Search

Smoking during breast radiotherapy (RT) may be associated with radiation-induced skin injury (RISI). We aimed to determine if a urinary biomarker of tobacco smoke exposure is associated with increased rates of RISI during and after breast RT.Women with Stage 0-IIIA breast cancer treated with breast-conserving surgery or mastectomy followed by RT to the breast or chest wall with or without regional nodal irradiation were prospectively enrolled on a multicenter study assessing acute/late RISI. 980 patients with urinary cotinine (UCot) measurements (baseline and end-RT) were categorized into three groups. Acute and late RISI was assessed using the ONS Acute Skin Reaction scale and the LENT-SOMA Criteria.Late Grade 2+ and Grade 3+ RISI occurred in 18.2% and 1.9% of patients, respectively-primarily fibrosis, pain, edema, and hyperpigmentation. Grade 2+ late RISI was associated with UCot group (P= 006). Multivariable analysis identified UCot-based light smoker/secondhand smoke exposure (HR 1.79, P= .10) and smoking (HR 1.60, p = .06) as non-significantly associated with an increased risk of late RISI. Hypofractionated breast RT was associated with decreased risk of late RISI (HR 0.51, P=.03). UCot was not associated with acute RISI, multivariable analysis identified race, obesity, RT site/fractionation, and bra size to be associated with acute RISI.Tobacco exposure during breast RT may be associated with an increased risk of late RISI without an effect on acute toxicity. Smoking cessation should be encouraged prior to radiotherapy to minimize these and other ill effects of smoking.

Purpose This study examined an inflammatory biomarker, high-sensitivity C-reactive protein (hsCRP), in radiotherapy (RT)-induced early adverse skin reactions or toxicities in breast cancer. Patients and Methods Between 2011 and 2013, 1,000 patients with breast cancer who underwent RT were evaluated prospectively for skin toxicities through the National Cancer Institute–funded Wake Forest University Community Clinical Oncology Program Research Base. Pre- and post-RT plasma hsCRP levels and Oncology Nursing Society skin toxicity criteria (0 to 6) were used to assess RT-induced skin toxicities. Multivariable logistic regression analyses were applied to ascertain the associations between hsCRP and RT-induced skin toxicities after adjusting for potential confounders. Results The study comprised 623 white, 280 African American, 64 Asian/Pacific Islander, and 33 other race patients; 24% of the patients were Hispanic, and 47% were obese. Approximately 42% and 15% of patients developed RT-induced grade 3+ and 4+ skin toxicities, respectively. The hsCRP levels differed significantly by race and body mass index but not by ethnicity. In multivariable analysis, grade 4+ skin toxicity was significantly associated with obesity (odds ratio [OR], 2.17; 95% CI, 1.41 to 3.34], post-RT hsCRP ≥ 4.11 mg/L (OR, 1.61; 95% CI, 1.07 to 2.44), and both factors combined (OR, 3.65; 95% CI, 2.18 to 6.14). Above-median post-RT hsCRP (OR, 1.93; 95% CI, 1.03 to 3.63), and change in hsCRP (OR, 2.80; 95% CI, 1.42 to 5.54) were significantly associated with grade 4+ skin toxicity in nonobese patients. Conclusion This large prospective study is the first to our knowledge of hsCRP as an inflammatory biomarker in RT-induced skin toxicities in breast cancer. We demonstrate that nonobese patients with elevated RT-related change in hsCRP levels have a significantly increased risk of grade 4+ skin toxicity. The outcomes may help to predict RT responses and guide decision making.

Background. Head and neck cancer (HNC) patients are at an increased risk for developing second primary tumors (SPTs). Diets rich in fruits and vegetables (FVs) may lower HNC risk. FV concentrates may offer a potential alternative to increasing FV intake. Methods. We conducted a randomized, double-blind, placebo-controlled trial to evaluate whether Juice PLUS+ (JP; a commercial product with multiple FV concentrates) has an effect on p27 and Ki-67, biomarkers associated with the risk of SPTs. During 2004-2008, we randomized 134 HNC patients to 12 weeks of JP (n = 72) or placebo (n = 62). Oral cavity mucosal biopsies and whole blood were obtained at baseline and after 12 weeks. All participants were given the opportunity to receive JP for 5 years following the end of the intervention period, and they were followed yearly for the development of SPTs. Results. After 12 weeks, patients on JP had significantly higher serum α-carotene ( P = .009), β-carotene ( P < .0001), and lutein ( P = .003) but did not differ significantly in p27 ( P = .23) or Ki-67 ( P = .95). JP use following the initial 12-week trial was not significantly associated with SPT prevention. Conclusions. Despite increased serum micronutrient levels, our results do not suggest a clinical benefit of JP in HNC patients. Future studies should focus on longer intervention periods and/or modified supplement formulations with demonstrated chemopreventive properties.

Purpose: WHO grade 2 low-grade gliomas (LGG) with high risk factors for recurrence are mostly lethal despite current treatments. We conducted a phase I study to evaluate the safety and immunogenicity of subcutaneous vaccinations with synthetic peptides for glioma-associated antigen (GAA) epitopes in HLA-A2+ adults with high-risk LGGs in the following three cohorts: (i) patients without prior progression, chemotherapy, or radiotherapy (RT); (ii) patients without prior progression or chemotherapy but with prior RT; and (iii) recurrent patients. Experimental Design: GAAs were IL13Rα2, EphA2, WT1, and Survivin. Synthetic peptides were emulsified in Montanide-ISA-51 and given every 3 weeks for eight courses with intramuscular injections of poly-ICLC, followed by q12 week booster vaccines. Results: Cohorts 1, 2, and 3 enrolled 12, 1, and 10 patients, respectively. No regimen-limiting toxicity was encountered except for one case with grade 3 fever, fatigue, and mood disturbance (cohort 1). ELISPOT assays demonstrated robust IFNγ responses against at least three of the four GAA epitopes in 10 and 4 cases of cohorts 1 and 3, respectively. Cohort 1 patients demonstrated significantly higher IFNγ responses than cohort 3 patients. Median progression-free survival (PFS) periods since the first vaccine are 17 months in cohort 1 (range, 10–47+) and 12 months in cohort 3 (range, 3–41+). The only patient with large astrocytoma in cohort 2 has been progression-free for more than 67 months since diagnosis. Conclusion: The current regimen is well tolerated and induces robust GAA-specific responses in WHO grade 2 glioma patients. These results warrant further evaluations of this approach. Clin Cancer Res; 21(2); 286–94. ©2014 AACR.

Doxorubicin (Dox) is widely used for breast cancer treatment but causes serious side- effects including cardiotoxicity that may adversely impact patient lifespan even if treatment is successful. The present invention relates to selective conjugation of Dox to a single site in a DNA hairpin resulting in a highly stable complex that enables Dos to be used more effectively. Selective conjugation of Dox to G15 in the hairpin loop was verified using site-specific labeling with [2- 15N3-2'-deoxyguanosme in conjunction with [1 H-15NJ 2D NM R while 1:1 stoichiometry for the conjugate was validated by ESI-QTOF mass spectrometry and UV spectroscopy. Molecular modeling indicated covalently bound Dox also intercalated into the stem of the hairpin and stability studies demonstrated the resulting Dox-conjugated hairpin (DCH) complex had a half-life > 30 h, considerably longer than alternative covalent and non- covalent complexes. Secondary conjugation of DCH with folic acid (FA) resulted in increased internalization into breast cancer cells. The dual conjugate, DCH-FA, can be used tor safer and more effective chemotherapy with Dox and this conjugation strategy can be expanded to include additional anti-cancer drugs.

The naturally occurring nitroalkenes, including nitrolinoleic (NO2-LA) and nitrooleic (NO2-OA)1 acids, are implicated in the modulation of multiple signaling pathways resulting in several important bioactivities including vasodilation, inhibition of inflammation, and inhibition of platelet activation and function (1-4). In addition, these nitrated unsaturated fatty acids are among the most potent endogenous ligand activators of PPARγ—a nuclear receptor involved in the transcription of genes associated with carbohydrate and lipid homeostasis, cellular differentiation, and inflammation (5-8). The physiological importance of these nitroalkenes is indicated by their relative abundance in vivo with aggregate levels reported to be around 1-2 μM in normal human plasma and erythrocytes (9)—levels in excess of those necessary to significantly activate PPARγ-dependent transcription in vitro (10, 11). In order to understand how nitroalkene activities are regulated at the cellular level, we previously demonstrated that NO2-LA forms conjugates with glutathione, rapidly and non-enzymatically, under physiological conditions (12). These conjugates are efficiently effluxed by MRP1, a ubiquitous ATP-dependent glutathione conjugate transporter, and combined conjugation plus MRP1-mediated efflux profoundly attenuates PPARγ-dependent transcription activation in response to NO2-LA (12). Here we demonstrate that activation of PPARγ by NO2-OA is similarly affected by non-enzymatic conjugation and efflux. Moreover, we investigated whether expression of representative isozymes of the soluble forms of glutathione S-transferase (GST) would influence NO2-LA and NO2-OA bioactivities either by catalyzing their conjugation with glutathione or by an alternative mechanism. Indeed, we show that while expression of GSTA1-1, GSTM1a-1a, or GSTP1a-1a significantly attenuates the activation of PPARγ-dependent transcription by NO2-LA and NO2-OA, none of these isozymes, or GSTA4-4, is able to catalyze glutathione conjugation of the nitroalkenes. Rather, these GSTs appear to influence transcription via avid covalent and non-covalent interactions with the nitroalkenes and their glutathione conjugates thereby sequestering them from their nuclear target, PPARγ.

Ferritin is a protein principally known for its role in iron storage. We have previously shown that ferritin can bind high-molecular-weight kininogen (HK). Upon proteolytic cleavage by the protease kallikrein, HK releases the proinflammatory peptide bradykinin (BK) and other biologically active products, such as two-chain high-molecular-weight kininogen, HKa. At inflammatory sites, HK is oxidized, which renders it a poor substrate for kallikrein. However, oxidized HK remains a good substrate for elastase and tryptase, thereby providing an alternative cleavage mechanism for HK during inflammation. Here we report that ferritin can retard the cleavage of both native HK and oxidized HK by elastase and tryptase. Initial rates of cleavage were reduced 45–75% in the presence of ferritin. Ferritin is not a substrate for elastase or tryptase and does not interfere with the ability of either protease to digest a synthetic substrate, suggesting that ferritin may impede HK cleavage through direct interaction with HK. Immunoprecipitation and solid phase binding studies reveal that ferritin and HK bind directly with a Kdof 134 nM. To test whether ferritin regulates HK cleavage in vivo, we used THP-1 cells, a human monocyte/macrophage cell line that has been used to model pulmonary inflammatory cells. We observed that ferritin impedes the cleavage of HK by secretory proteases in stimulated macrophages. Furthermore, ferritin, HK, and elastase are all present in or on alveolar macrophages in a mouse model of pulmonary inflammation. Collectively, these results implicate ferritin in the modulation of HK cleavage at sites of inflammation.

Objectives/Hypothesis: Exposure of laryngeal epithelia to pepsin during extra-esophageal reflux causes depletion of laryngeal protective proteins, carbonic anhydrase isoenzyme III (CAIII), and squamous epithelial stress protein Sep70. The first objective of this study was to determine whether pepsin has to be enzymatically active to deplete these proteins. The second objective was to investigate the effect of pH on the activity and stability of human pepsin 3b under conditions that might be found in the human esophagus and larynx. Study Design: Prospective translational research study. Methods: An established porcine in vitro model was used to examine the effect of active/inactive pepsin on laryngeal CAIII and Sep70 protein levels. The activity and stability of pepsin was determined by kinetic assay, measuring the rate of hydrolysis of a synthetic pepsin-specific substrate after incubation at various pH values for increasing duration. Results: Active pepsin is required to deplete laryngeal CAIII and Sep70. Pepsin has maximum activity at pH 2.0 and is inactive at pH 6.5 or higher. Although pepsin is inactive at pH 6.5 and above, it remains stable until pH 8.0 and can be reactivated when the pH is reduced. Pepsin is stable for at least 24 hours at pH 7.0, 37°C and retains 79% ± 11% of its original activity after re-acidification at pH 3.0. Conclusions: Detectable levels of pepsin remain in laryngeal epithelia after a reflux event. Pepsin bound there would be enzymatically inactive because the mean pH of the laryngopharynx is pH 6.8. Significantly, pepsin could remain in a form that would be reactivated by a subsequent decrease in pH, such as would occur during an acidic reflux event or possibly after uptake into intracellular compartments of lower pH.

Objectives: The objectives of this study were to define the conditions that give rise to a stress protein response in laryngeal epithelium and to investigate whether and how stress protein dysfunction contributes to reflux-related laryngeal disease. Methods: Western analysis was used to measure stress protein (squamous epithelial proteins Sep70 and Sep53 and heat shock protein Hsp70) and pepsin levels in esophageal and laryngeal tissue specimens taken from both normal control subjects and patients with pH-documented laryngopharyngeal reflux (LPR) who had documented lesions, some of whom had laryngeal cancer. A porcine organ culture model was used to examine the effects of low pH and pepsin (0.1% porcine pepsin A) on stress protein levels. A laryngeal squamous carcinoma (FaDu) cell line was used to examine uptake of human pepsin 3b-tetramethyl-5 and -6 isothiocyanate. Results: Sep70, Sep53, and Hsp70 were found to be expressed at high levels, and pepsin was not detected, in esophageal and laryngeal specimens taken from normal control subjects and in esophageal specimens taken from LPR patients. The patients with LPR were found to have significantly less laryngeal Sep70 (p = .027) and marginally less laryngeal Sep53 (p = .056) than the normal control subjects. Laryngeal Hsp70 was expressed at high levels in the LPR patients. The patients with laryngeal cancer had significantly lower levels of Sep70, Sep53 (p < .01), and Hsp70 (p < .05) than the normal control subjects. A significant association was found between the presence of pepsin in laryngeal epithelium from LPR patients and depletion of laryngeal Sep70 (p < .001). Using the organ culture model, we demonstrated that laryngeal Sep70 and Sep53 proteins are induced after exposure to low pH. However, in the presence of pepsin, Sep70 and Sep53 levels are depleted. Confocal microscopy analysis of cultured cells exposed to labeled pepsin revealed that uptake is by receptor-mediated endocytosis. Conclusions: These findings suggest that receptor-mediated uptake of pepsin by laryngeal epithelial cells, as may occur in LPR, causes a change in the normal acid-mediated stress protein response. This altered stress protein response may lead to cellular injury and thus play a role in the development of disease.

Objectives/Hypothesis: The objective was to investigate the potential use of pepsin and carbonic anhydrase isoenzyme III (CA-III) as diagnostic markers for laryngopharyngeal reflux disease. Study Design: Prospective cell biological investigation was conducted of laryngeal biopsy specimens taken from 9 patients with laryngopharyngeal reflux disease and 12 normal control subjects using antibodies specific for human pepsin (produced in the authors' laboratory within the Department of Otolaryngology at Wake Forest University Health Sciences, Winston-Salem, NC) and CA-III. Methods: Laryngeal biopsy specimens were frozen in liquid nitrogen for Western blot analysis and fixed in formalin for pepsin immunohistochemical study. Specimens between two groups (patients with laryngopharyngeal reflux disease and control subjects) were compared for the presence of pepsin. Further analyses investigated the correlation between pepsin, CA-III depletion, and pH testing data. Results: Analysis revealed that the level of pepsin was significantly different between the two groups (P

Short interfering RNAs (siRNAs) and microRNAs (miRNAs) have been widely used in mammalian tissue culture and model organisms to selectively silence genes of interest. One limitation of this technology is the lack of precise external control over the gene-silencing event. The use of photocleavable protecting groups installed on nucleobases is a promising strategy to circumvent this limitation, providing high spatial and temporal control over siRNA or miRNA activation. Here, we have designed, synthesized and site-specifically incorporated new photocaged guanosine and uridine RNA phosphoramidites into short RNA duplexes. We demonstrated the applicability of these photocaged siRNAs in the light-regulation of the expression of an exogenous green fluorescent protein reporter gene and an endogenous target gene, the mitosis motor protein, Eg5. Two different approaches were investigated with the caged RNA molecules: the light-regulation of catalytic RNA cleavage by RISC and the light-regulation of seed region recognition. The ability to regulate both functions with light enables the application of this optochemical methodology to a wide range of small regulatory RNA molecules.

Antisense oligonucleotides are powerful tools to regulate gene expression in cells and model organisms. However, a transfection or microinjection is typically needed for efficient delivery of the antisense agent. We report the conjugation of multiple HIV TAT peptides to a hairpin-protected antisense agent through a light-cleavable nucleobase caging group. This conjugation allows for the facile delivery of the antisense agent without a transfection reagent, and photochemical activation offers precise control over gene expression. The developed approach is highly modular, as demonstrated by the conjugation of folic acid to the caged antisense agent. This enabled targeted cell delivery through cell-surface folate receptors followed by photochemical triggering of antisense activity. Importantly, the presented strategy delivers native oligonucleotides after light-activation, devoid of any delivery functionalities or modifications that could otherwise impair their antisense activity.

Background Pepsin in saliva is a proposed biomarker for oropharyngeal reflux. Pepsin may be prevalent in saliva from subjects with gastro-esophageal reflux and may correlate with proximal reflux by intraluminal impedance/pH monitoring (MII/pH). Methods Patients (3 days to 17.6 years, n=90) undergoing 24-hour MII/pH monitoring and asymptomatic controls (2 months to 13.7 years, n=43) were included. Salivary pepsin was determined using a pepsin enzyme-linked immunosorbent assay. Eight saliva samples were collected from patients undergoing 24-hr MII/pH: (i) before catheter placement, (ii) before and 30 minutes after each of three meals, and (iii) upon awakening. One sample was collected from each control. Key Results In MII/pH subjects, 85.6% (77/90) had at least one pepsin-positive sample compared with 9.3% (4/43) in controls. The range of pepsin observed in individual subjects varied widely over 24 hours. The average pepsin concentration in all samples obtained within 2 hours following the most recent reflux event was 30.7±135 ng/mL, decreasing to 16.5±39.1 ng/mL in samples collected more than 2 hours later. The frequency of pepsin-positive samples correlated significantly with symptom index (rS=0.332, P=.0014), proximal (rS=0.340, P=.0010), and distal (rS=0.272, P=.0095) MII events. Conclusions & Inferences Concentration of salivary pepsin may not be an accurate measure of severity of reflux because of the wide range observed in individuals over 24 hours. Saliva samples must be obtained soon after a reflux event. Defining a regimen for optimal saliva collection may help to achieve the goal of using salivary pepsin as a biomarker for oropharyngeal reflux. Clinical Trial registry NCT01091805.

EphrinA1 is a glycosylphosphatidylinositol (GPI)-linked ligand for the EphA2 receptor, which is overexpressed in glioblastoma (GBM), among other cancers. Activation of the receptor by ephrinA1 leads to a suppression of oncogenic properties of GBM cells. We documented that a monomeric functional form of ephrinA1 is released from cancer cells and thus explored the mechanism of ephrinA1 release and the primary protein sequence. We demonstrate here that multiple metalloproteases (MMPs) are able to cleave ephrinA1, most notably MMP-1, -2, -9, and -13. The proteolytic cleavage that releases ephrinA1 occurs at three positions near the C terminus, producing three forms ending in valine-175, histidine-177, or serine-178. Moreover, deletion of amino acids 174 to 181 or 175 to 181 yields ephrinA1 that is still GPI linked but not released by proteolysis, underlining the necessity of amino acids 175 to 181 for release from the membrane. Furthermore, recombinant ephrinA1 ending at residue 175 retains activity toward the EphA2 receptor. These findings suggest a mechanism of release and provide evidence for the existence of several forms of monomeric ephrinA1. Moreover, ephrinA1 should be truncated at a minimum at amino acid 175 in fusions or conjugates with other molecules in order to prevent likely proteolysis within physiological and pathobiological environments.

Triplex-forming oligonucleotides (TFOs) are efficient tools to regulate gene expression through the inhibition of transcription. Here, nucleobase-caging technology was applied to the first temporal regulation of transcription through light-activated TFOs. Through site-specific incorporation of caged thymidine nucleotides, the TFO:DNA triplex formation is blocked, rendering the TFO inactive. However, after a brief UV irradiation, the caging groups are removed, activating the TFO, and leading to the inhibition of gene transcription. Furthermore, the synthesis and site-specific incorporation of caged deoxycytidine nucleotides within TFO inhibitor sequences was developed, and allows for the light-deactivation of TFO function and thus photochemical activation of gene expression. After UV-induced removal of the caging groups, the TFO forms a DNA dumbbell structure, rendering it inactive, releasing it from the DNA, and activating transcription. These are the first examples of light-regulated TFOs and their application in the photochemical activation and deactivation of gene expression. In addition, hairpin loop structures were found to significantly increase the efficacy of phosphodiester DNA-based TFOs in tissue culture.

Background Coenzyme Q10 (CoQ10) is a common antioxidant supplement with known cardioprotective effects and potential anticancer benefits. Objectives We performed a randomized, double-blind, placebo-controlled study of oral CoQ10 in female breast cancer patients with the primary objective of determining CoQ10's effects on self-reported fatigue, depression, and quality of life (QOL). Methods Eligible women with newly diagnosed breast cancer and planned adjuvant chemotherapy were randomized to oral supplements of 300 mg CoQ10 or placebo, each combined with 300 IU vitamin E, divided into 3 daily doses. Treatment was continued for 24 weeks. Blood tests, QOL measures, and levels of plasma CoQ10 and vitamin E were obtained at baseline and at 8, 16, and 24 weeks. Mixed-effects models were used to assess treatment differences in outcomes over time. Results Between September 2004 and March 2009, 236 women were enrolled. Treatment arms were well balanced with respect to age (range, 28-85 years), pathologic stage (stage 0, 91%; stage 1, 8%; stage II, 1%), ethnicity (white, 87%; black, 11%; Hispanic, 2%), and planned therapy. Baseline CoQ10 levels in the CoQ10 and placebo arms were 0.70 and 0.73 microg/mL, respectively; the 24-week CoQ10 levels were 1.83 and 0.79 microg/mL, respectively. There were no significant differences between the CoQ10 and placebo arms at 24 weeks for scores on the Profile of Mood States-Fatigue questionnaire (least squares means, 7.08 vs 8.24, P = .257), the Functional Assessment of Chronic Illness Therapy-Fatigue tool (37.6 vs 37.6, P = .965), the Functional Assessment of Cancer Therapy-Breast Cancer instrument (111.9 vs 110.4, P = .577), or the Center for Epidemiologic Studies-Depression scale (11.6 vs 12.3, P = .632). Conclusions Supplementation with conventional doses of CoQ10 led to sustained increases in plasma CoQ10 levels but did not result in improved self-reported fatigue or QOL after 24 weeks of treatment.

The photochemical regulation of biological systems represents a very precise means of achieving high-resolution control over gene expression in both a spatial and a temporal fashion. DNAzymes are enzymatically active deoxyoligonucleotides that enable the site-specific cleavage of RNA, and have been used in a variety of in vitro applications. We have previously reported the photochemical activation of DNAzymes and antisense agents through the preparation of a caged DNA phosphoramidite and its site-specific incorporation into oligonucleotides. The presence of the caging group disrupts either DNA:RNA hybridization or catalytic activity, until removed via a brief irradiation with UV light. Here, we are expanding this concept by investigating the photochemical deactivation of DNAzymes and antisense agents. Moreover, we report the application of light-activated and light-deactivated antisense agents to the regulation of gene function in mammalian cells. This represents the first example of gene silencing antisense agents that can be turned on and turned off in mammalian tissue culture.

To the Editors: We read with great interest the article by Hellstrom et al. ([1][1]) about characterization of soluble mesothelin proteins (SMP) in cancer patients. The authors found that the SMP in ascites from a patient with ovarian carcinoma contained the sequence of extracellular domain of a

Objectives/Hypothesis: To determine whether measurement of pepsin in throat sputum by immunoassay could be used as a sensitive and reliable method for detecting laryngopharyngeal reflux (LPR) compared with 24-hour double-probe (esophageal and pharyngeal) pH monitoring. Study Design: Patients with clinical LPR undergoing pH monitoring provided throat sputum samples during the reflux-testing period for pepsin measurement using enzyme-linked immunoadsorbent assay. Results: Pepsin assay results from 63 throat sputum samples obtained from 23 study subjects were compared with their pH monitoring data. Twentytwo percent (14/63) of the sputum samples correlated the presence of pepsin with LPR (pH < 4 at the pharyngeal probe), of which the median concentration of pepsin was 0.18 g/mL (range 0.003–22 g/mL). Seventyeight percent (49/63) of the samples unassociated with (pharyngeal) reflux contained no detectible pepsin. Mean pH values for pepsin-positive samples were significantly lower than negative samples at both esophageal probe (pH 2.2 vs. pH 5.0) (P < .01) and the pharyngeal probe (pH 4.4 vs. pH 5.8) (P < .01). When the pepsin assay results were compared with the pharyngeal pH data for detecting reflux (events pH < 4), the pepsin immunoassay was 100% sensitive and 89% specific for LPR. Conclusions: Detection of pepsin in throat sputum by immunoassay appears to provide a sensitive, noninvasive method to detect LPR. Key Words: Pepsin, immunoassay, larynx, laryngopharyngeal reflux, gastroesophageal reflux, GERD, pH monitoring, sputum, reflux laryngitis, diagnosis Laryngoscope, 115:1473–1478, 2005

A transition of G to A at nucleotide position 279 in exon 1 of the vasopressin gene has been identified in patients with familial central diabetes insipidus. The mutation predicts an amino acid substitution of Thr (ACG) for Ala (GCG) at the COOH terminus of the signal peptide in preprovasopression (preproVP). Translation in vitro of wild-type and mutant mRNAs produced 19-kD preproVPs. When translated in the presence of canine pancreatic rough microsomes, wild-type preproVP was converted to a 21-kD protein, whereas the mutant mRNA produced proteins of 21 kD and 23 kD. NH2-terminal amino acid sequence analysis revealed that the 21-kD proteins from the wild-type and the mutants were proVPs generated by the proteolytic cleavage of the 19-residue signal peptide and the addition of carbohydrate. Accordingly, mutant preproVP was cleaved at the correct site after Thr-19, but the efficiency of cleavage by signal peptidase was < 25% that observed for the wild-type preproVP, resulting in the formation of a predominant glycosylated but uncleaved 23-kD product. These data suggest that inefficient processing of preproVP produced by the mutant allele is possibly involved in the pathogenesis of diabetes insipidus in the affected individuals.

Human granulocyte elastase (EC 3.4.21.11) and cathepsin G (EC 3.4.21.20), porcine pancreatic elastase (EC 3.4.4.7), and bovine chymotrypsin-A α (EC 3.4.4.3) and trypsin (EC 3.4.4.4) are inhibited by aryl and alkyl sulfonyl fluorides at different rates. The 26 000-fold variance in inhibition rates reflects the intrinsic reactivity and specificity differences of these closely related serine proteases. Human granulocyte elastase is inhibited more rapidly than porcine pancreatic elastase by all of the sulfonyl flourides studied. In contrast, human cathepsin G. reacts more slowly with the series of sulfonyl flourides than does bovine chymotrypsin-A α . Trypsin is the least reactive of the five enzymes, reflecting its relatively more stringent specificity requirements. Reagents such as CH 3 SO 2 F, 4-CH 3 C 6 H 4 SO 2 F, 3-CH 3 COC 6 H 4 SO 2 F and 2-NH 2 C 6 H 4 SO 2 F exhibit little or no selectivity toward the five enzymes studied. On the other hand, phenylmethane sulfonyl fluoride shows a range of reactivity of 137-fold toward the various proteases and is most reactive with bovine chymotrypsin-A α . The peptide sulfonyl fluoride 2-(Ac-Ala-Ala-NHN(CH 3 )CONH)C 6 H 4 SO 2 F had a reactivity range of 41, with granulocyte elastase being inhibited most rapidly. Although none of the sulfonyl fluorides are completely specific, the examples reported in this paper show that structural changes have considerable potential for increasing both the selectivity of sulfonylating agents toward various serine proteases and their reactivities.