Stereotactic Body Radiation Therapy for Pulmonary Metastasis from Colorectal Adenocarcinoma: Biologically Effective Dose 150 Gy is Preferred for Tumour Control.

AIMS: To compare the local control rate of pulmonary metastatic lesions in colorectal adenocarcinoma treated with stereotactic body radiation therapy (SBRT) using a biologically effective dose with an α/ß ratio of 10 (BED10) of 150 Gy. MATERIALS AND METHODS: We analysed 231 pulmonary metastatic lesions from colorectal adenocarcinoma treated with SBRT in 135 patients. The patients were referred for the control of oligometastatic or oligoprogressive disease in the lungs. A dose of 40-60 Gy in three to eight fractions was delivered. The local control per tumour (LCpT) by BED10 was evaluated. The local control per patient (LCpP), pulmonary progression-free survival (PPFS), any progression-free survival (APFS) and overall survival were also reported as clinical outcomes. RESULTS: A significant difference was observed in the LCpT between the BED10 groups (P < 0.001). The 1-, 2- and 3-year LCpT were 38.9%, 25.9% and 25.9% in BED10 < 100 group; 84.1%, 62.6% and 60.4% in 100 ≤ BED10 < 150 Gy group; and 97.3%, 94.9% and 85.2% in BED10 ≥ 150 Gy group, respectively. BED10 ≥ 150 Gy remained significant in the multivariate analysis of LCpT. The 3-year LCpP, PPFS, APFS and overall survival rates were 62.7%, 26.5%, 24.8% and 67.7%, respectively. Oligoprogression (versus oligometastasis), multiple pulmonary nodules and extrapulmonary metastasis were associated with a poor prognosis. CONCLUSION: A BED10 ≥ 150 Gy may be required to achieve sufficient local control. The indications for SBRT and the extent of metastatic disease should be assessed for proper estimation of the clinical outcomes.

Neuropsychological adverse drug reactions of Remdesivir: analysis using VigiBase, the WHO global database of individual case safety reports.

OBJECTIVE: Although remdesivir (GS-5734) has recently demonstrated clinical benefits against the pandemic outbreak of coronavirus disease 2019 (COVID-19), neuropsychological adverse reactions (ADRs) remain to be examined in real-world settings. Therefore, we aimed to identify and characterize the neuropsychological ADRs associated with remdesivir use. MATERIALS AND METHODS: We obtained data for this international pharmacovigilance cohort study from individual case safety reports (ICSRs) in a World Health Organization database (VigiBase) from the first report on remdesivir on February 17, 2020, until August 30, 2020 (n=1,403,532). ADRs reported to be relevant to remdesivir were compared with the full database by using a Bayesian neural network method to calculate the information component (IC). RESULTS: A total of 2,107 reported cases of neuropsychological ADRs suspected to be associated with remdesivir were identified from among all ICSRs in the database during the observation period. Although 108 neuropsychological ADRs (64 neurologic events and 44 psychologic events) were reported in association with the medication, no statistically significant pharmacovigilance signal could be detected; the IC025 value was negative for all of the neuropsychological dysfunctions (anxiety [n=13, 0.62%], seizures [n=12, 0.57%], lethargy [n=6, 0.28%], agitation [n=5, 0.25%], cerebral infarction [n=3, 0.14%], ischemic stroke [n=3, 0.14%], and hemiparesis [n=3, 0.14%]). CONCLUSIONS: Our study demonstrates that remdesivir, a novel drug applied to the treatment of COVID-19, does not have a significant association with adverse neurologic or psychiatric reactions in the real-world setting.

Continuous nursing intervention on recovery of diabetic patients.

The aim of this study was to probe the influence of continuous nursing intervention on recovery of diabetic patients. From October 2016 to June 2017, 80 diabetic patients who received treatment in our hospital were selected and randomly divided into an intervention group and a control group. The intervention group received continuous nursing care including indirect follow-up, health education and home visit. The self-care ability and blood sugar of the two groups were compared three months later. The score of self-care ability in the intervention group was 89.64±1.64 and that in control group was 72.68±2.47, and a significant difference was observed (P less than 0.001). The fasting blood glucose level in the intervention group was 6.62±0.86 MMOL/L, and the 2-hour post-meal blood glucose level was 8.47±1.32 MMOL/L, which were both lower than those in the control group. Continuous nursing can help monitor the recovery of patients after discharge. It is helpful to improve the self-care ability of patients, control blood sugar level, and promote recovery. It is worth wide promotion.

Hepatoprotective and neuroprotective tocopherol analogues isolated from the peels of Citrus unshiu Marcovich.

Three tocopherol analogues methoxytocopherol (1), α-tocopherol (2) and γ-tocopherol (3) were isolated from the peels of Citrus unshiu Marcovich. The protective effects of the isolated compounds against tert-butyl hydroperoxide-induced hepatotoxicity in human liver-derived HepG2 cells and glutamate-induced oxidative stress in HT22-immortalised hippocampal cells were evaluated. Compounds 1-3 were significantly protective in HepG2 cells with EC50 values of 21.22 ± 2.01, 25.21 ± 2.11 and 25.25 ± 1.21 µM, respectively, and in HT22 cells, compounds 1-3 had EC50 values of 20.62 ± 1.36, 6.44 ± 1.65 and 9.52 ± 1.54 µM, respectively.

Squeezing water clusters between graphene sheets: energetics, structure, and intermolecular interactions.

The behavior of water confined at the nanoscale between graphene sheets has attracted much theoretical and experimental attention recently. However, the interactions, structure, and energy of water at the molecular scale underpinning the behavior of confined water have not been characterized by first-principles calculations. In this work we consider small water clusters up to the hexamer adsorbed between graphene sheets using density functional theory calculations with van der Waals corrections. We investigate the effects on structure, energy, and intermolecular interactions due to confinement between graphene sheets. For interlayer distances of about one nanometer or more, the cluster adsorption energy increases approximately linearly with the cluster size by 0.1 eV per molecule in the cluster. As the interlayer distance decreases, the cluster adsorption energy reaches a maximum at 6 to 7 Å with approximately 0.16 eV stabilization energy relative to large interlayer distances. This suggests the possibility of controlling the amount of adsorption in graphene nanomaterials by varying the interlayer distance. We also quantify the intermolecular hydrogen bonding in the clusters by calculating the dissociation energy required to remove one molecule from each cluster. For each cluster size, this is constant for interlayer distances larger than approximately 6 to 8 Å. For smaller distances the intermolecular interaction decreases rapidly thus leading to weaker cohesion between molecules in a squeezed cluster. We expect a mechanism of concerted motion for hydrogen-bonded water molecules confined between graphene sheets, as has been observed for water confined within the carbon nanotubes. Thus, the decrease in the dissociation energy we observed here is consistent with experimental results for water transport through graphene and related membranes that are of interest in nanofiltration. We also calculate the corrugation in the interaction potential between graphene sheets which suggests a switch from very small corrugation to stick-slip behavior at interlayer distances smaller than 6 Å. Our results for gas phase clusters agree reasonably with methods using more demanding quantum chemical methods to treat the van der Waals interactions, thus providing support for the relatively fast density functional theory methods used here for studying water-graphene interactions in nanoscale systems.

Serum uric acid and disorders of glucose metabolism: the role of glycosuria

Hyperuricemia has been associated with hypertension, diabetes mellitus, and metabolic syndrome. We studied the association between hyperuricemia and glycemic status in a nonrandomized sample of primary care patients. This was a cross-sectional study of adults ≥20 years old who were members of a community-based health care program. Hyperuricemia was defined as a value >7.0 mg/dL for men and >6.0 mg/dL for women. The sample comprised 720 participants including controls (n=257) and patients who were hypertensive and euglycemic (n=118), prediabetic (n=222), or diabetic (n=123). The mean age was 42.4±12.5 years, 45% were male, and 30% were white. The prevalence of hyperuricemia increased from controls (3.9%) to euglycemic hypertension (7.6%) and prediabetic state (14.0%), with values in prediabetic patients being statistically different from controls. Overall, diabetic patients had an 11.4% prevalence of hyperuricemia, which was also statistically different from controls. Of note, diabetic subjects with glycosuria, who represented 24% of the diabetic participants, had a null prevalence of hyperuricemia, and statistically higher values for fractional excretion of uric acid, Na excretion index, and prevalence of microalbuminuria than those without glycosuria. Participants who were prediabetic or diabetic but without glycosuria had a similarly elevated prevalence of hyperuricemia. In contrast, diabetic patients with glycosuria had a null prevalence of hyperuricemia and excreted more uric acid and Na than diabetic subjects without glycosuria. The findings can be explained by enhanced proximal tubule reabsorption early in the course of dysglycemia that decreases with the ensuing glycosuria at the late stage of the disorder.

Serum uric acid and disorders of glucose metabolism: the role of glycosuria.

Hyperuricemia has been associated with hypertension, diabetes mellitus, and metabolic syndrome. We studied the association between hyperuricemia and glycemic status in a nonrandomized sample of primary care patients. This was a cross-sectional study of adults ≥ 20 years old who were members of a community-based health care program. Hyperuricemia was defined as a value >7.0 mg/dL for men and >6.0 mg/dL for women. The sample comprised 720 participants including controls (n=257) and patients who were hypertensive and euglycemic (n=118), prediabetic (n=222), or diabetic (n=123). The mean age was 42.4 ± 12.5 years, 45% were male, and 30% were white. The prevalence of hyperuricemia increased from controls (3.9%) to euglycemic hypertension (7.6%) and prediabetic state (14.0%), with values in prediabetic patients being statistically different from controls. Overall, diabetic patients had an 11.4% prevalence of hyperuricemia, which was also statistically different from controls. Of note, diabetic subjects with glycosuria, who represented 24% of the diabetic participants, had a null prevalence of hyperuricemia, and statistically higher values for fractional excretion of uric acid, Na excretion index, and prevalence of microalbuminuria than those without glycosuria. Participants who were prediabetic or diabetic but without glycosuria had a similarly elevated prevalence of hyperuricemia. In contrast, diabetic patients with glycosuria had a null prevalence of hyperuricemia and excreted more uric acid and Na than diabetic subjects without glycosuria. The findings can be explained by enhanced proximal tubule reabsorption early in the course of dysglycemia that decreases with the ensuing glycosuria at the late stage of the disorder.

Interaction of magnetic transition metal dimers with spin-polarized hydrogenated graphene.

The coadsorption of hydrogen and transition metal dimers Fe2, Co2, Ni2, and FeCo on graphene is investigated using density functional theory calculations. Our work is motivated by observations that the magnetic moments of these transition metal dimers are large and that hydrogen adsorption partitions the graphene lattice into magnetic subdomains. Thus, we expect the magnetic dimers to interact strongly with the lattice. Our results show that the majority-spin direction of the lattice electronic states depends upon the dimer identity, the lattice spin polarization being in the same direction as the dimer spin polarization for Fe2 and FeCo, but opposite for Co2 and Ni2. We can understand this by examining the electronic density of states of the dimer and the lattice. We also show that coadsorption significantly increases the adsorption energies of both dimer and hydrogen leading to a more strongly-adsorbed dimer, while the bond length and magnetic moment of the upper dimer atom, the latter important for potential magnetic storage applications, are negligibly changed. Our work shows that the coadsorbed hydrogen and metal dimer interact over a long-range, this interaction being mediated by the hydrogen-induced spin-polarization of the graphene lattice. We obtain general insight into how the elemental identity of these magnetic dimers determines the spin-polarized states on the hydrogenated graphene lattice. These results could be important for potential applications of magnetic properties of decorated graphene lattices.

Hipk2 cooperates with p53 to suppress γ-ray radiation-induced mouse thymic lymphoma.

A genome-wide screen for genetic alterations in radiation-induced thymic lymphomas generated from p53+/- and p53-/- mice showed frequent loss of heterozygosity (LOH) on chromosome 6. Fine mapping of these LOH regions revealed three non-overlapping regions, one of which was refined to a 0.2 Mb interval that contained only the gene encoding homeobox-interacting protein kinase 2 (Hipk2). More than 30% of radiation-induced tumors from both p53+/- and p53-/- mice showed heterozygous loss of one Hipk2 allele. Mice carrying a single inactive allele of Hipk2 in the germline were susceptible to induction of tumors by γ-radiation, but most tumors retained and expressed the wild-type allele, suggesting that Hipk2 is a haploinsufficient tumor suppressor gene for mouse lymphoma development. Heterozygous loss of both Hipk2 and p53 confers strong sensitization to radiation-induced lymphoma. We conclude that Hipk2 is a haploinsufficient lymphoma suppressor gene.

Ion-orbital coupling in Car-Parrinello calculations of hydrogen-bond vibrational dynamics: case study with the NH3-HCl dimer.

We have performed Car-Parrinello molecular dynamics (CPMD) calculations of the hydrogen-bonded NH(3)-HCl dimer. Our main aim is to establish how ionic-orbital coupling in CPMD affects the vibrational dynamics in hydrogen-bonded systems by characterizing the dependence of the calculated vibrational frequencies upon the orbital mass in the adiabatic limit of Car-Parrinello calculations. We use the example of the NH(3)-HCl dimer because of interest in its vibrational spectrum, in particular the magnitude of the frequency shift of the H-Cl stretch due to the anharmonic interactions when the hydrogen bond is formed. We find that an orbital mass of about 100 a.u. or smaller is required in order for the ion-orbital coupling to be linear in orbital mass, and the results for which can be accurately extrapolated to the adiabatic limit of zero orbital mass. We argue that this is general for hydrogen-bonded systems, suggesting that typical orbital mass values used in CPMD are too high to accurately describe vibrational dynamics in hydrogen-bonded systems. Our results also show that the usual application of a scaling factor to the CPMD frequencies to correct for the effects of orbital mass is not valid. For the dynamics of the dimer, we find that the H-Cl stretch and the N-H-Cl bend are significantly coupled, suggesting that it is important to include the latter degree of freedom in quantum dynamical calculations. Results from our calculations with deuterium-substitution show that both these degrees of freedom have significant anharmonic interactions. Our calculated frequency for the H-Cl stretch using the Becke-exchange Lee-Yang-Parr correlation functional compares reasonably well with a previous second-order Møller-Plesset calculation with anharmonic corrections, although it is low compared to the experimental value for the dimer trapped in a neon-matrix.

A case of xanthoma disseminatum with spontaneous resolution over 10 years: review of the literature on long-term follow-up.

Xanthoma disseminatum (XD) is a rare and potentially progressive non-Langerhans-cell histiocytosis. To date, a few cases of XD with spontaneous complete resolution have been described. The present report describes a 16-year-old girl who presented with yellow to red-brown papules and nodules on her eyelids, cheeks, axillae, back and buttocks. Indirect laryngoscopy showed multiple xanthomatous plaques on the larynx, posterior pharynx, epiglottis, and vocal cords. Additional findings were polyuria, polydipsia, and amenorrhea. Skin biopsy and electron microscopy results confirmed the diagnosis of XD. The patient was treated with fenofibrate, simvastatin, desmopressin, and sex-hormone replacement therapy. Her skin lesions began to slowly fade 6 years after disease onset, eventually resolving spontaneously and completely, but leaving an atrophic scar, frank anetoderma, and persisting diabetes insipidus. This case report together with a review of the English-language literature on the long-term follow-up of XD patients provides additional information on the natural history of this disease.

Hard X-ray microbeam lithography using a Fresnel zone plate with a long focal length.

Focused hard X-ray microbeams for use in X-ray nanolithography have been investigated. A 7.5 keV X-ray beam generated at an undulator was focused to about 3 µm using a Fresnel zone plate fabricated on silicon. The focused X-ray beam retains a high degree of collimation owing to the long focal length of the zone plate, which greatly facilitates hard X-ray nanoscale lithography. The focused X-ray microbeam was successfully utilized to fabricate patterns with features as small as 100 nm on a photoresist.

Mid-life and late-life vascular risk factors and dementia in Korean men and women.

Dementia is one of the most important neurological disorders in the elderly population. The significance of vascular risk factors for dementia remains controversial. This study aimed to determine the effects of vascular risk factors, such as blood pressure, diabetes and smoking in the mid-life or the late-life on dementia risk. The data in this prospective cohort study came from 3252 dementia events occurring over 14 years among 848,505 Koreans aged 40-95 years insured by the National Health Insurance Corporation who had a biennial medical evaluation during 1992-1995. Data on clinical dementia during the period 1993-2006 were examined in relation to vascular risk factors. The age adjusted incidence per 100,000 was 31.9 for men and 45.0 for women, respectively. In multivariate Cox proportional hazard models, diabetes increased the risk of either dementia in Alzheimer's disease or vascular dementia in men and women, controlling for age, hypertension, total cholesterol, alcohol drinking, and smoking. Hypertension also increased vascular dementia in both men [Hazard ratio (HR)=2.6, 95% confidence interval (CI)=1.7-3.8] and women (HR=2.3, 95%CI=1.6-3.3). The association of hypertension or diabetes on risk of vascular dementia, however, among the group aged older than 65 was attenuated but remained as significant in men. There was no interaction between hypertension and diabetes on the risk of dementia. This study demonstrates that diabetes and hypertension increased the risk of vascular dementia. Treatment for these risk factors may reduce the risk of vascular dementia.

Coherent diffraction surface imaging in reflection geometry.

We present a reflection based coherent diffraction imaging method which can be used to reconstruct a non periodic surface image from a diffraction amplitude measured in reflection geometry. Using a He-Ne laser, we demonstrated that a surface image can be reconstructed solely from the reflected intensity from a surface without relying on any prior knowledge of the sample object or the object support. The reconstructed phase image of the exit wave is particularly interesting since it can be used to obtain quantitative information of the surface depth profile or the phase change during the reflection process. We believe that this work will broaden the application areas of coherent diffraction imaging techniques using light sources with limited penetration depth.

Efficacy and prognosis of a short course of prednisolone therapy for pediatric epilepsy.

PURPOSE: To evaluate the efficacy and safety of adjunctive prednisolone therapy in children with cryptogenic epileptic encephalopathy, other than infantile spasms, and to determine its prognosis. METHODS: Prednisolone, 2mg/kg per day for 6 weeks, tapered for a further 2 weeks, was given in combination with previously prescribed antiepileptic drugs. A retrospective assessment of 41 children thus treated included measurements of seizure frequency, electroencephalographic findings, global assessments of cognitive function, and adverse drug events. Long-term patient prognoses over a mean follow-up period of 3 years and 5 months (range, 14-90 months) were also examined. RESULTS: Of 41 patients, 32 had Lennox-Gastaut syndrome, 4 had Doose syndrome, 1 had Otahara syndrome, 2 had Landau-Kleffner syndrome, and 2 had other unspecified generalized epilepsies. After prednisolone therapy, 73% (30/41) of patients showed a reduction in seizure frequency of >50%, and 59% (24/41) became seizure free. However, only seven patients (four with Lennox-Gastaut syndrome, two with Doose syndrome, and one with unspecified generalized epilepsy) who became seizure free remained free of seizures at the time of the final follow-up. Electroencephalographic findings and global assessments of cognitive function correlated well with seizure outcomes. No significant demographic factors influenced the efficacy of prednisolone or patient prognoses after prednisolone tapering. Most adverse events were transient, or were tolerated well with conservative management, with maintenance of the medication. CONCLUSION: Prednisolone therapy may be a safe and effective adjunct in patients with cryptogenic epileptic encephalopathies, but the high relapse rate is of concern.

A comparison of perinatal mortality in Korea on holidays and working days.

OBJECTIVE: To examine whether the perinatal mortality of infants born during holidays differs from that of infants born on workdays, and to elucidate its cause. DESIGN: Cross-sectional study. Setting Vital statistics linked to the National Infant Mortality Survey data for 1999 births in Korea. POPULATION: In all, 628 485 births in 1999 in Korea. METHODS: Number of births and perinatal mortality were classified according to the day of the week using the occurrence index. After adjusting for confounding factors, the odds ratios (ORs) for increased holiday mortality were estimated using logistic regression. MAIN OUTCOME MEASURE: Birthweight-adjusted perinatal mortality. RESULTS: Births on holidays were 33% fewer and perinatal deaths 24% higher than expected (PMR, Perinatal Mortality Rate, 16.4 versus 12.8; OR, 1.3; 95% CI, 1.2-1.4). After the adjustment of birthweight, gender, plurality and congenital anomalies, the odds ratio for death of infants born during holidays was 1.2 (95% CI, 1.1-1.3). CONCLUSIONS: The higher perinatal mortality during holidays in Korea appears to be due to different qualities of perinatal care, rather than difference in case-mix.

Nanometer linear focusing of hard x rays by a multilayer Laue lens.

We report on a type of linear zone plate for nanometer-scale focusing of hard x rays, a multilayer Laue lens (MLL), produced by sectioning a multilayer and illuminating it in Laue diffraction geometry. Because of its large optical depth, a MLL spans the diffraction regimes applicable to a thin Fresnel zone plate and a crystal. Coupled wave theory calculations indicate that focusing to 5 nm or smaller with high efficiency should be possible. Partial MLL structures with outermost zone widths as small as 10 nm have been fabricated and tested with 19.5 keV synchrotron radiation. Focal sizes as small as 30 nm with efficiencies up to 44% are measured.

Influence of weight reduction by sibutramine on female sexual function.

BACKGROUND: It is well known that selective serotonin reuptake inhibitors (SSRIs) can cause sexual dysfunction, so it is possible that sibutramine, a serotonin and norepinephrine reuptake inhibitor, could induce sexual dysfunction. DESIGN AND SUBJECTS: The effect of sibutramine on sexual function was evaluated in 46 overweight and obese (body mass index (BMI) > or = 23 kg/m2) but otherwise healthy married women (28-44 years). Participants were randomly assigned at baseline to either the sibutramine or control group. The Female Sexual Function Index (FSFI) questionnaire was used to assess sexual function at baseline and after treatment with behavioral therapy plus sibutramine 10 mg once daily or behavioral therapy alone (control) for 8 weeks. RESULTS: Mean weight loss from baseline to week 8 was -6.03% in sibutramine group and -0.38% in the control group. There was significant improvement of FSFI total score, arousal domain score and lubrication domain score in the sibutramine group (P<0.05), and significant differences in arousal, orgasm, satisfaction domain score and total score (P<0.05) in favor of sibutramine. Decreases in body weight and BMI were correlated with the improvement of arousal (r = -0.44 and r = -0.48, respectively) and orgasm (r = -0.45 and r = -0.46, respectively) domains. CONCLUSION: Treatment with sibutramine plus behavioral therapy did not induce sexual dysfunction and sibutramine-induced weight reduction appeared to have a positive impact on sexual function in this small group of overweight and moderately obese women. The degree of improvement in sexual function was correlated with the degree of weight reduction.

Vagus nerve stimulation in pediatric intractable epilepsy: a Korean bicentric study.

OBJECTIVE: To present our experience with vagus nerve stimulation (VNS) and to evaluate the long-term efficacy and safety of the procedure in pediatric intractable epilepsy. METHODS: This study included sixteen patients, who were implanted with a vagus nerve stimulator and could be followed up for at least more than 12 months in two epilepsy centers. Data including seizure frequency, EEG, quality of life measures and adverse events were prospectively filed over a 5-year period. RESULTS: VNS resulted in a > 50% reduction in seizure frequency in 50.0% (8/16) of children with 31.3% (5/16) of patients achieving a > 90% reduction. Additionally, enhancements in quality of life were as follows: memory in 50.0% (8/16), mood in 62.5% (10/16), behavior in 68.8% (11/16), alertness in 68.8% (11/16), achievement in 37.5% (6/16), and verbal skills in 43.8% (7/16) of the patients. Adverse events included hoarseness in two patients, dyspnea during sleep in two patients, and sialorrhea in one patient. However, these events were tolerable or could be controlled by the adjustment of output currents. In one patient, wound revision was required. CONCLUSION: Our data supports the role of VNS as an alternative therapy for pediatric intractable epilepsy.

Mutational analysis of OGG1, MYH, MTH1 in FAP, HNPCC and sporadic colorectal cancer patients: R154H OGG1 polymorphism is associated with sporadic colorectal cancer patients.

MYH, OGG1 and MTH1 are members of base excision repair (BER) families, and MYH germline mutations were recently identified in patients with multiple adenomas or familial adenomatous polyposis (FAP). A total of 20 APC-negative Korean FAP patients were analyzed for OGG1, MYH and MTH1 germline mutations. A total of 19 hereditary nonpolyposis colorectal cancer (HNPCC), 86 suspected HNPCC, and 246 sporadic colorectal cancer cases were investigated for OGG1 and MYH mutations. A total of 14 R154H OGG1 polymorphisms were identified in hereditary, sporadic colorectal cancers, and normal controls. For the case-control analysis of OGG1 R154H, a total of 625 hereditary or sporadic colorectal cancer patients and 527 normal controls were screened. R154H was a rare polymorphism associated with sporadic colorectal cancer patents (OR: 3.586, P= 0.053). R154H does not segregate with cancer phenotypes. Upon examining the possibility of recessive inheritance of R154H, we could not identify any complementary mutations in OGG1, MYH or MTH1. Samples with R154H were further screened for mutations of K-ras, beta-catenin, APC, p53, BRAF and the microsatellite instability (MSI) status. Eight somatic mutations were identified in these genes and G:C to T:A transversion mutations were not dominant in samples harboring R154H. This result raises the possibility that OGG1 R154H may function as a low/moderate-penetrance modifier for colorectal cancer development.