The IUD. Time for a second look.
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Female↗
Biomedical subjects
T Pittman
Publications and source records attributed to T Pittman.
Headspace gas chromatographic method for the measurement of difluoroethane in blood.
OBJECTIVES: To develop a gas chromatographic assay for the analysis of difluoroethane, a volatile substance, in blood and to determine assay characteristics including linearity, limit of quantitation, precision, and specificity. SETTING: Referral toxicology laboratory RESULTS: Difluoroethane, a colorless, odorless, highly flammable gas used as a refrigerant blend component and aerosol propellant, may be abused via inhalation. A headspace gas chromatographic procedure for the identification and quantitation of difluoroethane in blood is presented. A methanolic stock standard prepared from pure gaseous difluoroethane was used to prepare whole blood calibrators. Quantitation of difluoroethane was performed using a six-point calibration curve and an internal standard of 1-propanol. The assay is linear from 0 to 115 mg/L including a low calibrator at 4 mg/L, the limit of quantitation. Within-run coefficients of variation at mean concentrations of 13.8 mg/L and 38.5 mg/L were 5.8% and 6.8% respectively. Between-run coefficients of variation at mean concentrations of 15.9 mg/L and 45.7 mg/L were 13.4% and 9.8% respectively. Several volatile substances were tested as potential interfering compounds with propane having a retention time identical to that of difluoroethane. CONCLUSIONS: This method requires minimal sample preparation, is rapid and reproducible, can be modified for the quantitation of other volatiles, and could be automated using an automatic sampler/injector system.
Administration, Inhalation↗
Stroke associated with marijuana abuse.
We present the case of a 15-year-old with a cerebellar infarct that involved multiple arterial territories. It was temporally related to, and probably caused by, heavy marijuana use. While the mechanism of marijuana-associated stroke is unclear, the drug is known to cause hypotension and to impair peripheral vasomotor reflexes. We suspect that the child had diminished cerebral autoregulatory capacity and developed the stroke during a period of hypotension.
Adolescent↗
Cranial vault expansion: a comparison of magnetic coupled distraction to traditional surgical repositioning.
We compared the effectiveness of transcutaneously activated magnetic distraction of an osteotomized cranial bone flap to surgical repositioning of the flap with immediate, rigid internal fixation. Thirty immature rabbits were studied. All 30 rabbits underwent complete circumferential osteotomies of both parietal bones and postoperatively all were fitted with head frames. The rabbits were divided into 4 groups. The experimental magnetic distraction group consisted of 10 animals (group 1). In these rabbits magnets were secured to both parietal bones and magnets of opposite polarity were placed in the headframes. Each morning, the magnets in the head-frames were moved 0.25 mm farther away from the skull; this continued for 20 days for a total setback of 5 mm. Five animals served as the magnetic distraction controls; in these animals magnets were placed on the parietal bones but none were attached to the headframes (group 2). The experimental surgical repositioning group consisted of 10 rabbits (group 3). In each the parietal bones were elevated and fixed 5 mm above the rest of the skull using vitallium mesh and screws. Five rabbits made up the surgical respositioning control group (group 4). In these animals, parietal osteotomies were performed but the bones were secured to the skull in their original positions using hardware identical to that used in the experimental group. Six weeks later all of the animals were sacrificed. Two significant differences were identified between the experimental groups: (1) the cranial contours of the animals in the magnetic distraction group were rounded while those of the surgically repositioned group were acutely angled; (2) the osteotomies in rabbits in the magnetic distraction group were essentially completely ossified while in rabbits in the surgically repositioned group there were obvious gaps at the osteotomy sites that were filled with fibrous tissue. These conclusions support the potential utility of magnetically activated distraction as an alternative to current methods of cranial vault remodeling.
Animals↗
Exophytic juvenile pilocytic astrocytomas of the posterior fossa.
In children, posterior fossa juvenile pilocytic astrocytomas are common tumors. Radiologically, primarily extra-axial brainstem pilocytic astrocytomas are uncommon and extra-axial cerebellar pilocytic tumors are exceptional. We report two cases of such exophytic tumors, contrasting their presentation, imaging appearance, and prognosis. We also report the radiographic features of posterior fossa juvenile pilocytic astrocytomas from a 5-year review of our institutional experience.
Astrocytoma↗
De novo expression of the class-A macrophage scavenger receptor conferring resistance to apoptosis in differentiated human THP-1 monocytic cells.
The class-A macrophage scavenger receptor (MSR) is a trimeric multifunctional protein expressed selectively in differentiated monomyeloid phagocytes which mediates uptake of chemically modified lipoproteins and bacterial products. This study investigated whether MSR plays a role in the regulation of apoptosis, a model of genetically programmed cell death. De novo expression of MSR occurred in human THP-1 monocytic cells differentiated with phorbol esters, which activated a nuclear transcription factor binding to the Ap1/ets-like domain of the MSR promoter. The phorbol ester-stimulated THP-1 cells also expressed increased levels of the pro-apoptotic gene products, caspase-3 and Fas ligand, but the cells exhibited no change in apoptosis. Global activation of GTP-binding proteins with fluoride anions triggered apoptosis of THP-1 cells in a time- and concentration-dependent manner, demonstrated by nuclear shrinkage and fragmentation and internucleosomal DNA fragmentation. However, the MSR-expressing THP-1 macrophage-like cells showed a significant reduction in apoptosis compared to undifferentiated control THP-1 cells, which produce MSR at undetectable levels. Fluoride stimulation also triggered apoptosis of human Jurkat T cells. Stimulation with phorbol ester made no difference in apoptosis between treated and untreated Jurkat cells. Finally, Chinese hamster ovary (CHO) cells overexpressing the class-A MSR type I by cDNA transfection showed markedly increased resistance to G-protein-coupled apoptosis. Thus, de novo expression of MSR associated with monocyte maturation into macrophages appears to confer the resistance of macrophages to apoptotic stimulation by G-protein activation.
Animals↗
Late shunt infections.
We reviewed the records of the 957 shunt-related operations performed at Cardinal Glennon Children's Hospital over a 10-year period. During that time, 94 shunt infections were recognized. Eight of the infections occurred more than 9 months postoperatively. These differed from early infections in two ways: (1) Staphylococcus aureus was not found to be a pathogen in any late infection. (2) Abdominal pseudocysts were much more frequently found in patients with late-developing infections. In addition, the pathogens involved and the temporal distribution of cases suggest most infections that occur more than 9 months postoperatively are more likely caused by secondary bacterial seeding than by bacterial inoculation at the time of operation.
Adolescent↗
Early hypotension worsens neurological outcome in pediatric patients with moderately severe head trauma.
PURPOSE: The objective of this study was to determine the morbidity associated with hypotension in the resuscitative phase of pediatric head trauma. METHODS: A retrospective review (1990 to 1995) was performed at a level-1 pediatric trauma facility. Inclusion criteria included a Glasgow coma score (GCS) of 6 to 8 and absence of penetrating trauma or bleeding disorders. The GCS was assigned using a postresuscitation examination by a neurosurgeon. Hypotension was defined as a blood pressure reading of less than the fifth percentile for age that lasted longer than 5 minutes. Episodes were monitored from the onset of injury through the first 24 hours of hospitalization. Glasgow outcome scale (GOS) was assigned based on a 3-month follow-up evaluation. Analysis of variance (ANOVA) and contingency table analysis were performed on all groups, and a P value of less than .05 was taken to represent statistical significance. RESULTS: Seventy-two patients met inclusion criteria. They had a mean GCS of 7.2 and a mean age of 6 years; 97% survived. Early hypotension was associated with worse neurological outcome (GOS) and prolonged hospitalization. There was no significant correlation between GOS and age, gender, injury mechanism, associated injuries, or transport time. CONCLUSIONS: These data suggest that maintaining adequate blood pressure during the early resuscitation of pediatric blunt head trauma patients may improve neurological outcome.
Child↗
Cranial vault expansion using transcutaneously activated magnetic implants.
The technique of distraction osteogenesis has not been widely used in the treatment of problems of the head and face because of the need for external fixators. By using magnetic, rather than mechanical, forces to drive bone movement we hope to expand the applications of the technique to include the treatment of cranial vault deformities. Thirty immature rabbits were studied. Twenty-six of the rabbits underwent operations. Each of the 26 had 2 magnets fixed to its skull: one on the left parietal bone and one on the right parietal bone. Incomplete circumferential osteotomies were then performed around each magnet on 13 of the rabbits. A head frame was attached to each animal. Head frames without magnets were placed on 6 of the rabbits (3 with osteotomy, 3 without osteotomy) while 20 of the animals (10 with osteotomy, 10 without osteotomy) had 2 magnets mounted on the frames which were of opposite polarity to those implanted. The remaining 4 rabbits served as nonoperative controls. Six weeks later all of the animals were sacrificed. There were significant differences in the cranial volumes and contours between the groups of animals. Many of the differences were increased by coincident osteotomy. Associated histologic findings are described.
Animals↗
Growing skull fractures: strategies for repair and reconstruction.
Most skull fractures in growing children heal rapidly and without significant contour irregularity. Skull fractures in infants associated with dural injuries, however, may progressively enlarge as a result of bone erosion by leptomeningeal herniation at the dural tear sites and are known as "growing skull fractures." Over a 6-year period, seven growing skull fractures occurred in a population of 592 consecutive pediatric head injuries at Cardinal Glennon Children's Hospital (prevalence, 1.2%). Prompt recognition of growing skull fractures, repair by regional craniectomy and pericranial dural inlay graft, and immediate contour reconstruction with rigidly fixed cranial bone graft ensure reliable aesthetic and functional restoration of the growing neurocranium.
Biocompatible Materials↗
Cranial vault moulding by the transcutaneous activation of implanted magnets.
The technique of distraction osteogenesis has not been widely used in the treatment of injuries of the head and face because of the need for external fixators. By using magnetic, rather than mechanical, forces to drive bone movement we hope to expand the applications of the technique to include the treatment of cranial vault deformities. Fifteen immature rabbits were studied. When they were 6 weeks old each had a magnet fixed to their left parietal bone. A head frame was attached and a magnet of either the opposite polarity to, (group 1), or the same polarity as, (group 2), the implanted magnet was mounted on the frame. Five weeks later the rabbits were sacrificed. There were significant differences in parietal skull width and in several measures of skull length between the animals in group 1 and those in group 2. These results demonstrate that, in this model, magnetic forces can be used to modify skull growth.
Animals↗
Simultaneous identification and quantitation of codeine, morphine, hydrocodone, and hydromorphone in urine as trimethylsilyl and oxime derivatives by gas chromatography-mass spectrometry.
Following enzymatic hydrolysis of urine, a gas chromatography-mass spectrometry method for the simultaneous determination of codeine, morphine, hydrocodone, and hydromorphone uses hydroxylamine to form oxime derivatives of the keto-opiates (i.e., hydrocodone, hydromorphone, oxycodone, and oxymorphone). These trimethylsilyl-derivatized forms no longer interfere with the detection and quantitation of codeine and morphine. Samples are extracted on solid-phase columns and quantitated by deuterated internal calibrations of each analyte with selected ion monitoring. Codeine, morphine, hydrocodone, and hydromorphone are completely separated, allowing simultaneous quantitation without interference and a chromatographic analysis time < 9 min.
Codeine↗
Two traffic fatalities related to the use of difluoroethane.
The 18-year-old white male driver and 17-year-old white male passenger of an automobile were killed when their vehicle crossed the median of a 4-lane highway and collided with a minivan. A can of airbrush propellant was found in the automobile of the deceased. The only drug detected during initial toxicological analyses was 130 mg/L ethanol in the blood of the driver. When performing ethanol analysis by headspace gas chromatography, an unidentified peak was observed in the blood of both deceased. This peak was identified as difuoroethane (Freon 152), the propellant in the aerosol can found in the automobile. The concentrations of difluoroethane in the blood of the driver and passenger were 78 mg/L and 35 mg/L, respectively. Based on a literature search we believe that this is the first report of the quantitation of difluoroethane in biological samples.
Accidents, Traffic↗
A shunt infection caused by Francisella tularensis.
We report the first case of a child with a shunt infection caused by Francisella tularensis, the causative agent of tularemia. This patient is also unique in that the disease was limited to the central nervous system.
Child, Preschool↗
Ethylene oxide allergy in children with spina bifida.
BACKGROUND: Allergic reactions to ethylene oxide (EtO-treated products have occurred in several children with myelomeningoceles. OBJECTIVE: The object of this study was to define the prevalence and significance of EtO-specific IgE among the children in our myelomeningocele clinic. METHODS: The study population comprised three groups: children clinic. METHODS: The study population comprised three groups: children with myelomeningoceles, chronically ill controls (defined as children who had undergone at least three major operations), and well-child controls. Serum specimens were collected from each child, and a commercially available ELISA designed to identify IgE directed against both EtO and latex was performed on the specimens. RESULTS: Seventeen of 75 (23%) children with myelomeningoceles had antibodies directed against EtO, as did 1 of 26 (4%) chronically ill controls. None of the 25 well controls had detectable levels of anti-EtO IgE. Children with antibodies directed against EtO were more likely to be atopic (p = 0.007) and to have a shunt (p = 0.021) and were markedly more likely to have antibodies directed against latex (p = 0.001). On average they had undergone more shunt revisions and other operations than had children without anti-EtO antibodies. CONCLUSION: During the period of study no child had anaphylaxis thought to have been due to EtO exposure.
Adolescent↗
Latex allergy in children with spina bifida.
We studied the prevalence of latex-specific IgE among the children in our myelomeningocele clinic and several groups of controls using skin tests, a commercially available ELISA and an in-house RAST. Thirty-nine of 83 (47%) children with myelomeningocele had antibodies directed against latex as did 6 of 40 (15.7%) chronically ill controls, 4 of 105 (3.8%) medical controls and 2 of 75 (2.7%) well controls. Within each study group the likelihood of a positive skin test increased with the number of operations the subject had undergone. Children with myelomeningocele were much more likely to have antibodies to latex than were chronically ill controls with similar surgical histories. A retrospective chart review of 18 years and a total of 646 operations disclosed only one episode of intraoperative anaphylaxis which appeared to be related to latex within our study group.
Adolescent↗
Chronic NMDA receptor blockade or muscimol inhibition of cerebellar cortical neuronal activity alters the development of spinocerebellar afferent topography.
The requirement for cerebellar cortical neuronal activity in the development of spinocerebellar afferent topography was investigated in neonatal rats. In adult rats lower thoracic-upper lumbar spinocerebellar projections are localized to sharply circumscribed patches in the granule cell layer of the cerebellar anterior lobe. In transverse sections these patches appear as sagittally oriented stripes. This pattern develops postnatally as many spinal axons which initially project between the incipient stripes are eliminated thereby sharpening the stripe boundaries. We attempted to alter cerebellar cortical neuronal activity in neonatal animals to study the effects of these changes on the development of spinocerebellar stripes. In some experiments glutaminergic excitatory synaptic transmission was chronically blocked with the N-methyl-D-aspartate (NMDA) receptor antagonist 2-aminophosphovaleric acid (APV). In other experiments postsynaptic activity was directly inhibited by the gamma-aminobutyric acid agonist muscimol. Chronic exposure to APV or to muscimol did not affect the initial development of spinocerebellar projections; many spinal axons were present in the anterior lobe and arranged in incipient stripes. Both the APV and the muscimol appeared to prevent the elimination of interstripe projections; consequently the boundaries of the stripes remained poorly defined. These findings suggest that cerebellar cortical neuronal activity is a necessary requirement for the refinement of spinal afferent topography in the anterior lobe.
2-Amino-5-phosphonovalerate↗
The role of ethylene oxide allergy in sterile shunt malfunctions.
Failure of an intact ventriculoperitoneal shunt, in the absence of an overt infection, is often due to its occlusion by cellular debris and/or an abdominal pseudocyst. This failure is thought to be caused by an infection by an organism which is difficult to culture or by some poorly defined allergic response to the shunt materials. Little attention has been directed to the treatment that the shunts receive prior to implantation: specifically, their exposure to ethylene oxide as a means of sterilization. We have found ethylene oxide metabolites in the spinal fluid of children with shunt malfunction months after their systems were implanted. Many of these patients had coincident CSF eosinophilia. In addition, two of the children had detectable serum IgE antibody directed against an albumin-ethylene oxide conjugated protein. Both of these children had several shunt malfunctions within a short period, yet neither child could be shown to have a shunt infection despite multiple cultures. We therefore suggest that in some patients proteins altered by ethylene oxide incite an IgE mediated response which may lead to shunt malfunction.
Adolescent↗