CD30 Expression in Oral and Oropharyngeal Diffuse Large B Cell Lymphoma, not Otherwise Specified.

Diffuse large B cell lymphoma, not otherwise specified (DLBCL, NOS) is the most frequent non-Hodgkin lymphoma subtype. This aggressive neoplasm may variably express the CD30 protein, which may be used as a therapeutic target for this tumor. However, CD30 expression in DLBCL NOS arising from the oral cavity and the oropharynx has not been investigated. Therefore, this study aims to determine the frequency of CD30 expression and its prognostic significance for patients affected by oral/oropharyngeal DLBCL NOS. Fifty cases were retrieved from pathology files and submitted to immunohistochemistry against CD30. Reactivity was accessed by two oral pathologists using two cut-off values (> 0% and > 20% of tumor cells) to determine positivity in each case. Clinical data were obtained from the patients' medical files to investigate the prognostic potential of the protein. Seven high-grade B cell lymphomas and two EBV-positive DLBCL NOS were identified. We found one CD30-positive case in each of these two groups of lymphomas. Among the remaining 41 DLBCL NOS, other four cases (three in the oral cavity and one in the oropharynx) were positive for CD30, but only two expressed the protein in > 20% of tumor cells, both in the oral cavity. Survival analysis demonstrated that CD30-positive cases had a higher five-year overall survival rate (75%) than CD30-negative cases (32.3%), although a statistically significant result was not achieved (p = 0.19). Only a minor subset of oral and oropharyngeal DLBCL NOS express CD30 and these patients seems to have a higher survival rate.

SARS-CoV-2 Detection in Fecal Sample from a Patient with Typical Findings of COVID-19 Pneumonia on CT but Negative to Multiple SARS-CoV-2 RT-PCR Tests on Oropharyngeal and Nasopharyngeal Swab Samples.

Reverse transcriptase polymerase chain reaction (RT-PCR) negative results in the upper respiratory tract represent a major concern for the clinical management of coronavirus disease 2019 (COVID-19) patients. Herein, we report the case of a 43-years-old man with a strong clinical suspicion of COVID-19, who resulted in being negative to multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR tests performed on different oropharyngeal and nasopharyngeal swabs, despite serology having confirmed the presence of SARS-CoV-2 IgM. The patient underwent a chest computed tomography (CT) that showed typical imaging findings of COVID-19 pneumonia. The presence of viral SARS-CoV-2 was confirmed only by performing a SARS-CoV-2 RT-PCR test on stool. Performing of SARS-CoV-2 RT-PCR test on fecal samples can be a rapid and useful approach to confirm COVID-19 diagnosis in cases where there is an apparent discrepancy between COVID-19 clinical symptoms coupled with chest CT and SARS-CoV-2 RT-PCR tests' results on samples from the upper respiratory tract.

Diagnosis of SARS-CoV-2 by RT-PCR Using Different Sample Sources: Review of the Literature.

OBJECTIVE: The most widely used diagnostic technique for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is real-time reverse transcriptase-polymerase chain reaction (RT-PCR). It can be done on different samples: nasopharyngeal swabs (NPS) or oropharyngeal swabs (OPS), and self-collected saliva. However, negative findings do not rule out infection. METHODS: A review was conceived to discuss advantages and limitations of the available diagnostic modalities for nonserologic diagnosis of SARS-CoV-2 based on RT-PCR; the article also proposes some practical suggestions to improve diagnostic reliability. RESULTS: A total of 16 papers (corresponding to 452 patients) of the 56 initially identified were included. Most of the papers describe findings from different samples obtained in limited case series; comparative studies are missing. CONCLUSIONS: Diagnostic accuracy of NPS and OPS is suboptimal and the risk of contaminated aerosol dispersal is not negligible. The SARS-CoV-2 RNA can be found in self-collected saliva specimens of many infected patients within 7 to 10 days after symptom onset. There is an urgent need for comparative trials to define the diagnostic modality of choice. Adequate education and training of health care personnel is mandatory.

The Importance of Extensional Rheology in Bolus Control during Swallowing.

Thickened fluids are commonly used in the medical management of individuals who suffer swallowing difficulty (known as dysphagia). Previous studies have shown that the rheological properties of a liquid affect the flow behavior of the bolus in swallowing, such as pharyngeal transit time. While there is no doubt that shear rheology is a highly important factor for bolus flow, it is suspected that extensional properties of a liquid bolus also plays an important role in swallowing, due to elongation of the bolus as it flows through the oropharynx. Our aim in this work was to observe the effect of extensional viscosity on pharyngeal transit time and elongation of the bolus during swallowing. Eight samples of thickened liquid barium that were shear-controlled, but varied in extensional viscosity and two samples that were extensional-controlled, but varied in shear viscosity were swallowed by eight healthy individuals. Data were collected under lateral view of videofluoroscopy swallow study (VFSS); measures of pharyngeal transit time and the ratio of the length to the width of the bolus on the frame of Upper Esophageal Sphincter (UES) opening were taken from the VFSS recordings. It was observed that the pharyngeal transit time generally increases when the fluids are thickened to higher IDDSI consistency. Additionally, higher extensional viscosity fluids reduced the elongation of the bolus during swallowing, thus potentially reducing the risk of post-swallow residue due to bolus breakage. This study confirmed the relevance of the extensional viscosity of the bolus in swallowing.

Association of p16 as Prognostic Factors for Oropharyngeal Cancer: Evaluation of p16 in 1470 Patients for a 16 Year Study in Northeast China.

Human papillomavirus (HPV) is an etiological risk factor for oropharyngeal squamous cell carcinomas (OPSCC). Our study investigates the prevalence, prognostic, and clinicopathologic features of HPV-related oropharyngeal cancer in Northeast China and elucidates the involvement of p16 in the tumorigenesis and progression of OPSCC. Specimens from 1470 OPSCC patients collected from 2000 to 2016 were analyzed using the status of HPV by polymerase chain reaction (PCR) and p16 immunohistochemistry. Overexpression of p16 was observed in 81 (5.51%) of the 1470 cases, and HPV positive was present in 78 cases (5.31%) of the 1470 cases. HPV positive and p16 overexpression have a good concordance. However, we found that the etiological fraction of HPV in cancers of the OPSCCs was obviously lower in Northeast China than other cohorts previously reported. Interestingly, nearly 89% of patients with p16 expression were smokers, and nearly 70% of patients with p16 expression had a history of alcohol. Our study also demonstrates that p16 expression is significantly associated with early stage primary OPSCCs and the patients with p16 expression tend to show better survival following surgery and radiotherapy.

Different cutoffs of the reflux finding score for diagnosing laryngopharyngeal reflux disease should be used for different genders.

OBJECTIVES: To assess the differences in Reflux Finding Score (RFS) between the genders and determine the suitable RFS threshold for diagnosing laryngopharyngeal reflux disease (LPRD) in each gender. METHODS: Asymptomatic volunteers and patients with LPRD, confirmed with an oropharyngeal Dx-pH monitoring system, were included. All study subjects underwent transnasal flexible fiber-optic video laryngoscopy. Reliability was assessed with intra-class correlation coefficients (ICCs) and Bland-Altman plots. The RFS cutoffs for determining the presence and absence of LPRD between the two genders were examined by receiver operating characteristic (ROC) analysis. RESULTS: One hundred seven asymptomatic volunteers and fifty-five LPRD patients were recruited. The mean RFS for LPRD subjects (9.4 ± 3.2) was significantly higher than that for control subjects (7.1 ± 2.6; p < 0.001). The mean RFS for asymptomatic females (6.1 ± 2.7) was significantly lower than that for males (7.7 ± 2.5; p < 0.001). The mean RFS for female subjects with LPRD (7.8 ± 2.6) was lower than that for males (11.0 ± 2.8; p < 0.001). According to ROC analysis, the best cutoffs were 9.0 for males and 6.0 for females. CONCLUSIONS: There was a significant difference in the RFS cutoff between the genders. For male subjects, we recommend a cutoff of 9.0 for diagnosing LPRD, and for female subjects, we recommend a cutoff of 6.0.

Quantifying Laryngopharyngeal Reflux in Singers: Perceptual and Objective Findings.

This study examines the relationship between laryngopharyngeal reflux (LPR) symptoms and oropharyngeal pH levels in singers. We hypothesized that reported symptoms would correlate with objective measures of pH levels from the oropharynx, including the number and total duration of reflux episodes. Twenty professional/semiprofessional singers completed the Reflux Symptom Index (RSI) and underwent oropharyngeal pH monitoring. Mild, moderate, or severe pH exposure was recorded during oropharyngeal pH monitoring. Correlations were performed to examine potential relationships between reflux symptoms and duration of LPR episodes. Symptom severity did not correlate with pH levels; however, we found a number of covariances of interest. Large sample sizes are necessary to determine if true correlations exist. Our results suggest that singers may exhibit enhanced sensitivity to LPR and may therefore manifest symptoms, even in response to subtle changes in pH. This study emphasizes the importance of sensitive and objective measures of reflux severity as well as consideration of the cumulative time of reflux exposure in addition to the number of reflux episodes.

Abilities of Oropharyngeal pH Tests and Salivary Pepsin Analysis to Discriminate Between Asymptomatic Volunteers and Subjects With Symptoms of Laryngeal Irritation.

BACKGROUND & AIMS: It has been a challenge to confirm the association between laryngeal symptoms and physiological reflux disease. We examined the ability of oropharyngeal pH tests (with the Restech Dx-pH system) and salivary pepsin tests (with Peptest) to discriminate between asymptomatic volunteers (controls) and subjects with a combination of laryngeal and reflux symptoms (laryngeal ± reflux). METHODS: We performed a physician-blinded prospective cohort study of 59 subjects at a single academic institution. Adult volunteers were recruited and separated into 3 groups on the basis of GerdQ and Reflux Symptom Index scores: controls (n = 20), laryngeal symptoms (n = 20), or laryngeal + reflux symptoms (n = 19). Subjects underwent laryngoscopy and oropharyngeal pH tests and submitted saliva samples for analysis of pepsin concentration. Primary outcomes included abnormal acid exposure and composite (RYAN) score for oropharyngeal pH tests and abnormal mean salivary pepsin concentration that was based on normative data. RESULTS: Complete oropharyngeal pH data were available from 53 subjects and complete salivary pepsin data from 35 subjects. We did not observe any significant differences between groups in percent of time spent below pH 4.0, 5.0, 5.5, 6.0, or RYAN scores or percent of subjects with positive results from tests for salivary pepsin (53% vs 40% vs 75%; P = .50, respectively). The laryngeal + reflux group had a significantly higher estimated mean concentration of salivary pepsin (117.9 ± 147.4 ng/mL) than the control group (32.4 ± 41.9 ng/mL) or laryngeal symptom group (7.5 ± 11.2 ng/mL) (P = .01 and P = .04, respectively). CONCLUSIONS: By using current normative thresholds, oropharyngeal pH testing and salivary pepsin analysis are not able to distinguish between healthy volunteers and subjects with a combination of laryngeal and reflux symptoms.

Correlation between oropharyngeal pH-monitoring and esophageal pH-impedance monitoring in patients with suspected GERD-related extra-esophageal symptoms.

BACKGROUND: 24-hour esophageal pH-impedance (pH-MII) is not totally reliable for laryngopharyngeal reflux (LPR). Oropharyngeal (OP) pH-monitoring with the Dx-pH probe may detect LPR better. The correlation between these two techniques is not thoroughly established. Aim of this study is to examine the correlation between OP pH-metry and esophageal pH-MII monitoring. METHODS: Thirty-six consecutive patients with suspected gastroesophageal reflux disease-related extra-esophageal symptoms were evaluated using 24-h OP-pH and concomitant esophageal pH-MII monitoring. OP events were defined as: drop in pH below thresholds of 5.5, 5.0, 4.5, 4.0 or drop in pH of at least 10% from a running baseline. Temporal relationship between OP and esophageal reflux events and outcomes of the two tests were evaluated. KEY RESULTS: 2394 refluxes were detected by pH-MII; of these only 120 were detected also by OP Dx-probe. On the other hand, the proportion of OP-pH events which were temporally related to an episode of distal reflux ranged from 0% to 17%, depending on the proximal pH criteria used. In 8/36 patients both tests were pathological, while in 10/36 they were both normal; 14/36 patients had pathological OP reflux, but a normal pH-MII test; 4/36 patients had pathological pH-MII, but a normal OP reflux. CONCLUSIONS & INFERENCES: The correlation between OP pH-metry and pH-MII was weak. At present, the absence of a reliable gold standard for the diagnosis of LPR and the uncertain etiology of the pharyngeal pH alterations make it difficult to decide which is the most reliable technique for the diagnosis of true LPR.

Prognostic significance of p16 and its relationship with human papillomavirus in pharyngeal squamous cell carcinomas.

IMPORTANCE: The prognostic significance of p16 in squamous cell carcinoma (SCC) of the hypopharynx (HP) and nasopharynx (NP) and relationship between human papillomavirus (HPV) and p16 is unclear. OBJECTIVES: To evaluate the prognostic significance of p16 in pharyngeal subsites (oropharynx [OP], HP, and NP) and assess the relationship between HPV and p16 in the HP and NP. DESIGN, SETTING, AND PARTICIPANTS: Retrospective medical record review of 172 patients with SCC of the pharynx treated with definitive radiation therapy from 2002 to 2013 at a university tertiary referral center, with tissue available for immunohistochemical analysis. The median follow-up was 30.1 months. INTERVENTIONS: A total of 118 patients were treated with chemoradiation, and 54 patients were treated with radiation alone. Immunohistochemical analysis for p16 was performed for all tumors. Hypopharynx and NP tumors were tested for HPV using in situ hybridization, and NP tumors were tested for Epstein-Barr virus. MAIN OUTCOMES AND MEASURES: Overall survival, locoregional control, and disease-free survival were analyzed according to p16, HPV, and Epstein-Barr virus status. RESULTS: Thirty-two patients had HP SCC, 127 had OP SCC, and 13 had NP SCC. p16 Was positive in the HP (34%), OP (66%), and NP (46%). Prevalence of HPV was 14% in the HP and 50% in the NP. As a test for HPV, p16 had a positive predictive value of 38% (HP) and 67% (NP) and a negative predictive value of 100% in HP and NP tumors. p16 Status was a significant predictor of all clinical outcomes for patients with OP SCC (P<.001), but not for patients with HP or NP SCC. Patients with Epstein-Barr virus- or HPV-associated NP SCC had improved clinical outcomes. CONCLUSIONS AND RELEVANCE: p16 Was not associated with improved outcomes in patients with HP or NP SCC. The positive predictive value of p16 as a test for HPV is too low for p16 testing alone in the HP and NP. However, p16 negativity is sufficient to rule out HPV. As a research approach, we recommend p16 immunohistochemistry as a screening test for HPV in NP SCC and HP SCC followed by confirmatory HPV in situ hybridization when p16 positive.

Beta-catenin and epithelial tumors: a study based on 374 oropharyngeal cancers.

INTRODUCTION: Although altered regulation of the Wnt pathway via beta-catenin is a frequent event in several human cancers, its potential implications in oral/oropharyngeal squamous cell carcinomas (OSCC/OPSCC) are largely unexplored. Work purpose was to define association between beta-catenin expression and clinical-pathological parameters in 374 OSCCs/OP-SCCs by immunohistochemistry (IHC). MATERIALS AND METHODS: Association between IHC detected patterns of protein expression and clinical-pathological parameters was assessed by statistical analysis and survival rates by Kaplan-Meier curves. Beta-catenin expression was also investigated in OSCC cell lines by Real-Time PCR. An additional analysis of the DNA content was performed on 22 representative OSCCs/OPSCCs by DNA-image-cytometric analysis. RESULTS AND DISCUSSION: All carcinomas exhibited significant alterations of beta-catenin expression (P < 0.05). Beta-catenin protein was mainly detected in the cytoplasm of cancerous cells and only focal nuclear positivity was observed. Higher cytoplasmic expression correlated significantly with poor histological differentiation, advanced stage, and worst patient outcome (P < 0.05). By Real-Time PCR significant increase of beta-catenin mRNA was detected in OSCC cell lines and in 45% of surgical specimens. DNA ploidy study demonstrated high levels of aneuploidy in beta-catenin overexpressing carcinomas. CONCLUSIONS: This is the largest study reporting significant association between beta-catenin expression and clinical-pathological factors in patients with OSCCs/OPSCCs.

An oropharyngeal pH monitoring device to evaluate patients with chronic laryngitis.

BACKGROUND: Diagnostics for gastro-esophageal reflux disease (GERD) are suboptimal because of limited sensitivity. We performed in vitro and in vivo studies to systematically assess the performance characteristics of an oropharyngeal pH probe. METHODS: In vitro studies compared the oropharyngeal probe with a standard pH catheter in liquid and aerosolized solutions, pH 1-7. The accuracy of measurements, deviation from target pH, and time to equilibrium pH were determined. Simultaneous distal esophageal pH measurements were obtained in 11 patients with GERD. Oropharyngeal and distal esophageal reflux parameters were measured for controls (n = 20), patients with GERD (n = 17), and patients with chronic laryngitis (n = 10). KEY RESULTS: In the liquid phase, at pH 4-5, the oropharyngeal probe had less deviation from the target value than the standard catheter; deviation in the vapor phase was similar (0.4 pH units). Median (interquartile) time to reach equilibrium pH was significantly (P < 0.001) faster with the oropharyngeal than the standard probe. In comparing simultaneous distal esophageal pH characteristics, 96% of recordings with the new and standard probes were in agreement to within ± 1.0 pH unit; 71% of recordings were in agreement within ± 0.5 pH units. Patients with chronic laryngitis had significantly higher levels of oropharyngeal acid exposure at pH <4, <5, and <6, in the upright position than patients with GERD or controls (P < .001). CONCLUSIONS & INFERENCES: Oropharyngeal pH monitoring appears to be more sensitive than traditional pH monitoring in evaluation of patients with extraesophageal reflux. It is a promising tool in evaluation of this difficult group of patients.

EGFR and P-GP expression in oropharyngeal mucosa in relation to smoking.

BACKGROUND: About two thirds of head and neck squamous cell carcinoma (HNSCC) cases are attributable to heavy tobacco and alcohol consumption. Tobacco carcinogens cause cellular damage in large areas of the upper aerodigestive tract mucosa and contribute to distinct molecular changes, such as increasing levels of epidermal growth factor receptor (EGFR), during carcinogenesis. P-Glycoprotein (P-GP) is a multidrug-resistance transporter protein capable of extruding not only cytotoxic drugs, but also certain tobacco-related carcinogens. EGFR plays a major role in the transcriptional and functional regulation of P-GP and previous studies in our laboratory showed that stimulation of EGFR protection protected oropharyngeal cells from a carcinogen that is substrate of P-GP. Therefore, we evaluated expression levels of EGFR and P-GP and looked for a possible association with the smoking status of patients. MATERIALS AND METHODS: Tissue cultures of healthy oropharyngeal mucosa were produced from 30 patients undergoing surgery at our Department. Expression levels of EGFR on P-GP were determined by immunohistochemical staining. To evaluate possible influences of EGFR on P-GP expression, we stimulated the receptor using transforming growth factor alpha (TGF-α) for 24, 48 and 72 h. RESULTS: Current and former smokers had significantly higher EGFR/P-GP levels than never smokers. While EGFR expression was detected in almost all samples, P-GP expression was largely restricted to former and current smokers. TGF-α had no detectable effect on EGFR/P-GP levels. CONCLUSION: These results show an association between tobacco use and levels of both proteins. Since both these proteins are involved in drug resistance of head and neck cancer, this study might help to further understand the differences in response to therapy and prognosis of tobacco-related and -unrelated cancer.

Aerosol delivery of nebulised budesonide in young children with asthma.

BACKGROUND: Lung deposition of inhaled steroids, likely to be of benefit in the anti-inflammatory treatment of asthma in young children, is low. This is explained by age specific anatomical and physiological characteristics as well as poor cooperation with aerosol therapy. However, total lung deposition and the ratio of lung deposition to oropharyngeal deposition are key determinants of clinical efficacy and of systemic side effects of aerosolized drugs. OBJECTIVES: The aim of this study was to determine lung deposition and ratio of lung deposition to oropharyngeal deposition using a modified vibrating membrane nebuliser to deliver budesonide with a small particle size, taking into account the needs of young children. PATIENTS AND METHODS: Ten asthmatic children (5 males), mean age 20.3 months (range 6-41 months) inhaled radiolabelled budesonide (MMD 2.6microm) through a modified vibrating membrane nebuliser (modified PARI e-Flow). Lung deposition expressed as a percentage of the emitted dose was measured using scintigraphy and the ratio of lung deposition to oropharyngeal deposition was calculated. RESULTS: Mean lung deposition (SD) expressed as percentage of emitted dose and mean lung to oropharyngeal deposition ratio (SD) in quietly breathing children (n=5) and in children crying during inhalation were 48.6% (10.5) versus 20.0% (10.9), and 1.0 (0.3) versus 0.3 (0.2), respectively. CONCLUSIONS: We have shown that by using an improved age-adjusted complementary combination of delivery device and drug formulation to deliver small particles, lung deposition and ratio of lung deposition to oropharyngeal deposition in young asthmatic children is highly improved. But the main factor limiting aerosol delivery in this age group remains cooperation.

p16(INK4A) immunohistochemical staining may be helpful in distinguishing branchial cleft cysts from cystic squamous cell carcinomas originating in the oropharynx.

BACKGROUND: We investigated p16(INK4A) expression in branchial cleft cysts and its utility in distinguishing branchial cleft cysts from metastatic head and neck squamous cell carcinomas (SCCs) in fine-needle aspiration biopsies (FNABs). METHODS: A study set comprising 41 resections (15 SCC and 26 branchial cleft cysts) and a test set of 15 FNABs (11 SCC and 4 branchial cleft cysts) were analyzed with p16(INK4A) immunohistochemistry and human papillomavirus (HPV) polymerase chain reaction (PCR)/pyrosequencing. Cases with discrepant p16(INK4A) and PCR/pyrosequencing results were further evaluated with HPV in situ hybridization (ISH). SCCs were divided into keratinizing SCC and nonkeratinizing SCC groups and site of origin. RESULTS: Metastatic oropharyngeal nonkeratinizing SCC in the study set exhibited diffuse, strong p16(INK4A) (7 of 7) and HPV16 DNA positivity (6 of 6), while keratinizing SCC from the larynx and oral cavity was negative for p16(INK4A). p16(INK4A) reactivity in the branchial cleft cyst study set was characterized by focal, strong staining (6 of 21) involving the superficial squamous epithelium. HPV DNA was identified in 7 of 19 branchial cleft cyst study set cases by PCR/pyrosequencing, but these cases were negative by HPV ISH. In the test set, oropharyngeal nonkeratinizing SCC exhibited diffuse, strong p16(INK4A) (3 of 3) and HPV16 DNA (2 of 2), while metastatic keratinizing SCC was negative for p16(INK4A) and HPV DNA. All 4 FNABs of branchial cleft cysts were negative for p16(INK4A). Diffuse, strong p16(INK4A) correlated with oropharyngeal origin (P=.001) and nonkeratinizing morphology (P=.0001). CONCLUSIONS: Branchial cleft cysts can exhibit focal strong reactivity limited to the superficial squamous epithelium and glandular epithelium. Although p16(INK4A) immunohistochemistry may be helpful in distinguishing oropharyngeal nonkeratinizing SCC from branchial cleft cysts in FNAB specimens, it is not helpful in cases of keratinizing SCC because these cases are typically negative for p16(INK4A).

Tonsil epithelial factors may influence oropharyngeal human immunodeficiency virus transmission.

Tonsil epithelium has been implicated in human immunodeficiency virus (HIV) pathogenesis, but its role in oral transmission remains controversial. To study characteristics of this tissue, which may influence susceptibility or resistance to HIV, we performed microarray analysis of the tonsil epithelium. Our data revealed that genes related to immune functions such as antibody production and antigen processing were increasingly expressed in tonsil compared with the epithelium of another oropharyngeal site, the gingival epithelium. Importantly, tonsil epithelium highly expressed genes associated with HIV entrapment and/or transmission, including the HIV co-receptor CXCR4 and the potential HIV-binding molecules FcRgammaIII, complement receptor 2, and various complement components. Immunohistochemical staining confirmed the increased presence of CXCR4 in the tonsil epithelium compared with multiple oral epithelial sites, particularly in basal and parabasal layers. This increased expression of molecules involved in viral recognition, binding, and entry may favor virus-epithelium interactions in an environment with reduced innate antiviral mechanisms. Specifically, secretory leukocyte protease inhibitor, an innate molecule with anti-HIV activity, was minimal in the tonsil epithelium, in contrast to oral mucosa. Collectively, our data suggest that increased expression of molecules associated with HIV binding and entry coupled with decreased innate antiviral factors may render the tonsil a potential site for oral transmission.

Saliva secretion and oral flora in prolonged nasogastric tube-fed elderly patients.

BACKGROUND: In a previous study we showed that prolonged nasogastric tube feeding is associated with pathogenic oral flora. OBJECTIVE: To reexamine the impact of prolonged nasogastric tube feeding on the oral microbiota and to explore the salivary flow and composition in elderly patients in long-term care. METHODS: We compared a group of elderly patients fed by nasogastric tube with a control group of elderly patients in long-term care who are fed orally. Bacteriologic studies were performed by culturing samples from the oropharynx. Saliva studies included quantitative and biochemical analysis of basal and stimulated salivary flow. RESULTS: Bacteriologic studies performed in 90 patients revealed a significantly higher prevalence of gram-negative bacteria in nasogastric tube-fed patients (73% vs. 13%, P < 0.001). It is emphasized that Pseudomonas aeruginosa and Klebsiella pneumoniae were commonly and exclusively isolated from the oral flora of the nasogastric tube-fed patients (P < 0.001, P < 0.05). In the saliva studies performed on 23 nasogastric tube-fed and 21 control patients, basal and stimulated salivary flow was not significantly different in the two groups, however the ratio of stimulated to basal flow was reduced in the nasogastric tube-fed group (P < 0.05). Significant differences were also found in the concentrations of sodium, amylase, phosphor and magnesium. Noteworthy was the concentration of uric acid, the main non-enzymatic antioxidant of saliva, which was significantly lower in nasogastric-tube fed patients (P < 0.002). CONCLUSIONS: These findings suggest that prolonged nasogastric tube feeding is associated with pathologic colonization of the oroparynx and with alterations in the saliva that are related to the risk of aspiration pneumonia. Further research is called for, as well as a thorough revision of the existing oral cleansing procedures in these patients.

Vimentin, cytokeratin 8 and cytokeratin 18 are not specific markers for M-cells in human palatine tonsils.

Standard immunohistochemical methods were used to detect the presence of vimentin, cytokeratin 8, cytokeratin 18, macrophages and Langerhans cells in the human tonsillar epithelium in formalin-fixed and frozen tissue specimens. Vimentin detection was restricted to infiltrating cells of the lymphoid series, dendritic and vascular endothelial cells. All epithelial cells were negative. Cytokeratin 8 and 18 were readily detected in a large proportion of epithelial cells lining the crypt, but these cells bore no resemblance to the intestinal M-cells. Langerhans cells and macrophages were seen in both the oropharyngeal and crypt epithelium and were more common in the latter. This study confirms the presence of antigen-presenting cells, macrophages and Langerhans cells in the tonsillar epithelium and shows that intermediate filament proteins, vimentin, cytokeratin 8 and 18 are unreliable markers for human tonsillar M-cells, if indeed such cells exist in human tonsils.

Glycosphingolipid binding specificities of Neisseria meningitidis and Haemophilus influenzae: detection, isolation, and characterization of a binding-active glycosphingolipid from human oropharyngeal epithelium.

The glycosphingolipid binding specificities of Haemophilus influenzae and Neisseria meningitidis were investigated as to the binding of radiolabeled bacteria to glycosphingolipids on thin-layer chromatograms. Thereby, similar binding profiles, for the binding of the two bacteria to lactosylceramide, isoglobotriaosylceramide, gangliotriaosylceramide, gangliotetraosylceramide, lactotetraosylceramide, neolactotetraosylceramide, and sialylneolactohexaosylceramide, were obtained. On a closer view the binding preferences of the bacteria could be differentiated into three groups. The first specificity is recognition of lactosylceramide. The second specificity is binding to gangliotriaosylceramide and gangliotetraosylceramide, since conversion of the acetamido group of the N-acetylgalactosamine of gangliotriaosylceramide and gangliotetraosylceramide to an amine prevented the binding of the bacteria, and thus the binding to these two glycosphingolipids represents a separate specificity from lactosylceramide recognition. Preincubation of H. influenzae with neolactotetraose inhibited the binding to neolactotetraosylceramide, while the binding to lactosylceramide, gangliotetraosylceramide, or lactotetraosylceramide was unaffected. Thus, the third binding specificity is represented by neolactotetraosylceramide, and involves recognition of other neolacto series glycosphingolipids with linear N-acetyllactosamine chains, such as sialyl-neolactohexaosylceramide. The relevance of the detected binding specificities for adhesion to target cells was addressed as to the binding of the bacteria to glycosphingolipids from human granulocytes, epithelial cells of human nasopharyngeal tonsils and human plexus choroideus. Binding-active neolactotetraosylceramide was thereby detected in human granulocytes and the oropharyngeal epithelium.