Predictors of early vs. late permanent shunt insertion after aneurysmal subarachnoid hemorrhage

Objective: Numerous studies have identified different predictors for secondary hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH), although predictors regarding timing of the shunt operation have never been reported. Predictors for an early shunt, which was defined as a shunt operation performed ≤30 days after SAH onset, and for a late shunt, performed at >40 days, were investigated.

Methods: A total of 735 consecutive SAH patients admitted to our hospital between 2003 and 2014 who underwent surgery for ruptured aneurysms within five days of onset were retrospectively assessed.

Results: Secondary hydrocephalus developed in 225 patients, including 70 with an early shunt and 96 with a late shunt. Multivariate analysis showed that predictors for secondary hydrocephalus were age ≥70 years, World Federation of Neurosurgical Society (WFNS) grade IV-V, Fisher grade 3–4, intraventricular hemorrhage, anterior cerebral artery aneurysms, and external drainage for acute hydrocephalus (p < 0.05). In the early and late shunt groups, multivariate analysis indicated that early shunt was significantly associated with coil embolization, and late shunt was correlated with middle cerebral artery aneurysms and cerebral infarction due to vasospasm (p < 0.05).

Discussion: The difference in the predictors between the early and late shunts implied that the mechanisms of secondary hydrocephalus differed between the early and late shunt groups. Knowledge of the associated risk factors might help to predict the timing of the shunt operation for early rehabilitation planning in the future.     

Cytochrome P450 2A6 polymorphism in nasopharyngeal carcinoma

Nitrosamine has been identified as a carcinogen for nasopharyngeal carcinoma (NPC). Here, we investigated if a nitrosamine metabolizing gene, cytochrome P450 2A6 (CYP2A6) played an important role in NPC development. Relationships between the disease and the CYP2A6 were studied in 74 NPC patients and 137 age-matched healthy controls by using PCR-RFLP assay to distinguish between a wide type allele, *1A, and two mutant alleles, *1B and *4C. Overall, a significant association between CYP2A6 polymorphism and NPC development was observed (P<0.05). Individual with mutant alleles had an increased risk for NPC when compared to those with *1A/*1A (OR=2.37, 95% CI=1.27–4.46). In addition, males who carried mutant alleles of CYP2A6 had a fivefold increased risk for NPC when compared with those who carried *1A/*1A genotype (OR=5.02, 95% CI=1.82–14.14). It is thus suggested that CYP2A6 polymorphism may play a crucial role in NPC susceptibility and it may be used as a risk marker for NPC.     

p53 mutations and aflatoxin B1 exposure in hepatocellular carcinoma patients from thailand

The prevalence and type of mutations in the p53 tumoursuppressor gene have been determined in 15 hepatocellular carcinomas (HCC) originating from Thailand. Direct sequencing of exons 5-8 revealed 2 mutations, an AGG to AGT (Arg → Ser) transversion at codon 249, and an ATC → AAC (lle → Asn) transversion at codon 254. Samples from the Thai patients were analyzed for the presence of aflatoxin-liver DNA and aflatoxinserum albumin adducts, and all but one were found negative. All the patients were genotyped for glutathione-S-transferase (GST) μ, an enzyme possibly involved in the detoxification of AFB₁, and 12 out of 15 had the null genotype. In general, the level of aflatoxin-albumin adducts in sera and the prevalence of p53 mutation at codon 249 in HCC were lower than in other areas at high risk of HCC, including southern China and parts of Africa.     

Organization and evolution of organized cervical cytology screening in Thailand

ObjectiveTo describe phase 1 of an organized cytology screening project initiated in Thailand by the Ministry of Public Health and the National Health Security Office.MethodsWomen aged 35–60 years were encouraged to undergo cervical screening in primary care units and hospitals through awareness programs. Papanicolaou smears were processed and reported at district or provincial cytology laboratories. Women with normal test results were advised to undergo repeat screening after 5 years, while those with precancerous and cancerous lesions were referred for colposcopy, biopsy, and treatment. Information on screening, referral, investigations, and therapy were logged in a computer database.ResultsBetween 2005 and 2009, 69.2% of the 4 030 833 targeted women were screened. In all, 20 991 women had inadequate smears; 27 253 had low-grade squamous intraepithelial lesions; 15 706 had high-grade squamous intraepithelial lesions; and 2920 had invasive cancers. Information on the management of precancerous lesions was available for only 17.4% of women referred for colposcopy.ConclusionAlthough follow-up data on women with positive test results were inadequately documented, the present findings indicate that provision of cytology services through the existing healthcare system is feasible.     

CYP1A1, GSTM1, and GSTT1 polymorphisms, smoking, and lung cancer risk in a pooled analysis among Asian populations

To evaluate the roles of CYP1A1 polymorphisms [Ile 462Val and T 6235C (MspI)] and deletion of GSTM1 and GSTT1 in lung cancer development in Asian populations, a pooled analysis was conducted on 13 existing studies included in Genetic Susceptibility to Environmental Carcinogenesis database. This pooled analysis included 1,971 cases and 2,130 controls. Lung cancer risk was estimated as odds ratios (OR) and 95% confidence intervals (95% CI) using unconditional logistic regression model adjusting for age, sex, and pack-year. The CYP1A1 6235C variant was associated with squamous cell lung cancer (TC versus TT: OR, 1.42; 95% CI, 0.96-2.09; CC versus TT: OR, 1.97; 95% CI, 1.26-3.07; P trend = 0.003). In haplotype analysis, 462Val-6235T and Ile-C haplotypes were associated with lung cancer risk with reference to the Ile-T haplotype (OR, 3.41; 95% CI, 1.78-6.53 and OR, 1.39; 95% CI, 1.12-1.71, respectively). The GSTM1-null genotype increased squamous cell lung cancer risk (OR, 1.36; 95% CI, 1.05-1.77). When the interaction was evaluated with smoking, increasing trend of lung cancer risk as pack-year increased was stronger among those with the CYP1A1 6235 TC/CC genotype compared with those with TT genotype (P interaction = 0.001) and with the GSTM1-null genotype compared with the present type (Pinteraction = 0.08, when no genotype effect with no exposure was assumed). These results suggest that genetic polymorphisms in CYP1A1 and GSTM1 are associated with lung cancer risk in Asian populations. However, further investigation is warranted considering the relatively small sample size when subgroup analyses were done and the lack of environmental exposure data other than smoking.     

Monitoring and evaluation of a model demonstration project for the control of cervical cancer in Nakhon Phanom province, Thailand

Cancer of the uterine cervix is the second most common cancer in females in the world with about half a million new patients per year. Since the introduction by Papanicolaou of cervical smear screening, the incidence of cervical cancer has declined in many developed countries. The decrease in the incidence of and mortality from cervical cancer is mainly due to the organized mass screening using Pap smear programmes. Uterine cervical cancer is the leading cancer among women in Thailand with age-standardized incidence rates of 24.7 per 100,000 in 1999. Most cases present at advanced stages with poor prognoses of survival and cure. In the present study, cervical cancer screening programme with cervical cytology was organized for Nakhon Phanom province, Thailand. The specific objectives were: 1) to evaluate the reduction in incidence and mortality from cervical cancer in the province by means of an organised low-intensity cervical cytology programme. 2) to demonstrate the different aspects of programme implementation as a potential model for nationwide implementation. The screening activities were integrated in the existing health care system. Organized screening for women in the target population (aged 35-54 years) at 5-year intervals was free of charge. Sample taking was done by trained nurses (midwives) and primary health care personnel in the local health care centers. Sample quality was under continuous controlled by the cytology laboratories and pathologists. Confirmation and treatment were integrated into the normal health care routines. The screening results of the programme, including histologically confirmed diagnosis, were registered at the National Cancer Institute using PapReg and CanReg 4 programmes. A population-based cancer registry in Nakhon Phanom province was also set up in 1997. In the period 1999-2002, 32,632 women aged 35-54 years were screened. Women with low-grade lesions returned for routine follow-up smears. High-grade preinvasive disease was further evaluated by repeating Pap smear, conization or biopsy and subsequent treatment through surgical removal or ablation. This organized low-intensity cervical cytology programme showed a considerable increase in early carcinoma in situ and CIN II -III cases and should reduce incidence of and mortality from cervical cancer in Nakhon Phanom province in the future. Screening with the Papanicolaou smear plus adequate follow-up diagnosis and therapy can achieve major reductions in both incidence and mortality rates.     

Transvenous embolization of cavernous sinus dural arteriovenous fistula through a thrombosed inferior petrosal sinus utilizing 3D venography

Objective

We report a new technique in approaching the cavernous sinus through an occluded inferior petrosal sinus (IPS) using three-dimensional (3D) venography.

Case presentation

A patient diagnosed with arteriovenous fistula of the right cavernous sinus underwent transvenous embolization. The IPS was not detectable on angiogram. Retrograde injection of contrast with 3D imaging of the internal jugular vein clearly demonstrated the remnant of the IPS. By referring to the images obtained, catheterization of the cavernous sinus by way of the IPS was performed without difficulties.

Conclusion

Three-dimensional venography for detecting the entrance to the IPS is a useful method and easy to perform. We believe that this technique should be considered whenever the access to an occluded IPS is necessary.     

Repair process in spontaneous intradural dissecting aneurysms in children: report of eight patients and review of the literature

Objective  The objective of this study is to present a series of eight pediatric patients (less than 16 years old) with complete spontaneous thrombosis of spontaneous intradural dissecting aneurysms. Material and methods  Since 1989, eight consecutive patients in whom the cerebral aneurysms (four in middle cerebral arteries, one in posterior cerebral artery, three in basilar arteries) were found complete spontaneous thrombosis on follow-up MRI/MRA or conventional angiography. Patient histories and angiographic features were retrospectively reviewed. Results  Complete thrombosis of aneurysms in between first few days to 7 months was found in eight out of 1,587 patients (0.5%) in this recent series. Aneurysm repair was related to multivariate processes. Headache (50%), vomiting, and hemiplegia (37.5%) were common presenting symptoms. Partial or total resolution of the symptoms in a few months was often seen. Associated parent artery occlusions (50%) were also observed. Conclusion  Spontaneous resolution of intradural dissecting aneurysm with or without parent artery occlusion is not uncommon even in the pediatric population. Aneurysm repair is a dynamic and multifaceted entity. Mural hematoma appears to be the most important factor promoting thrombosis and healing of the dissecting intracranial aneurysms.     

Infrequent microsatellite instability in liver fluke infection-associated intrahepatic cholangiocarcinomas from Thailand

The liver fluke infection-associated intrahepatic cholangiocarcinoma (ICC) is a major liver cancer in Northeast Thailand. The molecular basis of this ICC is poorly understood. To address possible roles of the DNA mismatch repair (MMR) system in ICC carcinogenesis, a fluorescence-labeling PCR/laser scanning technique with high sensitivity was employed to analyze genomic instability in the nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) in 24 fresh and 13 formalin-fixed, paraffin-embedded tissues of ICC and their corresponding normal parts. Microsatellite instability (MSI) was assessed in nDNA, using 12 highly polymorphic loci including 5 Bethesda markers. These loci were mainly related to major MMR genes, hMSH2 and hMLH1. Also 3 (C)n and/or (C)n(A)n repeat instability at 1 noncoding region in the displacement-loop (D-loop) and 2 coding sequences in NADH dehydrogenase subunit 1 and subunit 5 gene in mtDNA were analyzed. MSI was only detected in 1 (2.7%), 6 (16.7%), 1 (2.9%), 1 (2.9%) or 2 (6.3%) out of 37, 36, 35, 35 or 32 cases at BAT-25, D2S123, D3S1611, D11S904 or D17S250, respectively. LOH was found at D3S1298, D3S1561, D5S346 and TP53 in 4 (18.2%) out of 22, 2 (18.2%) out of 11, 6 (33.3%) out of 18 and 3 (12.5%) out of 24 informative cases, respectively. In mtDNA, none except a single case out of the 37 (2.7%) exhibited repeat sequence instability in the D-loop. We conclude that the liver fluke infection-associated ICC in Thailand is classified as low frequency MSI or microsatellite stable type and that DNA MMR system, through hMSH2 and hMLH1 gene mutations, does not play a major role in its carcinogenesis.