Clinical translation for targeting DNA damage repair in non-small cell lung cancer: a review

Despite significant advancements in screening, diagnosis, and treatment of non-small cell lung cancer (NSCLC), it remains the primary cause of cancer-related deaths globally. DNA damage is caused by the exposure to exogenous and endogenous factors and the correct functioning of DNA damage repair (DDR) is essential to maintain of normal cell circulation. The presence of genomic instability, which results from defective DDR, is a critical characteristic of cancer. The changes promote the accumulation of mutations, which are implicated in cancer cells, but these may be exploited for anti-cancer therapies. NSCLC has a distinct genomic profile compared to other tumors, making precision medicine essential for targeting actionable gene mutations. Although various treatment options for NSCLC exist including chemotherapy, targeted therapy, and immunotherapy, drug resistance inevitably arises. The identification of deleterious DDR mutations in 49.6% of NSCLC patients has led to the development of novel target therapies that have the potential to improve patient outcomes. Synthetic lethal treatment using poly (ADP-ribose) polymerase (PARP) inhibitors is a breakthrough in biomarker-driven therapy. Additionally, promising new compounds targeting DDR, such as ATR, CHK1, CHK2, DNA-PK, and WEE1, had demonstrated great potential for tumor selectivity. In this review, we provide an overview of DDR pathways and discuss the clinical translation of DDR inhibitors in NSCLC, including their application as single agents or in combination with chemotherapy, radiotherapy, and immunotherapy.

The Feasibility of Fast, Four-Dimensional Computed Tomography-Based O-Ring Linac Plans for Stereotactic Body Radiotherapy in Patients with Poor Performance Status

PURPOSE/OBJECTIVE(S)

As patients with poor performance status cannot endure long treatment times, it can lead to unplanned and prolonged radiation treatment or discontinuation of treatment. Moreover, prolonged radiation treatment appears to negatively affect survival for patients. We aimed to verify the feasibility of fast 4DCT-based O-ring linear accelerator (LINAC) treatment in lung 4D stereotactic body radiotherapy (SBRT).

MATERIALS/METHODS

This study included data of 38 patients who received lung 4D-SBRT. Gating20-70% plans were based on 4DCT data obtained at phase values ranging from 20-70% using a C-arm LINAC. Non-GatingFB plans were retrospectively established based on 4DCT data obtained at phase values of 0-90% using an O-ring LINAC. The prescribed dose of 4,800 cGy was delivered to PTV in four fractions. The conformity index (CI), homogeneity index (HI), and gradient measurement (GM) of the PTV were analyzed to compare dosimetric data between Gating20-70% and Non-GatingFB plans. Organs at risks (OARs) were analyzed in accordance with the RTOG 0915 protocol. Treatment delivery time and total monitor units (MU) were analyzed to compare the efficiency of treatment delivery. Statistical comparisons were performed using the Wilcoxon signed-rank test (p<0.05).

RESULTS

For the PTV, there was no significant difference in the CI or HI between Gating20-70% and Non-GatingFB plans (CI: 1.337±0.137, 1.335±0.174, HI: 0.939±0.015, 0.939±0.016, all at p>0.05). However, there was a significant difference in GM between Gating20-70% and Non-GatingFB plan (1.528±0.206 cm, 1.381±0.222 cm, p<0.001). For OARs, all plans met the criteria for dose constraint. There was a significant difference between Gating20-70% and Non-GatingFB plans except in the spinal cord. In particular, D1000cc and D1500cc values for the ipsilateral lung for Gating20-70% plans were 31.6% and 59.9% lower than those for Non-GatingFB plans (D1000cc: 50.780±132.061 cGy, 34.755±102.480 cGy, p<0.001, D1500cc: 6.641±14.598 cGy, 2.666±7.926 cGy, p<0.001). Treatment delivery time was 92% longer for Gating20-70% plans than for Non-GatingFB plans (5.0±0.4 min, 9.6±3.3 min, p = 0.043). The total MU value for Gating20-70% plans was 9.6% higher than that for Non-GatingFB plans (3665.8±230.7, 4016±236.9, p = 0.039).

CONCLUSION

When compared to OARs both plans were acceptable per RTOG-0915 protocol, but significant differences were between Non-GatingFB and Gating20-70% plans. However, treatment delivery time of Non-GatingFB plans decreased by 47.9% than Gating20-70% plans. We verified the feasibility of fast 4DCT-based O-ring LINAC treatment for patients who cannot endure long treatment times due to poor performance status in lung 4D-SBRT. In further study, we will analyze dosimetric differences and treatment delivery efficiency considering tumor motion according to tumor location.

Repurposing FDA-approved drugs as HIV-1 integrase inhibitors: an in silico investigation

The Human Immunodeficiency Virus (HIV) infection is a global pandemic that has claimed 33 million lives to-date. One of the most efficacious treatments for naïve or pretreated HIV patients is the HIV integrase strand transfer inhibitors (INSTIs). However, given that HIV treatment is life-long, the emergence of HIV strains resistant to INSTIs is an imminent challenge. In this work, we showed two best regression QSAR models that were constructed using a boosted Random Forest algorithm (r² = 0.998, q²_10CV = 0.721, q²_{external_test} = 0.754) and a boosted K* algorithm (r² = 0.987, q²_10CV = 0.721, q²_{external_test} = 0.758) to predict the pIC₅₀ values of INSTIs. Subsequently, the regression QSAR models were deployed against the Drugbank database for drug repositioning. The top-ranked compounds were further evaluated for their target engagement activity using molecular docking studies and accelerated Molecular Dynamics simulation. Lastly, their potential as INSTIs were also evaluated from our literature search. Our study offers the first example of a large-scale regression QSAR modelling effort for discovering highly active INSTIs to combat HIV infection.Communicated by Ramaswamy H. Sarma.

Preoperative N stage evaluation in advanced gastric cancer patients using multidetector CT: can the sum of the diameters of metastatic LNs be used for N stage evaluation?

AIM

To compare the diagnostic performance of total counts of metastatic lymph nodes (LN-sum) and conventional multidetector (MD) computed tomography (CT) staging in the nodal evaluation of advanced gastric cancer (AGC) patients.

MATERIALS AND METHODS

In total, 127 consecutive patients who underwent preoperative MDCT and gastrectomy for AGC were identified. Metastatic LNs on MDCT were defined as LNs with a short axis ≥8 mm, marked or heterogeneous enhancement, and morphological features (central necrosis, round shape, clustering). The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the N-stage using LN-sum and conventional MDCT staging were generated and compared. In addition, metastatic LN counts between the MDCT and the histopathological examinations and correlation between LN-sum and histopathological nodal status were analysed.

RESULTS

The total counts of metastatic LNs on MDCT was significantly smaller than those detected in histopathological assessments (p<0.0001). LN-sum showed significant correlation with the pathological N stage and the number of metastatic LNs (rho=0.69, 0.73, p<0.0001). The areas under the receiver operating characteristic curve were 0.896, and 0.835, for N stage ≥N2 and N3, with cut-off values of 12.5 and 23.5 mm, respectively. LN-sum provided better diagnostic performance than conventional MDCT staging for discriminating N0-2 versus N3; sensitivity, accuracy, PPV and NPV of LN-sum were significantly higher (80.4 versus 52.2%, 81.1 versus 68.5%, 71.2 versus 57.1%, and 88 versus 74.1%).

CONCLUSION

LN-sum may be sufficiently useful in assessing the N3 stage of AGC and may help to plan appropriate therapy for AGC patients.

Synthesis of geopolymer-supported zeolites via robust one-step method and their adsorption potential

The present study proposes a robust one-step hydrothermal treatment method for synthesis of high strength geopolymer-supported zeolites utilizing industrial by-products (fly ash and blast furnace slag), which can be potentially used as bulk-type solid adsorbents. The results revealed that the geopolymer-supported zeolites, possessing distinct strengths, zeolite phases (Na-P1, Na-chabazite, and analcime) and pore features depending on the mix design and synthesis conditions, can be easily synthesized employing the proposed one-step method. The geopolymer-supported zeolites exhibited the characteristics of mesoporous materials which are typically desired for commercial adsorbents. The maximum adsorption capacity for Pb²⁺ was found to be about 37.9 mg/g which is relatively higher than the other bulk-type adsorbents reported for Pb²⁺ to date. Since industrial by-products are used for synthesis of these materials, it will help in reducing the environmental hazards associated with the permanent disposal of such by-products, with an added advantage that these bulk-type solid adsorbents can be easily retrieved after use unlike granular adsorbents.

Mixed endometrial stromal and smooth muscle tumor of the uterus in a postmenopausal woman: morphologic and immunohistochemical features

Mixed endometrial stromal and smooth muscle tumor of the uterus is a rare occurrence, and it is truly challenging to diagnose or dif- ferentiate mesenchymal tumors of the uterine corpus, due to their many overlapping features. In most cases, the gross pathology of mixed endometrial stromal and smooth muscle tumor differs from that of pure endometrial stromal and pure smooth muscle tumors. A 59-year-old postmenopausal woman presented with vaginal spotting, low abdominal pain, and an uterine mass. Subsequent pelvic magnetic resonance imaging revealed a 4.0x3.8x3.4-cm sized uterine mass with enhancement. The mass showed restricted diffusion on diffusion-weighted images, and thus, was suspected to be uterine sarcoma rather than degenerative leiomyoma. Levels of tumor markers, CA 125, CA 19-9, and SCC, were within their normal ranges. The patient underwent exploratory laparotomy. Morphological and immunohistochemical evaluations were performed, and a final diagnosis of mixed endometrial stromal and smooth muscle tumor of the uterus was rendered. Her postoperative course was uneventful, and aromatase inhibitor adjuvant therapy was administered.

Efficacy of motivational interviewing and cognitive behavioral therapy for anxiety and depression symptoms following traumatic brain injury

BACKGROUND

Anxiety and depression are common following traumatic brain injury (TBI), often co-occurring. This study evaluated the efficacy of a 9-week cognitive behavioral therapy (CBT) program in reducing anxiety and depression and whether a three-session motivational interviewing (MI) preparatory intervention increased treatment response.

METHOD

A randomized parallel three-group design was employed. Following diagnosis of anxiety and/or depression using the Structured Clinical Interview for DSM-IV, 75 participants with mild-severe TBI (mean age 42.2 years, mean post-traumatic amnesia 22 days) were randomly assigned to an Adapted CBT group: (1) MI + CBT (n = 26), or (2) non-directive counseling (NDC) + CBT (n = 26); or a (3) waitlist control (WC, n = 23) group. Groups did not differ in baseline demographics, injury severity, anxiety or depression. MI and CBT interventions were guided by manuals adapted for individuals with TBI. Three CBT booster sessions were provided at week 21 to intervention groups.

RESULTS

Using intention-to-treat analyses, random-effects regressions controlling for baseline scores revealed that Adapted CBT groups (MI + CBT and NDC + CBT) showed significantly greater reduction in anxiety on the Hospital Anxiety and Depression Scale [95% confidence interval (CI) -2.07 to -0.06] and depression on the Depression Anxiety and Stress Scale (95% CI -5.61 to -0.12) (primary outcomes), and greater gains in psychosocial functioning on Sydney Psychosocial Reintegration Scale (95% CI 0.04-3.69) (secondary outcome) over 30 weeks post-baseline relative to WC. The group receiving MI + CBT did not show greater gains than the group receiving NDC + CBT.

CONCLUSIONS

Findings suggest that modified CBT with booster sessions over extended periods may alleviate anxiety and depression following TBI.

Abstract P3-12-17: Can radiation dosimetric parameters explain severe skin reaction during adjuvant whole breast irradiation applying field-in-field technique?

Aim: Although modern radiotherapy such as field-in-field technique decreased the radiation toxicity, skin reaction is still frequent and main problem during adjuvant whole breast irradiation. Our study investigated various radiation dosimetric and clinical parameters as the risk factors of severe skin reaction.

Methods: From January 2012 to December 2014, total 219 patients with breast conserving surgery and adjuvant whole breast irradiation were retrospectively reviewed. All patients took both whole breast irradiation (50 Gy/25 fractions) and boost to the tumor bed (10 - 15 Gy). Skin reaction was measured by comparing the photography of radiation field between the first day of whole breast irradiation and boost therapy. For each axilla and inferior fold, the intensity (score 1 to 5) and extent (score 0 to 1) of erythema were recorded and summed. The severe skin reaction was defined as score 5 or 6. The relations of various radiation dosimetric parameters for radiotherapy planning, personal breast characteristics and clinical factors to severe skin reaction were evaluated using the Logistic regression tests.

Results: Total 75 (34%) and 57 (26%) patients showed the severe skin reaction to axilla and inferior fold, respectively. The variables of P &lt; 0.2 in univariate analyses including age, the body mass index, the breast height, the V100, the calculated point dose in radiation planning system, the breast separation, the field size, and the gradient of inferior fold entered the multivariate analyses. Age (P=0.013 (OR = 0.950, 95% CI 0.913 - 0.989)), the body mass index (P = 0.015 (OR = 1.123, 95% CI 1.023 - 1.233)), the calculated axilla point dose (P = 0.091 (OR = 1.064, 95% CI 0.990 - 1.142)), and the gradient of inferior fold (P = 0.073 (OR = 1.029, 95% CI 0.997 - 1.063)) were risk factors for severe axilla skin reaction, whereas age (P = 0.018 (OR = 0.948, 95% CI 0.907 - 0.991)) and the V100 (P &lt; 0.001 (OR = 1.005, 95% CI 1.003 - 1.007)) were for severe inferior fold skin reaction.

Conclusion: In addition to clinical factor and personal breast characteristics, the radiation dosimetric parameters such as calculated point dose and V100 could be another predictive factors of severe skin reaction.

Citation Format: Yoon WS, Lee NK, Lee JA, Yang DS, Kim CY, Son GS, Chang YW. Can radiation dosimetric parameters explain severe skin reaction during adjuvant whole breast irradiation applying field-in-field technique?. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-17.

TRANSCRIPTION. Recruitment of RNA polymerase II by the pioneer transcription factor PHA-4

Pioneer transcription factors initiate cell-fate changes by binding to silent target genes. They are among the first factors to bind key regulatory sites and facilitate chromatin opening. Here, we identify an additional role for pioneer factors. In early Caenorhabditis elegans foregut development, the pioneer factor PHA-4/FoxA binds promoters and recruits RNA polymerase II (Pol II), often in a poised configuration in which Pol II accumulates near transcription start sites. At a later developmental stage, PHA-4 promotes chromatin opening. We found many more genes with poised RNA polymerase than had been observed previously in unstaged embryos, revealing that early embryos accumulate poised Pol II and that poising is dynamic. Our results suggest that Pol II recruitment, in addition to chromatin opening, is an important feature of PHA-4 pioneer factor activity.

Modelling complex features from histone modification signatures using genetic algorithm for the prediction of enhancer region

Using Genetic Algorithm, this paper presents a modelling method to generate novel logical-based features from DNA sequences enriched with H3K4mel histone signatures. Current histone signature is mostly represented using k-mers content features incapable of representing all the possible complex interactions of various DNA segments. The main contributions are, among others: (a) demonstrating that there are complex interactions among sequence segments in the histone regions; (b) developing a parse tree representation of the logical complex features. The proposed novel feature is compared to the k-mers content features using datasets from the mouse (mm9) genome. Evaluation results show that the new feature improves the prediction performance as shown by f-measure for all datasets tested. Also, it is discovered that tree-based features generated from a single chromosome can be generalized to predict histone marks in other chromosomes not used in the training. These findings have a great impact on feature design considerations for histone signatures as well as other classifier design features.

The effectiveness of gadolinium MRI to improve target delineation for radiotherapy in hepatocellular carcinoma: a comparative study of rigid image registration techniques

To achieve consistent target delineation in radiotherapy for hepatocellular carcinoma (HCC), image registration between simulation CT and diagnostic MRI was explored. Twenty patients with advanced HCC were included. The median interval between MRI and CT was 11 days. CT was obtained with shallow free breathing and MRI at exhale phase. On each CT and MRI, the liver and the gross target volume (GTV) were drawn. A rigid image registration was taken according to point information of vascular bifurcation (Method[A]) and pixel information of volume of interest only including the periphery of the liver (Method[B]) and manually drawn liver (Method[C]). In nine cases with an indefinite GTV on CT, a virtual sphere was generated at the epicenter of the GTV. The GTV from CT (VGTV[CT]) and MRI (VGTV[MR]) and the expanded GTV from MRI (V+GTV[MR]) considering geometrical registration error were defined. The underestimation (uncovered V[CT] by V[MR]) and the overestimation (excessive V[MR] by V[CT]) were calculated. Through a paired T-test, the difference between image registration techniques was analyzed. For method[A], the underestimation rates of VGTV[MR] and V+GTV[MR] were 16.4 ± 8.9% and 3.2 ± 3.7%, and the overestimation rates were 16.6 ± 8.7% and 28.4 ± 10.3%, respectively. For VGTV[MR] and V+GTV[MR], the underestimation rates and overestimation rates of method[A] were better than method[C]. The underestimation rates and overestimation rates of the VGTV[MR] were better in method[B] than method[C]. By image registration and additional margin, about 97% of HCC could be covered. Method[A] or method[B] could be recommended according to physician preference.

Is elective nodal irradiation beneficial in patients with pathologically negative lymph nodes after neoadjuvant chemotherapy and breast-conserving surgery for clinical stage II-III breast cancer? A multicentre retrospective study (KROG 12-05)

BACKGROUND

To evaluate the effects of elective nodal irradiation (ENI) in clinical stage II-III breast cancer patients with pathologically negative lymph nodes (LNs) (ypN0) after neoadjuvant chemotherapy (NAC) followed by breast-conserving surgery (BCS) and radiotherapy (RT).

METHODS

We retrospectively analysed 260 patients with ypN0 who received NAC followed by BCS and RT. Elective nodal irradiation was delivered to 136 (52.3%) patients. The effects of ENI on survival outcomes were evaluated.

RESULTS

After a median follow-up period of 66.2 months (range, 15.6-127.4 months), 26 patients (10.0%) developed disease recurrence. The 5-year locoregional recurrence-free survival and disease-free survival (DFS) for all patients were 95.5% and 90.5%, respectively. Pathologic T classification (0-is vs 1 vs 2-4) and the number of LNs sampled (<13 vs ≥13) were associated with DFS (P=0.0086 and 0.0012, respectively). There was no significant difference in survival outcomes according to ENI. Elective nodal irradiation also did not affect survival outcomes in any of the subgroups according to pathologic T classification or the number of LNs sampled.

CONCLUSIONS

ENI may be omitted in patients with ypN0 breast cancer after NAC and BCS. But until the results of the randomised trials are available, patients should be put on these trials.

Diffusion-weighted MRI for differentiation of benign from malignant lesions in the gallbladder

AIM

To investigate the value of diffusion-weighted imaging (DWI) for differentiating benign from malignant gallbladder lesions.

MATERIALS AND METHODS

One hundred and twenty-six patients who had undergone magnetic resonance imaging (MRI) with DWI, in whom the histopathological diagnosis of their gallbladder lesions was confirmed by biopsy or surgery were retrospectively analysed. Thirty-six malignant and 90 benign lesions were included. Two radiologists categorized gallbladder lesions into seven types on two imaging sets [T2-weighted imaging (WI) alone and combined T2WI and DWI (b = 800 s/mm(2))] according to the presence of wall thickening, layered patterns, morphology of the mass, and diffusion restriction. Disagreements were resolved in consensus. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each imaging set for diagnosing gallbladder carcinoma were calculated. The diagnostic performance of each imaging set was calculated using receiver operating characteristic (ROC) curve analysis. Additionally, ADC values of malignant and benign gallbladder lesions were compared separately for 1.5 and 3 T MRI.

RESULTS

The sensitivity, specificity, PPV, and NPV of diagnosis at T2WI were 97.2%, 86.7%, 74.5%, and 98.7%, respectively. The sensitivity, specificity, PPV, and NPV using combined T2WI and DWI were 97.2%, 92.2%, 83.3%, and 98.8%, respectively. Diagnostic accuracy for gallbladder carcinoma slightly improved after adding DWI, from 0.92 to 0.95 (p < 0.05). ADC values for gallbladder carcinoma were significantly lower than those for benign lesions. Mean ADC values of malignant and benign lesions were 0.97 ± 0.25 × 10(-3) and 1.72 ± 0.56 × 10(-3) mm(2)/s, respectively, at 1.5 T (p < 0.001), and 1.04 ± 0.38 × 10(-3) and 2.2 ± 0.72 × 10(-3) mm(2)/s, respectively, at 3 T (p < 0.001).

CONCLUSION

DWI can improve diagnostic accuracy for differentiating benign from malignant gallbladder lesions.

MDCT features in the differentiation of T4a gastric cancer from less-advanced gastric cancer: significance of the hyperattenuating serosa sign

OBJECTIVE

The purpose of our study was to evaluate CT findings to differentiate between T4a and less advanced gastric cancers.

METHODS

The institutional review board approved this study and waived informed consent. This study included 228 retrospectively identified patients with surgically confirmed gastric cancer (138 T1, 25 T2, 24 T3 and 41 T4a) and who had also undergone pre-operative CT scan. Transverse and multiplanar reconstruction scans were reviewed in consensus by two other blinded radiologists. The following CT findings that differentiate T4a from less advanced cancers were evaluated: nodular or an irregular outer layer of the gastric wall, haziness of the perigastric fat and a hyperattenuating serosa sign. The CT features of T4a and less advanced gastric cancers were compared by means of univariate and multivariate analyses.

RESULTS

In univariate analysis, nodular or an irregular outer layer of the gastric wall, haziness of the perigastric fat and the hyperattenuating serosa sign were significant in differentiation between T4a and less advanced gastric cancers. In addition, nodular or an irregular outer layer of the gastric wall and the hyperattenuating serosa sign were significant in differentiation between T3 and T4a. In multivariate logistic analysis, the hyperattenuating serosa sign was the most significant finding in differentiation between T3 and T4a (odds ratio, 4.210; 95% confidence intervals, 1.581-11.214; p=0.004).

CONCLUSION

The hyperattenuating serosa sign may be a useful CT finding in differentiation between T4a and less-advanced gastric cancers.

ADVANCES IN KNOWLEDGE

The hyperattenuating serosa sign is associated with gastric cancer with invading the serosa and can facilitate planning of the optimal pre-operative evaluation and treatment.

The relationship between mast cell density and tumour grade in transitional cell carcinoma of the bladder

This study investigated the relationship between mast cell numbers and the grade of bladder transitional cell carcinoma (TCC). Bladder TCC biopsies were obtained via transurethral resection and 45 stage T1 specimens were included in the study. Specimens were sorted into two groups, low grade (grade I) and high grade (grades II and III). Samples were stained using haematoxylin and eosin, toluidine blue and immunohistochemical staining for tryptase. Mast cells were examined by light microscopy and cell density was recorded. Mast cell density was significantly higher in high-grade TCC than low-grade TCC. There was also a significant relationship between the number of mast cells identified using toluidine blue staining or immunohistochemical staining for tryptase. Detailed studies of mast cell function will enable the development of more effective antitumour therapies via mast cell manipulation.

SOMEA: self-organizing map based extraction algorithm for DNA motif identification with heterogeneous model

Background

Discrimination of transcription factor binding sites (TFBS) from background sequences plays a key role in computational motif discovery. Current clustering based algorithms employ homogeneous model for problem solving, which assumes that motifs and background signals can be equivalently characterized. This assumption has some limitations because both sequence signals have distinct properties.

Results

This paper aims to develop a Self-Organizing Map (SOM) based clustering algorithm for extracting binding sites in DNA sequences. Our framework is based on a novel intra-node soft competitive procedure to achieve maximum discrimination of motifs from background signals in datasets. The intra-node competition is based on an adaptive weighting technique on two different signal models to better represent these two classes of signals. Using several real and artificial datasets, we compared our proposed method with several motif discovery tools. Compared to SOMBRERO, a state-of-the-art SOM based motif discovery tool, it is found that our algorithm can achieve significant improvements in the average precision rates (i.e., about 27%) on the real datasets without compromising its sensitivity. Our method also performed favourably comparing against other motif discovery tools.

Conclusions

Motif discovery with model based clustering framework should consider the use of heterogeneous model to represent the two classes of signals in DNA sequences. Such heterogeneous model can achieve better signal discrimination compared to the homogeneous model.

CT differentiation of pyogenic liver abscesses caused by Klebsiella pneumoniae vs non-Klebsiella pneumoniae

OBJECTIVE

Klebsiella pneumoniae is one of the organisms most commonly isolated from pyogenic liver abscesses in Asian populations. We compared CT findings in liver abscesses caused by K. pneumoniae with those caused by other bacterial pathogens.

METHODS

Of 214 patients with liver abscesses examined over a 5 year period, 129 patients with positive blood or aspirate cultures were enrolled. The patients were divided into two groups: the K. pneumoniae monomicrobial liver abscess (KLA) group (n = 59) and the non-K. pneumoniae monomicrobial or polymicrobial liver abscess (non-KLA) group (n = 70). Two radiologists blinded to the culture results evaluated the CT images, recording the number, size, location and configuration of abscesses, the thickness of the abscess wall, the pattern of rim enhancement, septal enhancement, the double target sign, internal necrotic debris, internal gas bubbles and underlying biliary disease. The presence of diabetes and metastatic infection was also compared between groups. Statistical analyses were performed using univariate (Student's t-test and χ(2) test) and multivariate analyses.

RESULTS

Multivariate analysis showed that a thin wall, necrotic debris, metastatic infection and the absence of underlying biliary disease were the most significant predictors of KLA. When three of the four criteria were used in combination, a specificity of 98.6% was achieved for the diagnosis of KLA.

CONCLUSION

A thin-walled abscess, internal necrotic debris, the presence of metastatic infection and the absence of underlying biliary disease may be useful CT findings in the early diagnosis of K. pneumoniae liver abscesses.

Measuring the kinetics of biomolecular recognition with magnetic colloids

We introduce a general methodology based on magnetic colloids to study the recognition kinetics of tethered biomolecules. Access to the full kinetics of the reaction is provided by an explicit measure of the time evolution of the reactant densities. Binding between a single ligand and its complementary receptor is here limited by the colloidal rotational diffusion. It occurs within a binding distance that can be extracted by a reaction-diffusion theory that properly accounts for the rotational Brownian dynamics. Our reaction geometry allows us to probe a large diversity of bioadhesive molecules and tethers, thus providing a quantitative guidance for designing more efficient reactive biomimetic surfaces, as required for diagnostic, therapeutic, and tissue engineering techniques.

[Restriction polymorphism of mitochondrial DNA in Koreans and Mongolians]

Using the data on mitochondrial DNA (mtDNA) restriction polymorphism, the gene pools of Koreans (N = 164) and Mongolians (N = 48) were characterized. It was demonstrated that the gene pools were represented by the common set of mtDNA haplogroups of East Asian origin (M*, M7, M8a, M10, C, D4, G*, G2, A, B*, B5, F1, and N*). In addition to this set, mtDNA haplogroups D5 and Y were identified in Koreans while Mongolians possessed haplogroup Z. Only in Mongolians, a European component with the frequency of 10.4% and represented by the mtDNA types belonging to haplogroups K, U4, and N1, was identified. Phylogenetic and statistical analyses of the data on mtDNA variation in the populations of South Siberia, Central, and East Asia suggested the existence of interpopulation differentiation within these regions, the main role in which was played by the geographical and linguistic factors. Analysis of the pairwise F(ST) distances demonstrated close genetic similarity of Koreans to Northern Chinese, which in turn, were clearly different from Southern Chinese populations. Mongolians occupied an intermediate position between the ethnic groups of South Siberia and Central/East Asia.

Urinary ascites and anuria caused by bilateral fungal balls in a premature infant

A case is reported of anuria and urinary ascites secondary to bilateral ureteropelvic obstruction by fungal balls. Management consisted of bilateral nephrostomy drainage with local irrigation with amphotericin B, and systemic antifungal treatment without surgery. Aspiration by paracentesis was performed for the urinary ascites and continuous drainage through an 8 Fr pig tail catheter for the urinoma. The literature on renal fungus balls in neonates and infants is reviewed.

Circumcision practice patterns in South Korea: community based survey

OBJECTIVES

To assess the prevalence of circumcision in South Korean young men dwelling in the community, investigate attitudes and perspectives about circumcision, and how they perceive physician involvement in the decision process.

METHODS

Between May and November 2001, this cross sectional survey was performed. Of 27 202 men aged 20 years dwelling in the community of Choong-chung South Province, 2700 were randomly selected at a 10.0% sampling fraction after a sampling process by census district and a total of 1742 (64.5%) agreed to participate in the study. These subjects completed self administered questionnaires and we included 1674 men (a response rate 62.0%) in the study.

RESULTS

The overall proportion of circumcised was 1306 (78.0%) and an additional 192 (11.5%) wished to be circumcised later. Circumcision was carried out mostly during their elementary and middle school years. Of men circumcised, the decision whether to circumcise was most often made by their parents. Of the subjects, 75.0% believed that circumcision is necessary, while 2.9% believed it to be unnecessary. Among those who believed circumcision to be necessary, the most common reason was to improve penile hygiene (89.1%).

CONCLUSIONS

Our results indicate a positive attitude toward circumcision in South Korean men, linking it with hygienic practices. Circumcision in South Korea depends on the perpetuation of cultural beliefs that support it.

Psychological problems in young men with chronic prostatitis-like symptoms

OBJECTIVE

To take a different perspective in assessing young men with chronic prostatitis-like symptoms, this study was designed since few prospective studies are available to survey a population of young men.

MATERIAL AND METHODS

One hundred and fifty men aged 20 years dwelling in the community were randomly selected. Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index and the selfreported scores for pain and urinary symptoms were used to identify chronic prostatitis-like symptoms. The psychological methods used were the Beck Depression Inventory, the State-Trait Anxiety Inventory, and the Bem Sex Role Inventory. A total of 87 men (a response rate 58%) completed self-administered questionnaires.

RESULTS

As the scores for pain and urinary symptoms increased, those for depression increased (p < 0.001 and p = 0.01, respectively). However, the mean scores for state and trait anxiety were not different according to the scores for pain and urinary symptoms. The mean masculinity scores were not different according to the scores for pain but those were significantly different according to the scores of urinary symptoms (p = 0.042). The mean femininity scores were not different according to the scores of pain and urinary symptoms.

CONCLUSIONS

Our findings suggest that psychological factors, especially depression and weak masculine identity may be associated with an early stage of chronic prostatitis-like symptoms. Young men with chronic prostatitis-like symptoms also have psychological problems.

Factors influencing testicular volume in young men: results of a community-based survey

OBJECTIVE

To investigate the factors influencing testicular volume in young men in the community.

SUBJECTS AND METHODS

Between May and November 2001, 2700 men aged 20 years and dwelling in the community were randomly selected at a 10% sampling fraction after a sampling process by census district; 2080 men agreed to participate in the study. All volunteers underwent a standard evaluation, including a detailed medical history and physical examination. After excluding those with testicular diseases the study comprised 1792 men.

RESULTS

There were significant but weak correlations between testicular volumes and height, body weight and body mass index. In a multivariate model, high environmental temperature was associated with a decreased likelihood (odds ratio, OR, 0.42; 95% confidence interval, CI, 0.29-0.60; P < 0.001) of a paired testicular volume being below the 25th percentile of all participants. The likelihood of a low paired testicular volume varied by area, with a 1.6-fold greater risk in men dwelling in large rural areas than in those in major towns. Increasing height was associated with a decreased likelihood (OR 0.60; 95% CI 0.38-0.96; P = 0.032) and low body weight with an increased likelihood of a low paired testicular volume (OR 2.54; 95% CI 1.57-4.12; P < 0.001).

CONCLUSION

These results establish that demographic and environmental factors have an effect on testicular size and suggest that body size may be important in determining testicular size in late adolescents.

Influence of environmental factors on chronic prostatitis-like symptoms in young men: results of a community-based survey

OBJECTIVES

To investigate the influence of environmental factors on chronic prostatitis-like symptoms among young men in a community.

METHODS

Of 28,841 men aged 20 years dwelling in the community, a total of 16,321 men (response rate 56.6%) were included in this study. The National Institutes of Health Chronic Prostatitis Symptom Index was used to identify men with chronic prostatitis-like symptoms. The questionnaire also queried sociodemographic characteristics. The Korean Meteorological Administration provided information on the weather of the community. We determined the risk factors of chronic prostatitis-like symptoms among these environmental factors using univariate and multivariate analyses.

RESULTS

Six percent of the men were identified as having significant prostatitis-like symptoms (perineal and/or ejaculatory pain and a total pain score of 4 or greater). The univariate logistic regression analysis indicated that education level, average duration of sunlight, and average temperature were risk factors for chronic prostatitis-like symptoms. As these variables increased, the scores of chronic prostatitis-like symptoms decreased. In the multivariate model used, the likelihood of chronic prostatitis-like symptoms varied by the final educational level, with middle school and high school graduates having 1.8 and 1.4-fold higher odds, respectively, than men attending college. In the same model, the average duration of sunlight was also an independent risk factor of chronic prostatitis-like symptoms (odds ratio 0.85; 95% confidence interval 0.77 to 0.95; P = 0.003), but the average temperature lost statistical significance.

CONCLUSIONS

Our findings suggest that the community-based prevalence of chronic prostatitis-like symptoms may be high in young men. Higher education and a longer time in sunlight were associated with a decreased likelihood of chronic prostatitis-like symptoms.

Is there a role of radial rigidity in the evaluation of erectile dysfunction?

RigiScan has been the most widely utilized device for measuring erectile rigidity. However, the use of the RigiScan in the evaluation of erectile dysfunction has questionable because the RigiScan device does not directly determine axial rigidity. The aim of this study is to clarify that radial rigidity measured by RigiScan reflects the intracorporeal pressure and erectile capability efficiently. From January 1998 to May 1999, a total of 23 patients with erectile dysfunction were involved in the study. They were evaluated by RigiScan and duplex ultrasonography after intracorporeal injection of prostaglandin E1. We investigated the relationship between radial rigidity and the resistance index. The results of radial rigidity were also compared with that of the degree of erection. For the entire group, significant correlations were found between radial rigidity and the resistance index (r=0.680, P<0.001 for tip rigidity; r=0.703, P<0.001 for base rigidity). In addition, for 12 patients whose tip rigidity exceeded 60% and for 10 whose base rigidity exceeded 60%, the correlations between radial rigidity and the resistance index remained (r=0.659, P=0.020 for tip rigidity; r=0.759, P=0.011 for base rigidity). Based on the response determined by patients, radial rigidity represented the degree of erection efficiently. Our findings suggest that RigiScan is a useful diagnostic tool. Radial rigidity represents the intracorporeal pressure efficiently and has an acceptable role in the evaluation of erectile dysfunction.

Is there a role for magnetic resonance imaging in renal trauma?

BACKGROUND

Computed tomography (CT) has been the most informative imaging method in renal trauma. Despite the good sensitivity of magnetic resonance imaging (MRI) to the presence of hematoma, edema and ischemia, MRI has not been widely studied in patients with renal trauma. The present study was initiated to evaluate the role of MRI in patients with renal trauma.

METHODS

Between June 1998 and September 1999, CT and MRI were prospectively performed on 12 patients who suffered from renal trauma and the results reviewed.

RESULTS

The presence and size of perirenal hematoma could be detected by both CT and MRI. Magnetic resonance imaging could differentiate intrarenal hematoma from perirenal hematoma more accurately, and provided additional information about the hematoma as T1- and T2-weighted MRI were able to determine recent bleeding in the hematoma by regional differences in signal intensity. Magnetic resonance imaging clearly revealed renal fracture with non-viable fragment and detected focal renal laceration that was not detected on CT due to perirenal hematoma associated with renal infarction. However, although MRI had many advantages over CT, it had also major drawbacks, which were that it required longer imaging time and increased the cost.

CONCLUSIONS

Magnetic resonance imaging may be useful in renal trauma. However, it is suggested that MRI should be limited to carefully selected patients, such as those with severe renal injury or equivocal findings on CT.

The prevalence of chronic prostatitis-like symptoms in young men: a community-based survey

We surveyed the prevalence of chronic prostatitis-like symptoms in young men using the National Institutes of Health (NIH) Chronic Prostatitis Symptom Index (CPSI) and determined the clinical validity of the NIH-CPSI among men in the community. Of 29,017 men aged 20 years dwelling in the community, 8,705 men were randomly selected at a 30.0% sampling fraction and a total of 6,940 men (a response rate 79.7%) completed a self-administered questionnaire. Six percent reported having pain or discomfort in more than one area . About 5% did not feel that the bladder emptied fully after urinating more than 1 time in 5 and 10.5% had to urinate again within 2 h more than 1 time in 5. As the scores for pain or discomfort increased, those for urinary symptoms and impact on quality of life increased (P < 0.001; Armitage test). As the scores for urinary symptoms increased, those for pain or discomfort and impact on quality of life also increased (P < 0.001; Armitage test). The community-based prevalence of chronic prostatitis-like symptoms were found to be high in young men as well as in older men. Our findings indicate that men with pain or urinary symptoms experience a negative impact on their quality of life and the NIH-CPSI provides a valid measure for the general population.

Infected hydrocele in a neonate

A case of infected hydrocele in a neonate is presented. We describe this unusual condition, and discuss the diagnosis, pathophysiology and treatment.

The excisional, plication and internal drainage techniques: a comparison of the results for idiopathic hydrocele

OBJECTIVE

To assess the results of the excision, plication and internal drainage techniques for hydrocele repair.

PATIENTS AND METHODS

Between January 1990 and June 1998, 132 patients (mean age 54.36 years, range 16-83) underwent repair for idiopathic hydrocele using one of three techniques (excision, eversion/plication or internal drainage); the complication and recurrence rates of each technique were evaluated.

RESULTS

The excisional technique resulted in the highest complication rate (81%) and the internal drainage technique the lowest (7%). Postoperative scrotal oedema occurred in 74% of patients after plication and this was the highest rate among the techniques (P < 0.001). Differences in the rates of wound infection and haematoma among the three techniques were not statistically significant. The internal drainage technique had the highest recurrence rate (85%) and the excisional technique the lowest (1.3%; P < 0.001).

CONCLUSIONS

Although useful, the internal drainage technique has a high recurrence rate and we suggest abandoning its use for hydrocele repair. The present results suggest that plication is better than excision, causing fewer complications, and better than internal drainage, as the results are more favourable.

Evidence for basolateral but not apical membrane localization of outwardly rectifying depolarization-induced Cl(-) channel in airway epithelia

The rat primary cultured-airway monolayer had been an excellent model for deciphering the ion channel after nystatin permeabilization of its basolateral or apical membrane (Hwang et al., 1996). After apical membrane permeabilization of rat primary cultured-airway monolayer, 4,4'-diisothiocyanatostilbene-2, 2'-disulfonic acid (DIDS)-sensitive outwardly rectifying depolarization-induced Cl(-) (BORDIC) currents were observed across the basolateral membrane in symmetrical NMG-Cl solution in this study. No significant Cl(-) current induced by the application of voltage clamping was observed across the apical membrane in symmetrical NMG-Cl solution after basolateral membrane permeabilization. The halide permeability sequence for BORDIC current was Br(-) = I(-) > Cl(-). BORDIC current was not affected by basolaterally applied bumetanide (0.5 mm). Basolateral DIDS (0.2 mm) but not apical DIDS inhibited CFTR mediated short-circuit current (I(sc)) in an intact monolayer of rat airway epithelia, a T84 human colonal epithelial cell line, and a Calu-3 human airway epithelial cell line. This is the first report showing that depolarization induced Cl(-) current is present on the basolateral membrane of airway epithelia.

Two cases of perineal ectopic testis

PURPOSE

Perineal ectopic testis is seen very rarely and here we report on two patients with perineal ectopic testis.

METHODS/RESULTS

We experienced two cases of perineal ectopic testis on which orchiopexies to the corresponding hemiscrotums were performed.

CONCLUSIONS

On surgical exploration, the gubernaculum testes were found to lie fixed to the perineum.

Hazardous alcohol use: its delineation as a subthreshold disorder, and approaches to its diagnosis and management

The last 20 years have seen a significant paradigm shift in how we view alcohol misuse. The dichotomous model of "alcoholism" and "normal drinking" has now been replaced by the concept of a spectrum of disorders. In this new framework, "hazardous alcohol use" is defined as a repeated pattern of drinking that confers the risk of harmful consequences. It is a typical example of a subthreshold disorder. Where actual physical or psychological harm or social problems have occurred, the terms "harmful alcohol use" and "alcohol abuse," respectively, are applied. These conditions would typically be considered to be above the clinical threshold. The most severe disorder, alcohol dependence, is a psychobiological syndrome with often severe physical, psychological, and social sequelae. This article describes how the concept of hazardous alcohol use originated, and reviews the intervention techniques that have been developed to induce and assist hazardous drinkers to reduce their consumption to nonhazardous levels. The findings from a series of World Health Organization (WHO) collaborative studies on brief interventions for hazardous alcohol use are described. This work has resulted in the development of the Alcohol Use Disorders Identification Test (AUDIT) screening instrument, which can detect over 90% of hazardous drinkers in a range of settings, and the demonstration that 5 minutes' structured advice can reduce hazardous consumption by 30%. The later phases of this program of work have examined strategies to promote the dissemination of brief interventions for hazardous alcohol use throughout primary health care, and the nationwide, systematic, and sustained utilization of these interventions.

The preventive effect of systemic treatment with interferon-alpha2B for infertility from mumps orchitis

OBJECTIVE

To evaluate the effect of interferon-alpha2B on mumps orchitis, often caused by postpubertal mumps and which can result in permanent testicular atrophy.

PATIENTS AND METHODS

The study included 21 patients with mumps orchitis, treated between May 1990 and June 1997. Patients were randomly assigned into two groups: in group 1, 13 patients received therapy with interferon-alpha2B (3 x 10(6) IU per day) and group 2 did not, acting as controls. All were evaluated by measurements of testis size, mumps virus titre, hormone level and semen analysis.

RESULTS

In group 1, the patients' symptoms resolved within 2-3 days and the volume of the testes returned to normal within 11 days; there was no testicular atrophy in any patient during the follow-up. However, asthenospermia continued to be detected in four patients (unilateral in two, bilateral in two). In group 2, the patients' symptoms resolved within 5-6 days and the volume of the testes returned to normal within 10 days; testes atrophied in three patients (unilateral in two, bilateral in one) during the follow-up. Asthenospermia continued in four patients (unilateral in two, bilateral in two).

CONCLUSION

These results suggest that treatment with systemic interferon-alpha2B is effective in preventing testicular atrophy when combined with standard symptomatic treatment.

The relationship of positive and negative alcohol expectancies to patterns of consumption of alcohol in social drinkers

Negative alcohol expectancies have recently come to occupy a more important position in the expectancy literature, but recent claims that positive expectancies are unimportant in the consumption of alcohol when compared with negative expectancies are based on potentially flawed methodology. This study investigated the relative contribution of positive and negative expectancies to the consumption of alcohol using an instrument designed to measure both positive and negative expectancies. One hundred ninety-three men and women from the general community participated in the study. Findings showed while negative expectancies accounted for the greater proportion of variance of frequency of consumption, positive expectancies remained an important predictor of consumption, accounting for the greater proportion of variance of quantity consumed per session. The interesting but sometimes counterintuitive directions of these relationships can be explained in terms of social learning principles. The relatively neglected concept of negative expectancies is worthy of further use and investigation.

The differential role of alcohol expectancies and drinking refusal self-efficacy in problem and nonproblem drinkers

OBJECTIVE

The present study aimed to examine the discriminatory ability of alcohol expectancies and drinking refusal self-efficacy and to identify the differential role of these constructs in social and problem drinkers.

METHOD

Drinkers (N = 276) were self-selected from general (n = 185) and clinical (n = 91) populations to complete a 40-minute questionnaire that asked about alcohol expectancies, drinking refusal self-efficacy, consumption, degree of dependence and demographics.

RESULTS

The results showed that in social drinkers both the expectancy and self-efficacy constructs were reliably able to discriminate between types of drinker. Expectancy was related to consumption in social drinkers, but did not appear to account for a significant proportion of the variance in problem drinkers.

CONCLUSIONS

The findings are discussed in terms of a two-process model of drinking behavior that suggests that expectancies operate differently in social and problem drinkers.

Alternatamides A-D: new bromotryptamine peptide antibiotics from the Atlantic marine bryozoan Amathia alternata

Four new bromotryptamine peptides, alternatamides A-D (1-4), have been isolated from the Atlantic bryozoan Amathia alternata. The structures of the alternatamides were assigned primarily on the basis of 2D NMR data. The absolute stereochemistry of the N-methylleucine amino acid was shown to be L (2'S) by hydrolysis and comparison with standards. The alternatamides show modest antibacterial activities against several Gram-positive bacteria.

Frequent allelic loss at chromosome arm 3p is distinct from genetic alterations of the Von-Hippel Lindau tumor suppressor gene in head and neck cancer

Previous molecular genetic studies revealed that allelic loss of chromosome arm 3p is a frequent event in upper aerodigestive tract squamous cell carcinoma (UADT SCC). Recently, the Von-Hippel Lindau (VHL) tumor suppressor gene was identified at chromosome band 3p25-26. To determine if the VHL locus is altered in these tumors, a paired series of 26 tumors and blood from patients with UADT SCC that were previously shown to exhibit allelic loss of 3p were tested for LOH surrounding the VHL locus using four different polymorphic markers. All of the samples (100%) exhibited LOH for at least 1 marker. However, no LOH was detected using a polymorphism within exon 1 of the VHL gene which was informative for 18 of the 26 cases. Furthermore, mutations of the VHL gene could not be identified by single-strand conformation polymorphism, dideoxyfingerprint or direct DNA sequence analysis. In addition, the VHL gene was not inactivated by hypermethylation in any of the 26 tumor samples studied. These findings demonstrate that allelic loss of chromosome arm 3p in UADT SCC involves regions surrounding the VHL locus but does not include the VHL gene. The VHL gene, therefore, does not appear to be involved in the pathogenesis of UADT SCC.

Endoscopic resection of the intranasal frontal sinus floor

The current accepted treatment for chronic frontal sinus disease unresponsive to medical management and endoscopic surgery is an external approach to either obliterate the sinus or restore communication to the nasal cavity. Here reported is an endoscopic approach for resection of the intranasal frontal sinus floor, a modification of a procedure first described by Lothrop in 1899. Eleven patients underwent this operation from April 1993 to December 1993. One complication, a cerebrospinal fluid leak treated successfully endoscopically, has occurred. Of the 7 patients followed up 3 months or longer after surgery, only 1 has developed symptoms of recurrent frontal sinusitis. On the basis of this limited preliminary experience, the endoscopic Lothrop procedure shows promise as an effective operation designed to establish a physiologic communication between the frontal sinus and the nasal cavity in selected patients who would otherwise be candidates for an external approach.

Allelic loss at chromosomes 3p, 8p, 13q, and 17p associated with poor prognosis in head and neck cancer

BACKGROUND

Little is known about the molecular genetic events that contribute to the pathogenesis of squamous cell carcinoma of the upper aerodigestive tract. Previous molecular genetic studies have been limited to the identification of mutations of the p53 (also known as TP53) tumor suppressor gene, activation of a limited set of oncogenes, allelic loss at 3p and other locations, and occasional association with human papillomavirus infection.

PURPOSE

Our purpose was to screen tumor tissue and blood from patients with squamous cell carcinoma of the upper aerodigestive tract for loss of heterozygosity at polymorphic loci corresponding to each of the autosomal chromosomes and to identify the locations of additional putative tumor suppressor genes, other than RB (also known as RB1) and p53, that may contribute to the pathogenesis of this disease.

METHODS

Tumor tissue and blood were obtained from 68 consecutive patients with squamous cell carcinoma of the upper aerodigestive tract. In all cases, tumor tissue was obtained from the center of the surgical specimen. The relative absence of non-neoplastic tissue was confirmed by frozen-section histologic examination of immediately adjacent tissue. Initially, 30 paired tissue and blood samples were tested for loss of heterozygosity by polymerase chain reaction (PCR) to amplify 43 different highly polymorphic sequences containing small oligonucleotide repeats. After PCR amplification, with unique oligonucleotides flanking the repeat, visualization and sizing of the alleles on DNA sequencing gels were performed. Specific loss of heterozygosity was distinguished from random genetic loss due to generalized chromosomal instability if it occurred in more than 20% of specimens tested for a particular marker.

RESULTS

Significant loss of heterozygosity (> 20%) occurred at alleles at chromosome bands 3p21 (32%), 3p25-26 (56%), 8pter-21.1 (31%), 13q14 (27%), and 17p12 (45%). Loss of heterozygosity at more than two loci was significant with a poor prognosis (P = .039).

CONCLUSIONS

These findings demonstrate that squamous cell carcinoma of the upper aerodigestive tract exhibits genetic alterations at multiple loci and that allelic loss at more than two locations is indicative of a poor prognosis (the likelihood of the patient dying of disease).

IMPLICATIONS

While tumor suppressor genes at 3p (VHL), 13q (RB), and 17p (p53) have been identified, altered genes at other loci on 3p and on 8p have not yet been characterized. Furthermore, the genotype at these loci for squamous cell carcinoma of the upper aerodigestive tract has prognostic importance and may identify the patients who should receive the most aggressive treatment.

p53, retinoblastoma, and human papillomavirus in squamous cell carcinoma and adjacent normal mucosa of the upper aerodigestive tract

OBJECTIVE

The primary objective of this study was to determine the incidence of p53 and retinoblastoma tumor suppressor gene mutations and human papillomavirus infection in squamous cell carcinoma and adjacent normal mucosa of the upper aerodigestive tract. The secondary objective was to associate these findings with clinical and histopathologic features.

DESIGN

Point mutations of p53 were identified by single-strand conformation polymorphism analysis and confirmed by direct DNA sequence analysis. Polymerase chain reaction-based methods were used to identify loss of heterozygosity of the retinoblastoma tumor suppressor gene and the presence of human papillomavirus sequences.

SETTING

University-based tertiary care center.

PATIENTS OR OTHER PARTICIPANTS

Forty-five consecutive cases of upper aerodigestive tract squamous cell carcinoma.

RESULTS

Eleven point mutations of p53 were identified in tumor samples (24%). No functional p53 mutations were detected in adjacent normal tissue from eight of these individuals nor was there evidence of p53 alteration in normal tissue adjacent to 12 of 30 additional tumors tested that demonstrated conformational alterations by single-strand conformation polymorphism analysis. The p53 mutations were significantly associated with local invasion. Loss of heterozygosity (which has a 20% chance of random occurrence in tumors) was detected at the retinoblastoma locus in 15% of the tumors tested. Five of the specimens (11%) were positive for human papillomavirus sequences (two of which also contained p53 mutations).

CONCLUSIONS

These findings suggest that p53 but not retinoblastoma or human papillomavirus is an important prognostic factor and is involved as a late event in the pathogenesis of upper aerodigestive tract squamous cell carcinoma.

Splenic and partial hepatic necrosis after vascular occlusion

A 74-year-old woman underwent two operations to correct an aortoduodenal fistula and to have an axillofemoral bypass graft inserted; these required temporary vascular occlusion. Her hepatic function test results began deteriorating. Initial and follow-up Tc-99m sulfur colloid studies revealed activity in the kidneys, consistent with disseminated intravascular coagulation. There was significant radiocolloid in the bone marrow and lungs, suggesting severe hepatic dysfunction. The spleen was not demonstrable on dynamic images or static views. In addition, there was a significant lateral hepatic defect, with a "lung overlap." The splenic lack of function and the hepatic lesion were due to necrosis (demonstrable on CT imaging), likely related to the prior vascular clamping.

The importance of alcohol expectancies and drinking refusal self-efficacy in the quantity and frequency of alcohol consumption

Expectancies about alcohol have been shown to be related to and predictive of alcohol consumption. Research to date, however, has often failed to make a clear distinction between expectations about the effects of alcohol (alcohol expectancies) and expectations about one's ability to resist drinking in certain situations (drinking refusal self-efficacy). There is some evidence that alcohol expectancies (AE) and drinking refusal self-efficacy (DRSE) can play differential roles in the prediction of consumption in terms of quantity and frequency of drinking. This study aimed to replicate and extend these findings to the community population. Subjects (N = 185) were recruited from the general community using a peer network system. They were given a booklet comprising six self-report measures, including the Drinking Expectancy Questionnaire (DEQ), the Drinking Self-Efficacy Questionnaire (DSEQ), and the Khavari Alcohol Test (KAT), which produces measures of usual and maximum quantity as well as frequency of the usual and maximum consumed. It was expected that AE would be related to frequency of consumption whereas DRSE would be related to both quantity and frequency. The findings confirmed the differential role of AE and DRSE in drinking, and the role of factors within the two concepts. Results indicated that low DRSE was related to higher frequency of general consumption and a larger maximum quantity on any one occasion. AE was related to frequency, but not to quantity, as expected. The findings are presented with respect to the theoretical constructs; clinical and research implications are also discussed.

Tumor suppressor genes

Tumor suppressor genes are negative regulators of cell growth. When their normal function is compromised, absence of their inhibitory effects can lead to unrestrained cell cycling and growth. Strong evidence now confirms that loss of proper function of these genes is a common occurrence leading to cancer. Their failure can be caused by alterations in the gene DNA or malfunction of their protein products. The recent extraordinary accumulation of knowledge about these genes reveals that normal carcinogenesis represents breakdown of normal regulatory processes.