Preclinical Evaluation of the ATR Inhibitor BAY 1895344 as a Radiosensitizer for Head and Neck Squamous Cell Carcinoma.

PURPOSE: Despite aggressive multimodal treatment that typically includes definitive or adjuvant radiation therapy (RT), locoregional recurrence rates approach 50% for patients with locally advanced human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). Thus, more effective therapeutics are needed to improve patient outcomes. We evaluated the radiosensitizing effects of ataxia telangiectasia and RAD3-related (ATR) inhibitor (ATRi) BAY 1895344 in preclinical models of HNSCC. METHODS AND MATERIALS: Murine and human HPV-negative HNSCC cells (MOC2, MOC1, JHU-012) were treated with vehicle or ATRi with or without 4 Gy. Checkpoint kinase 1 phosphorylation and DNA damage (γH2AX) were evaluated by Western blot, and ATRi half-maximal inhibitory concentration was determined by MTT assay for HNSCC cells and immortalized murine oral keratinocytes. In vitro radiosensitization was tested by clonogenic assay. Cell cycle distribution and mitotic catastrophe were evaluated by flow cytometry. Mitotic aberrations were quantified by fluorescent microscopy. Tumor growth delay and survival were assessed in mice bearing MOC2 or JHU-012 transplant tumors treated with vehicle, ATRi, RT (10 Gy × 1 or 8 Gy × 3), or combined ATRi + RT. RESULTS: ATRi caused dose-dependent reduction in checkpoint kinase 1 phosphorylation at 1 hour post-RT (4 Gy) and dose-dependent increase in γH2AX at 18 hours post-RT. Addition of RT to ATRi led to decreased BAY 1895344 half-maximal inhibitory concentration in HNSCC cell lines but not in normal tissue surrogate immortalized murine oral keratinocytes. Clonogenic assays demonstrated radiosensitization in the HNSCC cell lines. ATRi abrogated the RT-induced G2/M checkpoint, leading to mitosis with unrepaired DNA damage and increased mitotic aberrations (multinucleated cells, micronuclei, nuclear buds, nucleoplasmic bridges). ATRi and RT significantly delayed tumor growth in MOC2 and JHU-012 in vivo models, with improved overall survival in the MOC2 model. CONCLUSIONS: These findings demonstrated that BAY 1895344 increased in vitro and in vivo radiosensitivity in HPV-negative HNSCC preclinical models, suggesting therapeutic potential warranting evaluation in clinical trials for patients with locally advanced or recurrent HPV-negative HNSCC.

Differences in Receipt of Immunotherapy Treatment Among Patients With Head and Neck Cancer.

Importance: The US Food and Drug Administration approved immune checkpoint inhibitors (immunotherapy) for select cases of head and neck squamous cell carcinoma (HNSCC) in 2016. However, it is unclear whether there are clinical or sociodemographic differences among patients receiving immunotherapy as part of their care. Given the known disparities in head and neck cancer care, we hypothesized that there are differences in receipt of immunotherapy among patients with HNSCC based on clinical and nonclinical characteristics. Objective: To characterize clinical and nonclinical factors associated with receipt of immunotherapy among older patients with HNSCC. Design, Setting, and Participants: This retrospective cohort study included patients 65 years or older diagnosed with HNSCC (n = 4860) in a community oncology care setting. Electronic health records from Navigating Cancer were assessed from January 1, 2017, to April 30, 2022. Main Outcomes and Measures: Multivariable logistic regression was used to characterize clinical (tumor stage [localized vs advanced] and anatomical subsite [oropharyngeal vs nonoropharyngeal]) and nonclinical (age, smoking history, race and ethnicity, sex, and marital status) factors associated with receipt of immunotherapy. Results: In the study cohort of 4860 patients, 3593 (73.9%) were men; 4230 (87.0%) were White and 630 (13.0%) were of other races. A total of 552 patients (11.4%) had received immunotherapy. After adjusting for covariates, in the final model, White patients with HNSCC had 80% increased odds of receiving immunotherapy (adjusted odds ratio [AOR], 1.80 [95% CI, 1.30-2.48]) compared with patients of other races. There were no statistically significant differences in the odds of receiving immunotherapy based on age, sex, or smoking history. Patients with nonoropharyngeal disease were significantly more likely to receive immunotherapy than those with oropharyngeal cancer (AOR, 1.29 [95% CI, 1.05-1.59]), as were those with advanced compared with local disease (AOR, 2.39 [95% CI, 1.71-3.34]). Conclusions and Relevance: The findings of this cohort study suggest that among older patients with HNSCC, White patients may be more likely to receive immunotherapy as part of their care. Equitable access to immunotherapy and other treatment options will reduce cancer-related health disparities and improve survival of patients with HNSCC.

Salvage Surgery.

The Department of Veterans Affairs Laryngeal Cancer Study propelled the combination of chemotherapy and radiation therapy to the forefront of strategies used for the management of locally advanced laryngeal cancer. The organ preservation rate was 84%. However, over the past 30 years that these approaches have been in place, there have been concerns regarding long-term survival and high failure rates requiring salvage. Furthermore, salvage laryngectomy, if feasible when considering increased morbidity after CRT, is fraught with a higher risk of wound complications including fistula, longer hospitalization, and reduced quality of life.

Whole-Slide Cytometric Feature Mapping for Distinguishing Tumor Genomic Subtypes in Head and Neck Squamous Cell Carcinoma Whole-Slide Images.

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease where, in advanced stages, clinical and pathologic stages do not correlate with outcome. Molecular and genomic biomarkers for HNSCC classification have shown promise for prognostic and therapeutic applications. This study utilized automated image analysis techniques in whole-slide images of HNSCC tumors to identify relationships between cytometric features and genomic phenotypes. Hematoxylin and eosin-stained slides of HNSCC tumors (N = 49) were obtained from The Cancer Imaging Archive, along with accompanying clinical, pathologic, genomic, and proteomic reports. Automated nuclear detection was performed across the entirety of slides, and cytometric feature maps were generated. Forty-one cytometric features were evaluated for associations with tumor grade, tumor stage, tumor subsite, and integrated genomic subtype. Thirty-two features demonstrated significant association with integrated genomic subtype when corrected for multiple comparisons. In particular, the basal subtype was visually distinguishable from the chromosomal instability and immune subtypes based on cytometric feature measurements. No features were significantly associated with tumor grade, stage, or subsite. This study provides preliminary evidence that features derived from tissue pathology slides could provide insights into genomic phenotypes of HNSCC.

Human papillomavirus vaccine uptake among teens before and during the COVID-19 pandemic in the United States.

It is unclear how the COVID-19 pandemic impacted human papillomavirus (HPV) vaccine uptake and which sociodemographic groups may have been most impacted. We aimed to assess differences in HPV vaccine uptake (initiation and completion) before and during the pandemic in the United States. We conducted a cross-sectional study using data from the 2019 to 2020 National Immunization Surveys - Teen (NIS-Teen), comparing vaccine initiation and completion rates in 2019 vs. 2020, based on confirmed reports by a healthcare provider. Weighted logistic regression analysis estimated odds of vaccine initiation and completion for both adolescent and parental characteristics. There were 18,788 adolescents in 2019 and 20,162 in 2020. There was 3.6% increase in HPV vaccine initiation (71.5% vs. 75.1%) and a 4.4% in completion (54.2% vs. 58.6%) rates from 2019 to 2020. In 2020, Non-Hispanic White teens were significantly less likely to initiate (aOR = 0.62, 95% CI: 0.49, 0.79) and complete (aOR = 0.71, 95% CI: 0.58, 0.86) vaccine uptake compared with non-Hispanic Black teens. Additionally, teens who lived above the poverty line were also less likely to initiate HPV vaccination (aOR = 0.63, 95% CI: 0.49, 0.80) or complete them (aOR = 0.73, 95% CI: 0.60, 0.90), compared to those who lived below the poverty line. During the COVID-19 pandemic in 2020, some historically advantaged socioeconomic groups such as those living above the poverty line were less likely to receive HPV vaccine. The impact of the pandemic on HPV vaccine uptake may transcend traditional access to care factors.

Automated Nuclear Segmentation in Head and Neck Squamous Cell Carcinoma Pathology Reveals Relationships between Cytometric Features and ESTIMATE Stromal and Immune Scores.

The tumor microenvironment (TME) plays an important role in the progression of head and neck squamous cell carcinoma (HNSCC). Currently, pathologic assessment of TME is nonstandardized and subject to observer bias. Genome-wide transcriptomic approaches to understanding the TME, while less subject to bias, are expensive and not currently a part of the standard of care for HNSCC. To identify pathology-based biomarkers that correlate with genomic and transcriptomic signatures of TME in HNSCC, cytometric feature maps were generated in a publicly available data set from a cohort of patients with HNSCC, including whole-slide tissue images and genomic and transcriptomic phenotyping (N = 49). Cytometric feature maps were generated based on whole-slide nuclear detection, using a deep-learning algorithm trained for StarDist nuclear segmentation. Cytometric features in each patient were compared to transcriptomic measurements, including Estimation of Stromal and Immune Cells in Malignant Tumor Tissues Using Expression Data (ESTIMATE) scores and stemness scores. With correction for multiple comparisons, one feature (nuclear circularity) demonstrated a significant linear correlation with ESTIMATE stromal score. Two features (nuclear maximum and minimum diameter) correlated significantly with ESTIMATE immune score. Three features (nuclear solidity, nuclear minimum diameter, and nuclear circularity) correlated significantly with transcriptomic stemness score. This study provides preliminary evidence that observer-independent, automated tissue-slide analysis can provide insights into the HNSCC TME which correlate with genomic and transcriptomic assessments.

Differential Outcomes Among Survivors of Head and Neck Cancer Belonging to Racial and Ethnic Minority Groups.

Importance: Approximately 1 in 5 new patients with head and neck cancer (HNC) in the US belong to racial and ethnic minority groups, but their survival rates are worse than White individuals. However, because most studies compare Black vs White patients, little is known about survival differences among members of racial and ethnic minority groups. Objective: To describe differential survival and identify nonclinical factors associated with stage of presentation among patients with HNC belonging to racial and ethnic minority groups. Design, Setting, and Participants: This population-based retrospective cohort study used data from the 2007 to 2016 Surveillance, Epidemiology, and End Results (SEER) database and included non-Hispanic Black, Asian Pacific Islander, American Indian/Alaska Native, and Hispanic patients with HNC. The data were analyzed from December 2020 to May 2021. Main Outcomes and Measures: Outcomes were time to event measures: (HNC-specific and all-cause mortality) and stage of presentation. Covariates included nonclinical (age at diagnosis, sex, race and ethnicity, insurance status, marital status, and a composite socioeconomic status [SES]) and clinical factors (stage, cancer site, chemotherapy, radiation, and surgery). A Cox regression model was used to adjust associations of covariates with the hazard of all-cause death, and a Fine and Gray competing risks proportional hazards model was used to estimate associations of covariates with the hazard of HNC-specific death. A proportional log odds ordinal logistic regression identified which nonclinical factors were associated with stage of presentation. Results: There were 21 966 patients with HNC included in the study (mean [SD] age, 56.02 [11.16] years; 6072 women [27.6%]; 9229 [42.0%] non-Hispanic Black, 6893 [31.4%] Hispanic, 5342 [24.3%] Asian/Pacific Islander, and 502 [2.3%] American Indian/Alaska Native individuals). Black patients had highest proportion with very low SES (3482 [37.7%]) and the lowest crude 5-year overall survival (46%). After adjusting for covariates, Hispanic individuals had an 11% lower subdistribution hazard ratio (sdHR) of HNC-specific mortality (sdHR, 0.89; 95% CI, 0.83-0.95), 15% lower risk for Asian/Pacific Islander individuals (sdHR, 0.85; 95% CI, 0.78-0.93), and a trending lower risk for American Indian/Alaska Native individuals (sdHR, 0.85; 95% CI, 0.71-1.01), compared with non-Hispanic Black individuals. Race, sex, insurance, marital status, and SES were consistently associated with all-cause mortality, HNC-specific mortality, and stage of presentation, with non-Hispanic Black individuals faring worse compared with individuals of other racial and ethnic minority groups. Conclusions and Relevance: In this cohort study that included only patients with HNC who were members of racial and ethnic minority groups, Black patients had significantly worse outcomes that were not completely explained by stage of presentation. There may be unexplored multilevel factors that are associated with social determinants of health and disparities in HNC outcomes.

Activation PDGFR-α/AKT Mediated Signaling Pathways in Oral Squamous Cell Carcinoma by Mesenchymal Stem/Stromal Cells Promotes Anti-apoptosis and Decreased Sensitivity to Cisplatin.

Desmoplasia, a hallmark of a head and neck cancer, has both biologic and physiologic effects on cancer progression and chemotherapeutic response. Mesenchymal stem/stromal cells (MSCs), also known as mesenchymal stromal progenitor cells, have been shown to play a role in cancer progression, alter apoptotic responses, and confer resistance to chemotherapy in various carcinomas. The pathophysiology of MSCs with respect to tumorigenesis is widely reported in other cancers and is sparsely reported in oral squamous cell carcinomas (OSCCs). We previously reported paracrine mediated PDGF-AA/PDGFR-α signaling to underlie MSCs chemotaxis in OSCC. Given the poor clinical response to primary chemotherapy, we hypothesized that MSCs may alter cancer cell sensitivity to cisplatin through activation of PDGFR-α mediated signaling pathways. Co-culture of MSCs with human derived OSCC cell lines, JHU-012 and -019, resulted in a significant increase in the production of PDGF-AA and MCP-1 compared to cancer cells grown alone (p < 0.005) and was accompanied by an increase in the phosphorylation state of PDGFR-α (p < 0.02) and downstream target AKT at S473 (p < 0.025) and T308 (p < 0.02). JHU-012 and -019 cancer cells grown in co-culture were significantly less apoptotic (p < 0.001), expressed significantly higher levels of Bcl-2 (p < 0.04) with a concomitant significant decrease in bid expression (p < 0.001) compared to cancer cells grown alone. There was a significant increase in the cisplatin dose response curve in cancer cell clones derived from JHU-012 and 019 cancer cells grown in co-culture with MSCs compared to clones derived from cancer cells grown alone (p < 0.001). Moreover clones derived from JHU-012 cells grown in co-culture with MSCs were significantly more susceptible to cisplatin following pretreatment with, crenolanib, a PDGFR inhibitor, compared to cancer cells grown alone or in co-culture with MSCs (p < 0.0001). These findings suggest that crosstalk between cancer cells and MSCs is mediated, at least in part, by activation of autocrine PDGF-AA/PDGFR-α loop driving AKT-mediated signaling pathways, resulting in reduced cancer cell sensitivity to cisplatin through alterations in apoptosis.

PDGF-AA mediates mesenchymal stromal cell chemotaxis to the head and neck squamous cell carcinoma tumor microenvironment.

BACKGROUND: The robust desmoplasia associated with head and neck squamous cell carcinoma (HNSCC) suggests that the tumor microenvironment may be an important component in the pathophysiology of this cancer. Moreover, the high recurrence rate and poor clinical response to chemotherapy and radiation treatment further underscores that the non-cancerous cells of the microenvironment, such as mesenchymal stromal cells (MSCs), cancer associated fibroblasts (CAFs), and pericytes, may be important in the pathophysiology of HNSCC. METHODS: Confocal microscopy and immunohistomchemistry approaches were used to identify MSCs tumor microenvironment from patients with oral cavity and oral pharyngeal squamous cell carcinoma (SCC). In vitro Boyden chamber assays and multiplex magnetic bead assays were used to measure MSC chemotaxis and to identify the chemokines secreted by JHU-011, -012, -019, three cells lines derived from patients with oral pharyngeal SCC. RESULTS: We show here that MSCs reside in the tumor microenvironment of patients with oral cavity and oral pharyngeal SCC and are recruited via paracrine mediated tumor cell secretion of (platelet derived growth factor) PDGF-AA. The MSC markers CD90+, CD105+, and gremlin-1+ were found to co-localize on cells within the tumor microenvironment in oral cavity SCC specimens distinct from α-smooth muscle actin staining CAFs. The conditioned media from JHU-011, -012, and -019 caused a significant increase in MSC migration (>60%) and invasion (>50%; p < 0.0001) compared to oral keratinocyte (OKT) controls. Tumor cell induced MSC chemotaxis appears to be mediated through paracrine secretion of PDGF-AA as inhibition of the PDGF-AA receptor, PDGFR-α but not PDGFR-ß, resulted in near arrest of MSC chemotaxis (p < 0.0001). CONCLUSIONS: Tumor microenvironment expression of PDGFR-α has been shown to correlate with a worse prognosis in patients with prostate, breast, ovarian, non-small cell lung cancer and osteosarcoma. This is the first evidence that a similar signaling paradigm may be present in HNSCC. PDGFR-α inhibitors have not been studied as adjunctive treatment options in the management of HNSCC and may prove to be an important driver of the malignant phenotype in this setting.

Malignant melanoma induces migration and invasion of adult mesenchymal stem cells.

OBJECTIVES/HYPOTHESIS: To determine if melanoma cells secrete chemotactic factors that result in the migration of multipotent stem cells. STUDY DESIGN: In vitro cell culture. METHODS: Chemotaxis and invasion of human mesenchymal stem cells (hMSCs) was determined using the modified Boyden chamber assay. Quantification of growth factors secreted by melanoma cells (A375) was determined using enzyme-linked immunosorbent assay. RESULTS: Conditioned A375 melanoma media caused significant migration and invasion of hMSCs compared to serum-free controls and conditioned media from normal melanocytes (P < .0001). The migratory effect appeared maximal after the A375 media was conditioned for 48 hours. Physiologically relevant concentrations of fibroblast growth factor-2 (FGF2) (90 pg/mL) secreted by A375 melanoma cells caused significant migration of hMSCs (P < .001) compared to serum-free and normal melanocyte controls. Neutralization of FGF2 inhibited the migration of hMSCs to that of the negative controls (conditioned media from normal melanocytes). CONCLUSIONS: The melanoma tumor microenvironment may be maintained through chemotaxis and invasion of multipotent hMSCs, and this migratory effect appears to be mediated in part through secretion of FGF2 by melanoma cells.

Immediate eye rehabilitation at the time of facial nerve sacrifice.

OBJECTIVE: In the setting of known facial nerve sacrifice or injury, patients require precautions to prevent exposure keratitis and the morbidity that follows. One recommended treatment is surgical placement of a gold weight with or without lateral tarsal strip. In patients in whom the facial nerve has been sacrificed, it is unknown whether rehabilitation should be simultaneous or in the perioperative period. STUDY DESIGN AND SETTING: Case series with chart review of patients who underwent immediate rehabilitation of the eye (gold weight and lateral tarsal strip) following facial nerve resection. SUBJECTS AND METHODS: From 1998 to 2009, 52 patients were studied. Postoperative ophthalmologic complications and the need for revision surgeries were measured. RESULTS: A gold weight was placed in all patients, and 48 of 52 (92%) simultaneous lateral tarsal strips were performed. The facial nerve was sacrificed in 51 of 52 (88%) patients, and the remaining patient had a known preoperative facial nerve paralysis. Thirty-six of 52 (69%) required free tissue transfer for reconstruction, underscoring the extensive resections performed. A 1.2-g gold weight was placed in 50 of 52 (96%) patients. Three (6%) patients required gold weight revision with a larger weight and 3 (6%) for extrusion. Eight (16.7%) patients underwent revision of the lateral tarsal strip for ectropion. CONCLUSIONS: No patients developed ophthalmologic complications. Patients undergoing radical surgical resections with known or suspected injury of the facial nerve should be considered for simultaneous rehabilitation of the upper and lower eye.

Intraoperative bupivacaine for reduction of post-tonsillectomy pain: a randomized, placebo-controlled, double-blind study of 26 patients.

We conducted a randomized, controlled, double-blind, prospective study to evaluate the effect of intraoperative bupivacaine injection on postoperative pain control following Bovie cautery-assisted tonsillectomy in 26 adults. Sixteen patients were injected with 10 ml of 0.5% bupivacaine with 1:200,000 epinephrine, and 10 were injected with 10 ml of normal saline solution. For 10 days after surgery, patients completed a questionnaire to rate their overall pain and to record their narcotic consumption and oral intake. At study's end, there was no statistically significant difference in pain scores, narcotic use, and oral intake between the bupivacaine group and the controls (p = 0.13, 0.37, and 0.35, respectively). We conclude that the effects of perioperative bupivacaine on postoperative pain control in tonsillectomy patients are similar to those of placebo.

Identification of distant metastases with positron-emission tomography-computed tomography in patients with previously untreated head and neck cancer.

OBJECTIVES: To investigate the utility of positron-emission tomography-computed tomography (PET-CT) in identifying distant metastatic disease in patients with previously untreated head and neck squamous cell cancer (HNSCC) prior to definitive treatment. MATERIALS AND METHODS: Retrospective analysis of 27 consecutive patients with previously untreated HNSCC who underwent PET-CT imaging in addition to chest radiography (CXR) as part of their metastatic workup. RESULTS: The majority of patients (89%) had TNM stage III or IV disease. PET-CT was suspicious for pulmonary malignancy in four (15%) patients and indeterminate in one (4%) patient. CXR was suspicious for pulmonary malignancy in two (7%) patients. Pulmonary metastases or a new lung primary was present in 3 (11%) patients: 3 of 4 (75%) patients with positive PET-CT scans and 0 of 23 (0%) patients with negative or indeterminate PET-CT scans compared with 2 of 2 (100%) patients with positive CXR and 1 of 25 (4%) patients with negative CXR. The sensitivity and specificity of PET-CT in predicting pulmonary malignancy was 100% and 96%, respectively, with a positive predictive value of 75% and a negative predictive value of 100%. The sensitivity and specificity of CXR in predicting pulmonary malignancy was 67% and 100%, respectively, with a positive predictive value of 100% and a negative predictive value of 96%. Including nonpulmonary sites, the overall incidence of distant metastatic disease was 19% (5/27) with 11% (3/27) unsuspected prior to PET-CT. CONCLUSIONS: PET-CT improves detection of metastatic disease in the high-risk patient and should be performed as part of the routine pretreatment evaluation of patients with advanced stage HNSCC.

Laryngeal nerve monitoring and minimally invasive thyroid surgery: complementary technologies.

OBJECTIVE: To determine the feasibility of the combined use of laryngeal nerve monitoring and minimally invasive thyroid surgery. DESIGN: Prospective, nonrandomized analysis of single-surgeon experience. SETTING: Academic institution. PATIENTS: Consecutive series of patients undergoing both minimally invasive thyroid surgery and laryngeal nerve monitoring. MAIN OUTCOME MEASURES: Incision length and incidence of temporary or permanent laryngeal nerve injury. RESULTS: Two hundred eighty-three patients underwent thyroid surgery at the Medical College of Georgia, Augusta, between January 2004 and November 2006. Some type of minimal-access approach (endoscopic or nonendoscopic) was used in 137 cases (48.4%) in which general anesthesia was administered. Laryngeal nerve monitoring was performed in 73 (53.3%) of these 137 cases, although the proportion of cases in which it was performed increased significantly from 8.7% (2 of 23 cases) in 2004 to 95.2% (58 of 61 cases) in 2006 (P < .001). There were no cases of permanent nerve injury. The incidence of temporary recurrent laryngeal nerve paresis was 4.3% (4 of 92 nerves at risk) in the cases in which laryngeal nerve monitoring was used and 6.0% (5 of 84 nerves at risk) in the cases in which the nerve was visually identified without use of a monitor. This difference failed to reach statistical significance (P = .73), which may reflect an insufficient sample size. CONCLUSION: Monitoring of the laryngeal nerves is feasible in minimal-access thyroid surgery and may serve as a meaningful adjunct to the visual identification of nerves.

Correlation of intraoperative parathyroid hormone levels with parathyroid gland size.

OBJECTIVES: To study the relationship of intraoperative intact parathyroid hormone levels (iPTH) with parathyroid adenoma weight and volume in patients with primary hyperparathyroidism. METHODS: Retrospective evaluation of consecutive patients undergoing minimally invasive parathyroidectomy with iPTH measurement. Data collected include preoperative serum calcium, ionized calcium, and serum parathyroid hormone (PTH) levels, iPTH levels at baseline, 5 minutes, and 10 minutes, and parathyroid adenoma weight. Adenoma volume was calculated using an equation for the volume of a spheroid object. RESULTS: Thirty patients underwent minimally invasive parathyroidectomy with iPTH measurement for a single parathyroid adenoma between March 2004 and January 2006. There were 8 men and 22 women, with a mean age of 59.3 (range 26-92) years. A significant correlation between preoperative serum calcium and ionized calcium levels and parathyroid adenoma weight was identified (P = .0008 and P = .03, respectively). A significant correlation was also shown between baseline iPTH measurements and parathyroid adenoma volume (P = .03). There was no correlation between baseline iPTH levels and parathyroid adenoma weight. There was a significant correlation between parathyroid adenoma weight and percentage decrease of iPTH levels at 10 minutes compared to baseline (P = .04). CONCLUSION: Preoperative serum calcium and baseline iPTH levels may be useful in predicting parathyroid adenoma weight and volume, respectively. Adenoma weight may relate to the percentage decrease of iPTH levels at the 10-minute postparathyroidectomy interval.

DNA transfection of macaque and murine respiratory tissue is greatly enhanced by use of a nuclease inhibitor.

BACKGROUND: Nuclease activity present within respiratory tissues contributes to the rapid clearance of injected DNA and therefore may reduce the transfection activity of directly injected transgenes. Most gene transfer technologies transduce or transfect murine tissues more efficiently than corresponding primate tissues. Therefore, it is prudent to assess the utility of novel gene transfer strategies in both rodent and primate models before proceeding with further development. METHODS: This study analyzed the effects of ATA (a nuclease inhibitor) on the direct transfection of macaque and murine lung tissue; compared the levels of DNase activity in murine, primate, and human lung fluids; and tested the inhibitory activity of ATA on the DNase activity present in these samples. Fluorescent microspheres were used to detect areas of transfection in lung. RESULTS: Intratracheal administration of a nuclease inhibitor (ATA) with naked DNA (0.5 microg ATA/g body weight) enhanced direct transfection efficacy in macaque lung by over 86-fold and by over 54-fold in mouse lung. Hematoxylin and eosin staining showed no apparent tissue toxicity. Moreover, macaque, human, and mouse lung fluids were found to possess similar levels of DNase activity and this activity was inhibited by similar concentrations of ATA. The authors also successfully pioneered the use of carboxylate-modified microsphere tracers to identify areas of transfection and/or treatment. CONCLUSION: This work provides evidence that using direct nuclease inhibitors will enhance lung transfection and that nuclease activity is present in all lung fluids tested, which can be inhibited by the use of direct DNase inhibitors.