Suiko Iwase

Auditory brainstem response in neonates with asphyxia and intracranial haemorrhage

Auditory brainstem response (ABR) was used to assess possible brainstem damage in 76 neonates with asphyxia and intracranial haemorrhage (ICH). Fifty-eight neonates had ICH, 52 had neonatal asphyxia and 34 of these patients had both. Eighty-nine percent of the patients with neonatal asphyxia showed some abnormal patterns in response, the major one being an increase in the threshold of wave V. In the ICH group, abnormal patterns were observed in 62.5%, among whom the prolongation of the I–V interpeak latency (IPL) and of wave V latency was seen more frequently than the increase of threshold of wave V. In the case of neonatal asphyxia associated with ICH, both the prolongation of the latency and the increase of threshold were observed equally. These abnormalities of ABR were associated with worsening clinical condition and conversely normalized gradually following the improvement of the underlying disease. Especially the I–V IPL, wave V latency and the threshold of wave V could serve as indicators of the treatment.

Reliability of Urinary N-Acetyl-β-D-Glucosaminidase as an Indicator of Renal Tubular Damage in Neonates

Urinary N-acetyl-beta-D-glucosaminidase (NAG) was determined in infants during the first year of life to clarify its evolutional change and the reliability of this enzyme as a marker of renal tubular damage in the newborn period. During the first 2 weeks of life, there was no difference in the urinary levels between preterm (gestational age of 33-36 weeks) and full-term infants. The urinary NAG index (NAG is expressed as the ratio of the enzyme activity to milligrams of creatinine) during the first month of life was significantly elevated when compared with that of any other succeeding period and gradually decreased during the first year of life. The index in newborn infants on tobramycin was significantly elevated and maintained a higher value during the 5 days after withdrawal of the medication. Infants with asphyxia had a higher urinary NAG index during the first week of life. These data suggest that the urinary NAG index is a useful indicator of renal tubular damage during the newborn period.

Duplication of the caecum in a neonate simulating intussusception

A case of caecal duplication in a 36-h-old neonate is described. The patient presented with vomiting and an abdominal mass and the barium enema finding was initially suggestive of intussusception. At laparotomy a duplication cyst completely obstructing the lumen was found. This was considered to have given the radiological picture simulating intussusception.

Transdiaphragmatic duodenal duplication in a premature infant

A case of transdiaphragmatic duodenal duplication in a premature infant is presented. Vertebral abnormalities, which have invariably accompanied this disorder in reported cases so far, were characteristically absent. Therefore, the initial tentative diagnosis was right-sided diaphragmatic hernia. Barium examination was helpful in preoperative diagnosis.

Gentamicin nephrotoxicity in young rabbits

Gentamicin nephrotoxicity was investigated in 2 experimental models, Group I: young rabbits, age 10 to 12 d old (body weight 200 +/- 28 g) and Group II: growing rabbits, age 7 to 8 weeks old (body weight 1,470 +/- 116 g). Enzyme activity of Na-K-ATPase was measured in the inner cortex, the outer cortex and the medulla of the kidneys at 1, 1 1/2, 2 1/4, 3 and 4 h after a single injection of 150 mg per kg BW gentamicin and each result of group I was compared to that of group II. In group II animals, increase of this enzyme occurred in both the inner cortex and the outer cortex but not in the medulla, and changes occurred earlier in the outer cortex than in the inner cortex. In group I, the change of this enzyme activity was seen in the inner cortex only and occurred much later than in group II. These results indicate that gentamicin nephrotoxicity occurs earlier in adult rabbits than in young rabbits and also the change in enzyme activity was seen only in the inner cortex in the young rabbit kidney.

A mild case of nesidioblastosis with diagnostic and therapeutic difficulty.

A female infant with nesidioblastosis who showed mild clinical symptoms is reported. In this patient, insulin levels and insulin to glucose ratios (IRI/G) were often normal. Regular milk feedings supplemented with continuous glucose infusion (0.7‐2 mg/kg per min) or oral glucose feedings (4.5 mg/kg per min) prevented hypoglycemia. As leucine‐sensitivity was diagnosed at 2 months of age, she was started on diazoxide. This was, however, ineffective, and adverse effects appeared. Subtotal pancreatectomy (95%) was therefore attempted at 5 months of age, and persistent normoglycemia as well as normal growth and development followed up to 3 years after the operation. The pancreas showed characteristic signs of nesidioblastosis. The above clinical observation suggests that a patient with nesidioblastosis whose blood glucose level is easily controllable may develop an unexpected episode of hypoglycemia in the presence of a leucine sensitivity. In such a patient, diazoxide or, when it is of no avail, surgical intervention should promptly be instituted to prevent possible neurologic sequelae induced by hypoglycemia.

Diagnostic/prognostic significance of photo-evoked eyelid microvibration in neonates with intracranial hemorrhage

Photo-evoked eyelid microvibration (PEMV) was recorded in neonates with intracranial hemorrhage in order to determine whether it serves as a useful indicator of clinical course and also prognosis. Although the latency of PEMV was prolonged or absent in the acute stage of ICH, it returned to a normal range in these subjects with the improvement of symptoms. Three infants whose PEMV were still prolonged in the convalescent stage developed mental retardation or cerebral palsy. PEMV may be a useful predictor of the prognosis of neonatal ICH and its prolongation may signal later neurological sequelae.

Role of Atrial Natriuretic Peptide in the Diuresis of a Newborn Infant with the Syndrome of Inappropriate Antidiuretic Hormone Secretion

ABSTRACT. A fullterm infant had fetal distress and stained amnion. He underwent an exchange blood transfusion at 12 hours after birth because of hyperbilirubinemia. He developed oliguria combined with high urine osmolality during the first 27 hours of life despite normal creatinine clearance. The diagnosis of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) was made on the basis of high urine osmolality, low plasma osmolality and elevated plasma arginine vasopressin (AVP) concentration. We determined the plasma atrial natriuretic peptide (ANP) concentration for the first 4 days of life. After 27 hours after birth, urine volume increased while plasma AVP concentration remained high. On the other hand, plasma ANP concentration gradually increased after 27 hours of life. We speculate that ANP may play an important role in producing the spontaneous diuresis in the newborn infant with SIADH.

Relationship between plasma atrial natriuretic peptide concentrations and cardio-thoracic ratio during the early neonatal period.

ABSTRACT. Twenty‐seven neonates were examined at 2.6±1.5 hours of age (stage 1) and 21 ±4.9 hours of age (stage 2) to clarify the relationship between cardio‐thoracic ratio (CTR) on chest roentgenograms and plasma atrial natriuretic peptide (ANP) concentration. Among 22 infants who showed elevated plasma ANP, 14 had gained body weight (group A), while 8 other infants had lost weight (group B) at stage 2. The remaining 5 infants had decreased plasma ANP concentrations combined with weight loss at stage 2 (group C). All infants of group B had a patent ductus arteriosus. The plasma ANP concentration and CTR of groups A and B increased during the study period, while those of group C decreased. A linear relation was found between plasma ANP concentration and CTR in all cases (p<0.02). This study indicates that increased plasma levels of ANP are associated with an increased CTR.