Modeling Water Quality in Watersheds: From Here to the Next Generation

In this synthesis, we assess present research and anticipate future development needs in modeling water quality in watersheds. We first discuss areas of potential improvement in the representation of freshwater systems pertaining to water quality, including representation of environmental interfaces, in-stream water quality and process interactions, soil health and land management, and (peri-)urban areas. In addition, we provide insights into the contemporary challenges in the practices of watershed water quality modeling, including quality control of monitoring data, model parameterization and calibration, uncertainty management, scale mismatches, and provisioning of modeling tools. Finally, we make three recommendations to provide a path forward for improving watershed water quality modeling science, infrastructure, and practices. These include building stronger collaborations between experimentalists and modelers, bridging gaps between modelers and stakeholders, and cultivating and applying procedural knowledge to better govern and support water quality modeling processes within organizations.

Association of a Multidisciplinary Care Approach With the Quality of Care After Pediatric Tracheostomy

Importance

Incidence of tracheostomy placement in children is increasing, and these children continue to have high incidences of morbidity and mortality. A multidisciplinary tracheostomy program may help improve the quality of care received by these patients.

Objective

To determine whether implementation of a multidisciplinary tracheostomy program can improve the care of children who received a tracheostomy through reduction in tracheostomy-related adverse events (TRAEs), improved tracheostomy education, and caregiver preparedness.

Design, Setting, and Participants

A prospective cohort study was conducted from January 2015 to June 2018 at a pediatric tertiary referral center in Boston, Massachusetts. The participants included 700 children who had received a tracheostomy, most of whom were aged birth to 18 years, but some patients with congenital disorders were much older.

Exposures

Institution of a multidisciplinary tracheostomy team (MDT) whose activities included conducting staff meetings, organizing outpatient clinics, conducting inpatient tracheostomy ward rounds, and conducting inpatient tracheostomy rounds at a local rehabilitation hospital. Quality improvement initiatives included monitoring standardized TRAEs and distributing standardized tracheostomy "go-bags."

Main Outcomes and Measures

Reduction of TRAEs and improved caregiver preparedness through distribution of tracheostomy go-bags were assessed following the establishment of a multidisciplinary tracheostomy program.

Results

In total, 700 children who had received a tracheostomy during the study period were actively followed up by the MDT. Of these children, 378 (54.0%) were males and 322 (46.0%) were females; mean (SD) age was 4.1 (6.1) years. More than 60 new pediatric tracheostomies were performed annually at the referral center. Reported TRAEs were reduced by 43.0% from the first to the third year after the implementation of a standardized, closed-loop monitoring system (from a mean [SD] of 6.1 [5.2] TRAEs per 1000 inpatient tracheostomy-days in 2015 to a mean [SD] of 4.0 [2.5] in 2018). The most common TRAE was unplanned decannulation, which occurred 64 times during the study period. On average, 10 patients were seen in each monthly multidisciplinary tracheostomy clinic. Clinic interventions included continuing care (146 [52.5%]), communication enhancement (67 [23.6%]), plans for decannulation (52 [18.6%]), and referrals for comorbidities (13 [4.6%]). Approximately 19 inpatients were seen during biweekly rounds and 8 during monthly rounds at a local rehabilitation hospital. A total of 297 patients received standardized tracheostomy go-bags, and more than 70 positive bag checks were performed in the monthly MDT clinics. A positive bag check refers to the incidence when a family is given a go-bag and also uses it. In contrast, a negative bag check refers to when a family is given a go-bag but neither brings it to the clinic nor acknowledges that they use it.

Conclusions and Relevance

This study's findings suggest that a multidisciplinary tracheostomy program may be a powerful tool for enhancing patient safety and quality improvement. Ongoing studies will develop measurable pediatric tracheostomy outcome metrics and assess long-term outcomes.

Automatic Method for Processing Mass Data in Clinical Medicine (FOSDIC)

1. The need for automatic data processing techniques in investigative medicine is briefly-stated and stresse’d.

2. Among the more widely used methods for collection, storage and analysis of large scale data, the punch cards, although suitable for direct computer input, leave a limited input speed.

3. A new system developed jointly by the Bureau of the Census and the National Bureau of Standards, called FOSDIC is described.

4. FOSDIC is basically an analog scanner actuated by a digital computer. It automatically reads, recodes and transcribes the information on magnetic tape in binary language.

5. FOSDIC. consists of four parts: a scanning unit, a program unit, a tape unit and a console.

6. Printed documents of suitable size and format are used for data collection; they are microfilmed” and the information contained therein is automatically scanned and recorded on digital magnetic tape, suitable for direct input to a digital electronic computer.

7. Some of the advantages offered by this system are stressed: they are speed and versatility in the scanning and transcribing process, flexibility in the size and format of the printed document and space saving in the storage of microfilmed documents.

8. FOSDIC system is being used in several research projects in progress; in one project reduction of clinical information is the aim, in other ones correlation between analog records such as the electrocardiogram with clinical information is pursued. Since the clinical information is collected from more than one hospital, uniformity in the collected documents is an important factor.

The American Society of Transplantation Consensus Conference on the Use of Hepatitis C Viremic Donors in Solid Organ Transplantation

The availability of direct-acting antiviral agents for the treatment of hepatitis C virus (HCV) infection has resulted in a profound shift in the approach to the management of this infection. These changes have affected the practice of solid organ transplantation by altering the framework by which patients with end-stage organ disease are managed and receive organ transplants. The high level of safety and efficacy of these medications in patients with chronic HCV infection provides the opportunity to explore their use in the setting of transplanting organs from HCV-viremic patients into non-HCV-viremic recipients. Because these organs are frequently discarded and typically come from younger donors, this approach has the potential to save lives on the solid organ transplant waitlist. Therefore, an urgent need exists for prospective research protocols that study the risk versus benefit of using organs for hepatitis C-infected donors. In response to this rapidly changing practice and the need for scientific study and consensus, the American Society of Transplantation convened a meeting of experts to review current data and develop the framework for the study of using HCV viremic organs in solid organ transplantation.

Correlation of Vocal Fold Nodule Size in Children and Perceptual Assessment of Voice Quality

Objectives

We examined the relationship between the size of vocal fold nodules and perceptual rating of voice quality in children.

Methods

We carried out an Institutional Review Board-approved retrospective study in a voice clinic within a tertiary-care pediatric medical center. We studied children seen between 2000 and 2009 with a primary diagnosis of vocal fold nodules as the cause of their voice disturbance. Pediatric vocal fold nodule size was rated with a published validated scale, and voice quality was rated on the Consensus Auditory-Perceptual Evaluation of Voice scale.

Results

One hundred forty-five patients met the inclusion criteria. Small nodules were noted in 23% of patients, medium nodules in 39%, and large nodules in 37%. Univariate and multivariate analyses demonstrated a statistically significant relationship (p < 0.05) between vocal fold nodule size and rated perceptual qualities of overall severity of voice disturbance, roughness, strain, pitch, and loudness. With the exception of loudness, as vocal fold nodule size increased, the mean value of perceptual characteristics became larger. The age of the patient was a significant factor associated with the overall severity of the voice disturbance and roughness.

Conclusions

The overall severity of a child's voice disturbance and qualities of roughness, strain, pitch, and loudness have a strong correlational relationship with pediatric vocal fold nodule size, which is suggestive of causality.

International Pediatric Otolaryngology Group (IPOG) consensus recommendations: Routine peri-operative pediatric tracheotomy care

OBJECTIVES

To develop consensus recommendations for peri-operative tracheotomy care in pediatric patients.

METHODS

Expert opinion by the members of the International Pediatric Otolaryngology Group (IPOG). The mission of the IPOG is to develop expertise-based consensus recommendations for the management of pediatric otolaryngologic disorders with the goal of improving patient care. The consensus recommendations herein represent the first publication by the group.

RESULTS

Consensus recommendations including pre-operative, intra-operative, and post-operative considerations, as well as sedation and nutrition management are described. These recommendations are based on the collective opinion of the IPOG members and are targeted to (i) otolaryngologists who perform tracheotomies on pediatric patients, (ii) intensivists who are involved in the shared-care of these patients, and (iii) allied health professionals.

CONCLUSION

Pediatric peri-operative tracheotomy care consensus recommendations are aimed at improving patient-centered care in this patient population.

A critical update on endothelial nitric oxide synthase gene variations in women with idiopathic recurrent spontaneous abortion: genetic association study, systematic review and meta-analyses

A number of case-control studies investigated the association between idiopathic recurrent spontaneous abortion (IRSA) and variations in the gene encoding endothelial nitric oxide synthase (NOS3), but yielded contradictory results. Our aim was to test the association of the NOS3 variable number of tandem repeats (VNTR) in intron 4 and +894 G/T single-nucleotide polymorphism (SNP) with IRSA in Slovenian women (148 IRSA and 149 control women), conduct a systematic review of literature on the association between NOS3 gene variations and IRSA, and perform meta-analyses of studies that met the inclusion criteria, defined by virtue of the European Society for Human Reproduction and Embryology evidence-based guidelines for recurrent spontaneous abortion. Genotyping was performed using PCR and restriction fragment length polymorphism methods. The systematic review of literature (English language) was conducted using PubMed and Scopus databases, to 1 November 2014. We determined no association of IRSA with the VNTR in intron 4 and +894 G/T SNP in Slovenian women. Furthermore, 16 case-control studies were identified on the association between 15 NOS3 gene variations and IRSA. However, significant inconsistencies exist in the selection criteria of patients and controls between studies. The meta-analysis of VNTR in intron 4 was performed on five studies (894 patients, 944 controls), whereas the meta-analysis of +894 G/T SNP included six studies (1111 patients, 1121 controls). The association with IRSA was significant for the +894 G/T SNP under the dominant genetic model (GT+TT versus GG) based on fixed (odds ratio (OR) = 1.54, 95% confidence interval (CI) = 1.28-1.86, P = <0.01) and random effects models (OR = 1.54, 95% CI = 1.03-2.31, P = 0.03). In conclusion, the GT and TT genotypes of the +894 G/T SNP in women might contribute to a predisposition to IRSA. Additional genetic association and functional studies in different populations with larger numbers of participants and a uniformly defined IRSA are needed to clarify the contribution of NOS3 +894 G/T gene variation to IRSA.

Heart-hand syndrome of Slovenian type: a new kind of laminopathy

BACKGROUND

Heart-hand syndromes are a heterogeneous group of genetic disorders characterised by the association of congenital cardiac disease and limb deformities. Laminopathies are a group of diseases caused by mutations in the LMNA gene encoding A-type lamins.

RESULTS

We report a new LMNA mutation (c.1609-12T>G, IVS9-12 T>G) that creates a new cryptic splicing site with the retention of 11 intronic nucleotides in the mRNA. This LMNA mutation segregates with a new type of heart-hand syndrome in a previously reported family suffering from adult onset progressive conduction system disease, atrial and ventricular tachyarrhythmias, sudden death, dilated cardiomyopathy, and brachydactyly with predominant foot involvement. Analysis of the fibroblasts of two affected family members identified for the first time a truncated lamin A/C protein resulting from the frame shift created by the new splicing site, together with nuclear envelope abnormalities confirming that this LMNA mutation is pathogenic.

CONCLUSIONS

This new heart-hand syndrome should therefore be considered as a new kind of laminopathy. As part of laminopathies with heart involvement, patients presenting with this phenotype and their relatives are at risk for developing sudden cardiac death and should beneficiate from appropriate LMNA genetic diagnosis.

Scanning magnetoresistance microscopy of atom chips

Surface based geometries of microfabricated wires or patterned magnetic films can be used to magnetically trap and manipulate ultracold neutral atoms or Bose-Einstein condensates. We investigate the magnetic properties of such atom chips using a scanning magnetoresistive (MR) microscope with high spatial resolution and high field sensitivity. By comparing MR scans of a permanent magnetic atom chip to field profiles obtained using ultracold atoms, we show that MR sensors are ideally suited to observe small variations of the magnetic field caused by imperfections in the wires or magnetic materials which ultimately lead to fragmentation of ultracold atom clouds. Measurements are also provided for the magnetic field produced by a thin current-carrying wire with small geometric modulations along the edge. Comparisons of our measurements with a full numeric calculation of the current flow in the wire and the subsequent magnetic field show excellent agreement. Our results highlight the use of scanning MR microscopy as a convenient and powerful technique for precisely characterizing the magnetic fields produced near the surface of atom chips.

Factors affecting the ozone sensitivity of temperate European grasslands: an overview

This overview of experimentally induced effects of ozone aims to identify physiological and ecological principles, which can be used to classify the sensitivity to ozone of temperate grassland communities in Europe. The analysis of data from experiments with single plants, binary mixtures and multi-species communities illustrates the difficulties to relate individual responses to communities, and thus to identify grassland communities most at risk. Although there is increasing evidence that communities can be separated into broad classes of ozone sensitivity, the database from experiments under realistic conditions with representative systems is too small to draw firm conclusions. But it appears that risk assessments, based on results from individuals or immature mixtures exposed in chambers, are only applicable to intensively managed, productive grasslands, and that the risk of ozone damage for most of perennial grasslands with lower productivity tends to be less than previously expected.

Association between the apolipoprotein B signal peptide gene insertion/deletion polymorphism and male infertility

In male mice heterozygous for a null apolipoprotein B (apoB), allele infertility was noticed. These data led us to investigate a possible role of APOB gene polymorphism and male infertility in humans. In this case-control study, we searched for an association between the insertion/deletion (I/D) polymorphism of the APOB gene and male infertility in 560 Slovene Caucasian men. The study group consisted of 310 infertile patients: 115 with azoospermia and 195 with oligoasthenoteratozoospermia (OAT) and a control group of 250 fertile men. We found a statistically significant difference in the genotype distribution between the two groups (chi2 = 6.315, P = 0.043). A separate analysis of azoospermic and OAT patients demonstrated that significant differences in genotype distribution were limited to the OAT group (chi2 = 7.011, P = 0.030). The presence of the D allele (DD or ID genotypes) conferred a 1.6 risk [chi2 = 6.089, P = 0.014, 95% confidence interval (95% CI) = 1.102-2.347] for male infertility in the OAT group of patients. We did not find a correlation between the I/D polymorphism genotypes and the clinical characteristics of infertile men: sperm concentration (P = 0.102), rapid progressive motility (P = 0.449), normal morphology (P = 0.085) and Johnsen score (P = 0.531). These data suggest that genetic variation in the signal peptide of the APOB gene (I/D polymorphism) might be a risk factor for the development of male infertility.

Familial progressive sinoatrial and atrioventricular conduction disease of adult onset with sudden death, dilated cardiomyopathy, and brachydactyly. A new type of heart-hand syndrome?

We identified a family with 10 affected members in four generations suffering from adult-onset progressive sinoatrial and atrioventricular conduction disease, sudden death due to ventricular tachyarrhythmia, dilated cardiomyopathy, and a unique type of brachydactyly with mild hand involvement (short distal, middle, proximal phalanges and clinodactyly) and more severe foot involvement (short distal, proximal phalanges and metatarsal bones, short or absent middle phalanges, terminal symphalangism, duplication of the bases of the second metatarsals, extra ossicles, and syndactyly). The phenotype differences from other reported genetic abnormalities and linkage exclusion of Holt-Oram syndrome, ulnar-mammary syndrome, brachydactyly type B or Robinow syndrome, and cardiac conduction disease or Brugada syndrome loci suggest that we report on a new hereditary heart-hand syndrome.

Effects of elevated ozone on leaf delta13C and leaf conductance of plant species grown in semi-natural grassland with or without irrigation

Stable carbon isotope ratios (delta(13)C) and leaf conductance (g(s)) were measured (2002, 2003) in Holcus lanatus L., Plantago lanceolata L. Ranunculus friesianus (Jord.), and Trifolium pratense L. at two levels of ozone (O(3)) with or without irrigation. In non-irrigated control plots, R. friesianus showed the least negative delta(13)C, and the smallest response to the treatments. Irrigation caused more negative delta(13)C, especially in H. lanatus. Irrespective of irrigation, O(3) increased delta(13)C in relationship to a decrease in g(s) in P. lanceolata and T. pratense. The strongest effect of O(3) on delta(13)C occurred in the absence of irrigation, suggesting that under field conditions lack of moisture in the top soil does not always lead to protection from O(3) uptake. It is concluded that in species such as T. pratense plants can maintain stomatal O(3) uptake during dry periods when roots can reach deeper soil layers where water is not limiting.

Improvements in Single-Phase Paraffin Deposition Modeling

Summary

Paraffin deposition under single-phase flow conditions was investigated to determine its dependence on shear stripping, deposit aging, flow regime, temperature gradient, and fluid properties.

In this study, a new model for the prediction of single-phase wax deposition has been developed. Most of the models previously used assume that equilibrium exists at the deposit-fluid interface. A kinetic resistance of the fluid is considered in the new model. Therefore, the interfacial-wax concentration might be different from the equilibrium-wax concentration. The model also includes continuous diffusion of wax into the deposit. We believe that this enrichment of the deposit is responsible for the increasing hardness of the deposit with time - a process known as "aging." The effect of shear stripping may also be incorporated in the prediction.

The model predictions are compared with predictions from previous models, as well as with experimental data gathered at the Tulsa U. Paraffin Deposition Projects, with two different oils: a black oil and a condensate. Even though some tuning is required for each type of oil, the new model is based on physical phenomena, reducing the empiricism of previous models.

Introduction

In oil production and transportation systems, when the fluid temperature drops below the wax-appearance temperature, the long-chain normal paraffins of the formula CnH2n+2 where n&gt;20 will solidify and adhere to the pipe walls, if a radial heat flux to the surroundings exists. This phenomenon, known as "paraffin deposition," can cause a reduction in the effective flow area.

Paraffin deposition can result in significant operational and remedial costs, reduced or deferred production, well shut-ins, and pipeline replacements and/or abandonment. It is imperative to properly identify the conditions for paraffin precipitation and to predict paraffin deposition rates for the design and optimization of oil- and gas-production systems, as well as to implement proper strategies for prevention and remediation. Understanding the paraffin deposition process under single-phase flow conditions is crucial to properly model the phenomena under both the single-phase and multiphase flow conditions encountered in oil-production systems.

Model Enhancement

One of the main limitations in the current Tulsa U. (TU) single-phase paraffin deposition model1 is the assumption of constant oil fraction in the deposit that the user is required to specify as an input parameter. It is also assumed that all the mass flux from the bulk fluid contributes to deposit growth, and no diffusion into the deposit is considered. The current model does not consider the aging effect on the deposition process.

Singh et al.2 proposed a model that considers the diffusion of wax into the existing deposit. The boundary condition used at the deposit-fluid interface was that the diffusion flux at the interface is equal to the slope of the wax solubility curve in equilibrium with the deposit temperature gradient. In this thin film model, the wax fraction in the deposit changes with time, but it is uniform across the deposit. Also, Singh et al. did not consider any shear-stripping effects, as all of their tests were conducted under laminar flow conditions.

The new model proposed in this paper is analogous to the Singh et al. model in the sense that it also considers that part of the bulk flux will contribute to new deposit growth, and the rest will be diffused into the existing deposit. The model considers a kinetic resistance for the diffusion into the deposit; therefore, the interfacial concentration might be different from the equilibrium concentration at the interface temperature. The kinetic resistance would be different for different oils. Also, the proposed model assumes that the deposit layer is immobile.

Establishing Normative Voice-Related Quality of Life Scores Within the Pediatric Otolaryngology Population

OBJECTIVE

To establish normative values for voice-related quality of life across a broad pediatric otolaryngology population using the Pediatric Voice Outcome Survey (PVOS).

DESIGN

Longitudinal study.

SETTING

Multiphysician outpatient pediatric otolaryngology practice.

METHODS

The PVOS was completed by 385 parents of children and adolescents aged 2 to 18 years. Of the 385 parents, 75 were readministered the instrument 2 weeks after no intervention had been provided. Data were collected regarding the patients' age, main diagnosis, and operative intervention.

RESULTS

The PVOS demonstrated robust internal consistency with an overall Cronbach alpha value of.70. Test-retest reliability demonstrated a weighted kappa value of 0.89 (95% confidence interval, 0.84-0.95) The mean +/- SD converted score (based on a 0-100 scale) for the overall population was 80.5 +/- 19.9. Converted PVOS scores are provided for each subpopulation according to main diagnosis. The PVOS scores varied significantly according to age (P<.05) and preoperative and postoperative status following adenoidectomy (P<.05).

CONCLUSION

The PVOS represents a valid and reliable instrument to measure voice-related quality of life in a broad pediatric otolaryngology population.

Interferometer-type structures for guided atoms

We experimentally demonstrate interferometer-type guiding structures for neutral atoms based on dipole potentials created by microfabricated optical systems. As a central element we use an array of atom waveguides being formed by focusing a red-detuned laser beam with an array of cylindrical microlenses. Combining two of these arrays, we realize X-shaped beam splitters and more complex systems like the geometries for Mach-Zehnder and Michelson-type interferometers for atoms.

Micro-optical realization of arrays of selectively addressable dipole traps: a scalable configuration for quantum computation with atomic qubits

We experimentally demonstrate novel structures for the realization of registers of atomic qubits: We trap neutral atoms in one- and two-dimensional arrays of far-detuned dipole traps obtained by focusing a red-detuned laser beam with a microfabricated array of microlenses. We are able to selectively address individual trap sites due to their large lateral separation of 125 microm. We initialize and read out different internal states for the individual sites. We also create two interleaved sets of trap arrays with adjustable separation, as required for many proposed implementations of quantum gate operations.

The effect of Escherichia coli heat-stable toxin on the trans-epithelial intestinal elimination of ciprofloxacin in the rabbit

The effect of Escherichia coli heat-stable toxin (ST) on the intestinal trans-epithelial elimination of ciprofloxacin was studied in the rabbit model. Following a systemic 27 mg/kg dose, excreted amounts of ciprofloxacin during the 2 h experiment were: 9.3 (+/- 4.8); 12.5 (+/- 5.2) and 0.3 (+/- 0.1) microg/cm(2) surface of intestinal wall in ST-challenged jejunal, ileal and caecal loops, respectively. In control loops the corresponding amounts were: 5.0 (+/- 2.8), 6.5 (+/- 3.4) and 0.3 (+/- 0.1) microg/cm(2), respectively. The trans-epithelial elimination of ciprofloxacin was significantly higher in ST-challenged small bowel loops than in controls while caecal elimination was negligible.

Efficient asymmetric epoxidation of alpha,beta-unsaturated ketones using a soluble triblock polyethylene glycol-polyamino acid catalyst

[reaction: see text]. Polyethylene glycol (PEG)-bound poly-L-leucine acts as a THF-soluble catalyst for the Juliá-Colonna asymmetric epoxidation of enones. Excellent enantioselectivities may be obtained even with short chain length polyleucine. FT-IR investigations have determined that the catalytically active polyleucine components of these copolymers have an alpha-helical structure.

Environmental fate of amitrole: influence of dissolved organic matter

In this study the environmental fate of amitrole in terrestrial and aquatic model ecosystems was investigated. Under aerobic conditions mineralization of amitrole is the main degradation pathway. The experiments revealed that the leaching behaviour is low in the presence or the absence of dissolved organic matter (DOM) despite the high water solubility due to a strong binding of amitrole to soil constituents. Under anaerobic conditions the addition of DOM increases the transport of amitrole in soil columns. The tests with water/sediment model ecosystems showed that the mineralization of amitrole is lower in comparison to aerobic soil experiments. Up to 80.6% of the applied 14C-labelled amitrole transfer into the sediment and about 1/3 of this amount formed bound residues, which are not extractable.

EBV persistence in memory B cells in vivo

Epstein-Barr virus establishes latency in vitro by activating human B cells to become proliferating blasts, but in vivo it is benign. In the peripheral blood, the virus resides latently in resting B cells that we now show are restricted to the sIgD memory subset. However, in tonsils the virus shows no such restriction. We propose that EBV indiscriminately infects B cells in mucosal lymphoid tissue and that these cells differentiate to become resting memory B cells that then enter the circulation. Activation to the blastoid stage of latency is an essential intermediate step in this process. Thus, EBV may persist by exploiting the mechanisms that produce and maintain long-term B cell memory.

Application of a prognostic scoring system to critically ill patients in a small military facility

Two hundred one consecutive adult admissions to a 3-bed Special Care Unit in a 25-bed military hospital were scored using APACHE II (Acute Physiology and Chronic Health Evaluation). Outcome measures included APACHE II scores and mortality predictions; active intensive care interventions; transfers for specialized care; and mortality. Although higher scores generally reflected the need for intensive care intervention, admissions with nondiagnostic chest pain had scores that did not accurately predict their course. This finding could be explained by bias in the original APACHE case mix and by the need for further subclassification of cardiovascular disease. APACHE II scoring can be applied in small intensive care settings. Scoring criteria and logistic regression equations may need to be customized accordingly.

Resurfacing of a large laryngeal wound with mucosa grafting: a combined technique using endoscopic suture and laser soldering

Resurfacing of a large laryngeal wound has traditionally been accomplished via an open approach--transplanting free mucosa either onto the wound directly or upon a stent. This study proposes a new approach for wound resurfacing that combines endoscopic suturing with a laser welding technique. By means of a carbon dioxide (CO2) laser, a large (20 x 25 mm) defect in laryngeal mucosa involving the glottic and subglottic area was created in five dogs. Two of the animals served as controls and received no further treatment. In the remaining three animals the wound was resurfaced with buccal mucosal grafts fixed in place by standard suture placement and a technique of CO2 laser-assisted tissue soldering. The accessible edges of the graft were soldered endoscopically with human albumin-based tissue adhesive "activated" by low power (0.8 to 1.0 W) of a CO2 laser. All animals were examined endoscopically 1 week after surgery and sacrificed painlessly 4 weeks after surgery. The treated animals showed a viable mucosal graft with improved wound healing and voice function compared to that of the control animals. This new approach combines suture fixation of the inferior aspect of the mucosal graft, an area not well exposed endoscopically, and endoscopic laser soldering techniques for the repair of large laryngeal wounds.

Metabolic relationship between the CO dehydrogenase molybdenum cofactor and the excretion of urothione by Hydrogenophaga pseudoflava

Urothione was isolated as an excretion product of Hydrogenophaga pseudoflava and other bacteria at amounts approaching 253 micrograms/l of culture corresponding to 44 micrograms/g bacterial dry mass. The compound was identified as urothione by co-chromatography with urothione isolated from human urine, its characteristic ultraviolet and visible absorption spectra, oxidation to pterin-6-carboxylic-7-sulfonic acid by alkaline permanganate, 1H-NMR spectroscopy, double-quantum-filtered Fourier-transform 1H correlated spectroscopy, circular-dichroism spectroscopy and mass spectroscopy. A metabolic relationship between urothione and the carbon monoxide dehydrogenase molybdenum cofactor was suggested by a 1.1:0.5 molar ratio between urothione excreted and degradation of carbon monoxide dehydrogenase, a coincidence of urothione excretion and induction of carbon monoxide dehydrogenase with different species of carboxidotrophic bacteria, a structural relationship between molybdopterin cytosine dinucleotide of the carbon monoxide dehydrogenase molybdenum cofactor and urothione, and the demonstrated conversion of the carbon monoxide dehydrogenase molybdenum cofactor to urothione in vitro. A pathway for the conversion of the H. pseudoflava carbon monoxide dehydrogenase molybdenum cofactor to urothione has been proposed which involves molybdopterin cytosine dinucleotide, molybdopterin, phospho-norurothione and norurothione.

[Transposition of the fallopian tube as a therapeutic possibility in special cases of tubal sterility]

This is a report on a new method of microsurgical transposition of the Fallopian tube. It was developed to deal with congenital malformations or with the different anatomic remnants after pelvic surgery or pelvic inflammatory diseases. The tube is mobilised by severing the mesosalpinx with the unipolar microelectrode without damaging the longitudinal vessels. After mobilisation, the bends of the tube disappear and the length increases almost doublefold. Then the tube can be laid to the contralateral ovary without any tension. The tube must be fixed to the ovary in such a way, that the fimbrial end is mobile enough to lay onto the ovary during ovulation. Up to now, six patients with longstanding tubal sterility were operated upon. Three of them became pregnant, one twice. There were no ectopic pregnancies and no abortions.

Coagulation profile as a predictor for post-tonsillectomy and adenoidectomy (T + A) hemorrhage

The risk of hemorrhage after tonsillectomy and adenoidectomy (T + A) was studied in 1061 children. Twenty-seven (2.5%) had at least one abnormality on a preoperative coagulation profile consisting of a prothrombin time (PT), partial thromboplastin time (PTT), bleeding time (BT) and platelet count (PC). Of these 27 who had an initially abnormal test (PTT or bleeding times only), 8 had diagnosed coagulopathies by hematology evaluation (Group A), and 17 had repeat tests which returned to normal (Group B). Two borderline tests (PTT) were not repeated (Group C). Sixty-four patients (6.0%) bled after T + A. Six of these (9.3%) had an initially abnormal coagulation profile--one in Group A (12.5%), four in Group B (23.5%) and 1 in Group C (50%). This is in contrast to the bleed rate of 5.7% for the 1034 children with normal coagulation profiles. Although it is not surprising that 6 (22.2%) children with an initially abnormal coagulation profile bled, of note is that 4 of them had an initially abnormal coagulation profile which upon repeat testing returned to normal. However, none of these four bleeders required active intervention for control. Coagulopathies were newly diagnosed in 7 (0.57% of total group; 25.9% of 27 with abnormal laboratory values). One additional child had a known intrinsic platelet dysfunction prior to surgery. Only one child was newly identified by a positive family history for abnormal bleeding. These results suggest that new hematologic disorders were diagnosed infrequently. An initially abnormal coagulation profile may identify those more likely to bleed after surgery (22.6% vs. 5.5%). A coagulation profile which includes a PTT and BT may be a valuable screening tool for children undergoing T + A.

Similarity of primary radical pair recombination in photosystem II and bacterial reaction centers

We report temperature and magnetic field dependent measurements of the recombination dynamics of the radical pair P680+Pheo- in D1D2cytb559 reaction centers of photosystem II and compare the results to those obtained in bacterial reaction centers. In photosystem II the rate of recombination to the groundstate is found to be slower than in the bacterial reaction centers by a factor of at least 50. This difference arises from the different redox potentials of the pigments of plant and bacterial reaction centers. In contrast, the rate of recombination to the triplet state is similar in all reaction centers, indicating a similar electronic coupling which allows us to conclude upon the structural similarity.

Needle aspiration of peritonsillar abscess in children

Needle aspiration for the treatment of peritonsillar abscess was assessed in 43 consecutive children aged 7 to 18 years (mean age, 13.9 +/- 2.5 years) during the 3-year period from 1988 through 1991. A positive aspirate was obtained in 31 (76%) of the 41 patients who cooperated for needle aspiration; a mean of 2.9 +/- 1.9 mL of pus was withdrawn. Of the 31 children with a positive aspirate, in 27 (87%) the abscess resolved, two (6%) required a second aspiration for resolution, and two (6%) underwent immediate tonsillectomy for persistent abscess. Of the 10 children (24%) with negative aspirations, in six (60%) the abscess resolved with antibiotic treatment alone, three (30%) underwent immediate (quinsy) tonsillectomy, and in one (10%) the abscess spontaneously drained. No bleeding, airway obstruction, or anesthetic complications occurred. Needle aspiration of peritonsillar abscess in children, with tonsillectomy reserved for nonresponders, appears to be an efficacious and safe method of treatment.

Influence of time and osmolarity on nuclear area of tumor cells growing in vitro

We investigated the simultaneous influence of the time of cultivation and of the osmolarity of the medium on nuclear sizes in vitro. Cells from a permanent cell line (MaTu), derived from a human breast cancer, were used. We found a linear increase of nuclear size during the first 64 h in culture. In contrast to the important influence of time on nuclear size in culture, even distinct variations of the osmolarity of the medium had little influence on nuclear size. Only if the osmolarity rose by 28% was there a clear reduction of nuclear size.

Needle aspiration of neck abscesses in children

Needle aspiration of neck abscesses with CT-scan guidance was studied in 17 children with 18 abscesses from 1986 to 1991. Clinical and radiologic findings were analyzed according to treatment outcome. A majority of abscesses (55.6%) resolved after treatment with one to two attempts at needle aspiration and parenteral antibiotics. Unilocular abscesses were more likely than multilocular abscesses to resolve with needle aspiration. In general, abscesses in younger children who presented with smaller neck masses on physical examination and smaller abscess cavities on CT scan resolved with needle aspiration. The data support the use of needle aspiration as an effective initial treatment for pediatric neck abscesses. CT scan was found beneficial in documenting the abscesses and in guiding treatment. A treatment protocol is suggested for the use of needle aspiration in the management of neck abscesses in children.