Effects on breathing of carotid body denervation in neonatal piglets.

The purpose of these studies was to test the hypothesis that carotid chemoreceptor activity is necessary for postnatal maturation of the ventilatory control system. By using a lateral surgical access, 17 piglets were carotid body denervated (CBD) and 14 were sham denervated at 3-25 days of age. After surgery, there was no irregular breathing in any group. There was no significant hypoventilation when CBD was performed at less than 5 days of age (n = 5) and only a mild (arterial PCO(2) 5 Torr; P < 0.05) to moderate, transient (arterial PCO(2) 8 Torr; P < 0.5) hypoventilation in piglets denervated at 10-15 (n = 6) and 20-25 (n = 6) days of age, respectively. Three weeks after surgery, both breathing of a hypoxic gas mixture and jugular venous NaCN injections elicited a hyperpnea in the CBD piglets that was attenuated compared with that in sham CBD piglets. In the CBD piglets, there was no response to injections of NaCN in the carotid arteries, but there was a response to NaCN injected into the proximal descending aorta, suggesting the residual peripheral chemosensitivity was of aortic origin. Carotid chemoreceptor-intact piglets had carotid and aortic NaCN chemosensitivity by 2 days of age. The carotid response persisted for the 40 days of the study, but the aortic reflex persisted only until approximately 8 days of age. We conclude that 1) the major effect of CBD per se in neonatal piglets is age-dependent hypoventilation and 2) there is a high degree of plasticity in peripheral chemosensitivity in neonates that may contribute to minimizing the changes in breathing after CBD.

Effect of carotid body denervation on breathing in neonatal goats.

The objective of the present study was to determine in goats whether carotid body denervation (CBD) at 1-3 days of age causes permanent changes in breathing greater than those that occur after CBD in adult goats. Goats underwent CBD (n = 6) or sham CBD (n = 3) surgery at 1-3 days of age. In addition, one unoperated control animal was studied. Bolus intravenous injections of NaCN 2 days postsurgery verified successful CBD surgery. However, at 3, 11, and 18 mo of age, the CBD goats had regained a NaCN response that did not differ (P > 0.10) from that of intact goats. Intracarotid NaCN injections elicited a hyperpnea in the sham CBD but not the CBD goats. Only one animal exhibited highly irregular breathing [characterized by prolonged (>9-s) apneas] after CBD, and the irregularity disappeared by 3 mo of age. One CBD goat died at 35 days of age, and autopsy revealed that death was associated with pneumonia. After 3 mo of age, there were no statistically significant differences (P > 0.10) between sham and CBD goats in eupneic breathing, hypoxia and CO(2) sensitivity, and the exercise hyperpnea. It is, therefore, concluded that CBD at 1-3 days of age in goats does not appear to affect selected aspects of respiratory control after 3 mo of age, conceivably because of the emergence of other functional chemoreceptors that compensate for the loss of the carotid chemoreceptor.

Placental pathology casebook. Chorangiosis of the placenta increases the probability of perinatal mortality.

Two apparent acute problems that may occur in labor, nuchal cord and placental abruption, were associated with chorangiosis of the placenta. The importance of complete placental examination in perinatal mortality is re-emphasized. The association of apparent acute obstetrical conditions, e.g., nuchal cord and placental abruption with chorangiosis of the placenta, may be the cause of fetal-newborn deaths that were previously assumed to be issues of labor management.

Effect on breathing of ventral medullary surface cooling in neonatal goats.

The present study was designed to determine whether neurons near the ventral medullary surface (VMS) that are important to control of breathing in adult mammals are also important to control of breathing in neonates. In 7-day-old goats (n = 22), the VMS was surgically exposed under halothane anesthesia. Stainless steel thermodes (2 x 2 mm) were used to cool (20 degrees C) and thereby create neuronal dysfunction of discrete VMS sites. Bilateral cooling under anesthesia 0-2 or 2-4 mm lateral to the midline between the exit of cranial nerves VI and XII resulted in a reduction (P < 0.05) of breathing and most often in apnea. Cooling caudal or rostral to this area did not have a consistent effect on breathing. In 7-day-old goats (n = 8), 3 x 3-mm thermodes were chronically implanted bilaterally on the VMS surface between the exit of cranial nerves VI and XII. The goats recovered and were studied over several days thereafter. VMS cooling while the goats were awake caused breathing to decrease (P < 0.05), but apnea was never observed. The decrease was less (P < 0.05) than while the goats were anesthetized. After 10 s of cooling, the hypopnea while the goats were awake was uniform during eupnea, hypercapnia, hyperoxia, and hypoxia, but after 10 s of cooling, the decrease was relatively greater (P < 0.05) during hyperoxia and hypercapnia. These effects of VMS cooling are qualitatively the same as in adult goats; thus the data are consistent with mature VMS contribution to the control of breathing in neonatal goats.

Rapid quantitation of hemoglobin S by isoelectric focusing.

The feasibility of isoelectric focusing (IEF) to determine hemoglobin S (HbS) at a faster turn-around-time and to resolve the HbS and hemoglobin A (HbA) in presence of high concentrations of hemoglobin F (HbF) is evaluated. The IEF procedure is faster, and the results can be obtained in less than 45 minutes. The resulting data are comparable to gel electrophoresis. It is a superior procedure in resolving both HbS and HbA in the presence of high HbF and, therefore, a desirable technique to use for infants and children. Further, IEF is simpler than the gel electrophoresis, relatively inexpensive, easily adaptable for routine use, and suitable for "stat" conditions.

Neonatal hypotonia and cardiomyopathy secondary to type IV glycogenosis.

A neonate with deficiency of branching enzyme (glycogenosis type IV) presented symptoms of severe hypotonia pre- and postnatally, and dilated cardiomyopathy in early infancy. The classical clinical manifestation of liver cirrhosis was not present, although amylopectin-like inclusions were found in the hepatocytes. In contrast to a previous report, the neurons in the brain stem and spinal anterior horns contained PAS-positive, diastase-resistant deposits. The combined involvement of the muscles and motor neurones could account for the severity of hypotonia. The muscle biopsy, electromyogram and biochemical and enzyme assays were helpful in establishing the diagnosis.

GM1-gangliosidosis type 1 involving the cutaneous vascular endothelial cells in a black infant with multiple ectopic Mongolian spots.

GM1-gangliosidosis (GM1) is one of the metabolic storage diseases, of which a differential diagnosis requires an array of biochemical assays to determine the enzyme deficiency. This approach is not only time-consuming and costly but also unavailable to most hospital laboratories. However, a presumptive diagnosis of GM1 may be made on the basis of coarse facial feature, foamy endothelial cells in the cutaneous blood vessels and ectopic Mongolian spots, if present. A more definitive diagnosis of GM1 is then made on the demonstration of deficiency of GM1 beta-galactosidase in leukocytes, plasma or cultured skin fibroblasts. Thus, a battery of enzyme tests may be averted.

Anesthesia-induced rhabdomyolysis in infants with unsuspected Duchenne dystrophy.

Anesthesia-induced rhabdomyolysis in infancy may represent an unsuspected Duchenne dystrophy. In order to establish the diagnosis of this genetic disease more definitively, a dystrophin test is a requisite following the conventional creatine kinase test and light and electron microscopies of the muscle biopsy.

Optic chiasm glioma associated with inappropriate secretion of antidiuretic hormone, cerebral ischemia, nonobstructive hydrocephalus and chronic ascites following ventriculoperitoneal shunting.

An optic chiasm glioma may cause loss of vision, endocrine disturbances, hydrocephalus and cerebral ischemia due to its proximity to the pituitary, hypothalamus, III ventricle and internal carotids. A 3-month-old infant with optic chiasm glioma developed hypopituitarism and inappropriate secretion of antidiuretic hormone with plasma hypo-osmolality. The cerebrospinal fluid (CSF) protein concentration was markedly elevated. The impairment of fluid absorption via arachnoid villi and peritoneum by the high protein content, and reversed osmotic gradient between protein-rich CSF and hypo-osmolar plasma may have contributed to both nonobstructive hydrocephalus and recurrent ascites following ventriculoperitoneal shunting. Cerebral ischemia from carotid compression may have led to cerebral atrophy.

Limb body-wall complex in association with sirenomelia sequence.

Limb body-wall complex and sirenomelia sequence are uncommon birth defects and their association is extremely rare. Their overlapping manifestations and their concurrence in our patient suggest that they share a common cause and belong to a group of pathologically closely related conditions. Embryonic vascular disruption may be a common pathogenesis in both anomalies.

Inflammatory myofibrohistiocytic proliferation simulating sarcoma in children.

The term "inflammatory myofibrohistiocytic proliferation" (IMP) has been proposed to replace the conventional designations of plasma cell granuloma and inflammatory pseudotumor. Three cases of extrapulmonary IMP in children are reported, including an intracerebral lesion which has been formerly undescribed. In children, IMP may be associated with microcytic hypochromic anemia, hypergammaglobulinemia, and high erythrocyte sedimentation rate. In this clinical setting, differentiation of a rapidly growing but benign IMP from a bona fide sarcoma is of paramount importance.

Atypical total anomalous pulmonary venous connection: two channels leading to infracardiac terminations.

Reported is a rare case of total anomalous pulmonary venous connection (TAPVC) where veins from each lung joined a homolateral confluence. From each confluence, a vein descended into the abdomen, the vein from the right lung joining the ductus venosus, while the vein from the left joined the portal vein. In TAPVC to systemic veins, multiple connections are rare. Multiple connections are most common at supracardiac and cardiac levels, less common at supra- and infracardiac levels, and rare at cardiac and infracardiac levels. From the literature, it is evident that multiple connections at one body level, as in our case, are rare.

Oncocytic cardiomyopathy syndrome.

The case presented is the first report of oncocytic cardiomyopathy associated with congenital heart disease. The clinical presentation was typical of hypoplastic left heart syndrome, and the oncocytic cardiomyopathy was an unexpected finding at autopsy. The associated lesions of oncocytic metaplasia in thyroid and pituitary gland have been previously reported. Maternal serology and viral cultures from the infant were negative, indicating that the oncocytic lesions were not secondary to congenital viral infection. We support the theory that oncocytic cardiomyopathy is a hamartomatous lesion, and propose as a paradigm the association between cardiac rhabdomyoma and tuberous sclerosis. Careful follow-up of surgically "cured" oncocytic cardiomyopathy should uncover oncocytomas in other organs later in life.

Fetal infection with human parvovirus B19.

The case of premature infant with nonimmune hydrops secondary to human parvovirus B19 infection is presented. The infection was not suspected clinically. The fetal autopsy showed intranuclear inclusions in erythroid cells that stained positively with a DNA hybridization probe for B19 parvovirus.

Loiasis in an expatriate American child: diagnostic and treatment difficulties.

On the basis of this experience, we recommend the following when faced with possible filariasis in an expatriate from Western Central Africa: (1) Attempt a clinical differentiation between L loa and other filarial infections present in West Africa. It is important to suspect loiasis because this is the only filarial infection that is readily curable; (2) ophthalmologic assessment to diagnose onchocerciasis; (3) if L loa is suspected, thick blood smears should be obtained from midmorning to midafternoon and stained with Giemsa or hematoxylin stains, after a concentration technique is used. Nighttime blood specimens should be obtained if the patient has been in an area where W. bancrofti is prevalent; (4) skin snip biopsies prepared as follows: Bilateral symmetrical skin snips should be taken. In the case of suspected West African filariasis, the pelvic girdle, iliac crest, and back of scapula are thought to have the highest yield. One snip from each of six different sites should be obtained. Each skin snip should be approximately 2 to 3 mm (a cornealoscleral biopsy forceps can be used). Each skin snip is placed in 100 microL (approximately one drop) of normal saline in a flat-bottomed microtiter plate. The plate is incubated at room temperature and checked periodically for 24 hours under a dissecting microscope (X20 to X40). If present, the small worms will be seen wiggling and squirming in the drop of saline; (5) serologic diagnostic methods are most efficient if human filarial antigens are used; (6) if treatment is with diethylcarbamazine, the initial dose should be small.(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular ring in interruption of the aortic arch with bilateral patent ductus arteriosi.

The previously unreported occurrence of a true vascular ring in association with interruption of the aortic arch resulting from bilateral persistence of the ductus arteriosi is described. Division of both ductus is necessary to minimize the potential for tracheobronchial compression. This should be accomplished either during definitive (one-stage) repair of the interrupted aortic arch and associated anomalies or at the initial procedure of a staged repair.