/day low-carbohydrate diet in type 2 diabetes with poor glycemic control.

BACKGROUND & AIMS: The usefulness of low-carbohydrate diet (LCD) for Japanese patients with type 2 diabetes mellitus (T2DM) has not been fully investigated. Therefore, we compared the effectiveness and safety of LCD with calorie restricted diet (CRD). METHODS: This prospective, randomized, open-label, comparative study included 66 T2DM patients with HbA1c >7.5% even after receiving repeated education programs on CRD. They were randomly allocated to either the 130g/day LCD group (n = 33) or CRD group (n = 33). Patients received personal nutrition education of CRD or LCD for 30 min at baseline, 1, 2, 4, and 6 months. Patients of the CRD group were advised to maintain the intake of calories and balance of macronutrients (28× ideal body weight calories per day). Patients of the LCD group were advised to maintain the intake of 130 g/day carbohydrate without other specific restrictions. Several parameters were assessed at baseline and 6 months after each intervention. The primary endpoint was a change in HbA1c level from baseline to the end of the study. RESULTS: At baseline, BMI and HbA1c were 26.5 (24.6-30.1) and 8.3 (8.0-9.3), and 26.7 (25.0-30.0) kg/m2 and 8.0 (7.6-8.9) %, in the CRD and LCD, respectively. At the end of the study, HbA1c decreased by -0.65 (-1.53 to -0.10) % in the LCD group, compared with 0.00 (-0.68 to 0.40) % in the CRD group (p < 0.01). Also, the decrease in BMI in the LCD group [-0.58 (-1.51 to -0.16) kg/m2] exceeded that observed in the CRD group (p = 0.03). CONCLUSIONS: Our study demonstrated that 6-month 130 g/day LCD reduced HbA1c and BMI in poorly controlled Japanese patients with T2DM. LCD is a potentially useful nutrition therapy for Japanese patients who cannot adhere to CRD. This trial was registered at http://www.umin.ac.jp/english/ (University Hospital Medical Information Network: study ID number 000010663).

Gastric rupture with necrosis following acute gastric dilatation: report of a case.

Gastric rupture with necrosis following acute gastric dilatation (AGD) is a rare and potentially fatal event; usually seen in patients with eating disorders such as anorexia nervosa or bulimia. A 12-year-old lean boy with no remarkable medical history was brought to our Emergency Department suffering acute abdominal symptoms. Emergency laparotomy revealed massive gastric dilatation and partial necrosis, with rupture of the anterior wall of the fundus of the stomach. We performed partial gastrectomy and the patient recovered uneventfully. We report this case to demonstrate that AGD and subsequent gastric rupture can occur in patients without any underlying disorders and that just a low body mass index is a risk factor for this potentially fatal condition.