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.     

Effect of exogenous surfactant on total respiratory system compliance

We measured total respiratory system compliance (Crs) before and after instilling 25 mg artificial surfactant in 1 ml saline down the endotracheal tube of preterm babies requiring resuscitation at birth, and compared results with data from 6 similar babies receiving saline only. Surfactant did not produce a significant improvement in Crs.     

Effects of chronic stress on dendritic arborization in the central and extended amygdala

A differential role has been suggested for two important areas in the neural circuitry of stress, central nucleus of the amygdala (CeA) and bed nucleus of stria terminalis (BNST) in the extended amygdala, in regulating fear versus anxiety. Since chronic stress enhances anxiety and consolidation of aversive memories, we examined the effects of chronic immobilization stress (CIS) on neuronal morphology in the CeA and BNST of rats. In contrast to previous reports of stress-induced atrophy in the hippocampus, CIS does not cause dendritic atrophy in CeA and BNST neurons. While dendritic arborization in CeA neurons remains unaffected, it increases in BNST neurons after CIS. These results suggest a role for dendritic remodeling of BNST neurons in stress-induced facilitation of anxiety.