Monocanalicular silastic intubation for the initial correction of congenital nasolacrimal duct obstruction.

BACKGROUND: Treatment of persistent nasolacrimal duct (nasolacrimal duct obstruction) obstruction traditionally has consisted of simple probing. The most common complication with this approach has been recurrent obstruction, requiring another probing, often with the use of bicanalicular silastic intubation. Monocanalicular silastic tubing offers the possibility of increased success rates over simple probing while theoretically minimizing the insertion and removal difficulaties posed by bicanalicular techniques. We report, to our knowledge, the largest series to date of patients undergoing monocanalicular silastic intubation, as well as the first report evaluating this technique as the primary treatment for congenital nasolacrimal duct obstruction obstruction. METHODS: This was a retrospective chart review of 635 children treated by 3 pediatric ophthalmologists via probing with monocanalicular silastic intubation as the initial procedure for congenital nasolacrimal duct obstruction obstruction. Success was defined as good clearance of fluorescein dye and/or the absence of symptomatic tearing. Failure was defined as recurrent symptomatic tearing or inadequate clearance of fluorescein dye, leading to the performance of a second tear duct operation. RESULTS: We identified 635 children who underwent probing with monocanalicular intubation as the primary treatment for congenital nasolacrimal duct obstruction obstruction (mean age at time of probing 18 months). The overall success rate for the 803 eyes undergoing surgery was 96%. The success rate for treatment performed in infants younger than 24 months of age (684 eyes) was 97%, declining to 90% when surgery was performed in infants older than 24 months of age (119 eyes; p < 0.001). These success rates compare favorably to previous reports of primary probing without silastic intubation, especially in children older than 12 months at the time of the probing. The only complication in the current study was conjunctival-corneal abrasion, occurring in 2% of cases. CONCLUSIONS: Probing with monocanalicular silastic intubation as the initial surgical procedure for patients with congenital nasolacrimal duct obstruction obstruction is associated with a very high success rate and low complication rate, especially when performed by the age of 24 months.     

Formation and uptake of arylhydroxylamine-haptenated proteins in human dendritic cells.

Bioactivation of sulfonamides and the subsequent formation of haptenated proteins is believed to be a critical step in the development of hypersensitivity reactions to these drugs. Numerous lines of evidence suggest that the presence of such adducts in dendritic cells (DCs) migrating to draining lymph nodes is essential for the development of cutaneous reactions to xenobiotics. Our objective was to determine the ability of human DCs to form drug-protein covalent adducts when exposed to sulfamethoxazole (SMX), dapsone (DDS), or their arylhydroxylamine metabolites [sulfamethoxazole hydroxylamine (S-NOH) and dapsone hydroxylamine (D-NOH)] and to take up preformed adduct. Naive and immature CD34+ KG-1 cells were incubated with SMX, DDS, or metabolites. Formation of haptenated proteins was probed using confocal microscopy and ELISA. Cells were also incubated with preformed adduct (drug-bovine serum albumin conjugate), and uptake was determined using confocal microscopy. Both naive and immature KG-1 cells were able to bioactivate DDS, forming drug-protein adducts, whereas cells showed very little protein haptenation when exposed to SMX. Exposure to S-NOH or D-NOH resulted in protein haptenation in both cell types. Both immature and naive KG-1 cells were able to take up preformed haptenated proteins. Thus, DCs may acquire haptenated proteins associated with drugs via intracellular bioactivation, uptake of reactive metabolites, or uptake of adduct formed and released by adjacent cells (e.g., keratinocytes).     

Relations between the fetal circulation and pituitary-thyroid function.

OBJECTIVE--To study the relation between changes in the fetal thyroid hormone and thyroid stimulating hormone (TSH) concentrations and alterations in the fetal circulation as assessed by Doppler ultrasound. DESIGN--A cross-sectional study of small for gestational age (SGA) and red-cell isoimmunized fetuses undergoing cordocentesis and Doppler studies for the assessment and determination of fetal karyotype, acid-base balance and haemoglobin concentration. SETTING--Harris Birthright Research Centre for Fetal Medicine, King's College, London. SUBJECTS--38 growth retarded and 38 red-cell isoimmunised fetuses. INTERVENTIONS--Cordocentesis. MAIN OUTCOME MEASURES--Serum TSH total and free thyroxine (T4, FT4) and total and free triiodothyronine (T3, FT3) concentrations; middle cerebral artery (MCAVm) and descending thoracic aorta (AoVm) mean blood velocities; fetal Po2 and haemoglobin concentration (Hb). RESULTS--Delta values (delta) calculated as the number of SDs from the respective normal mean for gestation were used to compare the results with those from a previous study of normal fetuses. Mean AoVm was increased in the isoimmunized fetuses (P less than 0.001) but decreased in the SGA fetuses (P less than 0.001). Mean MCAVm was increased in both groups (P less than 0.01; P less than 0.001). There were significant associations between the gestational age adjusted values for TSH and MCAVm (r = 0.23, P less than 0.05) and between T4, FT4 or FT3 and AoVm (r = 0.41, P less than 0.01; r = 0.50, P less than 0.01; r = 0.36, P less than 0.01 respectively). In addition, T4 and FT4 were associated with delta Po2 and delta Hb. CONCLUSION--In the hypoxaemic hypoxia of growth retardation and the anaemic hypoxia of rhesus disease there are significant associations between changes in fetal thyroid hormone concentrations and changes in fetal blood flow as assessed by Doppler. Irrespective of whether altered blood flow is the cause or effect of changes in thyroid hormone concentrations, the observed changes could have beneficial effects for fetal survival, in the presence of a hostile intrauterine environment.     

Renal artery flow-velocity waveforms in normal and hypoxemic fetuses

Color flow mapping was used to identify the fetal renal artery and to obtain flow-velocity waveforms. A reference range of the fetal renal artery pulsatility index with gestation was constructed from a cross-sectional study of 114 appropriate for gestational age fetuses of 17 to 43 weeks' gestation. The pulsatility index decreased linearly with gestation, indicating a fall in impedance to flow, and presumably an increase in renal perfusion. The renal artery pulsatility index was also determined in 18 small-for-gestational-age fetuses and was higher than the appropriate-for-gestational-age group. The small-for-gestational-age fetuses also had fetal blood sampling performed by cordocentesis. A significant, direct correlation was found between blood oxygen deficit and increased renal artery pulsatility index.     

Reconstruction of chest wall defects following extirpative surgery

Reconstructive procedures following chest wall resection pose a special surgical challenge. With modern surgical technique, a wide range of reconstructive options are at the surgeon's disposal and, hence it is imperative that the appropriate procedure be selected in a given patient. A total of 64 patients underwent resection of malignant chest wall tumors at the Tata Memorial Hospital. The technique of preference at our institution for reconstruction of full-thickness chest wall defects uses a combination of autogenous fascia lata and Marlexmesh. We present our experience with chest wall reconstruction following extirpative surgery in these patients. © Wiley-Liss, Inc.     

Pleomorphic adenoma of the nose

A case of Pleomorphic adenoma of the nose in a 28 year old female, presenting as right sided nasal obstruction is presented, the tumour involved the maxilla.     

Early sonographic diagnosis of body stalk anomaly

Ultrasonographic features of a fetus at 18 weeks of gestation suggesting a body stalk anomaly are presented. These included a large abdominal anterior wall defect in apparent continuity with the placenta, severe kyphoscoliosis of the lower spine, the absence of one kidney, and a very short umbilical cord with only one umbilical artery. The amniotic fluid was reduced and the fetus was almost immobile at short-interval ultrasound examinations. The pregnancy was terminated and autopsy of the fetus showed abnormalities compatible with maldevelopment of both cephalic and caudal embryonic folds.     

Endotracheal resuscitation of preterm infants at birth.

The adequacy of initial ventilation in 21 preterm babies (25-36 weeks'' gestation), who required endotracheal intubation and positive pressure ventilation, were studied. Pressure and flow were measured at the proximal end of the endotracheal intubation tube and expiratory volume calculated from the flow trace. The results were compared with those from a group of 26 term infants who also required resuscitation. Five of 21 preterm babies (24%) had adequate tidal ventilation with the first inflation. This rose to seven of 21 (33%) by the third inflation. This was significantly less than the results in the term infants (chi 2 = 4.38 p less than 0.05). Respiratory reflex responses to resuscitation were seen in 41% of inflations in preterm and 56% of inflations in term infants. There was a significant correlation between reflex activity and adequate ventilation in the preterm group (chi 2 = 11.83, p less than 0.001) but not in the term group (chi 2 = 0.212, p = NS). No correlation was seen between initial ventilation and outcome.