Recombinant porcine lactoferrin expressed in the milk of transgenic mice enhances offspring growth performance

The European Commission has proposed a permanent ban on the use of antibiotics as an ingredient in animal feed to promote growth. Lactoferrin is a globular multifunctional protein that has been shown to play a role in iron absorption and to have antimicrobial and anti-inflammatory activities. Therefore, lactoferrin may serve as a nontherapeutic alternative to antibiotics in livestock husbandry. As a pilot study toward this goal, transgenic mice have been generated harboring a porcine lactoferrin (pLF) gene driven by the mammary gland-specific promoter of the bovine alpha-lactalbumin (alphaLA) gene. The alphaLA-pLF hybrid gene was confirmed to have been successfully integrated and transmitted stably through the germ-line in 9 (5 females and 4 males) of 14 transgenic founders. In the female progenies of six lines analyzed, the transgene copy numbers ranged from 1 to 20 with 1-4 integration sites. Significant levels of pLF protein in milk ranging from 40 to 106 microg/mL with physical characteristics similar to those of native pLF in sow's milk were achieved in three of the transgenic lines obtained. Tissue- and stage-specific pLF expressions were restricted to the mammary gland of the transgenic female mice during lactation. It was further demonstrated that the growth performance of animal pups is enhanced by directly feeding the genetically engineered milk containing enriched pLF protein in transgenic mice. Furthermore, this enhanced growth performance in suckling mice was proportional to the concentration of pLF present in milk.

CPP antagonizes hypoxia-induced changes in dopamine metabolism in the striatum of newborn rat

Treatment with 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), a potent and competitive N-methyl-D-aspartate antagonist, is able to reduce the hypoxia-induced increase in striatal dopamine level by 26% even after the hypoxic insult has occurred. The hypoxia-induced decrease of the striatal 3,4-dihydroxyphenylacetic acid level can also be reversed by CPP. This study demonstrates that CPP can antagonize the hypoxia-induced changes in the dopamine metabolism in the striatum of the newborn rat.

Cervical cord tethering mimicking focal muscular atrophy

Spinal cord tethering rarely occurs in the cervical region. In adults, it usually results from previous operations. However, congenital origin is always diagnosed and treated early in the infant period. We report a 12-year-old boy with cervical spinal dysraphism which was erroneously diagnosed as focal muscular atrophy, a benign form of motor neuron disease. The patient was brought to our hospital because of rapid deterioration of symptoms. Careful evaluation disclosed a hairy dimple at the nuchal area, which led to the correct diagnosis. X-ray of the cervical spine showed spina bifida from C(4) to C(6) levels and fusion of the laminae of C(4) and C(5). Spine MRI studies disclosed that the cervical cord was tethered caudally and dorsally, and the ventral nerve roots were markedly stretched, especially over the left side. Surgical intervention was undertaken and the patient's muscle power improved after untethering. The purpose of this report is to acquaint the reader with a surgically treatable condition that may appear to be benign focal amyotrophy. Skin lesion at the nuchal area should be carefully looked for.

Multimodal approach of cranial ultrasound in children

The potential uses of cranial ultrasound have been overlooked for years because of the advent of fascinating neuroimaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) study. In this article, the authors introduce the developments and refinement in modern pediatric neurosonology. In the past, only neonates with widely open fontanels seemed to be good candidates for cranial ultrasound study. Actually, any tiny skull defect can be used as an acoustic window. And the thin skulls of children do not hinder the ability of ultrasound to obtain acceptable image transcranially. Today, many CT and MRI studies can be replaced with the advanced cranial ultrasound if clinicians or neurologists recognize the advantages. Cranial ultrasound can provide Doppler hemodynamic studies which CT and MRI can not. Only ultrasound can provide convenient, real-time intraoperative guidance and continuous bedside monitoring in patients who need neurological intensive care. Cranial ultrasound also plays an important role in follow-up studies because it is convenient, economical, and safe, especially in children. To obtain all the benefits from an ultrasound study, one has to realize the "multimodal" applications of it, including the applications of all acoustic windows, multifrequency transducers, and hemodynamic study with the aid of power Doppler and contrast agents. With a multimodal approach, physicians can achieve the utmost from the powerful modern cranial ultrasound in pediatric patients.

Distribution and expression of the subunits of N-methyl-D-aspartate (NMDA) receptors; NR1, NR2A and NR2B in hypoxic newborn piglet brains

The purpose of this study was to identify the distribution and the expression of the NR1, NR2A and NR2B subunits of the NMDA receptor after cerebral hypoxia. Ten piglets were divided into control and hypoxic groups (n=5, each). The control piglets were ventilated with normoxia for 1 h, and the hypoxic piglets were ventilated with hypoxia until paO2 was below 20 mmHg. Tissue samples from the nine different regions of newborn piglet brain were obtained, and the protein amount of the NR1, NR2A, and NR2B subunits measured by immunoblot using the antibody to the NR1, NR2A, and NR2B subunits. The NR1, N2A, and NR2B subunits were distributed very differently; hippocampus and cortical area are more prominent than white matter and cerebellum. But the expression of the NR1, NR2A and NR2B subunits were not significantly different between the control and the hypoxic group, 1 h after hypoxic exposure, indicating no changes in the protein amount of NMDA receptor subunits. These results show a significantly higher amount of the NR1, NR2A and NR2B subunits in the hippocampus and the cerebral cortex of newborn brains, indicating that these structures could be highly vulnerable to excitotoxicity in the newborn brain.

Excitatory amino acid receptor antagonists decrease hypoxia induced increase in extracellular dopamine in striatum of newborn piglets

The present study tested the hypothesis that the increase in extracellular striatal dopamine during hypoxia is least partly associated with activation of N-methyl-D-aspartate (NMDA) and/or non-NMDA excitatory amino acid receptors. Studies were performed in anesthetized and mechanically ventilated 2-3 days old piglets. Hypoxic insult was induced by decreasing the oxygen fraction in inspired gas (FiO2) from 22 to 7% for 1 h, followed by 1 h reoxygenation at 22%. Cortical oxygen pressure was measured optically by oxygen dependent quenching of phosphorescence, and extracellular striatal dopamine was measured using in vivo microdialysis. The microdialysis probes were perfused with Ringer solution +/- 50 microM (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) or 50 microM 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline (NBQX). One hour of hypoxia decreased the cortical oxygen pressure from 46 +/- 3 Torr to 10 +/- 1.8 Torr. In striatum perfused with Ringer, statistically significant increase in extracellular dopamine, to 1050 +/- 310% of control, was observed after 20 min of hypoxia. By 40 min of hypoxia the extracellular level of dopamine increased to 4730 +/- 900% of control; by the end of the hypoxic period the values increased to 18,451 +/- 1670% of control. The presence of MK-801 in the perfusate significantly decreased the levels of extracellular dopamine during hypoxia. At 20, 40 and 60 min of hypoxia extracellular level of dopamine increased to 278 +/- 94% of control, 1530 +/- 339% of control and 14,709 +/- 1095 of control, respectively. The presence of NBQX caused a statistically significant decrease, by about 30%, in the extracellular dopamine compared to control, only at the end of the hypoxic period. It can be concluded that in striatum of newborn piglets, the excitatory NMDA receptors but not the non-NMDA receptors may be modulating the changes in extracellular levels of dopamine. The NMDA receptor antagonist, MK-801, may exert part of its reported neuroprotective effect to hypoxic stress in striatum by decreasing the levels of extracellular dopamine.

Combined encephalo-arterio-synangiosis and encephalo-myo-synangiosis in the treatment of moyamoya disease

From January 1990 to December 1995, a total of nine cases of Moyamoya disease were treated at the National Taiwan University Hospital with combined encephalo-arterio-synangiosis (EAS) and encephalo-myo-synangiosis (EMS). There were five males and four females and their ages ranged from 6 months to 31 years. Of these, two cases had their first symptom as intracranial hemorrhage and the rest of the cases had ischemic manifestations. Surgical treatment with combined EAS and EMS was performed on 16 hemispheres of the nine cases. The superficial temporal artery with its anterior and posterior branches was isolated and fixed to the pial surface. Then, the muscle pedicle from the bivalved temporal muscle was used as a dural graft to cover the artery. All the cases showed good neovascularization on follow-up angiography performed at 2-3 months after surgery. These two patients with hemorrhagic symptoms were followed for 52 and 61 months, respectively. Neither of these two cases showed recurrent bleeding. For patients with ischemic symptoms, the follow-up period ranged from 8 to 73 months (mean 41.7 months). All the patients showed improvement in their clinical symptoms.

Cerebral oxygen transport and metabolism during graded isovolemic hemodilution in experimental global ischemia

To verify the optimal hematocrit (Hct) level in the treatment of cerebral ischemia, cerebral oxygen transport (CTO2) and cerebral oxygen metabolism (CMRO2) in graded isovolemic hemodilution were evaluated during cerebral ischemia. Isovolemic hemodilution with low molecular weight dextran to stepwise lower Hct from 43% to 36%, 31%, and 26% was carried out in 13 splenectomized dogs, 6 h after global cerebral ischemia. Global ischemia of the animals was produced by multiple intra- and extracranial ligations of cerebral arteries. Cerebral blood flow (CBF) was measured with radioisotope labeled microspheres. CTO2, CMRO2, and oxygen extraction fraction (OEF) were calculated from CBF, arterial oxygen content (CaO2), and venous oxygen content (CvO2). In dogs with global cerebral ischemia, CBF increased with graded isovolemic hemodilution (r=-0.73, P<0.05). CTO2 reached its highest value at a Hct level of 31.3%. CTO2 at Hct of 36.1% and 31.3% was statistically different from the value measured at a Hct of 43.3%, and there was a decrease when Hct was lowered to 25.9%. CMRO2 was the highest when Hct was at 31.3% and differed significantly from the value measured at a Hct of 43.3%. There was a 10% increase of OEF when Hct was at 25.9%; however this change was not statistically significant compared with the OEF at Hct of 36.1% and 31.3%, respectively. These findings indicate that CTO2 and CMRO2 were the highest when Hct was reduced to 31% in hemodilution. Hct at 31% is the optimum for cerebral metabolism in ischemic status. Uncoupling of CTO2, CMRO2 with CaO2 was also observed in this study. This phenomenon suggests that hemodilution to augment cerebral circulation may be at least partially attributed to the beneficial effects of hemorheologic improvement in the microcirculation of the ischemic brain.

Supraorbital approach of the anterior cerebral artery: a new window for transcranial Doppler sonography

Usually, a transtemporal Doppler sonographic study of the anterior cerebral artery can insonate the A1 segment only. We found a new window just above the supraorbital ridge to approach the A2 segment and even the proximal portion of the pericallosal segment in 17 of 21 volunteers aged from 16 months to 39 years. The failed four cases had an average age of 23 years. We suggest that the supraorbital approach can be tried as another window during transcranial Doppler sonographic examinations, especially in the young patient and in those for whom the transtemporal approach has failed.

Sonographic lenticulostriate vasculopathy in infants: some associations and a hypothesis

PURPOSE

To describe the causes of infantile lenticulostriate vasculopathy (LSV) as demonstrated by sonography and propose the pathogenesis of these findings.

METHODS

Five hundred eighty-six infants were examined via echoencephalography because of seizures, psychomotor retardation, dysmorphism, congenital malformation, microcephaly, macrocephaly, bulging of anterior fontanel, consciousness disturbance, or prematurity. We directed our attention on the sonographic study to the basal ganglionic and thalamic areas. Twenty-eight of the 586 patients underwent color Doppler studies.

RESULTS

In 34 infants with gray-scale neurosonographic findings of LSV, 16 were associated with various causes that have been reported before. In 8 patients entities not previously associated with LSV were found: neonatal lupus, neonatal hypoglycemia, uncomplicated prematurity, encephalitis, and head injury. In the remaining 10 cases, a specific cause could not be found. The LSV was found in 16 (40%), 5 (14%), and 13 (3%) patients with perinatal, acquired, and nonspecific causes, respectively. Generally, this is an uncommon finding because it was observed in only 34 (5.8%) of the study infants; 24 of these 34 had a documented cause of the vasculopathy. With LSV associated with perinatal causes there was a greater chance of sonographic LSV's developing than with that of acquired causes.

CONCLUSIONS

We suggest that sonographic LSV is a nonspecific marker of a previous insult to the developing brain, and the special hemodynamics of the fetal brain plays an important role in its pathogenesis.

Spinal intradural arteriovenous fistula: a case with an unusual presentation

Spinal intradural arteriovenous fistula is a rare type of spinal vascular malformation. It is usually fed by the anterior spinal artery and causes episodic myelopathy in young adults. We present a pediatric patient with such a vascular malformation which was fed directly by a medullary artery. The clinical course, complete radiological study and the excellent outcome will be described in detail. This rare subtype of spinal vascular malformation will be discussed.

Choreoathetosis as an initial sign of relapsing of herpes simplex encephalitis

Twelve children with type 1 herpes simplex encephalitis (3 with relapse, 9 without) have been monitored during the past 7 years. Ten of the children received intravenous infusion of acyclovir (30 mg/kg/day) for 10 days, 1 child who experienced relapse received 15 mg/kg/day, and another relapsed child received no antiviral agents until relapse. Relapse occurred 20-36 days after initial onset. All relapsed patients underwent another 10 days of acyclovir treatment (30 mg/kg/day). Choreoathetosis appeared as the initial sign of relapse followed by rapidly progressive unresponsiveness in all 3 relapsed patients: in 1 nonrelapsed patient choreoathetosis occurred during the recovery period. In these 4 patients involuntary movement was remitted within 3 months to 2 years. One patient with choreoathetosis died of measles pneumonia 4 months after onset of herpes simplex encephalitis and the surviving 3 were severely retarded. Although neuroimaging sparing of basal ganglia does not indicate structural and functional abnormalities, the disturbance of the neural connection among the basal ganglia and the cerebral cortex, which manifested severe damage over frontal, temporal, and parietal mantles on CT, may be the source of movement disorders in these patients. We conclude that choreoathetosis may be the first sign of relapse of herpes simplex encephalitis in children and may be an indicator of poor prognosis. The neuropathogenesis of choreoathetosis requires further investigation.

Percutaneous lumbar discectomy: indications and surgical results in 35 consecutive cases

Thirty-five patients (27 men and eight women) who met our criteria of case selection for percutaneous lumbar discectomy (PLD) were treated by this method during the period May 1992 to June 1993. Thirty-six spaces, including one man with double disc disease, were decompressed. Patients ranged in age from 14 to 64 years. All patients but one were followed up for a minimum of six months. The operative results, evaluated by a more objective functional grading system, revealed a short-term (two months) success rate of 83% and a mid-term (six months) success rate of 76%. This discrepancy resulted from two recurrences of sciatic symptoms. It indicates that the medical conditions of those who have received PLD are by no means static, but instead may fluctuate. The operative result was similar to that of open discectomy, averaging 81.1% in reported series. Our "functional grading system" reflects these fluctuations quantitatively. With respect to the operative success rate, there was a statistical difference between the very good, good and fair-poor indication groups of patients, as were categorized by our major criteria of indications that included three clinical manifestation criteria and the other three radiographic findings. This result emphasizes the critical role of case selection in the operative success rate. Complications consisted of one disc infection which cleared without sequelae. This study provides an objective means of selecting cases and evaluating surgical results which, in turn, makes the use of this procedure convincing and predictable.

Solitary cerebellar metastasis from Ewing's sarcoma: case report and review of the literature

A rare case of Ewing's sarcoma metastatic to the cerebellum is presented. Neurosurgical intervention was required which played a significant role in the treatment of this patient. The incidence and treatment of central nervous system involvement from Ewing's sarcoma is reviewed and discussed.

Solitary cerebellar metastases: analysis of 11 cases

Solitary cerebellar metastatic tumors are rarely reported in the literature. We reviewed 240 posterior fossa tumors treated in the past eight years. There were 11 cases of solitary metastases in the cerebellum. The primary tumor was lung cancer in five cases and breast carcinoma in two cases; the remaining three cases had colon cancer, nasopharyngeal carcinoma (NPC) and Ewing's sarcoma, respectively. All patients underwent craniectomy and gross total excision of the tumor. Seven patients survived less than one year, two cases died in the second year, and one case of NPC survived for more than two years. The only survival is a case of Ewing's sarcoma who underwent surgery 14 months ago. The symptoms and signs of all patients improved satisfactorily after surgery. Four patients received postoperative irradiation to the posterior fossa and two cases of lung cancer had a thoracotomy for the primary lung lesion; however, the survival period was not prolonged. We suggest that a cancer patient or a patient in the fifth to seventh decades of life presenting headache, gait disturbance and vomiting should promptly undergo a computed tomography (CT) scan of the head. In selected cases, surgical intervention for solitary metastatic tumors in the tiny posterior fossa may be the best initial treatment. Adjuvant therapies should then be added according to the type of tumor.

Medical cure of a brainstem abscess and serial brainstem auditory evoked potentials

The brainstem abscess of a nine-year-old girl with tetralogy of Fallot was cured after six weeks of parenteral antibiotic therapy, without surgical intervention. Serial studies of brainstem auditory evoked potentials were undertaken until the patient was clinically normal. To the authors' knowledge, this is only the second medically cured case reported in the literature, and it is the first case studied with serial brainstem auditory evoked potentials. If the clinical status allows, medical treatment of a brainstem abscess with appropriate antibiotics could be tried before surgical intervention such as stereotactic aspiration for reducing the mass.