Miracle-dz/UniFAR-FTUs huggingface dataset:
Viral Hepatitis in Preg GJ.qxp

This Practice Bulletin was developed by the ACOG Committee on Practice Bulletins— Obstetrics with the assistance of Neil S. Silverman, MD. The information is designed to aid practitioners in making decisions about appropriate obstetric and gynecologic care. These guidelines should not be construed as dictating an exclusive course of treatment or procedure. Variations in practice may be warranted based on the needs of the individual patient, resources, and limitations unique to the institution or type of practice. Viral Hepatitis in Pregnancy
Risk Factors for Tracheostomy After Cervical Spinal Cord Injury: Qualitative Evidence Synthesized From a Systematic Literature Review

W e read with great interest the recent article by Tanaka et al. on the risk factors for tracheostomy in patients with cervical spinal cord injury (CSCI). The authors performed a retrospective cohort analysis of 199 patients in a single center. They found that neurological level of injury C4 or above and the presence of hematoma-like changes on magnetic resonance imaging (MRI) were independent risk factors for tracheostomy in the patients. We commend the authors for performing this interesting study, as quick identification of associated predictors may facilitate earlier tracheostomy, which has been shown to be beneficial in traumatic patients. However, we noted that the authors did not find American Spinal Injury Association impairment scale or completeness of injury to be an independent predictor, which contradicts the results from previous studies. Furthermore, although accumulating evidences concerning risk factors for tracheostomy after CSCI have been reported, the results are still inconclusive or controversial. Therefore, we aimed to further investigate the risk factors for tracheostomy in CSCI patients by performing a systematic review and to grade the evidence according to the quality of included studies. We identified 10 papers that presented data on risk factors for CSCI patients (Table 1). All studies were retrospective cohort studies with sample size ranging from 66 to 5265 patients with CSCI. Most of the reported patients were male. Five studies provided data on the mean time from injury to subsequent tracheostomy, varying from nearly 5 to 12 days. The reported incidence of tracheostomy after CSCI ranged from 10.03% to 69.0%. According to the quality assessment criteria, three studies were classified as high quality (491 patients) and seven studies (6790 patients) were classified as moderate quality (Table 1). There were 23 potential risk factors identified by more than one of the included studies (Table 2). In evidence grading according to the protocol described by Ma et al., we found no strong-evidence risk factors, but six moderate-evidence risk factors and 17 limited-evidence predictors were identified (Table 3). In conclusion, we provided a comprehensive overview of the current knowledge regarding risk factors of tracheostomy in CSCI patients. Although heterogeneity of the included studies and there are no definitive conclusions, we have identified six moderate-evidence risk factors and 17 limited-evidence predictors, which will contribute to a better understanding of the risk factors related to tracheostomy in CSCI population. However, high-quality, prospective studies are still required to clarify and evaluate the effects of these factors.
Mechanisms of Orbital Floor Fractures

Purpose: The purpose of this study was to investigate the two accepted mechanisms of the orbital blowout fracture (the hydraulic and the buckling theories) from a clinical, experimental, and theoretical standpoint. Methods: Clinical cases in which blowout fractures resulted from both a pure hydraulic mechanism and a pure buckling mechanism are presented. Twenty-one intact orbital floors were obtained from human cadavers. A metal rod was dropped, experimentally, onto each specimen until a fracture was produced, and the energy required in each instance was calculated. A biomathematical model of the human bony orbit, depicted as a thin-walled truncated conical shell, was devised. Two previously published (by the National Aeronautics and Space Administration) theoretical structural engineering formulas for the fracture of thin-walled truncated conical shells were used to predict the energy required to fracture the bone of the orbital floor via the hydraulic and buckling mechanisms. Results: Experimentally, the mean energy required to fracture the bone of the human cadaver orbital floor directly was 78 millijoules (mJ) (range, 29–127 mJ). Using the engineering formula for the hydraulic theory, the predicted theoretical energy is 71 mJ (range, 38–120 mJ); for the buckling theory, the predicted theoretical energy is 68 mJ (range, 40–106 mJ). Conclusion: Through this study, we have experimentally determined the amount of energy required to fracture the bone of the human orbital floor directly and have provided support for each mechanism of the orbital blowout fracture from a clinical and theoretical basis.
Ef ̄ux-mediated antibiotic resistance in Gram-positive bacteria

Ef ̄ux is a widely used mechanism of resistance to several toxic compounds, in both eukaryotic and prokaryotic cells, and it is a well-known mechanism of resistance to some antibiotics such as tetracyclines. Ef ̄ux-mediated resistance is being described increasingly for microorganisms in which, and antibiotics for which, it was previously unknown. In the 1990s ef ̄ux-mediated quinolone resistance was described in the important Gram-positive pathogens such as Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus agalactiae and enterococci. Ef ̄ux-mediated macrolide resistance mechanisms were described during recent years in pneumococci, group A Streptococcus pyogenes and other Gram-positive cocci. In fact, ef ̄ux is the main mechanism of resistance to macrolides in Streptococcus pyogenes in many areas. Ef ̄ux has also been described as an important mechanism of resistance to tetracyclines in Grampositive bacteria. In some cases, the increase in the mimimum inhibitory concentration derived from ef ̄ux is modest, and its impact on clinical resistance is unclear. In other cases, ef ̄ux can lead to clinical resistance by itself, and seems to have some in ̄uence on the rate of emergence of further mechanisms leading to higher level resistance. # 2002 Lippincott Williams & Wilkins
Regional Cortical Blood Flow

We conducted regional cortical blood flow studies using the xenon-133 clearance technique on 12 volunteers during the administration of 25% and 50% N2O and during baseline conditions (breathing room air or 100% O2). Global cortical blood flow was very highly significantly increased above baseline measures in all subjects by 50% N2O (mean increase 37% above 100% O2 condition). A smaller but still significant increase was observed with 25% N2O. Analysis of regional cortical blood flow revealed heterogeneity in the pattern of changes; that is, the baseline pattern was altered by the inhalation of N2O, most often resulting in an accentuation of relative frontal blood flow. The anterior-posterior gradient in N2O-induced blood flow changes differs from that observed with simple vasodilatory agents, such as CO2, with which the increase is purely systemic and the baseline pattern is preserved. This indicates that N2O has differential effects on cerebral metabolism that may well reflect the typical alterations in experiential state reported by subjects. (Stroke 1990;21:1293-1298)
Cancer stem cells in acute myeloid leukemia

Since the original description of leukemic stem cells (LSC) in acute myeloid leukemia (AML) as a rare subpopulation of leukemic cells located in the CD34+/CD38compartment much has changed. Supported by continuously improving immunodeficient mouse models, LSC were found in cells which were previously thought not to contain any LSC activity. Furthermore, the phenotype of LSCs as well as the phenotype of the offspring they form, were found to be astonishingly variable and dynamic over time, challenging the perception of LSCs as classical stem cells in a static developmental hierarchy. This thesis focusses on the change in perception of LSC in AML regarding their phenotype, development and differentiation and also touches on the subject of clonal evolution and development of AML LSCs.
RAPID COMMUNICATIONS PIG CELLS THAT LACK THE GENE FOR 1-3 GALACTOSYLTRANSFERASE EXPRESS LOW LEVELS OF THE GAL ANTIGEN

Background. The major antigen recognized on pig tissue by primate antibodies is a terminal gal 1-3gal carbohydrate structure (gal antigen) present on glycolipids and glycoproteins. The production of animals from somatic cells allows for the inactivation of specific genes. It is anticipated that the complete inactivation of the gene encoding 1-3 galactosyltransferase, the enzyme that synthesizes the gal 1-3gal linkage, will result in loss of that antigen from pig organs and tissue and will provide a survival benefit in pig-to-primate xenotransplants. Methods. Positive-negative selection was used to produce fetal-pig fibroblasts that were a heterozygous knockout ( / ) of the 1-3 galactosyltransferase gene. Nuclear transfer of these cells generated pig embryos and live born pigs with the appropriate genotype. Using a novel selection method with cells from ( / ) embryos, we produced homozygous ( / ) fetal-pig fibroblast cells. Results. Southern blot analysis of the 1-3 galactosyltransferase gene showed that we had produced ( / ) pig embryos, ( / ) live born pigs, and ( / ) pigfetal fibroblast cells. Fluorescence-activated cell sorter (FACS) analysis with some, but not all, mouse anti-gal monoclonal antibodies and sensitized human serum showed that ( / ) cells still synthesized the gal antigen at 1 to 2% of the level of control heterozygous cells. Conclusions. Fetal-pig fibroblasts homozygous for the knockout of the 1-3 galactosyltransferase gene appear to express low but detectable levels of the gal antigen.
Nutrient composition and seasonal losses of avocado trees.

SUMMARY Data are reported for the dry weight and nutrient element content of a bearing, sevenyear-old Mexican seedling avocado tree, for amounts of nutrients translocated from the leaves of Fuerte trees before abscission, and for the amounts of dry matter and nutrient elements lost in abscised leaves and blossoms by two thirteen-year-old Fuerte trees during a two-year period. The data indicate that half or more of the nitrogen and phosphorus and substantial amounts of potassium, magnesium and sulfur are returned to the tree from the leaves prior to leaf abscission. Losses of dry matter and nutrient elements approximately equivalent to 25 per cent of the dry weight of the tree, 40 per cent of the nitrogen, phosphorus and potassium, 60 per cent of the calcium, and 75 per cent of the magnesium may occur each year in the blossoms and leaves that are abscised by an avocado tree. The relationships between these translocations and losses and the number and nutrient composition of the blossoms and the effects on tree growth are discussed.
OPERATIVE NUANCES

Accepted, July 11, 2003. THE BASAL GANGLIA have important roles in somatic motor, oculomotor, limbic, and associative functions. These functions are represented in anatomically distinct territories in each basal ganglion nucleus. During surgery of the subthalamic nucleus for Parkinson’s disease, the primary goal is to influence the physiology of the motor territory without affecting nonmotor areas. This article describes the use of movementrelated cellular activity during single-unit microelectrode mapping to identify and to navigate within the motor territory of the subthalamic nucleus.
Roxithromycin induced hypersensitivity pneumonitis

CRP concentration. In this assay, 250 mL of buffer are added to the reaction cuvette. This is followed by 10 mL of sample and then 10 mL of reagent antibody solution. There is a single, static increase in absorbance following addition of sample. When reagent is added, a curvilinear increase in absorbance proportional to CRP concentration is observed. Occasionally, there will be some interaction between sample and buffer, leading to a curvilinear increase in absorbance before the addition of antibody reagent. This is recognised to occur in less than 1% of all samples and is idiosyncratic. The two absorbance curves are shown in Fig. 1. In reviewing these 25 absorbance curves, we found that the idiosyncratic curvilinear increase in absorbance when sample was added to buffer occurred 13 times. These results were not flagged by the analyser. From first principles it seemed that these should not yield valid results. Typically, a value of 16 mg/L was obtained by this method when an alternative nephelometric method gave a value of 4 mg/L, a difference both analytically and clinically. These discordant results supported the suspicion that these were not valid results. While 48% of the results were valid, 52% were not. Use of this assay in neonates is no longer approved by Beckman-Coulter. We are unsure of the cause of this phenomenon. We were unable to find an association with icterus or haemolysis. There was no association with capillary, venous or arterial specimens, or specimens obtained through indwelling vascular catheters. These babies differed considerably, with the only common characteristics being age and clinical indication for CRP measurement. We postulated that the expected high concentration of a-fetoprotein may have been a factor. Acute phase reactants in babies have different concentrations (both higher and lower) than adults and their quantitative responses to inflammation are generally unknown. Serum protein electrophoresis of an affected sample was normal. There are almost no assays specifically designed for use in neonates; newborn screening tests are the exception. Almost any assay on a laboratory’s chemistry menu has application in the neonate. In neonates, assays should be used with careful consideration. Maybe babies are different! Michael Metz* Corey Markus* Elaine Whitham{
Poisoning of raptors with organophosphorus and carbamate pesticides with emphasis on Canada, U.S. and U.K.

We reviewed cases of raptor mortality resulting from cholinesterase-inhibiting pesticides. We compiled records from the U.S., U.K. and Canada for the period 1985-95 (520 incidents) and surveyed the relevant literature to identify the main routes of exposure and those products that led to the greatest number of poisoning cases. A high proportion of cases in the U.K. resulted from abusive uses of pes- ticides (willful poisoning). The proportion was smaller in North America where problems with labeled uses of pesticides were as frequent as abuse cases. Poisoning resulting from labeled use was possible with a large number of granular pesticides and some seed treatments through secondary poisoning or through the ingestion of contaminated invertebrates, notably earthworms. With the more toxic products, residue levels in freshly-sprayed insects were high enough to cause mortality. The use of organophos- phorus products as avicides and for the topical treatment of livestock appeared to be common routes of intoxication. The use of insecticides in dormant oils also gave rise to exposure that can be lethal or
Aneurysmal Bone Cyst of the Mobile Spine

Study Design. Forty-one cases of aneurysmal bone cyst of the mobile spine were retrospectively reviewed. Objectives. To evaluate the role of surgical and nonsurgical treatment of aneurysmal bone cyst of the spine. Summary of Background Data. Ten to 30% of aneurysmal bone cysts arise from the mobile spine, frequently occurring in pediatric patients. The course of the disease depends on the aggressiveness of the tumor, as well as the treatment. Intralesional surgery seems to be an effective treatment, as well as radiotherapy and embolization. Methods. All charts, radiographs, and images were reviewed. The composite information provided by this review allowed for oncologic and surgical staging of these cases. Thirty-two patients underwent curettage (14 of them followed by radiotherapy), four were submitted to selective arterial embolization, three received radiotherapy alone, and two underwent en bloc excision. Results. All patients were found alive and disease free at final follow-up evaluation. Two recurrences followed one incomplete curettage and one embolization. The combination of curettage and radiotherapy, although effective, showed the greatest incidence of late axial deformity. Selective arterial embolization was curative in three of four cases and did not affect the possibility of surgery in case of local recurrence. Conclusions. If confirmed on larger series, selective arterial embolization seems to be the first treatment option for spine aneurysmal bone cyst, because of the low cost-tobenefit ratio. Diagnosis must be certain, based on pathognomonic radiographic pattern or on histologic study. In case of neurologic involvement, pathologic fracture, technical impossibility of performing embolization, or local recurrence after at least two embolization procedures, complete intralesional excision would be the therapy of choice. [
Point of View

The authors present the case of a polytrauma victim after a motor vehicle rollover. The patient presented with a scalp laceration and an open fracture of his right forearm. The authors noted there was no focal neck tenderness nor was there an appreciable gap or step-off of the spinous processes. The neurologic examination was recorded as normal. Because of the severity of the injury mechanism, the presence of neck pain and identification of distracting injuries, a computed tomography (CT) scan of the cervical spine was appropriately obtained. This policy is consistent with current literature that has identified the increased sensitivity, specificity, and, thus, necessity of the CT scan in the evaluation of the spine of a polytrauma patient. The benign appearance of the plain films further illustrates the value of a CT scan in these clinical settings. The patient underwent surgical treatment of his forearm injury while observing appropriate cervical spine precautions during both intubation and extubation. Cervical collar management was selected for the treatment of the nondisplaced articular pillar fracture. At this point, the seminal questions are raised: Should magnetic resonance imaging (MRI) be routinely obtained for all cervical fractures to evaluate (further) for clinical instability? If so, what specific findings on MRI lead to the diagnosis of “instability”? Similarly, in the polytrauma patient with a negative CT reading, can the cervical spine be deemed clear of a significant injury? The latter question (i.e., the need for additional studies) is even more pressing in the obtunded patient. In this particular clinical setting, an upright lateral radiograph in the collar would have identified the associated ligament injury before discharge. The use of upright films can complement static, supine films obtained at the time of initial evaluation, as they place the spine under a physiologic stress. If the upright films were normal, no additional studies would have been necessary until follow-up. There is no indication for flexion-extension films in this scenario. The controversy of the timing of an MRI also comes into light in this case. At 12 days postinjury, the MRI reportedly did not demonstrate a significant ligamentous injury, despite the presence of bilaterally subluxed facet joints. Despite published guidelines that imply improved sensitivity of an early (within 2 days of injury) MRI, there is no literature that demonstrates specifically when a positive MRI converts into a negative study. It is presumed that an early study would identify the associated edema and hemorrhage that accompany the injured ligament. However, MRIs obtained at later times should still reveal the presence of ligamentous discontinuity.
Chiari Type I Malformation Associated With Morning Glory Disc Anomaly

Morning glory disc anomaly (MGDA) is a congenital malformation of the optic disc that has been reported in association with midline craniofacial defects such as basal encephalocele, hypertelorism, cleft lip and palate, and agenesis of the corpus callosum. We describe a 44 year-old woman with MGDA and Chiari type I malformation, an association not previously reported. (J Neuro-Ophthalmol 2006;26:279–281) Morning glory disc anomaly (MGDA) is a congenital optic disc dysplasia (1). The term reflects the morphologic similarity of the condition to the flower of the morning glory plant (2). The incidence of the anomaly is unknown, although most authors agree that it is rare (3). It consists of an enlarged, funnel-shaped, excavated disc surrounded by an annulus of chorioretinal pigmentary disturbance (4). Although MGDA may be isolated, numerous other ocular abnormalities are associated with it. Nonocular associations include hypertelorism, basal encephalocele, agenesis of the corpus callosum, facial hemangiomas, renal anomalies, reversible and irreversible carotid artery narrowing, and hypopituitarism (1,4,5). Chiari type I malformation has not previously, to our knowledge, been described in association with MGDA. We report a single case of this association.
Progress Reviews Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage is one of the most important causes of cerebral ischemia, and is the leading cause of death and disability after aneurysm rupture. There are two definitions of cerebral vasospasm: angiographic and clinical. Care must be exercised to be certain that it is clear which entity is being addressed. The diagnosis of the clinical syndrome is one of exclusion and can rarely be made with absolute certainty. The pathogenesis of cerebral vasospasm is poorly understood. Most current theories focus on the release of factors from the subarachnoid clot. More attention must be given to the role of endothelial damage and alterations in the blood-arterial wall barrier. The application of modern techniques for studying vascular smooth muscle which have been developed as a result of research in the areas of hypertension and atherosclerosis must be applied to the problem of cerebral vasospasm. A stress test to select patients with angiographic arterial narrowing who have adequate cerebral vascular reserve to undergo surgery should be developed. The optimal treatment of vasospasm awaits development of agents for blocking or inactivating spasmogenic substances or blocking arterial smooth muscle contraction. Rheological or hemodynamic manipulations to prevent or reverse ischemic consequences of vasospasm are relatively effective, but complicated and hazardous, and should be viewed principally as interim measures awaiting development of more specific therapies for the arterial narrowing. Stroke Vol 16, No 4, 1985