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Biomedical subjects

R Cotton

Publications and source records attributed to R Cotton.

At least 55 records · Page 3Linked to original sources

Reassessment of White's classification and Pedersen's prognostically bad signs of diabetic pregnancies in insulin-dependent diabetic pregnancies.

The classification systems developed over 20 years ago by White and Pedersen identified diabetic pregnancies at increased risk for perinatal mortality. To assess whether these same criteria would currently be valid, 199 diabetic pregnancies with deliveries from 1977 to 1983 were reviewed. Perinatal mortality rates for White's Classes B gestational (n = 72), B (n = 27), C (n = 67), and D + F + R (n = 33) were 2.9%, 11.1%, 14.9%, and 21.1%, respectively (p less than 0.05). White's classes were also predictive of pulmonary morbidity (12.5%, 18.5%, 22.4%, and 42.4%, respectively). The presence of one or more of the prognostically bad signs of pregnancy (n = 76) increased the perinatal mortality rate to 17.1% versus 7.3% among insulin-dependent diabetic pregnancies without prognostically bad signs (p less than 0.05). The presence of any prognostically bad signs of pregnancy was also predictive of pulmonary morbidity in general (31.6% versus 16.3%, respectively) and hyaline membrane disease in particular (13.2% versus 4.1%, respectively). Thus with use of modern obstetric management and medical care of the pregnant diabetic patient, both White's classification and Pedersen's prognostically bad signs of pregnancy continue to be predictive of perinatal mortality.

Adult↗

Prevention of symptomatic patent ductus arteriosus with a single dose of indomethacin.

To determine the efficacy of indomethacin to prevent the occurrence of symptomatic patent ductus arteriosus (PDA), a randomized clinical trial was conducted involving 32 preterm infants weighing 750 to 1500 g at birth who had hyaline membrane disease. By random assignment, 15 infants were given a single dose of indomethacin, 0.2 mg/kg intravenously, 24 hours after birth. Seventeen infants composed a control group for which indomethacin was reserved as treatment for symptomatic PDA. Birth weight, gestational age, male/female ratio, black/white ratio, and severity of disease were similar for both groups. Only one of the 14 survivors who received prophylactic indomethacin had symptomatic PDA, compared with nine of the 16 survivors in the control group (P = 0.007). There was no difference between the groups in development of bronchopulmonary dysplasia, duration of time endotracheal intubation, was required, duration in oxygen, duration to reach full feedings and regain birth weight, and duration of hospital stay. There was no difference between the two groups in incidence of intraventricular hemorrhage, and none developed necrotizing enterocolitis. These results indicate that the use of prophylactic indomethacin is beneficial in prevention of symptomatic PDA; the lack of differences in pulmonary sequelae or other complications may have been related to a population sample size not large enough to impart sufficient statistical power.

Birth Weight↗

Transtracheal repair of recurrent tracheoesophageal fistula.

A recurrent tracheoesophageal fistula is generally associated with considerable mediastinal induration and inflammation. The conventional operative approach may be formidable with considerable blood loss and a high complication rate. For two infants with recurrent fistulae, we have employed a simplified low cervical transtracheal approach through noninflamed tissues. This brief atraumatic procedure was followed by gratifying results. Details of the approach are presented.

Bronchoscopy↗

The use of [3H]-[D-Pen2,D-Pen5]enkephalin as a highly selective ligand for the delta-binding site.

The characteristics of the binding of [3H]-[D-Pen2,D-Pen5]enkephalin were determined in homogenates of guinea-pig and rat brain. In the guinea-pig, the maximum binding capacity for [3H]-[D-Pen2,D-Pen5]enkephalin was 4.19 pmol g-1 and the KD 1.61 nM. In the rat, the corresponding values were 2.47 pmol g-1 and 5.42 nM. In both species, the maximum binding capacity and the affinity were not altered when mu-binding was suppressed with [D-Ala2,MePhe4,Gly-ol5]enkephalin. The mu-agonists, [D-Ala2,MePhe4,Gly-ol5]enkephalin and morphine, displaced a small portion of the binding of [3H]-[D-Pen2,D-Pen5]enkephalin with high affinities.

Animals↗

Changing patterns in retinopathy of prematurity.

In the past 20 years, the survival rates for premature infants have improved. To reassess the incidence of cicatricial retinopathy of prematurity, 197 consecutive premature infants were examined. Each child was seen at intervals until age 6 months. Changes that could influence visual acuity were found in 22% of those with birth weight less than 1,000 g; 10% of those between 1,001 and 1,250 g; and 0% of those greater than 1,250 g. These findings were compared to a similar study performed at our university a decade earlier. A significant reduction in the incidence of premature retinopathy was demonstrated. However, because greater numbers of profoundly premature infants are surviving, the number of children with retinopathy of prematurity appears to be increasing.

Birth Weight↗

Divergent structure activity relationships in series of enkephalin agonists and cognate antagonists.

Diallylation of the amino group of [Leu]enkephalin methyl ester yields a moderately potent, delta-selective opiate receptor antagonist. The diallyl congeners of a larger range of potent mu-and delta-selective enkephalin agonists have been prepared and were found to be weak, non-selective antagonists as assessed by their ability to antagonise the effects of normorphine and [Leu]enkephalin on the field-stimulated mouse vas deferens. Conversely, whereas [Gly3 psi (CH2S)Phe4,Leu5]enkephalin and [Gly3 psi(CH2S)-D-Phe4,Leu5]enkephalin are virtually inactive as opiate agonists the corresponding diallyl analogues are moderately potent, highly selective delta-antagonists. Analogues of diallyl[Leu]enkephalin in which the Gly2 and Gly3 residues have been replaced by D- and L- Ala have also been prepared and tested as delta-receptor antagonists. In addition, the empiric energy program ECEPP has been used to derive eighteen low energy conformations of diallyl[Leu]enkephalin and to estimate the effect of the D- and L-Ala substitutions on the conformer energies. Two conformers were identified for which there was a partial correlation between the variations in conformational energy and delta-antagonist potency.

Animals↗

Mica pneumoconiosis.

Two men developed pneumoconiosis after grinding and packing powdered mica. The disease was characterised by progressive dyspnoea, a restrictive impairment of ventilation, a reduced transfer factor, and hypoxaemia. Radiographs showed widespread fine nodular and linear shadows. Progression occurred after cessation of exposure, but this was much more pronounced in the man who died from coronary artery disease. Postmortem examination showed widespread fine fibrosis and nodules measuring up to 1.5 cm in diameter, all related to the deposition of doubly refractile crystals. Mineral formed over 9% of dry tissue weight, and electron microscopy and x-ray analysis showed it to be muscovite. Other minerals were not found.

Adult↗

Liposarcoma of the neck. Report of a case.

A case of lipoblastic liposarcoma of the neck is presented. The case is that of a 5-year-old female who underwent a modified neck dissection with a good result. A review of the literature reveals that this is an extremely rare tumor of the neck. It is usually found in the lower extremities, predominantly in adult males. Surgery is the treatment of choice. Lipoblastic liposarcoma is an extremely rare tumor when it occurs in the pediatric neck. Hudson and Saunders in their studies have shown that only 3 patients with this tumor have been reported since 1944. When a 5-year-old female presented with this primary neck mass, questions of diagnosis and treatment were raised. The following case report and discussion will demonstrate the diagnostic methods as well as the course of therapy followed in this type of lesion.

Child, Preschool↗

Does the Silastic Eustachian Tube prosthesis improve eustachian tube function?

This clinical study attempts to evaluate the effectiveness of Eustachian tube function in 30 ears, 11-29 months after insertion of the Silastic Eustachian tube prosthesis (SETP). Indications for the SETP were limited to persistent Eustachian tube dysfunction. Preoperatively, 13 patients had intact tympanic membranes with persistent serous otitis media. Seventeen patients underwent tympanoplasty and demonstrated persistent serous otitis media in the opposite ear. Postoperatively, aeration of the middle ear was evaluated by tympanometry, microscopic examination, and myringostomy. Microphotographs demonstrate the state of the middle ear. Histology of the middle ear mucosa was obtained in a few cases. Ninety-six percent of the ears with an SETP demonstrated confirmed persistent Eustachinan tube dysfunction beginning an average of six months after insertion. Complications were common.

Adult↗

Tracheoplasty for tracheal stenosis in the pediatric burned patient.

Until recently, the only therapy available for a tracheal stricture has been repeated dilations of the stenotic area or resection and anastomosis. Upper-airway burns in the pediatric patient have occasionally resulted in tracheal stenosis. Two children with a long tracheal stenosis secondary to inhalation injury have been successfully treated surgically. A costal cartilage graft has been used in these two children in the management of a long tracheal stenosis. Both have an adequate airway, and future surgical correction of a subglottic stenosis is planned for both. The results, although initially successful, will need to be tested by time before they can be considered the definitive treatment for long areas of tracheal stenosis.

Burns, Inhalation↗

Carotid artery rupture. Management and prevention of delayed neurologic sequelae with low-dose heparin.

Carotid artery ligation, whether elective or an emergency, is an operation that most head and neck surgeons do with some trepidation because of the possible neurologic consequences. Of 440 major head and neck operations for cancer in which the carotid artery was exposed, 20 (4.5%) patients suffered a carotid rupture or had the vessel ligated just prior to rupture. We describe the typical patient and his management. Of these 20 patients, five died as a direct result of rupture or ligation, ten survived rupture and/or ligation with neurologic sequelae, and five survived rupture and/or ligation without neurologica sequelae. Of the ten patients with neurologic problems, four had immediate strokes, and six had delayed strokes, ie, these occurred greater than eight hours after ligation. Seven patients who required carotid artery ligation, separate from the previously mentioned group, received 5,000 units of heparin sodium subcutaneously every 12 hours in a prospective study. Of these seven patients, one died immediately postoperatively, and six survived without any neurologic sequelae. We discuss the cause of delayed neurologic problems and the rationale for the use of low-dose heparin.

Carotid Artery Diseases↗

Middle ear ciliary defect in Kartagener's syndrome.

Patients with Kartagener's syndrome have shown electron photomicrographic abnormalities of nasal or bronchial cilia in addition to functional defects of mucociliary transport (immotile cilia syndrome). This report describes a boy with Kartagener's syndrome and chronic otitis media who demonstrates electron photomicrographic abnormalities of middle ear cilia, confirming the important role of cilia in providing protection against infection of the middle ear.

Child↗