Why would you remove half a brain? The outcome of 58 children after hemispherectomy-the Johns Hopkins experience: 1968 to 1996.

PURPOSE: To report the outcomes of the 58 hemispherectomies performed at Johns Hopkins between 1968 and January 1996. METHODS: Charts were reviewed of the 58 hemispherectomies performed at Johns Hopkins Medical Institutions by the Pediatric Epilepsy Group during the years 1968 to 1996. Twenty-seven operations were done for Rasmussen's syndrome, 24 operations for cortical dysplasias/hemimegalencephalies, and 7 for Sturge-Weber syndrome or other congenital vascular problems. Seizure control alone did not seem to adequately describe the outcomes of the procedure. Therefore, a score was constructed that included seizure frequency, motor disability, and intellectual handicap. This burden of illness score better described the child's handicap before and after surgery. RESULTS: Perioperative death occurred in 4 out of 58 children. Of the 54 surviving children, 54% (29/54) are seizure-free, 24% (13/54) have nonhandicapping seizures, and 23% (12/54) have residual seizures that interfere to some extent with function. Reduction in seizures was related to the etiology of the unilateral epilepsy. Eighty-nine percent of children with Rasmussen's, 67% of those with dysplasias, and 67% of the vascular group are seizure-free, or have occasional, nonhandicapping seizures. All operations were considered by the parents and the physicians to have been successful in decreasing the burden of illness. In 44 the procedure was very successful, in 7 it was moderately successful, and in 3 it was minimally successful. Success was related to the etiology, and early surgery was preferable. CONCLUSION: Hemispherectomy can be a valuable procedure for relieving the burden of seizures, the burden of medication, and the general dysfunction in children with severe or progressive unilateral cortical disease. Early hemispherectomy, although increasing the hemiparesis in children with Rasmussen's syndrome, relieves the burden of constant seizures and allows the child to return to a more normal life. In children with dysplasias, early surgery can allow the resumption of more normal development.

Hemispherectomy: a hemidecortication approach and review of 52 cases.

Between 1975 and 1994, 52 hemispherectomies, of which two were anatomical and 50 hemidecortications, were performed at Johns Hopkins Medical Institutions. Eighteen patients were 2 years old or less. There were three perioperative mortalities and one patient died 9 months later from causes not related to surgery. One patient developed hydrocephalus 6 years postsurgery and has been treated effectively. Seizure control and the functional status of each patient were measured as outcome variables. Forty-six (96%) of the surviving patients were seizure free or had reduced seizures as of their last follow-up examination. Twenty-one individuals (44%) were participating in age-appropriate classes or working independently, 18 were classified as semiindependent, and nine children will likely depend on a lifetime of assisted living. The relationships between the outcome variables and the patient's age at surgery, the interval to surgery, and the etiology of the disease were compared. The authors' clinical experiences strongly suggest the importance of a multidisciplinary approach to patient selection and follow-up care. Moreover, anesthetic management of infant surgery is a major component of success.

Emergency management of hypercyanotic crises in tetralogy of Fallot.

We report the case of a 3-month-old girl with tetralogy of Fallot who was resuscitated from a near-fatal hypercyanotic episode (Tet spell). While tetralogy of Fallot is rare (1 in 10,000 live births), failures of diagnosis or management may result in catastrophic outcomes for an eminently survivable condition. An understanding of the pathophysiology of hypercyanotic spells will allow the emergency specialist to understand and apply a treatment option--compression of the abdominal aorta--not previously reported in the emergency medicine literature.

Reducing perioperative pain and anxiety.

As outpatient surgery becomes the norm, pediatricians are increasingly involved in preparing children--and their families--for the experience. This anesthesiologist's approach can help you guide your patients toward a smooth recovery.

Perioperative approach to children.

There has been a tremendous amount of progress in the perioperative approach to the child since Levy wrote "Psychic trauma of operations in children and a note on combat neurosis" nearly 50 years ago. Recognition of prolonged behavioral derangements following the anesthetic-surgical-hospital experience and the prominent role that the parent and physician play in modifying these have dramatically changed the contemporary pediatric perioperative care. Of paramount importance is the psychological preparation of family and child. With increasing outpatient or same-day admission surgery and free-standing surgical centers, preoperative preparation will, of necessity, increasingly become the responsibility of the pediatrician.

Effects of hypoxia on interleukin-2 mRNA expression by T lymphocytes.

OBJECTIVE: To investigate the effects of hypoxia on T-lymphocyte expression of IL-2 messenger RNA (mRNA), after cell activation with phorbol ester and ionomycin. DESIGN: Prospective, controlled, cellular trial. SETTING: University research laboratory. SUBJECTS: EL4.6.1 cells, a murine T-cell lymphoma line. INTERVENTIONS: Tissue culture media was deoxygenated and flushed continuously with 100% helium to maintain a PO2 of 30 to 40 torr (< 40 torr [< 5.3 kPa]), or flushed with 10% oxygen/90% helium to maintain a PO2 of 45 to 55 torr (> 45 torr [> 6.0 kPa]). The pH was maintained between 7.3 and 7.6. The media was inoculated with EL4 cells. Aliquots of cells were obtained at intervals and divided into two groups: an immediate group, stimulated immediately, and an overnight group that was returned to normal incubator conditions of 5% CO2/humidified room air for 18 hrs before stimulation. MEASUREMENTS AND MAIN RESULTS: Gas tension, pH, cell count, and viability were determined for each aliquot. Cells were stimulated with phorbol myristate acetate and ionomycin for 4 hrs, at which time levels of interleukin-2 (IL-2) messenger RNA (mRNA) and gamma actin mRNA were measured by solution hybridization and enzyme immunoassay. The results were expressed as IL-2 mRNA/gamma actin mRNA ratio, normalised to baseline room air values. Cell viability and housekeeping functions (gamma actin mRNA expression) were unaffected by hypoxia. Cells exposed to a PO2 of < 40 torr (< 5.3 kPa) demonstrated a dramatic reduction in IL-2 mRNA expression with increasing duration of hypoxia. These effects persisted after an 18-hr recovery period. There was no effect on IL-2 mRNA expression when cells were exposed to a PO2 of > 45 torr (> 6.0 kPa). CONCLUSIONS: The regulation of IL-2 transcription in the T lymphocyte appears to be exquisitely sensitive to changes in oxygen tension. Exposure to a PO2 of < 40 torr (< 5.3 kPa) causes prolonged impairment of IL-2 mRNA expression. IL-2 is an important growth factor for T and NK cells, and plays a pivotal role in the regulation of the host's immune response. The long-lasting effects of brief hypoxic exposure may, in part, explain the critically ill patient's predisposition to infectious complications.

High-molecular weight kininogen. A secreted platelet protein.

Human platelets were studied immunochemically to determine if they contain high-molecular weight kininogen. On crossed immunoelectrophoresis with total kininogen antisera (antisera that recognizes both high- and low-molecular weight kininogen) extracts of platelets contained total kininogen antigen. Platelet total kininogen antigen showed complete antigenic identity with plasma total kininogen and displayed the same electrophoretic migration as plasma total kininogen. Using antisera monospecific to high molecular weight kininogen, a competitive enzyme-linked immunosorbent assay (CELISA) was developed to directly measure platelet high-molecular weight kininogen. By CELISA, 27-101 ng of high molecular weight kininogen antigen per 10(8) platelets was quantitated in detergent-soluble lysates of washed human platelets from nine normal donors with a mean level of 60 ng +/- 24/10(8) platelets. Plasma high-molecular weight kininogen, either in the platelet suspending medium or on the surface of the platelets, could only account for 5% of antigen measured in the solubilized platelets. On the CELISA, platelet high-molecular weight kininogen was immunochemically identical to plasma and purified high-molecular weight kininogen. Platelet high-molecular weight kininogen was secreted from platelets after exposure to ionophore A23187 (3-15 microM), collagen (5-150 micrograms/ml), and thrombin (1.6 U/ml). Secreted platelet high-molecular weight kininogen did not become a part of the platelet Triton-insoluble cytoskeleton. On cross immunoelectrophoresis secreted platelet total kininogen antigen had a similar electrophoretic migration to plasma total kininogen. Thus, human platelets contain high-molecular weight kininogen that can be secreted from platelets and that may participate in plasma coagulation reactions.

Emulsifier of Arthrobacter RAG-1: isolation and emulsifying properties.

The oil-degrading Arthrobacter sp. RAG-1 produced an extracellular nondialyzable emulsifying agent when grown on hexadecane, ethanol, or acetate medium. The emulsifier was prepared by two procedures: (i) heptane extraction of the cell-free culture medium and (ii) precipitation with ammonium sulfate. A convenient assay was developed for measurement of emulsifier concentrations between 3 and 75 micrograms/ml. The rate of emulsion fromation was proportional to both hydrocarbon and emulsifier concentrations. Above pH 6, activity was dependent upon divalent cations; half-maximum activity was obtained in the presence of 1.5 mM Mg2+. With a ratio of gas oil to emulsifier of 50, stable emulsions were formed with average droplet sizes of less than 1 micron. Emulsifier production was parallel to growth on either hydrocarbon or nonhydrocarbon substrates during the exponential phase; however, production continued after growth ceased.

Emulsifier of Arthrobacter RAG-1: chemical and physical properties.

The extracellular emulsifier of Arthrobacter RAG-1 was deproteinized by hot phenol treatment and purified by fractional precipitation with (NH(4))(2)SO(4). The active fraction, precipitating between 30 and 35% saturation [EF-RAG(UET) WA], appeared to be homogeneous by immunodiffusion and sedimentation analysis. EF-RAG(UET) WA had an intrinsic viscosity of 750 cm(3)/g, a sedimentation constant of 6.06S, a diffusion constant of 5.25 x 10(-8) cm(2) s(-1), and a partial molar volume of 0.712 cm(3) g(-1). From these data a weight average molecular weight of 9.76 x 10(5) and a viscosity average molecular weight of 9.88 x 10(5) were calculated. EF-RAG(UET)WA contained 46.7% C, 7.01% H, and 6.06% N. Titration of the nonreducing polymer gave a single inflection point (pK' = 3.05), corresponding to 1.5 mumol of carboxyl groups per mg. Direct estimation of O-ester and hexose content of the highly acidic polymer yielded 0.65 and 0.29 mumol/mg, respectively. Mild alkaline hydrolysis released fatty acids with an average molecular weight of about 231. Strong acid hydrolysis of EF-RAG(UET)WA yielded d-glucose (minor), d-galactosamine (major), and an unidentified amino uronic acid (major).

Bactericidal action of an antibiotic produced by Myxococcus xanthus.

Myxococcus xanthus produced an antibiotic during the end of its exponential growth phase which was capable of inhibiting growth of several gram-positive and gram-negative bacteria. The antibiotic was bactericidal to growing cultures only; chloramphenicol inhibited the bactericidal action of the antibiotic. Upon addition of the antibiotic to Escherichia coli B, deoxyribonucleic acid and ribonucleic acid as well as turbidity of the culture continued to increase even after the viable count decreased; the culture lysed about 60 min after addition of sufficient concentrations of the antibiotic. Spheroplasts could be prepared if the antibiotic was added to a culture growing in the presence of high concentrations of sucrose and MgSO(4). Mutants of M. xanthus FB which are incapable of fruiting body formation or glycerol-induced myxospore formation also produced the antibiotic. A mutant of E. coli resistant to the purified antibiotic was isolated in order to study the role of the antibiotic in the predatory behavior of myxococci.