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Biomedical subjects

R F Ward

Publications and source records attributed to R F Ward.

At least 19 recordsLinked to original sources

Identification of novel eubacteria from spent mushroom compost (SMC) waste by DNA sequence typing: ecological considerations of disposal on agricultural land.

A small study was undertaken to examine the microbiological characteristics of spent mushroom compost (SMC), which is the major waste by-product of the mushroom industry and which is regularly disposed off by application to agricultural land. The primary aim of this study was to examine SMC for the presence of faecal bacterial pathogens, including Campylobacter spp., Salmonella spp. and Listeria monocytogenes. Secondly it was desirable to quantify bacterial and fungal populations within SMC, and also qualitatively identify the diversity of bacterial populations within SMC, through employment of rDNA PCR and direct sequencing techniques on the culturable microflora. Conventional microbiological analyses of SMC material (n=30) from six commercial operations in both Northern Ireland and the Republic of Ireland, failed to detect Salmonella spp, Listeria spp. or Campylobacter spp. in any of the SMC material examined. Total aerobic plate counts gave a mean count of log10 7.01 colony forming units (cfu) per gram SMC material (range: log10 6.53-7.52 cfu/g). Fungal counts gave a mean count of log(10) 4.57 cfu per gram SMC material (range: log10 3.93-4.98 cfu/g). From a total of greater than 50 colony picks, a total of 12 bacterial morphotypes were identified and were further examined by employment of partial 16S rRNA gene amplification and sequencing techniques, yielding several genera and species, including Bacillus licheniformis, Bacillus subtilis, Klebsiella/Enterobacter sp. Microbacterium sp. Paenibacillus lentimorbus, Pseudomonas mevalonii, Sphingobacterium multivorum and Stenotrophomonas sp. This is the first preliminary report on the microbial diversity of SMC waste and demonstrates the presence of several species that have not been previously described in SMC, in addition to two potentially novel species within the genera Microbacterium and Stenotrophomonas. It is thereby important to examine the ecological microbe-microbe and plant-microbe interactions that are occurring between the native bacterial soil flora and those added annually (theoretically estimated at approximately 10(18) cells) through the application of SMC. Such studies would be beneficial in helping to ascertain the ecological consequences involved in the disposal of SMC waste on agricultural land.

Agaricales↗

Congenital nasal pyriform aperture stenosis: non-surgical management and long-term analysis.

Congenital nasal pyriform aperture stenosis is a rare cause of airway obstruction in the newborn. Immediate recognition and therapy are essential for this potentially life-threatening condition. After initial management, which includes establishment of an oral airway, surgical repair of the stenotic bony inlet has been traditionally considered. We present a long-term follow-up of two patients with congenital pyriform aperture stenosis, who were managed expectantly. Pertinent embryology, clinical presentation, and general treatment strategies for these patients are also discussed.

Follow-Up Studies↗

Use of potassium titanyl phosphate (KTP) laser in management of subglottic hemangiomas.

OBJECTIVE: to study the role of KTP laser in management of subglottic hemangioma. DESIGN: retrospective analysis of patients with subglottic hemangioma treated by the senior authors. SETTING: tertiary care teaching hospital. PATIENTS: twelve patients with subglottic hemangiomas. INTERVENTION: patients were treated with KTP laser (eight cases), CO(2) laser (two cases) or observation (two cases). MAIN OUTCOME MEASURE: resolution of symptoms, decrease in size of subglottic hemangioma or tracheotomy decannulation. RESULTS: All patients treated with KTP laser or CO(2) laser had resolution of symptoms and five tracheotomy-dependent children were decannulated. CONCLUSION: subglottic hemangioma is a potentially life-threatening disease seen in young children. Most authors recommend use of either CO(2) or open surgical excision. There is very little data available on the use of KTP lasers in the management of subglottic hemangiomas. The KTP laser beam is preferentially absorbed by hemoglobin making this laser system more applicable to the treatment of vascular tumors such as the hemangioma. KTP laser is a good tool for management of subglottic hemangioma with a low incidence of complications.

Child↗

Atypical indications for OtoScan laser-assisted myringotomy.

OBJECTIVE: To describe the role of OtoScan laser-assisted myringotomy (OtoLAM) for indications other than chronic otitis media or recurrent acute otitis media. STUDY DESIGN: Cross-sectional review. METHODS: Twenty-seven office-based OtoLAM procedures were performed in 21 patients for "atypical" reasons. The indications included middle ear dysfunction with necessary air travel (n = 10) or hyperbaric oxygen treatment (n = 6), mastoiditis with postauricular cellulitis (n = 2), canal exostosis prohibiting tympanostomy (n = 1), acute otitis media accompanied by seizures (n = 1), and chronic middle ear effusion in a patient with hemophilia (n = 1). RESULTS: In each of the 20 cases available for follow-up, middle ear disease resolved with closure of the laser-assisted myringotomy. At a later date, two patients (10%) underwent another OtoLAM in the opposite ear and four patients (20%) required repeat OtoLAM in the same or both ears. Three patients (15%) ultimately underwent myringotomy tube placement because of recurrent middle ear dysfunction. CONCLUSIONS: Although this report contains preliminary data, the data suggest that OtoLAM may provide an additional option in the care of certain patients who have previously been treated with myringotomy tubes.

Acute Disease↗

Epidermal inclusion cyst versus thyroglossal duct cyst: sistrunk or not?

Epidermal inclusion cyst (EIC) is a recognized cause of an anterior neck mass in children. Controversy exists as to the proper surgical management of an anterior neck EIC: is simple excision adequate treatment, or is a Sistrunk procedure necessary? A retrospective review of the operative logs of the two senior authors (M.M.A., R.F.W.) from 1993 to the present revealed 16 children, ages 6 months to 9 years (mean, 4.5 years), with a diagnosis of anterior neck EIC. An accurate intraoperative diagnosis of an EIC in all cases allowed for a simple excision of the mass rather than a Sistrunk procedure. The final histologic diagnosis was EIC in all 16 patients. Follow-up of these 16 patients for a mean of 4.5 years revealed no recurrences or complications. When the diagnosis of EIC can be made confidently in the operating room, simple excision is an adequate surgical treatment.

Child↗

Airway growth after cricotracheal resection in a rabbit model and clinical application to the treatment of subglottic stenosis in children.

OBJECTIVE: To evaluate the effects of a partial resection of the anterior cricoid arch on the growth of the laryngotracheal complex in an animal model and to study the lumen caliber and cross sectional surface area following resection as the animals are allowed to grow. Laryngeal, subglottic, and tracheal measurements in the infant and pediatric larynges in autopsy specimens are also investigated. DESIGN: A controlled animal study was done comparing the operated rabbit group to the nonoperated group. Twenty-nine infant rabbits were compared to a control group of ten rabbits. In addition, autopsy dissections were performed on infant and pediatric larynges to obtain measurements of various laryngeal and cricoid relationships. METHODS: Thirty-nine pasteurella-free New Zealand white female rabbits between the ages of 8 and 11 weeks were used in this study. In the experimental group, cricotracheal resections were performed by removing the anterior cricoid cartilage and the first tracheal ring. A primary anastomosis was then performed. The animals were kept alive for 4 months and then humanely euthanized. The laryngeal complex was then removed and histological sections of the cricotracheal region were mounted on glass slides and stained with H&E. Measurements were taken of the cricoid and upper tracheal lumen and cross-sectional area. RESULTS: Twenty-seven of the study group survived until the time of sacrifice. All of the control group survived during the study period. The two groups were comparable in regard to weight, lumen size, and cross-sectional area There were no statistical differences between the groups. CONCLUSIONS: The experimental data support the hypothesis that partial cricotracheal resections can be performed safely and effectively in young rabbits. The potential clinical significance is described in light of the autopsy data.

Age Factors↗

Role of otoscan-assisted laser myringotomy in hyperbaric oxygen therapy.

Patients undergoing hyperbaric oxygen (HBO2) therapy often experience middle ear barotrauma. Not infrequently this disrupts therapy and may require myringotomy tube placement. A new, simple, office-based procedure known as OtoScan Laser Assisted Myringotomy (OtoLAM) provides temporary middle ear ventilation, which offers significant potential benefis for HBO2 patients. Five patients whose middle ear disease complicated their HBO2 therapy have undergone nine OtoLAM procedures in 11 ears. All patients tolerated the procedure without complications and immediately returned to HBO2 treatment. Based on this preliminary experience, we recommend OtoLAM for selected HBO2 patients with problematic middle ear dysfunction.

Adolescent↗

Mitomycin-C in the treatment of tracheal cicatrix after tracheal reconstruction.

OBJECTIVE: To demonstrate the potential use of Mitomycin-C (MMC) in the treatment of difficult and recurrent tracheal stenosis. DESIGN: Case series. SETTING: Tertiary care setting. PATIENTS: A retrospective chart review was performed on five pediatric patients with severe, recurrent tracheal granulation and cicatrix after tracheal reconstruction who were treated with topical MMC as an adjunct to bronchoscopy and laser treatment. MMC was applied intraoperatively on saturated pledgets at a dose of 0.1 mg/ml for 2 min to the area where the cicatrix had been lysed. The five patients were able to be decannulated. DISCUSSION: Mitomycin-C is an anti metabolite known to inhibit fibroblast proliferation in vitro. This agent has been used with a high success rate in glaucoma filtration surgery to promote patency of the trabecula. The results of this preliminary application in the pediatric airway as well as the mechanism of action will be discussed.

Administration, Topical↗

Effects of scalpel, electrocautery, and CO2 and KTP lasers on wound healing in rat tongues.

OBJECTIVE: Evaluate wound healing of incisions created by the scalpel, electrocautery, CO2 laser, and potassium titanyl phosphate (KTP) laser in the upper aerodigestive tract in an animal model. STUDY DESIGN: Prospective randomized study in an animal model. METHODS: Postoperative oral intake, histologic depth of injury, and tensile mechanical strength were measured in rat tongues after creating incisions using a scalpel, electrocautery, CO2 laser, and KTP laser. An unpaired, two-tailed Student's t-test was used to compare results between the experimental groups. RESULTS: Oral intake, indirectly assessed by postoperative weight loss, by the third postoperative day was significantly decreased in the electrocautery (P = 0.004), CO2 laser (P = 0.001), and KTP laser (P = 0.0001) groups as compared with the scalpel group. The depth of the wound healing, as assessed by histologic examination, was successively greater for the scalpel (75 +/- 13 microm), electrocautery (110 +/- 10 microm), CO2 laser (145 +/- 10 microm), and KTP laser (195 +/- 23 microm) groups. However, this difference was only statistically significant for the CO2 laser (P = 0.006) and KTP laser (P = 0.01) groups relative to the scalpel group. Wounds created by the KTP laser had the lowest strength (76.5 +/- 6.9 kPa) as compared with the CO2 laser (156 +/- 28.4 kPa), electrocautery (153 +/- 15.7 kPa), and scalpel groups (249 +/- 61.8 kPa). This difference was only statistically significant for the KTP laser group (P = 0.02) when compared with the scalpel group. CONCLUSIONS: Wounds created in the upper aerodigestive tract of rats by scalpels result in the least postoperative weight loss, tissue destruction, and decrease in tensile strength, whereas wounds created by the KTP laser demonstrated a significantly greater postoperative weight loss, depth of wounding, and decrease in tensile strength.

Animals↗

Diagnosis, management, and follow-up of congenital head and neck teratomas.

OBJECTIVE: To describe our clinical experience with congenital teratomas of the head and neck. STUDY DESIGN: A retrospective review of the six patients as well as a review of the literature in the setting of academic referral centers. METHODS: In six infants with teratomas, four in the cervical region and two arising from the nasopharynx, surgical excision of all tumors was performed. Outcome measures were clinical and radiographic follow-up and the use of a-fetoprotein (AFP) for postoperative monitoring. RESULTS: There was no recurrence of teratomas. CONCLUSIONS: Surgical excision is the treatment for congenital teratomas. Postoperative monitoring for recurrences should include AFP levels in difficult cases.

Female↗

Modifications of airway reconstruction in children.

We review our treatment experience of subglottic stenosis in 66 children. Sixty-one of these children required some form of airway expansion using cartilage grafts. Eight children had grade I (Cotton classification), 15 grade II, 28 grade III, and 15 grade IV stenosis. All patients with grade I and II lesions were decannulated. Ninety-three percent of grade III patients and 67% of grade IV patients were also ultimately decannulated. Laryngotracheal reconstruction with costal cartilage grafting has become widely accepted for treatment of severe laryngotracheal stenosis. Several modifications of this technique have been employed to treat our patients. Recently, we have used a modified single-stage technique with an endotracheal tube stent, externally secured for 1 week, to avoid postoperative intensive care unit admission for sedation and/or paralysis, and its related complications. Posterior graft design and placement without sutures was also performed in 20 cases. A two-surgeon technique that involves a simultaneous endoscopic control of incision of the stenotic area was employed. These modifications will be described in detail.

Adolescent↗

Glutathione metabolism in newborns: evidence for glutathione deficiency in plasma, bronchoalveolar lavage fluid, and lymphocytes in prematures.

Respiratory distress in premature newborns is associated with deficiency of surfactant in the bronchoalveolar lining fluid; this may be influenced by a local deficiency of antioxidants. Severe L-buthionine-S,R-sulfoximine-induced depletion of glutathione (GSH, a major antioxidant) in rodents is associated with lung type 2 cell lamellar body damage and decreased concentrations in lung and bronchoalveolar lavage fluid (BALF) of phosphatidyl choline (a major component of surfactant). At birth, prematurely born newborns (30-34 weeks) had lower peripheral venous plasma GSH concentrations than term (> 36 weeks) babies; these levels decreased further with increasing prematurity (< 27 weeks, with respiratory distress). On day 2, the peripheral venous plasma GSH concentrations reached a nadir, and the lowest levels were found in the most premature newborns. Lymphocyte GSH concentrations were lowest on day 2 and day 7, and in prematures (< 27 weeks, with respiratory distress) remained below adult lymphocyte GSH levels for at least 4 weeks. At birth, prematures (< 27 weeks, with respiratory distress) had a central plasma arterio-venous (A-V) GSH gradient across the lung (an estimate of lung uptake of GSH) of 0.72 +/- 0.15 (mean +/- SD) mumol/L; on day 2, the A-V gradient did not change significantly (0.49 +/- 0.09 mumol/L). At birth, these prematures had markedly decreased BALF GSH concentrations (compared with adult levels), and they were not significantly changed during the first 4 weeks of life. These results suggest that GSH deficiency is present in prematures and that it increases with the degree of prematurity. At birth, GSH deficiency will compromise the lungs' defense against oxidative stress injury. Oxidative stress is likely to increase if hyperoxic treatment is given for respiratory distress in these infants.

Bronchoalveolar Lavage Fluid↗

Current trends in pediatric tracheotomy.

A retrospective analysis was performed on 103 pediatric patients, less than 5 years of age, undergoing tracheotomy at New York Hospital between 1980 and 1990. Charts were reviewed with respect to primary diagnosis, indication for tracheotomy, duration of the tracheotomy, complication rate and mortality rate. Approximately 62% of the tracheotomies were performed in patients less than 12 months of age, with the most common indication being an acquired or congenital airway abnormality. The number of patients receiving tracheotomies for neurological disorders, however, increased more than threefold over the course of this review. Approximately one-third of the patients experienced immediate, early or delayed complications. There was a significant correlation between the complication rate and weight at the time of the tracheotomy as well as the degree of prematurity of the child. Over one half of the infants under 2000 g suffered complications. A mortality rate of 2.9% was noted in our study with mucous plugging of the tracheotomy being the most common etiology of death.

Airway Obstruction↗

Complete nasal agenesis with bilateral microphthalmia and unilateral duplication of the thumb.

Complete nasal aplasia is an extremely rare clinical entity and most infants are stillborn when this is associated with holoprosencephaly. A viable 3-year-old infant born with frontonasal arrest without holoprosencephaly is presented. The child's main complaint was lack of a nasal airway, which made eating extremely difficult. A method for craniofacial reconstruction of the nasopharynx is presented.

Abnormalities, Multiple↗

Surgical management of congenital saccular cysts of the larynx.

Congenital saccular cysts of the larynx are unusual lesions that commonly present with respiratory obstruction in infants and children. The saccular cyst may result from an atresia of the laryngeal saccule orifice or may represent the retention of mucus in the collecting ducts of submucosal glands located around the ventricle. Traditionally, the treatment of the lesions has been endoscopic unroofing or marsupialization. Frequently, this modality requires multiple procedures as well as concomitant tracheotomy. There also have been reports of acquired subglottic stenosis. We have found that removal of the recurrent saccular cyst can be achieved relatively safely and effectively via a lateral cervical approach to the thyrohyoid membrane. We review our experience with four patients with congenital saccular cysts and detail the evaluation and surgical management of these lesions.

Cysts↗