Renin-angiotensin system blockers and modulation of radiation-induced brain injury

Radiation-induced brain injury remains a major cause of morbidity in cancer patients with primary or metastatic brain tumors. Approximately 200,000 individuals/year are treated with fractionated partial or whole-brain irradiation, and > half will survive long enough (≤6 months) to develop radiation-induced brain injury, including cognitive impairment. Although short-term treatments have shown efficacy, no long-term treatments or preventive approaches are presently available for modulating radiation-induced brain injury. Based on previous preclinical studies clearly demonstrating that renin-angiotensin system (RAS) blockers can modulate radiation-induced late effects in the kidney and lung, we and others hypothesized that RAS blockade would similarly modulate radiation-induced brain injury. Indeed, studies in the last 5 years have shown that both angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor antagonists (AT(1)RAs) can prevent/ameliorate radiation-induced brain injury, including cognitive impairment, in the rat. The mechanistic basis for this RAS blocker-mediated effect remains the subject of ongoing investigations. Putative mechanisms include, i] blockade of Ang II/NADPH oxidase-mediated oxidative stress and neuroinflammation, and ii] a change in the balance of angiotensin (Ang) peptides from the pro-inflammatory and pro-oxidative Ang II to the anti-inflammatory and anti-oxidative Ang-1-7). However, given that both ACEIs and AT(1)RAs are 1] well-tolerated drugs routinely prescribed for hypertension, 2] exhibit some antitumor properties, and 3] can prevent/ameliorate radiation-induced brain injury, they appear to be ideal drugs for future clinical trials, offering the promise of improving the quality of life of brain tumor patients receiving brain irradiation.

Transplantation of immortalized human fetal hepatocytes prevents acute liver failure in 90% hepatectomized mice

AIM

The aim of this study was to investigate whether human fetal hepatocytes are amenable to simian virus 40 large T-antigen (SV40Tag) mediated immortalization and whether the immortalized cells rescue mice with acute liver failure induced by 90% hepatectomy.

METHODS

We constructed a retroviral vector expressing a thermolabile mutant SV40Tag for transfer into primary human fetal hepatocytes. We quantitatively detected the synthetic ability for albumin and urea by the immortalized cells, which were subcutaneously inoculated into mice with severe combined immunodeficiency (SCID) to evaluate tumorigenzcity. The immortalized cells were also transplanted into the spleens of mice with acute liver failure.

RESULTS

One clone resulting after selection, referred to as HepCL, was highly differentiated, growing steadily in a chemically defined serum-free medium. HepCL cells were positive for albumin, cytokeratin 18, and cytokeratin 19 immunocytochemical staining. The average synthetic efficacies of HepCL cells for albumin and urea were comparable to that of unmodified primary human fetal hepatocytes. The population doubling time of HepCL cells in the logarithmic growth phase was approximately 17 hours. HepCL cells showed no oncogenicity in immunodeficient mice at 16 months. Mice receiving HepCL cells (G1) and primary human fetal hepatocytes (G2) showed significantly lower blood ammonia levels after 90% hepatectomy. Pairwise comparisons between the 4 groups showed that xenotransplantation of HepCL (G1) or primary fetal hepatocytes (G2) significantly improved survivals of recipient mice.

CONCLUSIONS

HepCL may be useful as a source of hepatic function for cell-based therapeutics in acute liver failure.

Human parechovirus infections in monkeys with diarrhea, China

Information about human parechovirus (HPeV) infection in animals is scant. Using 5' untranslated region reverse transcription-PCR, we detected HPeV in feces of monkeys with diarrhea and sequenced the complete genome of 1 isolate (SH6). Monkeys may serve as reservoirs for zoonotic HPeV transmissions and as models for studies of HPeV pathogenesis.

Human parechovirus infections in monkeys with diarrhea, China

Information about human parechovirus (HPeV) infection in animals is scant. Using 5′ untranslated region reverse transcription–PCR, we detected HPeV in feces of monkeys with diarrhea and sequenced the complete genome of 1 isolate (SH6). Monkeys may serve as reservoirs for zoonotic HPeV transmissions and as models for studies of HPeV pathogenesis.

Diphenhydramine modulates cytokines and induces apoptosis in experimental acute pancreatitis

In this study, we investigated the therapeutic potential of diphenhydramine (DPH), a H(1) receptor antagonist, on taurocholate-induced acute pancreatitis and the underlying mechanisms involved. Rats were randomly divided into sham-operated, model, DPH-treated, octreotide-treated and the DPH plus octreotide combination therapy groups (n = 30 per group). Animals were sacrificed 3, 6 and 24 h after modeling and drug administration (n = 10 per time point) and sera, pancreas and lungs were harvested for further studies. DPH and octreotide monotherapy relieved histopathological injuries in multiple organs when compared to the model group. Combination therapy (DPH + octreotide) demonstrated better therapeutic potential than monotherapy. Data indicated that combination therapy had a better ability to reduce average mortality rates in rats, decrease the number of inflammatory cells, attenuate necrosis, upregulate the levels of amylase, TNF-alpha and IL-8 and downregulate the levels of IL-10 in the serum. Moreover, enhanced expression of Bax in the pancreas and lung were recorded suggesting a pro-apoptotic mechanism involved in the therapeutic potential of DPH. Our study demonstrated the therapeutic potential of DPH in acute pancreatitis and suggested a novel strategy for clinical management of this disease.

Establishment and evaluation of a model of a community health service in an underdeveloped area of China

OBJECTIVES

To develop and evaluate an applicable model for a community health service (CHS) in an underdeveloped area of China that ensures efficient, convenient and affordable primary healthcare access for all residents.

STUDY DESIGN

The current study was carried out in Puyang, a typical medium-sized city in central-eastern China. Based on the healthcare requirements of the residents in Puyang, a CHS network was set up and its operation was evaluated from 1999 to 2006. The system is characterized by its focus on community health education (CHE).

METHODS

Firstly, 8231 residents, selected at random, were surveyed to investigate the healthcare requirements of the local residents. Meanwhile, the operation of the pre-existing healthcare resources was investigated in Puyang. Based on the information gained, a network-based CHS system was proposed and established, with CHE as the major focus. This study compared CHS operation prior to and after establishment of the network. Finally, an analytic hierarchy process based evaluation model was applied to evaluate the operation of the CHS network.

RESULTS

There was a high prevalence (86.98 per thousand) of chronic diseases among the residents who participated in this investigation. The majority (84.39%) of the residents who had healthcare requirements resorted to professional health care; the other residents did not have access to health services. Among those residents who sought professional treatment, 71.3% visited primary healthcare institutions. This information reflects the enormous requirement for a CHS in primary health care but the lack of accessibility among the residents; this motivated the authors to establish a system to solve the problem. The improvement in CHS operation after the network was established suggests the importance of a network for optimizing the primary healthcare system. The improvement was indicated by better understanding of the residents regarding the CHS, and enhanced capability of self-monitoring for chronic diseases such as hypertension after the network was established. Moreover, the residents' knowledge of health care was significantly increased and, accordingly, the incidence of health risk behaviour was reduced after the network was established. Furthermore, the CHE index between 1999 and 2006 showed good correlation (r=0.988, p<0.005) with the CHS index, suggesting the important role of CHE in CHS development.

CONCLUSIONS

A network-characterized CHS system was established in Puyang, and improved the primary healthcare situation. This study provides a feasible model for the development of a CHS in medium and small cities in underdeveloped parts of China.

Quantitative online analysis of liquid-phase products of methanol oxidation in aqueous sulfuric acid solutions using electrospray ionization mass spectrometry

We describe a novel method and setup for quantitative online analysis of the liquid-phase methanol oxidation products in acidic aqueous solutions by electrospray ionization mass spectrometry (ESI-MS). This includes a specially designed flow system, which allows continuous online mixing, derivatization, extraction, separation, and quantitative detection within ca. 3 min. For electrospray ionization of formaldehyde, it is first online-derivatized by 2,4-dinitrophenyl hydrazine to form the easily ionizable 2,4-dinitrophenyl hydrazone. Then, both formic acid and derivatized formaldehyde are online extracted into an immiscible organic phase, which, after separation from the aqueous phase, is piped to the ESI-MS for analysis. This strategy ensures complete removal of the highly corrosive sulfuric acid from the analyte and allows the liquid-phase methanol oxidation reaction (MOR) products (formaldehyde and formic acid) to be quantitatively detected by ESI-MS. Finally, the potential of this method for online analysis in electroanalysis and electrocatalysis is discussed.

Association of TBX21 gene haplotypes in a Chinese population with systemic lupus erythematosus

OBJECTIVE

T-cell-specific T-box transcription factor (T-bet) is a member of the T-box family of transcription factors regulating type 1 T-helper (Th1) cell development and is thought to be linked with several autoimmune diseases including systemic lupus erythematosus (SLE). The aim of this study was to evaluate whether T-bet gene (TBX21) polymorphisms or its haplotypes are associated with SLE in a Chinese population.

METHODS

The study included 248 cases with SLE and 261 gender- and age-matched healthy controls. The polymorphisms T-1993C (rs4794067) and T-1514C (rs17250932) in the TBX21 promoter were identified by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

RESULTS

The frequency of both the -1993T and the -1514T allele were significantly higher in SLE patients than in controls. By haplotype analysis, there was significantly decreased frequency of the haplotype at positions -1993C/-1514C in the case group compared with the control group (p = 0.0002). Multifactorial logistic regression analysis showed that individuals with CC/CC haplotype homozygotes had a decreased susceptibility to SLE [p = 0.0004, odds ratio (OR) 0.316, 95% confidence interval (CI) 0.167-0.599].

CONCLUSION

Our results suggest that the -1993C/-1514C haplotype may be a protective factor for genetic susceptibility to SLE in the Chinese population.

Synthetic radiation-inducible promoters mediated HSV-TK/GCV gene therapy in the treatment of oral squamous cell carcinoma

OBJECTIVE

To investigate the therapeutic effect of herpes simplex virus thymidine kinase (HSV-TK) gene mediated by synthetic radiation-inducible promoters in the treatment of oral squamous cell carcinoma (OSCC) in vitro and in vivo.

METHODS

The plasmids pcDNA3.1(+)E6-HSV-TK were constructed, in which the HSV-TK genes were mediated by synthetic radiation-inducible promoters. The recombined plasmids were transfected into the Tca8113 cells and golden hamster buccal carcinoma, respectively. Low-dose radiotherapy was used to upregulate the HSV-TK genes expression. HSV-TK mRNA was assayed by RT-PCR. Apoptosis and proliferating cell nuclear antigen were detected respectively by in situ end-labeling and immunohistochemical method.

RESULTS

Compared with control group, the comparative survival rate of Tca8113 cells in HSV-TK/GCV/IR group was markedly decreased and the golden hamster buccal carcinoma in HSV-TK/GCV/IR group was obviously suppressed. Up-regulation of HSV-TK gene expression was found in the Tca8113 cells and in the golden hamster buccal carcinoma resulting from exposure to low-dose irradiation. The apoptosis indexes in Tca8113 cells or golden hamster buccal carcinoma with irradiation were markedly higher than those without irradiation. At the same time, the proliferation indexes in Tca8113 cells or golden hamster buccal carcinoma with irradiation were markedly lower than those without irradiation.

CONCLUSION

The results indicate that the synthetic radiation-inducible promoters can serve as a molecular switch to adjust the expression of HSV-TK gene in the treatment of OSCC, and low-dose induction radiation can significantly improve therapeutic efficiency.

Central mucoepidermoid carcinoma of the maxilla: a case report

BACKGROUND AND OBJECTIVE

Primary mucoepidermoid carcinoma of the jaw is a rare lesion, comprising 2-3% of all mucoepidermoid carcinomas reported in literature. Central mucoepidermoid carcinoma of the maxilla is rarer, comprising only 8% of the mucoepidermoid carcinomas found in the jaw.

METHODOLOGY

A 52-year-old man suffered from central mucoepidermoid carcinoma of the right maxilla with cervical metastasis, and underwent partial maxillectomy and neck dissection in our hospital. The diagnosis was confirmed by histopathology, dental orthopantomography, CT, and PET/CT scans.

RESULT

The man was followed-up regularly and was disease free after 21 months.

CONCLUSION

Primary central mucoepidermoid carcinoma of the jaw is a rare lesion and radical surgical resection is the preferred treatment.