Morphological changes in pancreatic islets of KATP channel-deficient mice: the involvement of KATP channels in the survival of insulin cells and the maintenance of islet architecture

The ATP-sensitive potassium channel (KATP channel) is an essential ion channel involved in glucose-induced insulin secretion. The KATP channel is composed of an inwardly rectifying potassium channel, Kir6.2, and the sulfonylurea receptor (SUR 1); in the pancreas it is reported to be shared by all endocrine cell types. A previous study by our research group showed that Kir 6.2-knockout mice lacked KATP channel activities and failed to secrete insulin in response to glucose, but displayed normal blood glucose levels and only mild impairment in glucose tolerance at younger ages. In some aged knockout mice, however, obesity and hyperglycemia were recognizable. The present study aimed to reveal morphological changes in pancreatic islets of Kir 6.2-knockout mice throughout life. At birth, there were no significant differences in the islet cell arrangement between the knockout mice and controls. At 14 postnatal weeks glucagon cells appeared in the central parts of islets, and this image became more pronounced with aging. In animals older than 50 weeks insulin cells decreased in numbers and intensity of insulin immunoreactivity; most islets in 70- and 80-week-old mice were predominantly composed of glucagon cells and peptide YY (PYY)-containing cells. Staining of serial sections and double staining of single sections from these old mice demonstrated the frequent coexpression of glucagon and PYY, which is a phenotype for the earliest progenitor cells of pancreatic endocrine cells. These findings suggest that the KATP channel is important for insulin cell survival and also regulates the differentiation of islet cells.     

Hydrothermal Synthesis and Characterization of Zeolite A from Corn (Zea Mays) Stover Ash

This study deals with the impact of calcination, alkalinity, and curing time parameters on the hydrothermal synthesis of zeolite A. The zeolite A sample, produced from corncob-stalk-and-leaves (corn stover) ash was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that calcination, alkalinity, and curing time have significant effects on the crystallization and the morphology of zeolite A. In addition, these parameters also impacted the cation exchange capacity. Furthermore, the synthesized zeolite A was obtained using a calcination temperature of 500 °C within two hours of airflow, which is much lower than the temperatures previously reported in the literature for an agricultural waste and other waste materials. A fusion ratio of corn stover ash:NaOH of 1.0:1.5 and a curing time of nine hours were achieved. This is a major result as this curing time is much lower than those featured in other studies, which can reach up to twenty-four hours. In this paper, cubic crystal with rounded edge of zeolite A, having a cation exchange capacity of 2.439 meq Na⁺/g of synthesized anhydrous zeolite A, was obtained, which can be a good candidate for ion-exchange separation.     

Epidemiology of Staphylococcus aureus Harboring the mecA or Panton-Valentine Leukocidin Genes in Hospitals in Java and Bali,Indonesia

Data of Staphylococcus aureus carriage in Indonesian hospitals are scarce. Therefore, the epidemiology of S. aureus among surgery patients in three academic hospitals in Indonesia was studied. In total, 366 of 1,502 (24.4%) patients carried S. aureus. The methicillin-resistant S. aureus (MRSA) carriage rate was 4.3%, whereas 1.5% of the patients carried Panton-Valentine leukocidin (PVL)-positive methicillin-sensitive S. aureus (MSSA). Semarang and Malang city (odds ratio [OR] 9.4 and OR 9.0), being male (OR 2.4), hospitalization for more than 5 days (OR 11.708), and antibiotic therapy during hospitalization (OR 2.6) were independent determinants for MRSA carriage, whereas prior hospitalization (OR 2.5) was the only one risk factor for PVL-positive MSSA carriage. Typing of MRSA strains by Raman spectroscopy showed three large clusters assigned type 21, 24, and 38, all corresponding to ST239-MRSA-SCCmec type III. In conclusion, MRSA and PVL-positive MSSA are present among patients in surgical wards in Indonesian academic hospitals.     

Combined panel of serum human tissue kallikreins and CA-125 for the detection of epithelial ovarian cancer

Objective

To determine the predictive accuracy of the combined panels of serum human tissue kallikreins (hKs) and CA-125 for the detection of epithelial ovarian cancer.

Methods

Serum specimens collected from 5 Indonesian centers and 1 Vietnamese center were analyzed for CA-125, hK6, and hK10 levels. A total of 375 specimens from patients presenting with ovarian tumors, which include 156 benign cysts, 172 epithelial ovarian cancers (stage I/II, n=72; stage III/IV, n=100), 36 germ cell tumors and 11 borderline tumors, were included in the study analysis. Receiver operating characteristic analysis were performed to determine the cutoffs for age, CA-125, hK6, and hK10. Sensitivity, specificity, negative, and positive predictive values were determined for various combinations of the biomarkers.

Results

The levels of hK6 and hK10 were significantly elevated in ovarian cancer cases compared to benign cysts. Combination of 3 markers, age/CA-125/hk6 or CA-125/hk6/hk10, showed improved specificity (100%) and positive predictive value (100%) for prediction of ovarian cancer, when compared to the performance of single markers having 80-92% specificity and 74-87% positive predictive value. Four-marker combination, age/CA-125/hK6/hK10 also showed 100% specificity and 100% positive predictive value, although it demonstrated low sensitivity (11.9%) and negative predictive value (52.8%).

Conclusion

The combination of human tissue kallikreins and CA-125 showed potential for improving prediction of epithelial ovarian cancer in patients presenting with ovarian tumors.     

Magnetic resonance imaging pitfalls in determining myometrial invasion in stage I endometrial cancer: A case report and literature review

The degree of myometrial invasion (MI) is crucial in the preoperative diagnosis of endometrial cancer (EC) using MRI in terms of therapeutic and prognostic implications. However, several pitfalls should be kept in mind when using this modality. We report a case of EC on a 64-year-old woman, identified preoperatively without MI based on ultrasonography and MRI, implying a low risk of lymph node metastasis; surprisingly, the uterine incision showed the lesion had invaded <50% of the myometrium. Thus, a total laparoscopic hysterectomy and bilateral salpingo-oophorectomy were performed, and histopathologic analysis confirmed that the EC was on stage IA (cancer is in the endometrium only or less than halfway through the myometrium). In our case, thinning myometrium and uterine atrophy due to aging, multiple leiomyomas, previous curettage, and blood clots were all pitfalls for MRI in detecting MI. By detecting tiny or isointense tumors and depicting distinct vascularity of the malignancy in postmenopausal women, functional MRI techniques such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) can help reduce pitfalls when assessing MI. Clinicians can employ DWI preoperatively, which is more reliable and superior to DCE-MRI in determining tumor areas without contrast injection and perform a postoperative histopathological examination to confirm MI in EC.