Cerebral blood volume measured using near-infrared spectroscopy and radiolabels in the immature lamb brain.

Near-infrared spectroscopy (NIRS) is a technique that is increasingly being used for the noninvasive measurement of cerebral blood volume (CBV) in newborn infants, but it has not been fully validated against established methods. These experiments in immature lambs (gestation 92+/-1 d, mean+/-SEM) compared CBV measured using NIRS-derived estimates of oxygenated Hb (n = 5) with CBV estimated with radiolabeled indicators (125I-labeled serum albumin and 51Cr-labeled red blood cells, n = 10). Total brain CBV (mL/100 g tissue) measured using NIRS was 2.5+/-0.2 compared with 2.5+/-0.2 using radiolabels (NS). Regional tissue plasma, red blood cells, and whole blood volumes from radiolabels varied significantly (p < or = 0.05) throughout the brain. Whole blood volume (mL/100 g tissue) was largest in choroid plexus (16.2+/-2.1) and least in white matter (0.7+/-0.1) with a significant hierarchy evident among regions: choroid plexus > cerebellum > cortex > brain stem = midbrain > white matter. Regional plasma and red blood cell distributions were similar to whole blood, being highest in choroid plexus (13.0+/-1.6 and 3.2+/-0.9, respectively), and least in white matter (0.8+/-0.1 and 0, respectively). These data from the immature lamb brain indicate that total CBV measured with NIRS is essentially identical with the volumes obtained using intravascular radiolabels. Among cerebral regions, white matter contributes little to the global blood volume measured with NIRS because its red blood cell content is very low.

Detection of gonadal carcinoma in situ in childhood and implications for management.

Cells with the characteristic features of carcinoma in situ (CIS) were detected in histological sections of the gonads of three of seven children with clinical syndromes associated with a high risk of gonadal neoplasia. It is suggested that early detection of these cells may be useful in resolving problems of management, including gonadectomy and decisions about sex of rearing. Early detection of CIS cells may have a place in the management of the undescended testis.

Unilateral enlargement of the testis in childhood: does it need exploration?

Unilateral testicular enlargement in the pubertal boy is not an indication for exploration and biopsy, if the clinical features and investigations show no evidence of malignancy. In the prepubertal boy, unilateral testicular enlargement is not necessarily an indication for exploration if there are no clinical or investigational grounds for suspicion of neoplasia. Close follow-up is essential.

Fetal lung growth in laryngeal atresia and tracheal agenesis.

Three cases of airway obstruction in fetuses born at 21, 32 and 40 weeks gestation are reported. The first had laryngeal atresia, cystic dysplastic kidneys, oligohydramnios and immense fluid-filled lungs. The second had upper tracheal agenesis, a tracheo-oesophageal fistula, a cystic dysplastic horseshoe kidney, oligohydramnios and normal-sized lungs. The third had a pin-hole mucosal tract through an otherwise atretic larynx, normal kidneys, no oligohydramnios and normal-sized lungs. Lung weight:body weight ratios, radial alveolar or radial canalicular counts and point-counting of sections of lungs in cases 1 and 2 show that laryngeal or tracheal obstruction may prevent or reduce the pulmonary hypoplasia associated with renal dysplasia, and in cases 2 and 3, that grossly enlarged, hyperplastic lungs may not be seen unless obstruction is complete.

Ultrasound and necropsy study of periventricular haemorrhage in preterm infants.

The diagnostic accuracy of cerebral ultrasound for periventricular haemorrhage was determined by comparing this with necropsy findings in 30 preterm neonates of 30 weeks' gestation or less and birthweight under 1500 g. Ultrasound gave an accurate diagnosis of 85% in infants with germinal layer haemorrhage, 92% in intraventricular haemorrhage, and 97% in intracerebral haemorrhage. False positive errors were caused by vascular congestion; false negative errors occurred when the maximum dimension of haemorrhage was less than 3 mm. Cerebral ultrasound gave a diagnostic accuracy of 63% for periventricular leucomalacia. False negative errors occurred when periventricular leucomalacia was microscopic or when it was out of range of the scanner. The maximum width of the germinal layer was measured in 77 neonates of gestational age 23 to 36 weeks who died and had no periventricular haemorrhage at necropsy. The progressive involution of the germinal layer with increasing gestational age paralleled the steady decrease in incidence of periventricular haemorrhage diagnosed over the same gestational age range. Neonates of the youngest gestational age who had the most extensive germinal layers also had the highest risk for periventricular haemorrhage.

The pathogenesis of renal dysplasia. I. Quantification of hypoplasia and dysplasia.

In order to assess the relative effects of abnormal ureteric orifice position and abnormal urodynamics on the morphogenesis of hypoplasia and dysplasia in kidneys obtained from infants, we devised a method of quantifying the renal structures. The method was based on radial glomerular counts which ranged from zero to normal (seven to nine), a score for dysplastic structures, and the ratio of normal to abnormal tissues present. These three values, when plotted against each other, correlated closely. The glomerular count, with occasional minor adjustment for inconsistencies, was the best parameter of hypodysplasia. Severe to moderate grades of hypodysplasias fell in the low and middle ranges and hypoplasia through to normal in the highest range. By grading kidneys in this way, we were able to compare the effects of ureteral ectopy and abnormal urinary dynamics on the developing kidney.

The pathogenesis of renal dysplasia. III. Complete and incomplete urinary obstruction.

We graded obstructed kidneys of infants on the hypodysplasia scale to assess the influence of complete and partial obstruction on the pathogenesis of hypodysplasia. Kidneys with complete obstruction exhibited severe grades; those with partial ureteral obstruction had near normal grades. Those kidneys subjected to partial urethral obstruction ranged from mild to severe grades which correlated with degrees of lateral ectopy of the urethral office. Renal parenchymal development was impaired by complete obstruction but was tolerant to incomplete obstruction. Abnormal orifice positions associated with urethral obstructions were considered to be manifestations of ectopic ureteric buds and the hypodysplasia to be evidence of abnormal induction of abnormal renal blastema.

The pathogenesis of renal dysplasia. II. The significance of lateral and medial ectopy of the ureteric orifice.

Renal hypoplasia and dysplasia may be primary malformations linked to a panureteric bud deformity or result from damage to the developing nephrons caused by abnormal urodynamic pressures, Kidneys with misplaced ureteric orifices were graded, according to histologic criteria, on the hypodysplasia scale. With lateral ectopy of the ureteric orifices with and without congenital urethral obstruction, the grades correlated with specific orifice positions. The grades of kidneys with caudal ectopy of the ureters indicated a more general correlation. Dysgenesis of the bud and nephrogenic mesenchyme may account for the renal hypodysplasia when the ureteric orifice is found to be ectopic.

Importance of early diagnosis and gonadectomy in 46, XY females.

Gonadal neoplasms developed in three 46, XY females aged 3 yr and 10 mo, 15 yr, and 19 yr. One patient died from metastatic neoplasia. Early diagnosis of 46, XY gonadal dysgenesis is essential, and should be considered in female infants and children with any features of Turner's syndrome, ambiguous genitalia, phallic hypertrophy, excessive height, large hands and feet, failure of development of secondary sexual characteristics, primary amenorrhea, abdominal mass, or unexplained hypertension. Any female with gonadal dysgenesis and a Y chromosome in her karyotype should have prophylactic gonadectomy as soon as possible. The absence of Sertoli cells in these patients, causing lack of androgen binding protein with deficient local concentration of androgens and consequent failure of maturation of spermatogonia, may lead to unregulated proliferation of germ cells, and hence explain the frequency of gonadal neoplasia in the 46, XY female.

Results of the use of autotransplantation of the intraabdominal testis using microsurgical vascular anastomosis.

This study indicates that where facilities are available, the use of autotransplantation of the intraabdominal testis with microsurgical anastomosis to vessels of the groin is an acceptable, and possibly the best, alternative to orchidectomy for the intraabdominal testis. It is certainly justifiable in the case of the bilateral intraabdominal testis but in the case of the unilateral intraabdominal testis with a normally descended and apparently normal testis in the opposite hemiscrotum, the incresed incidence of neoplasia in intraabdominal testes should be taken into account in the decision on the method of treatment.

Normal position of the ureteral orifice in infancy and childhood: a quantitative study.

Normal values for the distance between the vesicoureteral orifice and the internal urethral orifice are given for different ages, heights, weights, crown-to-rump lengths and surface areas of infants and children. A simple estimate of approximate mean values for these measurements also is included.

Germ cells and ova in dysgenetic gonads of a 46-XY female dizygotic twin.

The frequency of germ cell neoplasms in girls with 46-XY gonadal dysgenesis suggests that germ cells may persist in the dysgenetic gonads for many years. A phenotypic female infant with a karyotype of 46-XY in blood, skin, and gonads had a few ova in primordial follicles and numerous germ cells in her dysgenetic gonads at the age of 3 months. At 3 years and 10 months of age her gonads contained no primordial follicle and the only remaining germ cells were in a gonadoblastoma. We propose that germ cells are lost from dysgenetic gonads much more rapidly than from normal gonads, but that the rate of loss in patients with a karyotype of 46-XY may be less than the rate of loss in patients with a karyotype of 45-XO.

The use of microsurgery in the treatment of the undescended testis.

An experimental method of orchidopexy for high inguinal or abdominal testes, in the dog, using microsurgical anastomosis of the testicular vessels to vessels of the thigh or inferior epigastric vessels, is described. Experimental results suggest that this is a feasible method of treatment of such testes. A clinical trial of the method has commenced.

Congenital granular-cell myoblastoma.

The clinical and pathologic features of congenital granular-cell myoblastoma in five infant girls are reported. One lesion, treated expectantly, progressively decreased in size and after 3 yr and 9 mo could not be detected, while two lesions which were imcompletely excised did not recur. It is suggested that congenital granular-cell myoblastoma is caused by an intrauterine stimulus, and that this stimulus may possible be production of estrogen by the fetus. Congential granular-cell myoblastoma should be treated expectantly or by limited excision, and has an excellent prognosis.