Frontiers in antibiotic alternatives for Clostridioides difficile infection

Clostridioides difficile (C. difficile) is a gram-positive, anaerobic spore-forming bacterium and a major cause of antibiotic-associated diarrhea. Humans are naturally resistant to C. difficile infection (CDI) owing to the protection provided by healthy gut microbiota. When the gut microbiota is disturbed, C. difficile can colonize, produce toxins, and manifest clinical symptoms, ranging from asymptomatic diarrhea and colitis to death. Despite the steady-if not rising-prevalence of CDI, it will certainly become more problematic in a world of antibiotic overuse and the post-antibiotic era. C. difficile is naturally resistant to most of the currently used antibiotics as it uses multiple resistance mechanisms. Therefore, current CDI treatment regimens are extremely limited to only a few antibiotics, which include vancomycin, fidaxomicin, and metronidazole. Therefore, one of the main challenges experienced by the scientific community is the development of alternative approaches to control and treat CDI. In this Frontier article, we collectively summarize recent advances in alternative treatment approaches for CDI. Over the past few years, several studies have reported on natural product-derived compounds, drug repurposing, high-throughput library screening, phage therapy, and fecal microbiota transplantation. We also include an update on vaccine development, pre- and pro-biotics for CDI, and toxin antidote approaches. These measures tackle CDI at every stage of disease pathology via multiple mechanisms. We also discuss the gaps and concerns in these developments. The next epidemic of CDI is not a matter of if but a matter of when. Therefore, being well-equipped with a collection of alternative therapeutics is necessary and should be prioritized.     

Serotypes and antimicrobial resistance of streptococcus pneumoniae in Thailand 2002-2004

Information on pneumococcal isolates is limited in Asia. Among children younger than 5 years in rural Thailand, nasopharyngeal colonization was 60%, and 55% of carried and 62% of invasive isolates were serotypes in the 7-valent pneumococcal conjugate vaccine. Nonsusceptibility was common among the serotypes included in the vaccine. Pneumococcal conjugate vaccine might be a useful prevention tool in Thailand.     

Role of P57KIP2 Immunohistochemical Expression in Histological Diagnosis of Hydatidiform Moles

Purpose: To determine the significance of P57KIP2 immunohistochemistry expression in the histopathological diagnosis of hydatidiform mole. Materials and Methods: Hydatidiform mole patients at King Chulalongkorn Memorial Hospital between January 1999 and December 2011 were recruited. Two gynecologic pathologists reviewed histopathologic slides to confirm diagnosis. Formalin-fixed, paraffin-embedded tissue sections were stained using a bstandard immunostaining system with monoclonal antibodies against P57KIP2 protein. Correlations among pathological features, immunohistochemical expression and clinical data were analyzed. Results: One hundred and twenty-seven hydatidiform mole patients were enrolled. After consensus review, 97 cases were diagnosed as complet (CHM) and 30 cases as partial (PHM). Discordance between the first and final H and E diagnoses was found in 19 cases (14.9%, k= 0.578). Significant pathological features to classify the type of hydatidiform mole are central cisterns, trophoblastic proliferation, trophoblastic atypia, two populations of villi, fetal vessels and scalloped borders. After performing immunohistochemistry for P57KIP2, 107 cases were P57KIP2 negative and 20 cases positive. Discordant diagnoses between final H and E diagnosis and P57KIP2 immunohistochemistry was identified in 12 cases (9.4%). Sensitivity of final H and E diagnosis for CHM was 89.7%; specificity was 95.0%. PHM sensitivity and specificity of final H and E diagnosis was 95.0% and 89.7%, respectively. Conclusions: Histopathological diagnosis alone has certain limitations in accurately defining types of hydatidiform mole; P57KIP2 immunohistochemistry is practical and can be a useful adjunct to histopathology to distinguish CHM from non-CHM.     

HPV genotyping in adenocarcinoma of the uterine cervix in Thailand

Objective

To determine the distribution of human papillomavirus (HPV) genotypes in cervical adenocarcinoma in Thailand and to evaluate the clinicopathologic characteristics associated with common HPV genotypes.

Methods

Formalin-fixed, paraffin-embedded tissues from 150 patients with adenocarcinoma were collected from 4 areas of Thailand. Infection with HPV was detected by nested polymerase chain reaction (PCR) with primers MY09/11 and GP5 +/6 +. Genotyping was performed using a linear array assay, followed by type-specific PCR targeting the E6/E7 regions of HPV-16, HPV-18, and HPV-52 if the linear array test was negative.

Results

Human papillomavirus DNA was detected in 145 (97%) adenocarcinomas (132 single infections; 11 multiple infections; 2 tumors with undetermined HPV type). Genotype 18 was most common (66%), followed by HPV-16 (30%) and HPV-45 (3%). Infection with only HPV-16 and/or HPV-18 accounted for 88% of the HPV-positive tumors. Patients with HPV-18 infection had a younger age (P = 0.009) and higher tumor grade (P < 0.001) than patients with HPV-16 infection.

Conclusion

The HPV detection rate in cervical adenocarcinomas in Thailand is high. The predominant genotype is HPV-18, being twice as common as HPV-16. Genotype variations are associated with patient age and tumor grade. Vaccination against HPV-16/HPV-18 might prevent almost 90% of adenocarcinomas.     

Cyclin A1 promoter hypermethylation in human papillomavirus-associated cervical cancer

Background  

The aim of this study was to evaluate epigenetic status of cyclin A1 in human papillomavirus-associated cervical cancer. Y. Tokumaru et al., Cancer Res 64, 5982-7 (Sep 1, 2004)demonstrated in head and neck squamous-cell cancer an inverse correlation between cyclin A1 promoter hypermethylation and TP53 mutation. Human papillomavirus-associated cervical cancer, however, is deprived of TP53 function by a different mechanism. Therefore, it was of interest to investigate the epigenetic alterations during multistep cervical cancer development.     

Concurrent radiotherapy with temozolomide followed by adjuvant temozolomide and cis-retinoic acid in children with diffuse intrinsic pontine glioma

The prognosis of children with diffuse intrinsic pontine glioma (DIPG) is very poor. Radiotherapy remains the standard treatment for these patients, but the median survival time is only 9 months. Currently, the use of concurrent radiotherapy with temozolomide (TMZ) has become the standard care for adult patients with malignant gliomas. We therefore investigated this approach in 12 children diagnosed with DIPG. The treatment protocol consisted of concurrent radiotherapy at a dose of 55.8-59.4 Gy at the tumor site with TMZ (75 mg/m(2)/day) for 6 weeks followed by TMZ (200 mg/m(2)/day) for 5 days with cis-retinoic acid (100 mg/m(2)/day) for 21 days with a 28-day cycle after concurrent radiotherapy. Ten of the 12 patients had a clinical response after the completion of concurrent radiotherapy. Seven patients had a partial response, four had stable disease, and one had progressive disease. At the time of the report, 9 of the 12 patients had died of tumor progression, one patient was alive with tumor progression, and two patients were alive with continuous partial response and clinical improvement. The median time to progression was 10.2 +/- 3.0 months (95% confidence interval [CI], 4.2-16.1 months). One-year progression-free survival was 41.7% +/- 14.2%. The median survival time was 13.5 +/- 3.6 months (95% CI, 6.4-20.5 months). One-year overall survival was 58% +/- 14.2%. The patients who had a partial response after completion of concurrent radiotherapy had a longer survival time (p = 0.036) than did the other patients (those with stable or progressive disease). We conclude that the regimen of concurrent radiotherapy and TMZ should be considered for further investigation in a larger series of patients.     

Lack of prognostic significance of HER-2/neu in early epithelial ovarian cancer

A total of 74 patients with apparent early stage epithelial ovarian cancer who underwent exploratory laparotomy at King Chulalongkorn Memorial Hospital or other hospitals and were referred for further treatment, were evaluated. Formalin fixed paraffin-embedded ovarian tissue specimens were collected and immuno-stained with HER-2/neu antibodies for comparison with clinicopathologic data after median follow up of 46 months (range 3 - 83 months). The prevalence of HER-2/neu overexpression in these patients was 10.2%. No significant correlation between HER-2/neu overexpression and clinicopathological parameters (stage, ascites, capsular rupture, capsular adherence, histological subtype and histological grade) was found. Disease free survival and overall survival did not statistically differ between those with lesions positive or negative for HER-2/neu overexpression.     

Roles of the MEK1/2 and AKT pathways in CXCL12/CXCR4 induced cholangiocarcinoma cell invasion

AIM:To evaluate the expression of C-X-C motif chemokine receptor 4(CXCR4)and its signaling cascades,which were previously identified as a key factor for cancer cell progression and metastasis,in cholangiocarcinoma cell lines.METHODS:The expression of CXCR4 and its signaling cascades were determined in the cholangiocarcinoma cell lines(RMCCA1 and KKU100)by Western blotting.The invasion assays and the detection of actin polymerization were tested in these cholangiocarcinoma cells treated with CXC chemokine ligand-12(CXCL12).RESULTS:Expression of CXCR4 was detected in both cholangiocarcinoma cell lines and activation of CXCR4 with CXCL12 triggered the signaling via the extracellular signal-regulated kinase-1/2(ERK1/2)and phosphoinositide 3-kinase(PI3K)and induction of cholangiocarcinoma cell invasion,and displayed high levels of actin polymerization.Addition of CXCR4 inhibitor(AMD3100)abrogated CXCL12-induced phosphorylation of MEK1/2 and Akt in these cells.Moreover,treatment with MEK1/2 inhibitor(U0126)or PI3K inhibitor(LY294 002)also attenuated the effect of CXCL12-induced cholangiocarcinoma cell invasion.CONCLUSION:These results indicated that the activation of CXCR4 and its signaling pathways(MEK1/2 and Akt)are essential for CXCL12-induced cholangiocarcinoma cell invasion.This rises Implications on a potential role for the inhibition of CXCR4 or its signal cascades in the treatment of cholangiocarcinoma.     

Neonatal seizures and familial hypomagnesemia with secondary hypocalcemia

This report describes two female siblings suffering from hypomagnesemia with secondary hypocalcemia, diagnosed at the third and fifth week of age. They both presented with recurrent generalized convulsions. Because their serum calcium levels were low at the early stage, the diagnosis of late-onset neonatal hypocalcemia was mistakenly made. Their seizures did not respond to parenteral calcium initially, but were completely terminated after the administration of magnesium. The possible cause of hypomagnesemia in these two patients was the selective defect of magnesium absorption in the small intestine. Both patients continued to receive daily supplement of magnesium orally to the last follow-up appointment at the ages of 23 and 12 years, respectively. Despite having several generalized seizures before the correct diagnosis and proper treatment, normal physical and mental development was achieved in both patients.