Perioperative blood transfusions and survival in resected pancreatic adenocarcinoma patients given multimodality therapy.

BACKGROUND AND OBJECTIVES: The impact of perioperative blood transfusion (PBT) on outcomes for pancreatic ductal adenocarcinoma (PDAC) patients given multimodality therapy (MMT) remains undefined. We sought to evaluate the association of PBT with survival after PDAC resection. METHODS: Pancreatectomy patients (July 2011-December 2017) who received MMT were abstracted from a prospective database. Overall survival (OS) was compared by PBT within 30 days, 24 h (24HR-BT), or 24 h until 30 days (Postop-BT). RESULTS: Most (76.6%) of 312 MMT patients underwent neoadjuvant therapy (NT). Eighty-nine patients (28.5%) received PBT; 58 (18.6%) 24HR-BT, and 31 (9.9%) Postop-BT. Compared with surgery-first, NT patients received more 24HR-BTs (22.2% vs. 6.8%, p = 0.003) and PBTs overall (32.6% vs. 15.1%, p = 0.004). Overall median OS was 45 months. The association of PBT with shorter median OS appeared limited to first 24-h transfusions (34 months 24HR-BT vs. 48 months Postop-BT vs. 53 months no-PBT, p = 0.009) and was dose-dependent, with a median OS of 52 months for 0 units 24HR-BT, 35 months for 1 unit, and 25 months for ≥2 units (p = 0.004). Independent predictors of OS included node-positivity (hazard ratio [HR]: 1.93, p < 0.001), perineural invasion (HR: 1.64, p = 0.050), postoperative pancreatic fistula (HR: 1.94, p = 0.018), and 24HR-BT (HR: 1.75, p = 0.001). CONCLUSIONS: Transfusions given within 24 h are associated with dose-dependent decreases in survival after pancreatectomy for PDAC.

Randomized clinical trial of accelerated enhanced recovery after minimally invasive colorectal cancer surgery (RecoverMI trial).

BACKGROUND: Minimally invasive surgery (MIS) and enhanced recovery protocols (ERPs) have improved postoperative recovery and shortened length of hospital stay (LOS). Telemedicine technology has potential to improve outcomes and patient experience further. This study was designed to determine whether the combination of MIS, ERP and a structured telemedicine programme (TeleRecovery) could shorten total 30-day LOS by 50 per cent. METHODS: This was a phase II prospective RCT at a large academic medical centre. Eligible patients aged 18-80 years undergoing minimally invasive colorectal resection using an ERP were randomized after surgery. The experimental arm (RecoverMI) included accelerated discharge on postoperative day (POD) 1 with or without evidence of bowel function and a televideoconference on POD 2. The control arm was standard postoperative care. The primary endpoint was total 30-day LOS (postoperative stay plus readmission/emergency department/observation days). Secondary endpoints included patient-reported outcomes measured by EQ-5D-5L™, Brief Pain Inventory (BPI) and a satisfaction questionnaire. RESULTS: Thirty patients were randomized after robotic (21 patients) or laparoscopic (9) colectomy, including 14 patients in the RecoverMI arm. Median 30-day total LOS was 28·3 (i.q.r. 23·7-43·6) h in the RecoverMI arm and 51·5 (43·8-67·0) h in the control arm (P = 0·041). There were no differences in severe adverse events or EQ-5D-5L™ score between the study arms. The BPI revealed low pain scores regardless of treatment arm. Satisfaction was high in both arms. CONCLUSION: In patients having surgery for colorectal neoplasms, the trimodal combination of MIS, ERP and TeleRecovery can reduce 30-day LOS while preserving patients' quality of life and satisfaction. Registration number: NCT02613728 ( https://clinicaltrials.gov).

ANTECEDENTES: La cirugía mínimamente invasiva (minimally invasive surgery, MIS) y los protocolos de recuperación intensificada (enhanced recovery protocols, ERP) han mejorado la recuperación postoperatoria y acortan la duración de la estancia (length of stay, LOS). La tecnología de la telemedicina tiene potencial para mejorar aún más los resultados y la experiencia del paciente. Este estudio se diseñó para determinar si la combinación de MIS, ERP y un programa estructurado de telemedicina (TeleRecovery) podría acortar la LOS total a los 30 días en un 50%. MÉTODOS: Se efectuó un ensayo controlado aleatorizado, prospectivo, de fase II en un gran centro médico académico. Los pacientes elegibles de 18-80 años de edad que se sometieron a resección colorrectal MIS mediante ERP se asignaron al azar después de la resección quirúrgica. El brazo experimental (RecoverMI) incluyó el alta acelerada en el día 1 del postoperatorio (postoperative day, POD) con o sin evidencia de recuperación del tránsito intestinal y una televideoconferencia en el día 2 POD. Los pacientes en el grupo control recibieron los cuidados postoperatorios habituales. El criterio de valoración principal fue la LOS total (estancia postoperatoria más reingreso/estancia en urgencias/días de observación) a los 30 días. Los criterios de valoración secundarios incluyeron los resultados referidos por los pacientes medidos por los cuestionarios EQ-5D-5L, el Cuestionario Breve del Dolor (Brief Pain Inventory, BPI) y un cuestionario de satisfacción. RESULTADOS: Treinta pacientes fueron aleatorizados después de una colectomía robótica (21) o laparoscópica (9), incluidos 14 pacientes en el grupo de RecoverMI. La mediana de la LOS total a los 30 días fue de 28,3 horas (rango intercuartílico, RIQ 23,7-43,6) en el grupo de RecoverMI y de 51,5 horas (RIQ 43,8-67,0) en el grupo control (P = 0,04). No hubo diferencias entre los grupos de estudio en los eventos adversos graves o en las puntuaciones del EQ-5D-5L. El BPI mostró puntuaciones bajas de dolor independientemente del grupo de tratamiento. La satisfacción fue alta en ambos grupos. CONCLUSIÓN: Entre los pacientes que se someten a cirugía por cáncer colorrectal, la combinación trimodal de MIS, ERP y TeleRecovery puede reducir la LOS a los 30 días, preservando la calidad de vida y la satisfacción del paciente.

Inpatient Opioid Use After Pancreatectomy: Opportunities for Reducing Initial Opioid Exposure in Cancer Surgery Patients.

BACKGROUND: Despite advances in enhanced surgical recovery programs, strategies limiting postoperative inpatient opioid exposure have not been optimized for pancreatic surgery. The primary aims of this study were to analyze the magnitude and variations in post-pancreatectomy opioid administration and to characterize predictors of low and high inpatient use. METHODS: Clinical characteristics and inpatient oral morphine equivalents (OMEs) were downloaded from electronic records for consecutive pancreatectomy patients at a high-volume institution between March 2016 and August 2017. Regression analyses identified predictors of total OMEs as well as highest and lowest quartiles. RESULTS: Pancreatectomy was performed for 158 patients (73% pancreaticoduodenectomy). Transversus abdominus plane (TAP) block was performed for 80% (n = 127) of these patients, almost always paired with intravenous patient-controlled analgesia (IV-PCA), whereas 15% received epidural alone. All the patients received scheduled non-opioid analgesics (median, 2). The median total OME administered was 423 mg (range 0-4362 mg). Higher total OME was associated with preoperative opioid prescriptions (p < 0.001), longer hospital length of stay (LOS; p < 0.001), and no epidural (p = 0.006). The lowest and best quartile cutoff was 180 mg of OME or less, whereas the highest and worst quartile cutoff began at 892.5 mg. After adjustment for inpatient team, only epidural use [odds ratio (OR) 0.3; p = 0.04] predicted lowest-quartile OME. Preoperative opioid prescriptions (OR 8.1; p < 0.001), longer operative time (OR 3.4; p = 0.05), and longer LOS (OR 1.1; p = 0.007) predicted highest-quartile OME. CONCLUSIONS: Preoperative opioid prescriptions and longer LOS were associated with increased inpatient OME, whereas epidural use reduced inpatient OME. Understanding the predictors of inpatient opioid use and the variables predicting the lowest and highest quartiles can inform decision-making regarding preoperative counseling, regional anesthetic block choice, and novel inpatient opioid weaning strategies to reduce initial postoperative opioid exposure.

Accelerated enhanced Recovery following Minimally Invasive colorectal cancer surgery (RecoverMI): a study protocol for a novel randomised controlled trial.

INTRODUCTION: Definitive treatment of localised colorectal cancer involves surgical resection of the primary tumour. Short-stay colectomies (eg, 23-hours) would have important implications for optimising the efficiency of inpatient care with reduced resource utilisation while improving the overall recovery experience with earlier return to normalcy. It could permit surgical treatment of colorectal cancer in a wider variety of settings, including hospital-based ambulatory surgery environments. While a few studies have shown that discharge within the first 24 hours after minimally invasive colectomy is possible, the safety, feasibility and patient acceptability of a protocol for short-stay colectomy for colorectal cancer have not previously been evaluated in a prospective randomised study. Moreover, given the potential for some patients to experience a delay in recovery of bowel function after colectomy, close outpatient monitoring may be necessary to ensure safe implementation. METHODS AND ANALYSIS: In order to address this gap, we propose a prospective randomised trial of accelerated enhanced Recovery following Minimally Invasive colorectal cancer surgery (RecoverMI) that leverages the combination of minimally invasive surgery with enhanced recovery protocols and early coordinated outpatient remote televideo conferencing technology (TeleRecovery) to improve postoperative patien-provider communication, enhance postoperative treatment navigation and optimise postdischarge care. We hypothesise that RecoverMI can be safely incorporated into multidisciplinary practice to improve patient outcomes and reduce the overall 30-day duration of hospitalisation while preserving the quality of the patient experience. ETHICS AND DISSEMINATION: RecoverMI has received institutional review board approval and funding from the American Society of Colorectal Surgeons (ASCRS; LPG103). Results from RecoverMI will be published in a peer-reviewed publication and be used to inform a multisite trial. TRIAL REGISTRATION NUMBER: NCT02613728; Pre-results.

Tumor necrosis factor-alpha induces the expression of DR6, a member of the TNF receptor family, through activation of NF-kappaB.

The tumor necrosis factor (TNF) receptor family are ligand-regulated transmembrane proteins that mediate apoptosis as well as activation of the transcription factor NF-kappaB. Exogenous expression of DR6, a recently identified member of the TNF receptor family, induced apoptosis in untransformed or tumor-derived cells and the apoptotic function of DR6 was inhibited by co-expression of Bcl-2, Bcl-x(L) or the inhibitor-of-apoptosis (IAP) family member, survivin. Expression of a dominant negative mutant of FADD failed to protect from DR6-mediated apoptosis indicating that unlike TNFR1 and Fas, DR6 induced apoptosis via a FADD-independent mechanism. Despite the ability of exogenous DR6 expression to induce apoptosis, DR6 mRNA and protein were found to be elevated in prostate tumor cell lines and in advanced stages of prostate cancer. Analysis of several anti-apoptotic proteins revealed that Bcl-x(L) levels and serine 32 phosphorylation of IkappaB, the natural inhibitor of NF-kappaB, were similarly elevated in cells expressing high levels of DR6, suggesting that NF-kappaB-regulated survival proteins may protect from DR6-induced apoptosis and that DR6 is a target of NF-kappaB regulation. Treatment of LnCAP cells with TNF-alpha resulted in increases in both DR6 mRNA and protein levels, and this induction was suppressed by inhibitors of NF-kappaB. Similarly, treatment of cells expressing high levels of DR6 with indomethacin and ibuprofen, compounds also known to perturb NF-kappaB function, resulted in a dose-dependent decrease in DR6 protein and mRNA levels. These results demonstrate that TNF-alpha signaling induces the expression of a member of its own receptor family through activation of NF-kappaB.

Bronchoalveolar inflammation following airway infection in preterm infants with chronic lung disease.

Chronic lung disease (CLD) of the newborn is associated with pulmonary inflammation. However, the origin of this inflammation is not known. We evaluated the impact of airway infection on bronchoalveolar inflammation in mechanically ventilated preterm infant at risk for CLD (n = 68). Mean and maximum concentrations of the inflammatory mediators (IM) interleukin-1 and interleukin-8 were assayed in the tracheobronchial aspirate fluid (TAF) of neonates with perinatal airway infection (Ureaplasma urealyticum, or bacteria), postnatal nosocomial airway infection, or respiratory disease without airway infection from days 1-10 of postnatal age. Patients with CLD (n = 23;) exhibited increased levels of IM in TAF compared to neonates without CLD. Within the three subgroups, concentrations of IM were increased in CLD patients with perinatal infection and in CLD patients with respiratory disease without airway infection, but not in CLD patients with nosocomial airway infection. Although airway colonization with Gram-negative bacteria was more frequently found in CLD patients within the first month of life, there were no differences between levels of IM in patients colonized with Gram-negative bacteria or coagulase-negative staphyloccoci. We conclude that perinatal infections with Ureaplasma urealyticum or bacteria and respiratory disease without infection, but not nosocomial airway infection, contribute to the bronchopulmonary inflammatory response in neonates with CLD.

Detection by ELISA of low transferrin levels in bronchoalveolar secretions of preterm infants.

Transferrin levels in bronchoalveolar secretions (BAS) are very low compared to serum levels in humans. For the exact measurement of transferrin concentrations in BAS a very sensitive assay was developed as a double sandwich enzyme immunoassay using the combination of a polyclonal and a monoclonal antibody against human transferrin. The measurable range of the assay was 1.5 to 100 ng/ml of human transferrin. The lowest measurable value was 0.84 ng/ml and the sensitivity of the assay was 0.88 ng/ml. The coefficient of variation was 14.1% for 25 ng/ml (intra-assay) and 11-20% (inter-assay). The levels measured in 123 samples of BAS of preterm infants ranged between 0.03 and 8.93 (microgram/microgram secretory component (SC)). The determination of transferrin in BAS of preterm infants is helpful in determining oxidative damage, e.g. the availability of free iron, in the neonatal lung. The transferrin concentration in BAS of neonates who recovered from respiratory distress syndrome (RDS) in the first six days of life was 0.48 compared to 0.52 ((microgram/microgram SC), median range) for infants who developed chronic lung disease.

Hyperspectral diagnostic imaging of the cervix: report on a new investigational device.

OBJECTIVE: To describe our experience with a noncontact in vivo fluorescence imaging device for the detection and localization of cervical intraepithelial neoplasia (CIN). MATERIALS AND METHODS: Sixty-two women with abnormal Papanicolaou (Pap) smears, and 4 women with normal Pap smears, were recruited to undergo fluorescence imaging of the cervix during colposcopy. After topically applying dilute acetic acid, the surface of the cervix was scanned with 365 nm ultraviolet light for about 12 sec. Colposcopy and biopsies of visualized lesions were then performed. The fluorescence emission curves generated by normal cervical tissue and various states of cervical pathology were inspected and assigned relative scores of 1-5 based on the height and slope of the curves at peak fluorescence emissions. A score of 1 indicated a curve with high magnitude and distinct peak, and a score of 5 described a curve of low magnitude and rounded/flattened peak. Scores of 2-4 represented curves with incremental changes of about 25% in the height of the curve between scores of 1 and 5. Biopsies were classified as high grade (HG, CIN 2/3), low grade (LG, HPV/CIN 1), or nondysplastic (ND). Among women with abnormal Pap smears, only those who had biopsies with concordant interpretations by two independent pathologists were included in the descriptive analysis. All of the patients with normal Pap smears were included. RESULTS: A total of 35 women were included in the analysis. Of 62 women with abnormal Pap smears who underwent fluorescence imaging and colposcopy, 31 met the inclusion criteria. Among these 31 women, Pap smears consisted of 6 atypical squamous cells of undetermined significance (ASCUS), 16 low-grade squamous intraepithelial lesions (LGSILs), and 9 high-grade squamous intraepithelial lesions (HGSILs). Of the 4 women with normal Pap smears, 1 had an abnormal colposcopy and a nondysplastic biopsy. Among all 35 women, 42 total biopsies were included, consisting of 11 HG, 25 LG, and 6 ND. Normal squamous tissue generated a score of 1, normal metaplastic tissue a score of 2 or 3, and normal columnar tissue of score of 5 in 35/35 (100%) women. Among the 11 HG lesions, 8 had a score of 4 and 2 had a score of 5. One case was uninterpretable due to a low signal-to-noise ratio. Among the 25 LG lesions, 15 had a score of 3, 6 had a score of 4 or 5, 2 had a score of 1, and 2 cases were uninterpretable. CONCLUSIONS: HG lesions generated spectra distinct from normal tissue in 8/10 (80%) evaluable cases, but LG lesions generated spectra indistinguishable from that of normal metaplastic tissue. Further modifications to this technique are needed before an objective, reproducible, and discriminatory scoring system can be developed. ▪.

Effects of inhaled beclomethasone compared to systemic dexamethasone on lung inflammation in preterm infants at risk of chronic lung disease.

The purpose of this study was to compare the effects of daily inhaled beclomethasone (3 x 500 microg) started on day 3 of life, with that of systemic dexamethasone (0.5 mg/kg/day) started between days 11-13 on clinical variables, lung inflammation, and pulmonary microvascular permeability in preterm infants at risk for chronic lung disease (CLD). Following administration of surfactant, preterm neonates with RDS and a birth weight of less than 1,200 g were included in this comparative observational pilot study when still mechanically ventilated and with an oxygen requirement on the third day of life. The patients (gestational age 26.1+/-0.9 weeks, birth weight 826+/-140 g, mean+/-SD) were alternately allocated to prophylactic treatment with inhaled beclomethasone (n = 7), or to early systemic dexamethasone therapy after day 10 of life, if clinically indicated (n = 9). Pulmonary inflammation and lung permeability were assessed by analyzing the levels of interleukin-8, elastase alpha1 proteinase inhibitor, free elastase activity, and albumin in tracheal aspirates on days 10 and 14 of life. The secretory component of IgA served as reference protein. We observed no significant differences in the concentrations of interleukin-8, elastase alpha1 proteinase inhibitor, and albumin between the two groups on day 10 of life. On day 14, 3 (median; range, 1-3) days following initiation of dexamethasone treatment, concentrations of the inflammatory mediators and of albumin were significantly lower in the group on systemic steroid therapy than in the group treated with inhaled steroids (P < 0.01). Additionally, there was a significant difference in oxygen requirements between both groups on day 14. In the group treated with inhaled steroids, concentrations of the inflammatory mediators, albumin, and oxygen requirements did not show a difference between day 10 and 14. We conclude that, in contrast to systemic dexamethasone treatment, a 12-day course of inhaled beclomethasone does not affect lung inflammation and pulmonary microvascular permeability in preterm infants at risk for CLD within the first 2 weeks of life.

Observations of basic diagnostic profile patterns seen in some common disorders of backyard poultry species.

Poultry species--chickens, ducks, geese--are becoming increasingly popular as pets. As such, requests for accurate diagnoses and treatment are being received by the veterinary community from the public. Unlike the food animal and production-oriented aspects of poultry medicine, success with these pet birds is contingent on preserving the human-pet bird bond, as defined by the individual client. This article presents some of this author's observations in diagnostic profiles on some selected disorders of backyard poultry.

Comparison of pulmonary inflammatory mediators in preterm infants treated with intermittent positive pressure ventilation or high frequency oscillatory ventilation.

Ventilated preterm infants prone to the development of bronchopulmonary dysplasia have been shown to have increased inflammatory mediators in their tracheal aspirates. High frequency oscillatory ventilation (HFOV) is thought to be less traumatic than intermittent positive pressure ventilation (IPPV) in premature infants with surfactant deficiency, and therefore may reduce the inflammatory response in tracheobronchial aspirates. We randomized 76 premature infants requiring mechanical ventilation (birth weight 420-1830 g, median 840 g, gestational age 23 3/7 to 29 2/7 wk, median 26 4/7 to receive either an IPPV with a high rate (60-80/min) and low peak pressures, or an HFOV aiming at an optimization of lung volume, within 1 h of intubation. Tracheal aspirates were systematically collected during the first 10 d of life and analyzed for albumin, IL-8, leukotriene B4 (LTB4), and the secretory component (SC) for IgA as a reference protein. Bacterially colonized samples were excluded. On the treatment d 1, 3, 5, 7, and 10, the resulting median values of albumin (milligrams/mg of SC) were 28, 23, 24, 18, and 10, in IPPV-ventilated infants, and 33, 28, 18, 25, and 39 in HFOV-ventilated infants, respectively. Median IL-8 values (nanograms/mg of SC) were 671, 736, 705, 1362, and 1879 (IPPV) and 874, 1713, 1029, 1426, and 1823 (HFOV), respectively, and median LTB4 values (nanograms/mg of SC) were 26, 13, 27, 22, and 11 (IPPV) and 15, 12, 7, 12, and 16 (HFOV), respectively. Values were similar in IPPV- and HFOV-ventilated infants, and no significant differences were noted. We conclude that HFOV, when compared with a high rate low pressure IPPV, does not reduce concentrations of albumin, IL-8, and LTB4 in tracheal aspirates of preterm infants requiring mechanical ventilation.

Natural porcine surfactant (Curosurf) down-regulates mRNA of tumor necrosis factor-alpha (TNF-alpha) and TNF-alpha type II receptor in lipopolysaccharide-stimulated monocytes.

We have previously shown that Curosurf, a natural porcine surfactant, and its phospholipids effectively suppressed secretion of tumor necrosis factor (TNF-alpha) by resting and through lipopolysaccharide (LPS)-stimulated human monocytes. In this study the effect of Curosurf on monocyte mRNA for TNF-alpha and TNF-alpha type II-receptor (TNF-alpha-RII) were analyzed to evaluate the cellular mechanisms involved in the modulation of TNF-alpha expression. LPS-stimulated monocytes simultaneously exposed to Curosurf (500 microg/mL for 24 h) expressed approximately 70% less TNF-alpha mRNA when compared with control subjects (p < 0.05). In addition, 86% less TNF-alpha RII mRNA was found in monocytes exposed to Curosurf (p < 0.001). Decreased mRNA expression was clearly associated with significantly reduced secretion of TNF-alpha protein (Curosurf-exposed LPS-stimulated monocytes 3628 +/- 1873 pg/mL TNF, LPS-stimulated monocytes 31,376 +/- 2524 pg/mL TNF; mean +/- SEM, p < 0.001). The activation of the transcription factor nuclear factor-kappaB upon LPS stimulation is not affected by Curosurf incubation. This excludes that the decrease in mRNA and protein levels of TNF-alpha and TNF-alpha-RII is due to an inhibition of nuclear factor-kappaB activation by Curosurf. We conclude that Curosurf affects TNF-alpha release of LPS-stimulated monocytes at a pretranslational site by down-regulating both mRNA for TNF-alpha and TNF-alpha-RII, therefore acting as an anti-inflammatory agent within alveolar space.

Management of avian flock emergencies.

Managing avian flock emergencies requires a thorough history, physical examination, and record review before instituting appropriate therapy. Although the general thought processes are similar between approaching a sick individual bird and a "diseased" aviary, the actual steps are different. Infectious diseases are often a component of aviary emergencies but are rarely the primary cause of flock "disease." Managing flock emergencies typically goes beyond addressing individual pathogens. Recognizing, evaluating, and treating flock emergencies are discussed with the intent to provide a better understanding of flock health medicine principles.

Inflammatory bronchopulmonary response of preterm infants with microbial colonisation of the airways at birth.

The inflammatory indicators in the tracheobronchial aspirate (TA) of 81 ventilated preterm infants with microbial colonisation of the airways and in non-colonised neonates were analysed on the first day of life. TA was assessed for chemotactic activity, neutrophil cell count, and concentrations of leukotriene B4, C5a, interleukin-1, interleukin-8, elastase-alpha 1-proteinase inhibitor, free elastase and albumin. Concentrations of mediators were related to concentrations of the secretory component of IgA. The infants' gestational age was mean (SD) 27.9 (2.0) weeks, birthweight 945 (179) g. In 12 infants (15%) microbial colonisation of the airways was present (Ureaplasma urealyticum n = 7; bacteria n = 5). Compared with non-colonised neonates (n = 69), chemotactic activity, neutrophil count, and concentrations of interleukin-1, leukotriene B4 and elastase-alpha 1-proteinase inhibitor were significantly higher in the colonised group. The difference was most pronounced for IL-1 concentrations, both with and without correction for secretory component. There was also a trend towards increased concentrations of interleukin-8 in the latter group. There were no differences for concentrations of C5a and albumin in the TA of both groups. It is concluded that airway colonisation with U urealyticum or bacteria at birth is associated with a clinically relevant bronchopulmonary inflammatory response. Increased concentrations of interleukin-1 in TA on the first day of life may be a marker of perinatal colonisation of the airways.

The mxaAKL genes of Methylobacter albus BG8.

The facultative methanol utilizer Methylobacterium extorquens AM1 contains at least three genes (mxaA, K and L) that encode functions involved in providing calcium to the holoenzyme of methanol dehydrogenase, the enzyme that oxidizes methanol to formaldehyde in this strain. Methane-utilizing bacteria (methanotrophs) also contain methanol dehydrogenase, and evidence suggests that similar methanol oxidation (Mox) functions may be present in some of these strains. DNA fragments from Methylobacterium extorquens AM1 specific to mxaA, mxaK and mxaL were isolated for use as hybridization probes against genomic digests of a variety of methanotrophic bacteria. Only the mxaL probe showed substantial hybridization, and it was used to identify and isolate an 8.5 kb HindIII fragment from Methylobacter albus BG8 (a Type I methanotroph). Hybridization of restriction digests of this fragment to individual probes for Methylobacterium extorquens AM1 mxaA, K and L indicated that the relative mxa gene order in Methylobacter albus BG8 is A-K-L. A T7 dual promoter/polymerase protein expression system indicated that five polypeptides are expressed from a 4.5 kb region of Methylobacter albus BG8 DNA in Escherichia coli, all transcribed in the same direction, and they apparently correspond to mxaACKDL. The functions of mxaC and mxaD are currently not known, but the order of mxaDL is reversed in Methylobacter albus BG8 compared to Methylobacterium extorquens AM1. When subclones of the Methylobacter albus BG8 fragment containing these genes were used as hybridization probes to genomic digests of methanotrophic bacteria, specific bands were detected that suggested a similar gene order in most cases. These data indicate that the mxaAKL region is relatively highly conserved in methanotrophs, and that in most cases the mxaAKL genes are grouped together in the same order as in the facultative methanol utilizer Methylobacterium extorquens AM1.

Sequence of the gene for a NAD(P)-dependent formaldehyde dehydrogenase (class III alcohol dehydrogenase) from a marine methanotroph Methylobacter marinus A45.

A fragment of Methylobacter marinus A45 DNA has been cloned and sequenced, and an open reading frame has been identified that could code for a 46-kDa polypeptide. Comparison of the deduced amino acid sequence of the polypeptide against the protein data bank has revealed strong similarity with a number of alcohol dehydrogenases, with highest similarity towards class III alcohol dehydrogenases, which recently have been shown to be identical to glutathione-dependent formaldehyde dehydrogenases. We were unable to measure appreciable levels of NAD(P)-dependent formaldehyde dehydrogenases or alcohol dehydrogenase activities using aldehydes or primary or secondary alcohols in cell-free extracts from batch cultures of M. marinus A45. However, formaldehyde dehydrogenases activity was detected on zymograms. Our data suggest that, although NAD(P)-linked formaldehyde dehydrogenase or alcohol dehydrogenase activities are undetectable in cell-free extracts of most methylotrophs employing the ribulose monophosphate pathway for formaldehyde assimilation and dissimilation, the gene encoding formaldehyde dehydrogenase is present in M. marinus A45 and may be present in more of these organisms as well.

Association of pulmonary inflammation and increased microvascular permeability during the development of bronchopulmonary dysplasia: a sequential analysis of inflammatory mediators in respiratory fluids of high-risk preterm neonates.

OBJECTIVE: Bronchopulmonary dysplasia (BPD) of preterm neonates is associated with an increased recruitment of inflammatory cells into the airways. To evaluate further the role of inflammation in the pathogenesis of BPD, tracheobronchial aspirate fluid of neonates with birth weight < 1200 g (n = 59) was sequentially analyzed in a prospective study. METHODS: Tracheobronchial aspirate fluid was assessed for chemotactic activity, neutrophil cell count, concentrations of elastase-alpha 1-proteinase inhibitor and activity of free elastase, concentrations of chemoattractants (complement component C5-derived anaphylatoxin, leukotriene B4, interleukin-8), and albumin concentrations as well as alpha 1-proteinase inhibitor activity. The secretory component for immunoglobulin A was used as reference protein. Only specimens without evidence of microbiological colonization were studied. RESULTS: In neonates with prolonged respiratory disease (BPD-risk neonates, n = 24, fraction of inspired oxygen > or = 0.3 and/or peak inspiratory pressure > or = 16 cm H2O at day 10 postnatal age, birth weight 892 +/- 36 g, gestational age 27.2 +/- 0.3 weeks) chemotactic activity, cell count, concentrations of the chemoattractants complement component C5-derived anaphylatoxin, leukotriene B4, interleukin-8, as well as levels of elastase-alpha 1-proteinase inhibitor were significantly higher at day 10 and/or day 15 of postnatal age compared with neonates without chronic pulmonary disease (total n = 35; day 10, n = 11; day 15, n = 8). There was no difference in free elastolytic activity. Concentrations of albumin as well as alpha 1-proteinase inhibitor activity were higher in BPD-risk patients on day 15, indicating an increased pulmonary leak. CONCLUSION: We conclude that preterm neonates at risk for the development of BPD show an enhanced inflammatory reaction in the lungs and an associated increase in pulmonary microvascular permeability. We speculate that inflammation may play an important role in the pathogenesis of BPD.

Effects of dexamethasone on chemotactic activity and inflammatory mediators in tracheobronchial aspirates of preterm infants at risk for chronic lung disease.

To evaluate the effects of dexamethasone on pulmonary inflammation and permeability in preterm infants at high risk for chronic lung disease (birth weight < 1200 gm), we assessed tracheobronchial aspirate fluid for chemotactic activity and concentrations of mediators of inflammation. In a prospective study, 21 infants still undergoing mechanical ventilation at day 10 of postnatal age who required a fraction of inspired oxygen > or = 0.3, a peak inspiratory pressure > or = 16 cm H2O, or both were randomly assigned to treatment with dexamethasone at day 10 (early treatment group, n = 10) or day 16 (late treatment group, n = 11). The groups were compared with respect to all measurements on day 15; the late treatment group served as a control group. Additionally, the effects of dexamethasone within both groups were evaluated. In the early treatment group, the chemotactic response of peripheral blood neutrophils exposed to tracheobronchial aspirate fluid was significantly reduced 5 days after initiation of dexamethasone treatment compared with pretreatment values of the late treatment group (median (25th to 75th percentile): migratory distance before dexamethasone, 149 microns (140 to 173 microns); after dexamethasone, 81 microns (68 to 114 microns); p < 0.01). In addition, the following values were decreased after dexamethasone therapy in the early treatment group: number of neutrophils in tracheobronchial aspirate fluid (p < 0.05), and concentrations of leukotriene B4 (p < 0.01), interleukin-1 (p < 0.01), elastase-alpha 1-proteinase inhibitor (p < 0.01), and albumin (p < 0.01). Free elastase activity was found in only two infants; detectable activity of protective alpha 1-proteinase inhibitor was present in the others. Analysis of dexamethasone effects within the groups showed that all measurements were significantly decreased after both the early and the late treatment regimens, with the exception of leukotriene B4 and interleukin-1, which declined only after early dexamethasone treatment. Our results indicate that the pulmonary inflammatory response and microvascular permeability are decreased by dexamethasone, which affects the release of inflammatory mediators and neutrophil influx into the airways of preterm infants who require mechanical ventilation.

Bacterial resistance to tetracycline: mechanisms, transfer, and clinical significance.

Tetracycline has been a widely used antibiotic because of its low toxicity and broad spectrum of activity. However, its clinical usefulness has been declining because of the appearance of an increasing number of tetracycline-resistant isolates of clinically important bacteria. Two types of resistance mechanisms predominate: tetracycline efflux and ribosomal protection. A third mechanism of resistance, tetracycline modification, has been identified, but its clinical relevance is still unclear. For some tetracycline resistance genes, expression is regulated. In efflux genes found in gram-negative enteric bacteria, regulation is via a repressor that interacts with tetracycline. Gram-positive efflux genes appear to be regulated by an attenuation mechanism. Recently it was reported that at least one of the ribosome protection genes is regulated by attenuation. Tetracycline resistance genes are often found on transmissible elements. Efflux resistance genes are generally found on plasmids, whereas genes involved in ribosome protection have been found on both plasmids and self-transmissible chromosomal elements (conjugative transposons). One class of conjugative transposon, originally found in streptococci, can transfer itself from streptococci to a variety of recipients, including other gram-positive bacteria, gram-negative bacteria, and mycoplasmas. Another class of conjugative transposons has been found in the Bacteroides group. An unusual feature of the Bacteroides elements is that their transfer is enhanced by preexposure to tetracycline. Thus, tetracycline has the double effect of selecting for recipients that acquire a resistance gene and stimulating transfer of the gene.