Transradial Versus Transfemoral Arterial Access in Liver Cancer Embolization: Randomized Trial to Assess Patient Satisfaction.

PURPOSE: To determine whether transradial access (TRA) or transfemoral access (TFA) provides better patient satisfaction during intra-arterial therapy (IAT) for liver cancer. MATERIALS AND METHODS: This randomized, prospective, intra- and interpatient controlled trial compared TRA vs TFA accesses in patients with primary or metastatic liver cancer undergoing IAT. After having one of each type of access (1 TRA and 1 TFA), all patients selected their preferred access regardless of whether a third intervention was indicated. The primary endpoint was patient access preference; secondary endpoints were access-related complications, procedure time, contrast agent volume, and radiation doses to the patient and operator. Patients were evaluated on postprocedure days 1 and 30. RESULTS: Fifty-five patients with liver cancer (31 hepatocellular carcinoma, 24 metastatic disease) were enrolled, and 124 IAT procedures were performed. A total of 36 patients underwent at least 1 intervention each with TRA and TFA. Of those, 29 patients (81%) preferred TRA and 7 (19%) preferred TFA (ratio, 4:1; P < .001). Median radiation exposure to the operator was significantly lower for TRA (5.5 mrem) vs TFA (13 mrem; P = .01). Incidences of complications, procedure time, contrast agent volume, and radiation exposure to patients were similar between groups. CONCLUSIONS: TRA was the preferred access for the majority of patients and was associated with less radiation exposure to the operator. No differences were detected in incidence of adverse events, procedure time, contrast agent volume, or patient radiation exposure.

Microwave spectra of the deuterium isotopologues of cis-hexatriene and a semiexperimental equilibrium structure.

Microwave transitions and ground state rotational constants are reported for five newly synthesized deuterium isotopologues of cis-1,3,5-hexatriene (cHTE). These rotational constants along with those of the parent and the three (13)C species are used with vibration-rotation constants calculated from an MP2/cc-pVTZ model to derive an equilibrium structure. That structure is improved by the mixed estimation method. In this method, internal coordinates from good-quality quantum chemical calculations (with appropriate uncertainties) are fit simultaneously with moments of inertia of the full set of isotopologues. The new structure of cHTE is confirmed to be planar and is stabilized by an interaction between the hydrogen atoms H2 and H5, which form a bond and participate in a six-membered ring. cHTE shows larger structural effects of π-electron delocalization than does butadiene with the effects being magnified in the center of the molecule. Thus, strong structural evidence now exists for an increase in π-electron delocalization as the polyene chain lengthens.

Semiexperimental equilibrium structure of the lower energy conformer of glycidol by the mixed estimation method.

Rotational constants were determined for (18)O-substituted isotopologues of the lower energy conformer of glycidol, which has an intramolecular inner hydrogen bond from the hydroxyl group to the oxirane ring oxygen. Rotational constants were previously determined for the (13)C and the OD species. These rotational constants have been corrected with the rovibrational constants calculated from an ab initio cubic force field. The derived semiexperimental equilibrium rotational constants have been supplemented by carefully chosen structural parameters, including those for hydrogen atoms, from medium level ab initio calculations. The combined data have been used in a weighted least-squares fit to determine an equilibrium structure for the glycidol H-bond inner conformer. This work shows that the mixed estimation method allows us to determine a complete and reliable equilibrium structure for large molecules, even when the rotational constants of a number of isotopologues are unavailable.

Ventricular width and complicated recovery following deep brain stimulation surgery.

BACKGROUND: Candidates for deep brain stimulation (DBS) must be carefully evaluated to balance expected benefits with the possibility of serious complications. Several predictive factors exist but are imperfect. OBJECTIVES: The aim of this study was to determine whether linear measurements of the lateral ventricles predict complications following DBS. METHODS: We retrospectively studied a cohort of DBS patients. The primary outcome was postoperative confusion; secondary outcomes were discharge disposition and all in-hospital complications. For each case, a control matched for age, sex, diagnosis, and DBS target was identified. Linear measurements were made from routine preoperative axial MRIs for both cases and controls. RESULTS: A total of 40 patients met one or more of the end points. Patients with postoperative confusion had a significantly larger minimum width of the lateral ventricles than controls. Patients discharged to a higher level of care and those with any complications also had significantly greater maximum and minimum ventricular widths than controls. CONCLUSIONS: These results suggest that preoperative measurement of the maximum and minimum width of the lateral ventricles may help predict which patients are at risk for complicated recoveries following DBS.

Rotational spectra and computational analysis of two conformers of leucinamide.

Rotational spectra were recorded for two isotopic species of two conformers of the amide derivative of leucine in the range of 10.5-21 GHz and fit to a rigid rotor Hamiltonian. Ab initio calculations at the MP2/6-311++G(d,p) level identified the low energy conformations with different side chain configurations; the rotational spectra were assigned to the two lowest energy ab initio structures. We recorded 16 a- and b-type rotational transitions for conformer 1; the rotational constants of the normal species are A = 2275.6(2), B = 1033.37(2) and C = 911.71(5) MHz. We recorded 23 a- and b-type rotational transitions for conformer 2; the rotational constants of the normal species are A = 2752.775(8), B = 843.502(1) and C = 796.721(1) MHz. The rotational spectra of the (15)N(amide) isotopomer of each conformer were recorded and the atomic coordinates of the amide nitrogen were determined by Kraitchman's method of isotopic substitution. The experimentally observed structures are significantly different from the crystal structures of leucinamide and the gas-phase structures of leucine, and a natural bond orbital analysis revealed the donor-acceptor interactions governing side chain configuration.

Toward a Mobile Platform for Real-world Digital Measurement of Depression: User-Centered Design, Data Quality, and Behavioral and Clinical Modeling.

BACKGROUND: Although effective mental health treatments exist, the ability to match individuals to optimal treatments is poor, and timely assessment of response is difficult. One reason for these challenges is the lack of objective measurement of psychiatric symptoms. Sensors and active tasks recorded by smartphones provide a low-burden, low-cost, and scalable way to capture real-world data from patients that could augment clinical decision-making and move the field of mental health closer to measurement-based care. OBJECTIVE: This study tests the feasibility of a fully remote study on individuals with self-reported depression using an Android-based smartphone app to collect subjective and objective measures associated with depression severity. The goals of this pilot study are to develop an engaging user interface for high task adherence through user-centered design; test the quality of collected data from passive sensors; start building clinically relevant behavioral measures (features) from passive sensors and active inputs; and preliminarily explore connections between these features and depression severity. METHODS: A total of 600 participants were asked to download the study app to join this fully remote, observational 12-week study. The app passively collected 20 sensor data streams (eg, ambient audio level, location, and inertial measurement units), and participants were asked to complete daily survey tasks, weekly voice diaries, and the clinically validated Patient Health Questionnaire (PHQ-9) self-survey. Pairwise correlations between derived behavioral features (eg, weekly minutes spent at home) and PHQ-9 were computed. Using these behavioral features, we also constructed an elastic net penalized multivariate logistic regression model predicting depressed versus nondepressed PHQ-9 scores (ie, dichotomized PHQ-9). RESULTS: A total of 415 individuals logged into the app. Over the course of the 12-week study, these participants completed 83.35% (4151/4980) of the PHQ-9s. Applying data sufficiency rules for minimally necessary daily and weekly data resulted in 3779 participant-weeks of data across 384 participants. Using a subset of 34 behavioral features, we found that 11 features showed a significant (P<.001 Benjamini-Hochberg adjusted) Spearman correlation with weekly PHQ-9, including voice diary-derived word sentiment and ambient audio levels. Restricting the data to those cases in which all 34 behavioral features were present, we had available 1013 participant-weeks from 186 participants. The logistic regression model predicting depression status resulted in a 10-fold cross-validated mean area under the curve of 0.656 (SD 0.079). CONCLUSIONS: This study finds a strong proof of concept for the use of a smartphone-based assessment of depression outcomes. Behavioral features derived from passive sensors and active tasks show promising correlations with a validated clinical measure of depression (PHQ-9). Future work is needed to increase scale that may permit the construction of more complex (eg, nonlinear) predictive models and better handle data missingness.

Rotational spectra of o-, m-, and p-cyanophenol and internal rotation of p-cyanophenol.

Rotational spectra of p-, m-, and o-cyanophenol have been measured in the range of 10.5-21 GHz and fit using Watson's A-reduction Hamiltonian coupled with nuclear quadrupole coupling interaction terms for the (14)N nuclei. Ab initio calculations at the MP2/6-311++G(d,p) and CCSD(T)/6-311++G(d,p) levels predict the cis conformers of m- and o-cyanophenol to be more stable than the corresponding trans conformers. A natural bond orbital analysis of the hydrogen bonding interaction in o- and m-cyanophenol revealed an intramolecular hydrogen bond that preferentially stabilizes the cis conformer of o-cyanophenol but there was no evidence of hydrogen bonding interactions in cis m-cyanophenol. We recorded 25 a- and b-type rotational transitions for cis o-cyanophenol; the rotational constants are A = 3053.758(2) MHz, B = 1511.2760(3) MHz, and C = 1010.7989(2) MHz. The trans conformer of o-cyanophenol was not observed. We recorded 14 a- and b-type rotational transitions for cis m-cyanophenol and 16 a- and b-type rotational transitions for trans m-cyanophenol. The rotational constants are A = 3408.9200(2) MHz, B = 1205.8269(2) MHz, and C = 890.6672(1) MHz and A = 3403.1196(3) MHz, B = 1208.4903(2) MHz, and C = 891.7241(2) MHz for the cis and trans species, respectively. Rotational transitions of the p-cyanophenol monomer are split due to the internal rotation of the hydroxyl group with respect to the aromatic ring. We recorded 25 a- and b-type rotational transitions for p-cyanophenol; the b-type transitions are split by 40 MHz. The rotational constants are A = 5612.96(2) MHz, B = 990.4283(6) MHz, and C = 841.9363(6) MHz. The ground state spitting DeltaE is 20.1608(6) MHz and the barrier to internal rotation, V(2), is 1413(2) cm(-1) from a fit of the rotational transitions to an internal axis system Hamiltonian. The barrier to internal rotation was modeled at the MP2/6-311++G(d,p) level and the effects of substituents on the phenolic ring and the barriers to internal rotation are discussed.

Microwave, Raman, and infrared spectra; adjusted r(0) structural parameters; conformational stability; and vibrational assignment of germylcyclohexane.

The FT-microwave spectrum of germylcyclohexane, c-C(6)H(11)GeH(3), has been recorded, and more than 40 transitions for the (70)Ge, (72)Ge, and (74)Ge isotopomers (isotopologues) have been assigned for the chair-equatorial conformer. The heavy atom adjusted r(0) structural parameters have been determined [distances, C(gamma)-C(delta) = 1.533(3) A, C(gamma)-C(beta) = 1.532(3) A, C(alpha)-C(beta) = 1.540(3) A, C(alpha)-Ge = 1.957(3) A; angles, angleC(gamma)C(delta)C(beta) = 111.2(5) degrees , angleGeC(alpha)C(beta) = 111.1(5) degrees , with the dihedral angle angleC(gamma)C(delta)C(beta)C(alpha) = 55.6(10) degrees ]. Raman and/or infrared spectra of gas, liquid, and solid germylcyclohexane have been recorded. The temperature dependency of the Raman spectrum of the conformer pair 712 (equatorial)/683 (axial) cm(-1) gives an enthalpy difference of 453 +/- 38 cm(-1) (1.30 +/- 0.11 kcal/mol) with the chair-equatorial conformer the more stable form. At ambient temperature, the abundance of the axial conformer is 11 +/- 1%. Substituent effects on the enthalpy difference and structure of monosubstituted cyclohexanes are discussed for a number of molecules.

Infrared spectra of CF(2)=CHD and CF(2)=CD(2): scaled quantum-chemical force fields and an equilibrium structure for 1,1-difluoroethylene.

Infrared (IR) spectra in the gas phase are reported for CF(2)=CHD and CF(2)=CD(2) in the region 350-4000 cm(-1). Ab initio calculations of an harmonic force-field and anharmonicity constants have been made with an MP2/aug-cc-pVTZ model. These enable a number of Fermi resonances in each species to be analyzed and a complete set of "observed" harmonic frequencies to be derived. The latter are combined with similar data for CF(2)=CH(2) in a scaling of the model harmonic force field to both anharmonic and harmonic frequencies. Inspection of the scale factors reveals minor defects of the model, evident in the out-of-plane wagging modes and in the CF stretch/CF stretch interaction force constant. Fermi resonance treatments involved in all isotopomers studied are compatible with the overall force-field refinement results. The treatment leaves a small anomaly in the (13)C shift on nu(1). Improved microwave spectra are reported for five isotopic species, and a semiexperimental equilibrium structure for F(2)C=CH(2) is determined and compared favorably with the structure obtained from new high-level ab initio calculations. Centrifugal distortion constants are predicted for the five isotopic species, and those for F(2)C=CH(2) are compared with values fit to microwave spectra.

Favorable outcomes of autoimmune hepatitis in a community clinic setting.

BACKGROUND AND AIM: Autoimmune hepatitis (AIH) is an idiopathic disease with diverse clinical manifestations. The aims of the present study were: (i) to describe the clinical characteristics of AIH patients in a community clinic setting; and (ii) to determine factors which were associated with poor clinical outcomes. METHODS: A retrospective review was performed on 72 AIH patients who: (i) had pretreatment sera: (ii) were treatment-naïve at presentation; and (iii) had a minimum of 24 months of follow up. RESULTS: On initial presentation, 22 (30%) had an acute onset of symptoms simulating acute viral hepatitis, 34 (47%) had chronic symptoms of greater than 6 months duration, and the remaining 16 (22%) were asymptomatic. Twenty-six (36%) had coexisting autoimmune diseases. Anti-nuclear antibody (ANA) was positive in 73% of the patients, and antismooth muscle antibody was positive in 15% of ANA-negative patients. Those few patients who tested positive for soluble liver antigen, anti-liver-kidney, microsomal antibody type-1, and anti-mitochondrial antibody were all also ANA positive. The median (range) duration of follow up was 98 (24-331) months. After immunosuppressive therapy, 26 of 72 (36%) remained in remission without further treatment. However, 46 (64%) required maintenance immunosuppression. Three patients who presented under the age of 20 years progressed to liver failure while on therapy and died while waiting for liver transplantation. Two other patients developed hepatocellular carcinoma (HCC) while on therapy and died. CONCLUSIONS: A majority of AIH patients have an excellent prognosis. However, presentation at a younger age is a predictor of poor disease outcome and, although uncommon, HCC may develop during the late stages of cirrhosis.

Feeding the open abdomen.

BACKGROUND: The purpose of this study was to determine if early enteral nutrition improves outcome for trauma patients with an open abdomen (OA). METHODS: Retrospective review was used to identify 78 patients who required an OA for >or=4 hospital days, survived, and had available nutrition data. Demographic data and nutrition data comprising enteral nutrition initiation day and daily % target goal were collected. Patients were divided into 2 groups: early enteral feeding (EEN), initiated 4 days). Outcomes included infectious complications, early closure of the abdominal cavity (<8 days from original celiotomy), and fistula formation. RESULTS: Fifty-three of 78 (68%) patients were men, with a mean age of 35 years; 74% had blunt trauma. Forty-three of 78 (55%) patients had EEN, whereas 35 of 78 (45%) had LEN. There was no difference with respect to demographics, injury severity, or infectious complication rates. Thirty-two of 43 (74%) patients with EEN had early closure of the abdominal cavity, whereas 17 of 35 (49%) patients with late feeding had early closure (p = .02). Four of 43 (9%) patients with EEN demonstrated fistula formation, whereas 9 of 35 (26%) patients with late feeding formed fistulae (p = .05). The EEN group had lower hospital charges (p = .04) by more than $50,000. CONCLUSIONS: EEN in the OA was associated with (1) earlier primary abdominal closure, (2) lower fistula rate, (3) lower hospital charges.

The clinical utility of using Catrimox-14-treated whole blood in detecting hepatitis C virus RNA.

BACKGROUND: Measuring hepatitis C virus (HCV) RNA in serum or plasma may underestimate the true HCV burden. Extracting viral RNA from whole blood (WB) with a cationic surfactant (Catrimox-14) has resulted in HCV RNA concentrations up to 1000-fold higher than from serum or plasma in some studies, but not others. We compared the Catrimox-14 WB assay with a standard serum assay. METHODS: Seventy-two chronic HCV patients received 48 weeks of standard or pegylated interferon alpha-2b and ribavirin therapy. Catrimox-14-treated WB and corresponding serum samples were obtained at baseline and weeks 12, 24, 48 and 72. HCV RNA concentrations from WB and serum were quantified by a previously validated RT-PCR assay. RESULTS: Overall mean (+/- SD) baseline serum log10 HCV RNA concentration was 6.5 ((+/- 0.58) copies/ml. Out of 72 patients, 33 had no detectable virus at 72 weeks. Neither assay detected virus in these patients at 12 weeks and neither WB nor serum assays detected virus at end-of-treatment in the 10 patients who subsequently relapsed at 72 weeks. HCV RNA concentrations from WB and serum assays were linearly correlated (R2 = 0.73; P < 0.001), although mean serum HCV RNA concentrations were 0.5 log10, copies/ml higher in serum than in WB [6.0 (+/- 0.82) vs 5.5 ((+/- 0.84), respectively, P = 0.12]. CONCLUSIONS: Catrimox-14-treated WB assays detect changes in HCV RNA, but do not offer clinical advantage over a conventional serum RT-PCR based assay.

Changes in the presence of multiple markers of circulating melanoma cells correlate with clinical outcome in patients with melanoma.

PURPOSE: Melanoma cells can be found in the circulation of patients with melanoma. The following study was conducted to examine whether changes in their presence could provide an early marker of response to therapy. EXPERIMENTAL DESIGN: We measured the presence of several markers of melanoma cells in the peripheral blood of 118 patients with resected stage IIb, III, or IV melanoma before and after immunotherapy with a polyvalent, shed antigen, melanoma vaccine using reverse transcription-PCR assays for tyrosinase, gp100, MART-1, and MAGE-3. Assays were conducted at baseline and after 3, 5, and 11 months of therapy. RESULTS: Overall, 47% of patients were positive for at least one marker during the study. Before vaccine treatment, circulating melanoma cell markers were present in 23% of patients. After 5 and 7 months of vaccine therapy, the proportion of patients with circulating markers decreased by 27% and 55%, respectively (P for trend = 0.02). The recurrence-free survival of patients whose melanoma cell markers disappeared during vaccine treatment was significantly longer than that of patients in whom they increased, i.e., the percentage of patients who were recurrence free at 1 year was 80% versus 58% (P = 0.03). CONCLUSIONS: Therapy with a polyvalent melanoma vaccine was associated with clearance of melanoma cell markers from the circulation, and the clearance was associated with an improved prognosis. These findings suggest that the sequential assay of tumor cells in the circulation by reverse transcription-PCR may provide an early indication of the effectiveness of cancer therapy.

Homogeneous quasispecies in 16 out of 17 individuals during very early HIV-1 primary infection.

OBJECTIVE: To measure HIV-1 quasispecies diversity in very recently infected male and female plasma donors. METHODS: HIV-1 RNA testing of blood and plasma donations was used to select anti HIV-1 antibody negative, HIV-1 RNA positive plasma samples from 13 males and four females undergoing primary infection. To determine whether these early viral populations were clonal or oligoclonal, heteroduplex mobility assays were performed on multiple independently generated envelope PCR products. Genetically heterogeneous quasispecies where subcloned and their divergent envelope variants sequenced. RESULTS: Because of frequent plasma donations in this population, HIV-1 RNA quasispecies could be studied during very early primary infection. Heteroduplex mobility assays detected the presence of genetically distinct variants in four of the 17 plasma donors. DNA sequence analysis showed that one case was due to a G to A hyper-mutation event and that two cases were caused by the presence of in-frame insertions/deletions resulting in DNA heteroduplex mobility shifts. The early plasma quasispecies of one female contained highly divergent variants differing by up to 6% substitution and multiple insertions/deletions, a level of divergence unlikely to have been generated de novo following transmission. V3 loop sequences analysis indicated the presence of non-syncitium inducing genotypes in 14 out of 17 primary infection cases. CONCLUSION: Plasma viremia is generally genetically homogeneous even during the very early phase of primary infection when viremia is first detected and still rising exponentially. Evidence for the transmission of multiple variants was detected in only one out of four women and none of 13 men undergoing primary infection with subtype B HIV-1.

Dynamics of HIV viremia and antibody seroconversion in plasma donors: implications for diagnosis and staging of primary HIV infection.

OBJECTIVES: The characterization of primary HIV infection by the analysis of serial plasma samples from newly infected persons using multiple standard viral assays. DESIGN: A retrospective study involving two sets of archived samples from HIV-infected plasma donors. (A) 435 samples from 51 donors detected by anti-HIV enzyme immunoassays donated during 1984-1994; (B) 145 specimens from 44 donors detected by p24 antigen screening donated during 1996-1998. SETTING: Two US plasma products companies. MAIN OUTCOME MEASURES: The timepoints of appearance of HIV-1 markers and viral load concentrations during primary HIV infection. RESULTS: The pattern of sequential emergence of viral markers in the 'A' panels was highly consistent, allowing the definition and estimation of the duration of six sequential stages. From the 'B' panels, the viral load at p24 antigen seroconversion was estimated by regression analysis at 10 000 copies/ml (95% CI 2000-93 000) and the HIV replication rate at 0.35 log copies/ml/day, corresponding to a doubling time in the preseroconversion phase of 20.5 h (95% CI 18.2-23.4 h). Consequently, an RNA test with 50 copies/ml sensitivity would detect HIV infection approximately 7 days before a p24 antigen test, and 12 days before a sensitive anti-HIV test. CONCLUSION: The sequential emergence of assay reactivity allows the classification of primary HIV-1 infection into distinct laboratory stages, which may facilitate the diagnosis of recent infection and stratification of patients enrolled in clinical trials. Quantitative analysis of preseroconversion replication rates of HIV is useful for projecting the yield and predictive value of assays targeting primary HIV infection.

Induction of IL-1Ra in resistant and responsive hepatitis C patients following treatment with IFN-con1.

Hepatitis C virus (HCV) infection is resistant to interferon-alpha (IFN-alpha) in some patients. The mechanism of this resistance is unknown. Interleukin-1 receptor antagonist (IL-1Ra) is induced by IFN-alpha and is a good indicator of IFN activity. In the current study, we compared IL-1Ra levels in rapid virologic responders and flat responders who showed resistance to IFN. Three groups of patients were examined, including those who received a single dose of consensus IFN (IFN-con1), patients who received daily IFN-con1 for 1 week, and patients who received IFN-con1 daily for 24 weeks. Serum IL-1Ra, IL-6, and HCV RNA were measured serially in all groups. Serum IL-1Ra levels increased rapidly in all patients with hepatitis C after IFN-alpha administration, irrespective of their virologic response. IL-1Ra levels remained elevated at 1 week but were similar to baseline by week 2 of treatment in patients receiving continuous therapy. IL-6 levels also increased acutely but rose more slowly than IL-1Ra levels. The increase in IL-1Ra and IL-6 observed in both flat and rapid virologic responders indicates that IFN receptors are functioning in patients with IFN-resistant hepatitis C and that the lack of response is related to other virologic or immunologic factors.

Linear measurements of the cerebral ventricles are correlated with adult ventricular volume.

Computation of ventricular volume has important clinical applications but is challenging. We compared linear ventricular measurements to ventricular volume to find a simple to perform quantitative measurement of ventricular size. Linear measurements were correlated with ventricular volumes to different degrees and were reproducible between investigators. Linear measurements provide a quick and simple quantification of ventricular size for use in clinical settings.

Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability, and vibrational assignment of allyl thiol.

FT-microwave spectrum of allyl thiol, H(2)CCHCH(2)SH, has been recorded, and 19 transitions have been assigned for the most abundant isotopologue of Gg conformer, and the rotational constants have been determined; A=20,041.439 (4), B=2795.830 (1), C=2701.084 (1). From the determined microwave rotational constants and ab initio MP2(full)/6-311+G(d,p) predicted structural values, adjusted r(0) parameters are reported with distances (Å): rCC=1.343 (3), rC-C=1.496 (3), rC-S=1.827 (3) and angles (°) ∠CCC=123.4 (5), ∠CCS=112.5 (5), and τC(γ)C(ß)C(α)S=118.7 (5). Variable temperature (-55 to -100°C) infrared spectra (3600-400cm(-1)) were recorded of allyl thiol in liquid xenon and the Gg conformer was determined to be the most stable form. The enthalpy differences relative to the Gg form are for Cg 120±9cm(-1) (1.44±0.11kJ/mol), for Gg' 337±34cm(-1) (4.03±0.41kJ/mol), and for Gt 360±36cm(-1) (4.31±0.43kJ/mol). The relative amounts present at ambient temperature are Gg 52±1%, Cg 29±1%, Gg' 10±1%, and Gt 9±1%. The conformational stabilities have been predicted from ab initio calculations with many basis sets up to aug-cc-pVTZ and the predicted stabilities are in agreement with the experimentally determined order. Vibrational assignments are reported with support by ab initio predictions and results are discussed.

Decision making for the extent of thyroidectomy in the patient with atypical cytologic results.

OBJECTIVE: to identify additional preoperative factors that could reliably be used to aid in determining the appropriate extent of thyroidectomy. DESIGN: retrospective chart review. SETTING: tertiary care academic hospital. PATIENTS: two hundred consecutively treated patients who underwent thyroid surgery after having a fine-needle aspiration biopsy procedure yielding a specimen that met the criteria for atypical cytologic features. MAIN OUTCOME MEASURE: final histopathologic diagnosis of malignant vs benign disease. RESULTS: the final diagnosis was benign in 42.5% of patients and malignant in 57.5%. The presence of microcalcifications within the nodule on ultrasonography (US) was significantly associated with a higher risk of malignant disease (relative risk = 1.31, P = .04). When examined individually, age, sex, family history of thyroid malignant disease, exposure to head and neck irradiation, nodule size, rim enhancement on US, and intranodular vascularity on US were not significantly associated with an increased risk of malignant disease. Mulivariate stepwise logistic regression modeling was used to identify a model that could reliably predict a higher probability of malignant disease. The final model determined that patients with microcalcifications on US and a nodule of 2.0 cm or larger had a 74.3% risk of malignant disease vs a 47.5% risk in patients with no microcalcifications and a nodule smaller than 2.0 cm. This difference was statistically significant. When the predicted probabilities of malignant disease were compared with the observed probabilities, the goodness-of-fit test revealed no significant difference (P = .95). CONCLUSION: microcalcifications and nodule size can be used to risk-stratify patients with an atypical fine-needle aspiration biopsy result and aid in determining the appropriate extent of thyroidectomy.

Relationship of smoking and fibrosis in patients with chronic hepatitis C.

BACKGROUND & AIMS: Preliminary studies have suggested that in patients with chronic hepatitis C (CHC), cigarette smoking increases the risk for developing liver fibrosis. Hypoxia caused by smoking may induce expression of the cytokines' vascular endothelial growth factor (VEGF) and VEGF-D and their corresponding soluble tyrosine kinase receptors fms-like tyrosine kinase receptor (s-Flt) and kinase insert domain receptor (s-KDR). These cytokine levels are increased in animals with cirrhosis and in human beings with CHC. We studied whether the concentrations of VEGF, VEGF-D, s-Flt, and s-KDR were increased in CHC smokers with and without hepatic fibrosis. METHODS: A total of 170 CHC patients were identified retrospectively from a single center's database. In 59 patients, serum levels of VEGF, VEGF-D, s-Flt, and s-KDR were measured using an enzyme-linked immunosorbent assay. RESULTS: All 170 patients were hepatitis C virus RNA positive, 117 (69%) were men, 43 (25%) were smokers, and their mean (+/-SD) age was 47 (+/-6) years. Overall, 21% of smokers had Metavir fibrosis scores of 3 and 4 compared with 14% of nonsmokers (P < .01). In an age-weighted multivariate model using step-wise logistic regression, smoking, infection with hepatitis C virus genotype 1, male sex, and increased VEGF-D concentration all were significant independent predictors of more severe liver fibrosis (P < .05 for all observations). CONCLUSIONS: These data suggest that CHC patients who smoke may have more hepatic fibrosis. The data also suggest that increased VEGF and VEGF-D concentrations are associated with smoking and may be involved in the molecular mechanisms of fibrogenesis.