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Objective: The aim of this study was to review the long-term complications associated with treatment of patients with sinonasal malignancies (SNMs) and risk factors for these complications., Methods: A retrospective analysis of all patients treated for SNMs at a tertiary care center between 2001 and 2018. A total of 77 patients were included. The primary outcome measure was post-treatment long-term complications., Results: Overall, long-term complications were identified in 41 patients (53%), and the most common were sinonasal (22 patients, 29%) and orbital/ocular-related (18 patients, 23%). In a multivariate regression analysis, irradiation was the only significant predictor of long-term complications (p = 0.001, OR = 18.86, CI = 3.31-107.6). No association was observed between long-term complications and tumour stage, surgical modality, or radiation dose/modality. Mean radiation dose ≥ 50 Gy to the optic nerve was associated with grade ≥ 3 visual acuity impairment (100% vs 3%; p = 0.006). Radiation therapy for disease recurrence was associated with additional long-term complications (56% vs 11%; p = 0.04)., Conclusions: Treatment of SNMs has substantial long-term complications, which are significantly associated with radiation therapy., (Copyright © 2023 Società Italiana di Otorinolaringoiatria e Chirurgia Cervico-Facciale, Rome, Italy.)

Epistaxis is a common debilitating manifestation in hereditary hemorrhagic telangiectasia (HHT), due to mucocutaneous telangiectases. The epistaxis can be difficult to control despite available treatments. Dysregulated angiogenesis has been shown to be associated with telangiectases formation. Topical propranolol has demonstrated antiangiogenic properties. We performed a two-phase study, i.e., a double-blind placebo-controlled phase, followed by an open-label phase. The aim of the study was assessment of safety and efficacy of nasal propranolol gel in HHT-related epistaxis. Twenty participants with moderate-severe HHT-related epistaxis were randomized to eight weeks of propranolol gel 1.5%, or placebo 0.5 cc, applied to each nostril twice daily; and continued propranolol for eight weeks in an open-label study. For the propranolol group, the epistaxis severity score (ESS) improved significantly (-2.03 ± 1.7 as compared with -0.35 ± 0.68 for the placebo group, p = 0.009); hemoglobin levels improved significantly (10.5 ± 2.6 to 11.4 ± 2.02 g/dL, p = 0.009); and intravenous iron and blood transfusion requirement decreased. The change in nasal endoscopy findings was not significant. During the open-label period, the ESS score improved significantly in the former placebo group (-1.99 ± 1.41, p = 0.005). The most common adverse event was nasal mucosa burning sensation. No cardiovascular events were reported. Our results suggest that topical propranolol gel is safe and effective in HHT-related epistaxis.

Background: Chordomas are locally invasive neoplasms, arising from notochordal remnants and can appear anywhere along the axial skeleton. Local recurrences are common, and distant metastases may occur years after the initial presentation., Methods: Literature review of current treatment strategies for chordomas of the skull base., Results: Surgery is the mainstay of treatment and complete resection has paramount importance for prognosis.When complete resection is not achieved recurrent disease is common. The anatomical complexity of the skull base makes resection complex. Endonasal endoscopic approaches to the clivus has become increasingly favored in recent years although addressing reconstruction of the skull base to prevent CSF leak may be challenging.Evidence suggests that radiotherapy should not be considered as a primary single modality when trying to achieve cure of the disease. Nonetheless, immediate post-operative radiotherapy improves survival. Many strategies have been suggested to preserve sensitive vital structures in the skull base during treatment but as for survival there is no evidence of advantage when comparing adjuvant therapy with photon radiotherapy, gamma knife surgery, proton beam therapy, and carbon ion radiation therapy.There is no evidence to support cytotoxic chemotherapy in the treatment of chordomas but targeted therapies have started to show promise. Several optional molecular targets exist. Brachyury is overexpressed in 95% of chordomas but not in other mesenchymal neoplasms. However, its precise role in chordoma pathogenesis is currently unclear, and its cellular location in the nucleus makes it difficult to target. The inhibition of brachyury in chordoma cell lines induces growth arrest and apoptosis. This does not have clinical application to date. There are retrospective results with different molecular targeted therapies for advanced chordomas with some effectiveness., Conclusion: Despite improvements made in the past 10 years in our knowledge of chordoma biology, available therapies still offer a limited benefit. There is an unmet need for new therapeutic options for patients with advanced disease. Therefore, patients with advanced disease should be encouraged to participate in clinical trials when and where available., Competing Interests: None., (© 2020 The Authors.)

Background: Endoscopic sinus surgery (ESS) is often recommended for symptomatic patients with recurrent acute or chronic rhinosinusitis who have failed conservative treatment. Postoperative care has been felt to be critical for both maintaining the surgical patency of the operated sinuses and improving patient symptoms. Debridement of the sinonasal cavities is one such postoperative care measure that has frequently been studied in the literature, often with conflicting conclusions., Objectives: To assess the effects of postoperative sinonasal debridement versus no debridement following endoscopic sinus surgery., Search Methods: The Cochrane ENT Information Specialist searched the ENT Trials Register; Central Register of Controlled Trials (CENTRAL, via the Cochrane Register of Studies); PubMed; EMBASE; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 21 May 2018., Selection Criteria: Randomised controlled trials comparing postoperative nasal debridement versus no debridement in adult patients with recurrent acute or chronic rhinosinusitis undergoing endoscopic sinus surgery. We included studies in which the patients acted as self-controls (i.e. one side of the nose underwent debridement and the other side did not) only for the secondary endoscopy outcomes., Data Collection and Analysis: We used the standard methodological procedures expected by Cochrane. Our primary outcome measures were: health-related quality of life, disease severity (patient-reported symptom scores) and significant adverse effects (bleeding requiring intervention, severe pain, iatrogenic injury). Secondary outcomes were: postoperative endoscopic appearance of the sinonasal surgical cavities (endoscopic scores), recorded use of postoperative medical treatment and rate of revision surgery. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics., Main Results: We included four studies (152 participants), with a follow-up duration ranging from three months to 12 months. In two studies patients acted as self-controls, i.e. one side of the nose underwent debridement and the other side did not ('split-nose' studies). The risk of bias in all studies was high, mostly due to the inability to blind the patients to the debridement procedure.Primary outcomesDisease-specific health-related quality of life scoresOnly one study (58 participants) provided data for disease-specific health-related quality of life. At six months follow-up, lower disease-specific health-related quality of life scores, measured using the Sino-Nasal Outcome Test-22 (SNOT-22, range 0 to 110), were noted in the debridement group but the difference was not statistically significant (9.7 in the debridement group versus 10.3 in the control group, P = 0.47) (low-quality evidence).Disease severity (patient-reported symptom score)Only one study (60 participants) provided data for disease severity measured by visual analogue scale (VAS) score. No significant differences in total symptom score were observed between groups postoperatively (low-quality evidence).Significant adverse effectsSignificant adverse effects related to the debridement procedure were not reported in any of the included studies, however it is not clear whether data regarding adverse effects were not collected or if none were indeed observed in any of the included studies.Secondary outcomesAll four studies assessed thepostoperative endoscopic appearance of the sinonasal cavities using the Lund-Kennedy score (range 0 to 10). A pooled analysis of endoscopic scores in the two non 'split-nose' studies revealed better endoscopic scores in the debridement group, however this was not a statistically significant difference (mean difference -0.31, 95% confidence interval (CI) -1.35 to 0.72; I² = 0%; two studies; 118 participants) (low-quality evidence). A sub-analysis of the adhesion formation component of the endoscopic score was available for all four studies and revealed a significantly lower adhesion rate in the debridement group (risk ratio 0.43, 95% CI 0.28 to 0.68; I² = 29%; four studies; 152 participants). Analysis of the number needed to treat to benefit revealed that for every three patients undergoing debridement, the endoscopic score would be decreased by one point in one patient. For every five patients undergoing debridement adhesion formation would be prevented in one patient.Use of postoperative medical treatment was reported in all studies, all of which recommended nasal douching. Steroids (systemic or nasal) were administered in two studies. However, the data were very limited and heterogeneous, therefore we could not analyse the impact of concomitant postoperative medical treatment.The rate of revision surgery was not reported in any of the included studies, however it is not clear whether these data were not recorded or if there were no revision surgeries in any of the included studies., Authors' Conclusions: We are uncertain about the effects of postoperative sinonasal debridement due to high risk of bias in the included studies and the low quality of the evidence. Sinonasal debridement may make little or no difference to disease-specific health-related quality of life or disease severity. Low-quality evidence suggests that postoperative debridement is associated with a significantly lower risk of adhesions at three months follow-up. Whether this has any impact on longer-term outcomes is unknown.

Clinically useful molecular tools to triage gastric cancer patients are not currently available. We aimed to develop a molecular tool to predict gastric cancer risk in endoscopy-driven biopsies obtained from high-risk gastric cancer clinics in low resource settings.We discovered and validated a DNA methylation biomarker panel in endoscopic samples obtained from 362 patients seen between 2004 and 2009 in three high-risk gastric cancer clinics in Lima, Perú, and validated it in 306 samples from the Cancer Genome Atlas project ("TCGA"). Global, epigenome wide and gene-specific DNA methylation analyses were used in a Phase I Biomarker Development Trial to identify a continuous biomarker panel that combines a Global DNA Methylation Index (GDMI) and promoter DNA methylation levels of IRF4, ELMO1, CLIP4 and MSC.We observed an inverse association between the GDMI and histological progression to gastric cancer, when comparing gastritis patients without metaplasia (mean = 5.74, 95% CI, 4.97-6.50), gastritis patients with metaplasia (mean = 4.81, 95% CI, 3.77-5.84), and gastric cancer cases (mean = 3.38, 95% CI, 2.82-3.94), respectively (p < 0.0001). Promoter methylation of IRF4 (p < 0.0001), ELMO1 (p < 0.0001), CLIP4 (p < 0.0001), and MSC (p < 0.0001), is also associated with increasing severity from gastritis with no metaplasia to gastritis with metaplasia and gastric cancer.Our findings suggest that IRF4, ELMO1, CLIP4 and MSC promoter methylation coupled with a GDMI>4 are useful molecular tools for gastric cancer risk stratification in endoscopic biopsies.

Objective: The clinical presentation of sphenoid sinusitis can be highly variable. Rarely, sphenoid sinusitis may present with cranial nerve complications due to the proximity of these structures to the sphenoid sinus., Method: A case series from Rabin Medical Center and all cases of cranial nerves palsies secondary to sphenoid sinusitis that have been reported in the literature were reviewed., Results: Seventeen patients were identified. The abducent nerve was the most common cranial nerve affected (76%), followed by the oculomotor nerve (18%). One patient had combined oculomotor, trochlear and abducent palsies. The most common pathology was isolated purulent sphenoid sinusitis in 64% followed by allergic fungal sinusitis (AFS) in 18%, and fungal infection in 18%. 94% had an acute presentation. The majority (85%) received a combined intravenous antibiotics and surgical treatment. The remainder received conservative treatment alone. Complete recovery of cranial nerve palsy was noted in 82% during follow up., Conclusion: Sphenoid sinusitis presenting as diplopia and headaches is rare. A neoplastic process must be ruled out and early surgical intervention with intravenous antimicrobial therapy carry an excellent outcome with complete resolution of symptoms.

Spontaneous meningoencephalocele (SME) of the sphenoid wing is a rare cause of cerebrospinal fluid (CSF) leakage. Surgical closure of the fistula is usually required. The approach taken depends on the location of the defect and the extension of the meningoencephalocele. The endoscopic transpterygoid approach may be useful. We prospectively analyzed the three cases of SME of the sphenoid wing with lateral sphenoid sinus extension treated endoscopically at Stanford over the last 3 years with regard to imaging findings, operative technique, and operative morbidity. In our three cases, the extent of pterygopalatine fossa (PPF) exposure undertaken, complete in one and partial in two, depended on the defect site. Follow-up ranged from 17 to 25 months. The fistula was completely closed in all three cases. Extant literature reports a 97% rate of successful closure (N = 65 of 67, with a mean follow-up of 25 months) and no major complications. Endoscopic transpterygoid repair is a useful, safe alternative to traditional approaches for repair of SME of the sphenoid wing. Its feasibility depends on the site of the defect, which can be identified by preoperative imaging. Larger PPF exposure and postoperative lumbar drainage of CSF can be useful and have a low risk of morbidity.

Obstructive sleep apnea (OSA) is a common disorder, characterized by cyclic cessation of airflow for 10 seconds or more. There is growing awareness that OSA is related to the development and progression of cardiovascular disease. However, only a few studies have associated OSA directly to major cardiovascular events. The aim of this study was to evaluate the relationship between OSA and cardiovascular morbidity in a well defined population of patients.The electronic database of the central district of a major health management organization was searched for all patients diagnosed with OSA in 2002-2010. For each patient identified, an age- and sex-matched patient was randomly selected from the members of the same health management organization who did not have OSA. Data on demographics, socioeconomic status, and relevant medical parameters were collected as well.The study population included 2797 patients, average age 58.1, in which 76.6% were males. There was a significant correlation between OSA and the presence of ischemic heart disease (P < 0.001), pulmonary hypertension (P < 0.001), congestive heart failure (P < 0.001), cardiomyopathy (P = 0.003), and arrhythmia (P < 0.001). OSA was also significantly correlated with low socioeconomic status (P < 0.001).OSA and cardiovascular disease were strongly correlated. As such, early diagnosis and treatment of OSA may change the course of both diseases. We suggest that sleep disordered breathing should be routinely assessed in patients with cardiovascular problems. An ear-nose-throat evaluation may also be important to rule out anatomic disorders that cause upper airway obstruction.

Purpose: Prior studies have demonstrated tumor-specific alternative splicing events in various solid tumor types. The role of alternative splicing in the development and progression of head and neck squamous cell carcinoma (HNSCC) is unclear. Our study queried exon-level expression to implicate splice variants in HNSCC tumors., Experimental Design: We performed a comparative genome-wide analysis of 44 HNSCC tumors and 25 uvulopalatopharyngoplasty (UPPP) tissue samples at an exon expression level. In our comparison we ranked genes based upon a novel score-the Maximum-Minimum Exon Score (MMES)--designed to predict the likelihood of an alternative splicing event occurring. We validated predicted alternative splicing events using quantitative RT-PCR on an independent cohort., Results: After MMES scoring of 17,422 genes, the top 900 genes with the highest scores underwent additional manual inspection of expression patterns in a graphical analysis. The genes LAMA3, DST, VEGFC, SDHA, RASIP1, and TP63 were selected for further validation studies because of a high frequency of alternative splicing suggested in our graphical analysis, and literature review showing their biological relevance and known splicing patterns. We confirmed TP63 as having dominant expression of the short DeltaNp63 isoform in HNSCC tumor samples, consistent with prior reports. Two of the six genes (LAMA3 and DST) validated by quantitative RT-PCR for tumor-specific alternative splicing events (Student's t test, P<0.001)., Conclusion: Alternative splicing events of oncologically relevant proteins occur in HNSCC. The number of genes expressing tumor-specific splice variants needs further elucidation, as does the functional significance of selective isoform expression.

Object: In this study the authors share their experience using intraoperative spinal navigation and imaging for endoscopic transnasal approaches to the odontoid in 5 patients undergoing C1-2 surgery for basilar invagination at Stanford Hospital and Clinics from 2010 to 2013., Methods: Of these 5 patients undergoing C1-2 surgery for basilar invagination, 4 underwent a 2-tiered anterior C1-2 resection with posterior occipitocervical fusion during a first stage surgery, followed by endoscopic endonasal odontoidectomy in a separate setting. Intraoperative stereotactic navigation was performed using a surgical navigation system in all cases. Navigation accuracy, characterized as target registration error, ranged between 0.8 mm and 2 mm, with an average of 1.2 mm. Intraoperative imaging using a CT scanner was also performed in 2 patients., Results: Endoscopic decompression of the brainstem was achieved in all patients, and no intraoperative complications were encountered. All patients were extubated within 24 hours after surgery and were able to swallow within 48 hours. After appropriate initial reconstruction of the defect at the craniocervical junction, no postoperative CSF leakage, arterial injury, or need for reoperation was encountered; 1 patient developed mild postoperative velopharyngeal insufficiency that resolved by the 6-month follow-up evaluation. There were no deaths and no patients required tracheostomy placement. The average inpatient stay after surgery varied between 72 and 96 hours, without extended intensive care unit stays for any patient., Conclusions: Technologies such as intraoperative CT scanning and merged MRI/CT can provide the surgeon with detailed, virtual real-time information about the extent of complex endoscopic vertebral segment resection and brainstem decompression and lessens the prospect of revision or secondary procedures in this challenging surgical corridor. Moreover, patients experience limited morbidity and can tolerate early oral intake after transnasal endoscopic odontoidectomy. Essential to the successful undertaking of these endoscopic adventures is 1) an understanding of the endoscopic nasal, skull base, and neurovascular anatomy; 2) advanced and extended-length instrumentation including navigation; and 3) a team approach between experienced rhinologists and spine surgeons comfortable with endoscopic skull base techniques.

Cervical cancer is a major health concern among women in Latin America due to its high incidence and mortality. Therefore, the discovery of molecular markers for cervical cancer screening and triage is imperative. The aim of this study was to use a genome wide DNA methylation approach to identify novel methylation biomarkers in cervical cancer. DNA from normal cervical mucosa and cervical cancer tissue samples from Chile was enriched with Methylated DNA Immunoprecipitation (MeDIP), hybridized to oligonucleotide methylation microarrays and analyzed with a stringent bioinformatics pipeline to identify differentially methylated regions (DMRs) as candidate biomarkers. Quantitative Methylation Specific PCR (qMSP) was used to study promoter methylation of candidate DMRs in clinical samples from two independent cohorts. HPV detection and genotyping were performed by Reverse Line Blot analysis. Bioinformatics analysis revealed GGTLA4, FKBP6, ZNF516, SAP130, and INTS1 to be differentially methylated in cancer and normal tissues in the Discovery cohort. In the Validation cohort FKBP6 promoter methylation had 73% sensitivity and 80% specificity (AUC = 0.80). ZNF516 promoter methylation was the best biomarker, with both sensitivity and specificity of 90% (AUC = 0.92), results subsequently corroborated in a Prevalence cohort. Together, ZNF516 and FKBP6 exhibited a sensitivity of 84% and specificity of 81%, when considering both cohorts. Our genome wide DNA methylation assessment approach (MeDIP-chip) successfully identified novel biomarkers that differentiate between cervical cancer and normal samples, after adjusting for age and HPV status. These biomarkers need to be further explored in case-control and prospective cohorts to validate them as cervical cancer biomarkers.

The majority of the epigenomic reports in hepatocellular carcinoma have focused on identifying novel differentially methylated drivers or passengers of the oncogenic process. Few reports have considered the technologies in place for clinical translation of newly identified biomarkers. The aim of this study was to identify epigenomic technologies that need only a small number of samples to discriminate HCC from non-HCC tissue, a basic requirement for biomarker development trials. To assess that potential, we used quantitative Methylation Specific PCR, oligonucleotide tiling arrays, and Methylation BeadChip assays. Concurrent global DNA hypomethylation, gene-specific hypermethylation, and chromatin alterations were observed as a hallmark of HCC. A global loss of promoter methylation was observed in HCC with the Illumina BeadChip assays and the Nimblegen oligonucleotide arrays. HCC samples had lower median methylation peak scores and a reduced number of significant promoter-wide methylated probes. Promoter hypermethylation of RASSF1A, SSBP2, and B4GALT1 quantified by qMSP had a sensitivity ranging from 38% to 52%, a specificity of 100%, and an AUC from 0.58 to 0.75. A panel combining these genes with HCC risk factors had a sensitivity of 87%, a specificity of 100%, and an AUC of 0.91.

The methylated DNA immunoprecipitation method (MeDIP) is a genome-wide, high-resolution approach that detects DNA methylation with oligonucleotide tiling arrays or high throughput sequencing platforms. A simplified high-throughput MeDIP assay will enable translational research studies in clinics and populations, which will greatly enhance our understanding of the human methylome. We compared three commercial kits, MagMeDIP Kit TM (Diagenode), Methylated-DNA IP Kit (Zymo Research) and Methylamp™ Methylated DNA Capture Kit (Epigentek), in order to identify which one has better reliability and sensitivity for genomic DNA enrichment. Each kit was used to enrich two samples, one from fresh tissue and one from a cell line, with two different DNA amounts. The enrichment efficiency of each kit was evaluated by agarose gel band intensity after Nco I digestion and by reaction yield of methylated DNA. A successful enrichment is expected to have a 1:4 to 10:1 conversion ratio and a yield of 80% or higher. We also evaluated the hybridization efficiency to genome-wide methylation arrays in a separate cohort of tissue samples. We observed that the MagMeDIP kit had the highest yield for the two DNA amounts and for both the tissue and cell line samples, as well as for the positive control. In addition, the DNA was successfully enriched from a 1:4 to 10:1 ratio. Therefore, the MagMeDIP kit is a useful research tool that will enable clinical and public health genome-wide DNA methylation studies.

Purpose: Although promoter hypermethylation has been an accepted means of tumor suppressor gene inactivation, activation of otherwise normally repressed proto-oncogenes by promoter demethylation has been infrequently documented., Experimental Design: In this study we performed an integrative, whole-genome analysis for discovery of epigenetically activated proto-oncogenes in head and neck cancer tumors. We used the 47K GeneChip U133 Plus 2.0 Affymetrix expression microarray platform to obtain re-expression data from 5-aza treated normal cell line and expression data from primary head and neck squamous cell carcinoma (HNSCC) tumor tissues and normal mucosa tissues. We then investigated candidate genes by screening promoter regions for CpG islands and bisulfite sequencing followed by QUMSP and RT PCR for the best candidate genes. Finally, functional studies were performed on the top candidate gene., Results: From the top 178 screened candidates 96 had CpG islands in their promoter region. Seven candidate genes showed promoter region methylation in normal mucosa samples and promoter demethylation in a small cohort of primary HNSCC tissues. We then studied the demethylation of the top 3 candidate genes in an expanded cohort of 76 HNSCC tissue samples and 17 normal mucosa samples. We identified MAGEB2 as having significant promoter demethylation in primary head and neck squamous cell carcinoma tissues. We then found significantly higher expression of MAGEB2 in tumors in a separate cohort of 73 primary HNSCC tissues and 31 normal tissues. Finally, we found that MAGEB2 has growth promoting effects on minimally transformed oral keratinocyte cell lines but not a definite effect on HNSCC cell lines., Conclusion: In conclusion, we identified MAGEB2 as activated by promoter demethylation in HNSCCand demonstrates growth promoting effects in a minimally transformed oral keratinocyte cell line. More studies are needed to evaluate MAGBE2's exact role in HNSCC.

The management of uncontrolled bleeding in trauma patients is difficult in the prehospital setting, especially when transfer time to a care facility is prolonged. The goal of treatment is to stabilize the patient until surgery can be performed. In modem practice, the major aspects of optimal patient stabilization are the timing and volume of resuscitation and the use of blood products. The main problems are the logistics of handling the blood products as well as achieving the appropriate endpoint of resuscitation, while balancing the need to maintain blood pressure with the need to avoid deleterious coagulopathy. This work reviews current therapeutic modalities for prehospital management of uncontrolled bleeding trauma patients, namely low volume resuscitation, packed red blood cells, hemoglobin solutions, perfluorocarbons, hypertonic saline solutions, and recombinant activated factor VII.

Background: Physicians' decisions regarding provision of life-sustaining treatment may be influenced considerably by non-medical variables., Objectives: To examine physicians' attitudes towards end-of-life decisions in Israel, comparing them to those found in the United States., Methods: A survey was conducted among members of the Israel Society of Critical Care Medicine using a questionnaire analogous to that used in a similar study in the USA., Results: Forty-three physicians (45%) responded, the majority of whom hold responsibility for withholding or withdrawing life-sustaining treatments. Preservation of life was considered the most important factor by 31 responders (72%). The quality of life as viewed by the patient was generally considered less important than the quality of life as viewed by the physician. Twenty-one responders (49%) considered withholding treatment more acceptable than withdrawing it. The main factors for decisions to withhold or withdraw therapy were a very low probability of survival of hospitalization, an irreversible acute disorder, and prior existence of chronic disorders. An almost similar percent of physicians (93% for Israel and 94% for the U.S.) apply Do Not Resuscitate orders in their intensive care units, but much less (28% vs. 95%) actually discuss these orders with the families of their patients., Conclusions: Critical care physicians in Israel place similar emphasis on the value of life as their U.S. counterparts and assign DNR orders with an incidence equaling that of the U.S. They differ from their U.S. counterparts in that they confer less significance to the will of the patient, and do not consult as much with families of patients regarding DNR orders.

Rifampin, in addition to interfering with intracellular growth of the ribonucleic acid-containing phage MS2, also inhibits the release of mature phage particles from Escherichia coli cells.

The release of the ribonucleic acid (RNA)-containing phage MS2 from Escherichia coli is accompanied by cellular lysis at 37 C, whereas at 30 C phage are released from intact cells. Chloramphenicol or rifampin prevents the release of progeny phage particles at both temperatures. Neither drug causes an immediate cessation of phage release and after inhibition of protein synthesis by chloramphenicol phage release proceeds for about 17 min at 37 C and about 35 min at 30 C. Rifampin does not inhibit phage release from mutant cells possessing a rifampin-resistant deoxyribonucleic acid-dependent RNA polymerase. The results indicate that a short-lived host-controlled protein(s) is essential for the release of RNA phage particles at both temperatures.